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#1074279 07/06/22 12:22 AM
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I ordered a new LS7 570 HP engine for the car today after waiting for months for inventory. I also have a complete speed tech suspension with coil overs, AFX spindles, and C 6 brakes. Along with tons of other parts that have been shelved for nearly two decades which include many new GM interior and many other NOS parts. The plan will be to build a stock appearing car with some heavy modifications that just better the car all the way around. Framework, suspension, engine, trans, body and paint. All the factory stripes will be reapplied in paint with candy colors.

I will post pics of the car after the LS3 was pulled, Frame, parts and engine soon.


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Originally Posted by 1 Slow SS
I ordered a new LS7 570 HP engine for the car today after waiting for months for inventory. I also have a complete speed tech suspension with coil overs, AFX spindles, and C 6 brakes. Along with tons of other parts that have been shelved for nearly two decades which include many new GM interior and many other NOS parts. The plan will be to build a stock appearing car with some heavy modifications that just better the car all the way around. Framework, suspension, engine, trans, body and paint. All the factory stripes will be reapplied in paint with candy colors.

I will post pics of the car after the LS3 was pulled, Frame, parts and engine soon.


My experience has been that in an autox/track situation the LS3 makes more torque than I could ever use, why the LS7 choice?


86 SS 6.2l LS3, Ilmor intake, Summit Stage 4 Cam, Stainless long tube headers, Stainless 3in exhaust, Tremec T-56 Magnum 6 speed, Eaton Truetrac 8.8 LSD, UMI Cornermax Front Suspension, 3-link Rear suspension w/ UMI Control Arms, UMI Front & Rear Braces, Brembo Brakes
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My choice was based on what I wanted, a build that is more unique. LS3 engines are great and make great power, but they are too common. For that matter I could have done a 416 and made more power but I really wanted those tri Y Z28 exhaust manifolds on the LS7 and a bunch of other goodies.


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Is this for the same white car you did all the frame, body work and paint on years ago Ron?


Lance
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Yes Lance that’s the car, so yes I’m starting on a very nice roller.


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So all the hard work is already done then, just fun stuff now. laugh


Lance
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Not sure which car or cars you remember? I have had four white SS cars all with frame work, only one with a LS3 around 2010. This car is nice but I need to build a frame for it, paint and assemble everything as it will be torn down.


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Couple links on the engine.

https://www.chevrolet.com/performance-parts/crate-engines/ls/ls427-570

https://www.motortrend.com/news/ls7-engine-discontinued/

The build is on, I have been hording parts for years for this car!


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Originally Posted by 1 Slow SS
Couple links on the engine.

https://www.chevrolet.com/performance-parts/crate-engines/ls/ls427-570

https://www.motortrend.com/news/ls7-engine-discontinued/

The build is on, I have been hording parts for years for this car!


I know the desire for a unique engine. my buddy got me two sets of the Dart Pro1 12 degree LS7 NASCAR truck series cylinder heads and the corresponding 2 piece intake. Which is great, but now I have to build a 4.185 inch bore Dart LS Next aluminum block lol.


86 SS 6.2l LS3, Ilmor intake, Summit Stage 4 Cam, Stainless long tube headers, Stainless 3in exhaust, Tremec T-56 Magnum 6 speed, Eaton Truetrac 8.8 LSD, UMI Cornermax Front Suspension, 3-link Rear suspension w/ UMI Control Arms, UMI Front & Rear Braces, Brembo Brakes
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Originally Posted by 1 Slow SS
Not sure which car or cars you remember? I have had four white SS cars all with frame work, only one with a LS3 around 2010. This car is nice but I need to build a frame for it, paint and assemble everything as it will be torn down.



I remember what I think was the first one you posted the project on here, a real nice white one that was mostly OEM, think it was a low mile car also.

Then I remember one that was nice but the frame was really rough...but it had sentimental value of some sort?

It's hell getting old... laugh


Lance
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Can't wait to see what you come up with!

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This one would be the "really rough frame", sentimental of some sort.


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Last edited by 1 Slow SS; 07/12/22 12:52 AM.

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Originally Posted by Travis Jones
[quote=1 Slow SS] Couple links on the engine

I know the desire for a unique engine. my buddy got me two sets of the Dart Pro1 12 degree LS7 NASCAR truck series cylinder heads and the corresponding 2 piece intake. Which is great, but now I have to build a 4.185 inch bore Dart LS Next aluminum block lol.


That will be a serious build and should be very unique, I'll look forward to following that thread.


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I was cleaning out my basement and found the T56 magnum, clutch, and other parts for the car. I love these 3 inch tail pipes that are one off, I'll always do my best to make these builds as close to factory looking as possible while paying close attention to detail.

[img]https://hosting.photobucket.co...=960&height=720&fit=bounds[/img]

[img]https://hosting.photobucket.co...=960&height=720&fit=bounds[/img]

[img]https://hosting.photobucket.co...=960&height=720&fit=bounds[/img]

[img]https://hosting.photobucket.co...=960&height=720&fit=bounds[/img]


Last edited by 1 Slow SS; 08/18/22 01:47 AM.

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Looks good!

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Found this today for the frame, I hope it makes a difference??

[img]https://hosting.photobucket.co...=960&height=720&fit=bounds[/img]


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Is that the hellwig kit?

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Yes it is, I had bought this a few years ago when I started hoarding suspension parts from speedtech.


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Hi 1 Slow - it's hard to tell from that box how all that integrates with the frame. Does it make the open side C-channels into closed tubes?

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Hello MAP,

That's just a FX frame box kit for the center section, Unfortunately I will have to open the front and rear sections of the factory frame rails and weld in the tube front to back. The FX box kit will cover the long tubes running down each side throughout the center section.

The intent of this modification will be to run a more road compliant front sway bar and a bit softer front suspension while retaining good handling. I see too much distortion in body gaps and the front facia covers of these cars from too much front frame rail flex while wheeling them around cones, IMO. I want to reduce that attribute, if need be I might scrap the GM frame when I get into it and build a complete new frame with elastic modulus of say 205 GPa 29700 ksi.

I have built many cars over thirty plus years for customers and myself, if done right I might have something worth looking at? Will it be so involved as the projects others like Bob take on, no. I'm going to build a whole car in a year completely redoing everything I did 12 years ago. So I can't dwell on one project for months, going to school, designing, and fabricating. If I rebuild a frame or build a frame my time line is a few weeks, perfect or not we will see if it's worth anything over stock quality?? I do plan to run a rack and pinion steering. But again this will just be glued together, or just bolting parts together with little to no thought and it will work very good, experience sometimes makes things more transparent. I would like to build a car others can replicate with off the shelf parts, and not such a deep knowledge of G body's and engineering principles. And no three link unfortunately, I'm keeping the exhaust tail pipes I made with my father before loosing him.



Regards,
Ron

Last edited by 1 Slow SS; 08/25/22 05:06 PM.

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Hi 1 Slow,

OK - if that kit turns the open C-channel into a closed box, then you will see a big improvement in torsional rigidity. No matter how I read what you're saying, I can't see anything but very good results coming. And the car needs all the help it can get! But are you saying you're adding a tube inside of this box? (200-ish GPa: yup, steel. Btw, I didn't know this about your background - how interesting!)

Best,
MAP

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Hi Mark,

Yes, I will section the frame running one piece of steel tube inside each frame rail end to end replacing the original structure after. The engine will be moved back as fare as possible. With the lighter relocated engine, rack, and heavy 12 bolt out back she might be a bit better balanced with a full belly?

I was engineer for a major OEM for many years, I always like asking questions about things I know the answers to for some reason? dunno In fact my grandfather Harley was a GM engineer that was part of the corvette fuel injection development team in the 50's, with several years of carburetor development well into the 60's. I still have his GM tie tack along with many other small items passed to the engineering teams of that time.


Regards,
Ron


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Hi 1 Slow,

What an interesting background! I'll bet you have many stories to tell!

OK, so you're putting a tube inside of a tube. Since tube torsional stiffness goes in direct proportion to its skin thickness and as the cube of its diameter, that inner tube won't help you much unless it's nearly as big as the outer tube. And at that point, you might as well dispense with the inner tube altogether and just put the saved mass into additional skin thickness for the outer tube. Or even better: conserve skin thickness, but strive to make that outer tube as big as can possibly fit into the car. For me, I gladly accepted a 1" reduction in ground clearance directly underneath the factory side rails.

It sounds like you're well on track to move the COM rearwardly, which is another thing the car very much needs. Have fun!

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Well after a day of thinking... frown I'm realizing Mark is right, no matter how I look at it, the frame work will be a cobbled together mess. frown As much as I want to resist buying a killer chassis and build one to prove a point, I won't. I'm contacting Speedtech first and if they will do the frame I'm in, if they won't I will order a new Schwartz chassis near the end of the year. This way I can remove the body selling off all my new parts, modifying the trunk and wheel tubs to fit massive tires, then I have to make the tail pipes work. The new N90 17's will be sent out to be re hooped as 18's and much wider!

The bad news is no IRS as it's over 10K.

Regards,
Ron

Last edited by 1 Slow SS; 08/30/22 02:56 AM.

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Last year in September I ordered my new 2022 Camaro LT1 for my daily driver to split with the company car. It's now a 2023 and finally on its way to my dealer! I haven't been this excited since I ordered my 1996 SS SLP car. Kind of crazy I'm so excited over this, it's my last new Camaro / sport car I will order before I retire.


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You know the last sports car old retired GM car guys buy is a Vette. When you are old enough in another ten years to retire those Vettes will be electric and merely 1200 hp to use as a cruiser.

Just funnin.
Bob

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Originally Posted by mmc427ss
You know the last sports car old retired GM car guys buy is a Vette. When you are old enough in another ten years to retire those Vettes will be electric and merely 1200 hp to use as a cruiser.

Just funnin.
Bob



Hi Bob, I could never afford paying a mortgage payment on a car regardless of the quality at my age. I'm actually selling the last of my Pontiac toys to pay a good chunk of the 37K it costs after my employee discount. I've been very fortunate in my career but by no means could I afford anything north of 40K in a payment form. Cash is king and this G body has rung me dry after the LS7...LOL


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Hi Ron,

So if for a given length we take torsional stiffness ~ t*phi^3, and weight ~ t*phi, and we assume:

1. Scenario 1: an inner tube of outer phi = 1.75", t = 1/8", PLUS the (now closed) outer box with an average outer phi = 4", t = 1/8".
2. Scenario 2: a maximally-expanded tube based on the existing frame rail with average outer phi = 4.75", t = 1/8".

It's easy to compute their relative torsional stiffnesses and weights.

For torsional stiffness, the second configuration is 58% stiffer than the first.
For weight, the second scenario is 16% lighter.

Diameter completely dominates. In the first scenario, the inner tube has only 7.4% of the torsional stiffness of the outer tube, but 42% of its weight, so its presence represents a net loss.

If we form a ratio of torsional stiffness to weight, then the second scenario is 88% better than the first.
So it's not even close - the second scenario wins.

HTH,
MAP

Last edited by MAP; 08/27/22 10:57 PM.
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Mark,

Your killing me, the result is better performing than the math. It's how the new tube is integrated into the existing tube rail that makes it work well. I have to dig the frame out of the weeds in a month and at that time I will decide what I will do and how I will do it? I want a car holding the factory vibe. I have two good sources for frame modeling software that I will visit. Maybe we get out in the weeds and drop another chunk of cash into it's chassis?



Regards,
Ron


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Hi Ron,

Well, I wish you all the best. When I had my '78 Malibu I added 1" x 3" rectangular steel tubing to the underside of each frame rail to stiffen it up. You could see a small difference in the car's appearance from a distance, but if you weren't looking for it, you'd probably miss it. But the added stiffness was very noticeable and welcome.

Ultimately you'll decide what holds the factory vibe and what doesn't, of course. Have fun!

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Last edited by 1 Slow SS; 08/28/22 01:46 AM.

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Hi Ron,

I wish I had a G-body to measure but don't, so I can't comment about that rack. My general recollection is that the front LCAs are too long, and thus their inner pivots in the frame are too close to each other, to permit a rack of more than insufficient length to fit. I'm also guessing that unless the rack is specifically made for an A/G body, the odds of it creating negligible bumpsteer are low.

Hate to say it but I think you're probably better off coughing up the coin and getting an entire front-end that's dimensionally and structurally compatible with the car, and that has good R&P steering. I haven't checked vendors for this in a long time but you can always start with the usual suspects. Detroit Speed is certainly a good one but they're usually pretty pricey - if you're up for it, in your shoes, I'd call them and ask to speak to an engineer and not a salesperson, and talk through the whole situation in exhaustive detail.

Best,
MAP

Last edited by MAP; 08/28/22 10:35 PM.
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Hey Mark,

I did a cutlas with a rack about 6 years ago, it's doable and works well with some significant surgery. The bump steer is the easiest part and was almost non existent, I'll make measurements this time around. This mod will be a bit close to my heart as I'm not a fan of the gear box. I won't invest a lot of time with writing though, generally what I did and the values for steering radius and bump steer.

As fare as my frame... I will add the external support on the inside of the rails near the floor pan area with a X brace! Oh, and two loops over the front suspension. cool

But for sure find everything in theory wrong with the retrofit and I'll put up values to counter it to the best of my ability. beer

Last edited by 1 Slow SS; 08/28/22 11:52 PM.

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Hi Ron,

Well, whether you go with the tube-in-a-tube approach or not, the one sure thing is that it will be a very big improvement over the stock wet-noodle frame. Do take torsional stiffness measurements before and after for all to read, please! One possible methodology: put rigid jack-stands under the frame right above where the CL of the rear axle resides. Then, support the front of the frame on a knife-edge that sits under the center of the engine cross-member. Get something to measure angle from the vertical with high accuracy and use this to measure frame transverse orientation. Then, apply a known longitudinal moment to the frame, and determine the angular change. One stock frame I tested years ago, which was coupled to the body with factory bushings, measured a positively lousy 2,100 (ish) ft-lb/degree.

Me, I always sweat not only the improvement in rigidity but its increase in relation to weight. Inertia is the sworn enemy of acceleration, and hot-rodding is all about acceleration.

And when you talk about a loop over the front suspension, would that be the triangulating brace from the windshield base of the A-pillar down to the frame by the UCA?

Last edited by MAP; 08/30/22 03:35 AM.
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Hi Ron,

I forgot a critical part of the torsion-measuring methodology: apply the upsetting moment to the frame at the front axle CL.

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Hi Mark,

After much thought I have decided NOT to build a frame. Two reasons, MAP you have pointed out several issues, among a cobbled together frame. Secondly is my time is slim and too valuable. I want something new and the best in the industry poke ! I want this car to be the first off of the best, in a series of G body builds that it gives G body owners a new option! I have reached out to the best suspension and chassis builder I know of in the business and proposed a first off build of a G body frame and suspension kit that can be marketed to the masses.

I hope I can pull this off!

Regards,
Ron

Last edited by 1 Slow SS; 08/31/22 12:28 AM.

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Ron - really love to see such a frame/suspension (steering?) kit.
Others have invested and built (Schwartz for example) How would it be different or just more approachable economically for us, or ....?
Dearly wish I had that as an option when I started.
Would it enable/anticipate EV conversion at a later time?
Your thoughts at this point if you can share?
Gordon


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Hi Gordon,

At this time it's only a proposition to a very capable custom shop. Schwartz is a awesome option 'that I might have to visit" but that has been done, I want a different flavor.

EV conversion isn't on my mind and for sure not on theirs either at this point, as I have no gas powered commitment.

Economical is subjective, for a complete chassis at Schwartz your in the 11k - 30K range, I can't say this option would be any cheaper. Especially if you mini tub and buy top of the line options in brakes, wheels, tires, shocks, and many other areas. A build could easily climb close to or more than 6 figures with guys doing much of the work?

Regards,
Ron


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Wow! Big news! All the best!

Ron, you know I like to attack an idea from all angles. If we extend the idea of a tube's torsional stiffness going as the cube of its diameter, we have to arrive at the conclusion that if we can integrate the frame with the body into a rigid whole, then this will give us the lightest structure possible for a given torsional stiffness. I return to my soda can analogy.

If you only rely on the frame for torsional stiffness, you'll be adding weight - maybe something like 100lb.

But, if you want something that would appeal to a wider market than the near-insane customer or two who would consider a unibody conversion (like myself,) then this is probably the next-best thing. But may I make a suggestion? Whoever designs this beastie should do extensive FEA 3-D modeling to ensure it's as light as possible in relation to its stiffness. I've seen some dubious attempts by well-known chassis builders - including Schwartz.

Maybe you can get some weight back (50lb?) by making the front end lighter than the stout factory design. (Just add some lightweight crash protection like energy-absorbing foam, however.)

Best,
MAP

Last edited by MAP; 08/31/22 04:20 AM.
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After waiting a couple days and talking with two frame shops nobody is interested as of yet to build a G body frame. I even offered the first choice of mine a premium to build it and the owner has no interest. I will try two more shops and then replan.


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Last edited by 1 Slow SS; 09/04/22 12:59 AM.

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Hi Ron,

My quick opinion is that I think that frame has a lot of fat in it. Guessing from the photos, it might weigh about 150lb more than the factory frame. That rear also looks prone to binding in roll. If I got that frame, I'd ask them to delete some sections or at least leave some sections unwelded. This frame looks overbuilt versus the Schwartz frame which looks underbuilt. Not sure which makes the better starting point. Btw, $19k? Wow.

Last edited by MAP; 09/04/22 08:15 AM.
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Hey Mark,

I would think any 4 link with bushings would bind? If I were to build the frame with them the rear would be addressed with rotating joints.

The 19K wouldn't do it, I would be into the rolling frame for 30K all day long and additional chunk too widen the wheel wells for an additional 4" track width.

One other point folks miss. When considering the cost of something you must consider how long it takes you to make that much money and how long it would take completing the project plus materials.

Regards,
Ron

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I have friends that are very close with the peeps at Roadster Shop. They make a fantastic product. I don't have any direct experience with their G Bosy frame but can vouch for them as a Company overall.

If you found something there that fit your build, I'm certain you'd be happy with it Ron.


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Good news Lance, Thanks.

I’m looking to build a sweet looking car that performs very well but yet drives great.

Regards,
Ron

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Hi Ron,

That Roadster frame does look good, and really if you make any frame stout enough and heavy enough, it will also work well.

But the real trick is making it stiff and light too. And it's on that count that the Roadster frame falls short IMO. It's got a lot of fat situated under the floorboards. The junctions of the front and rear narrowed sections with the side rails look needlessly overdone. I would ask them the weight of that frame in its bare form (no suspension or rear attached,) and compare it to the stock frame in the same state. Again, I'm guessing the Roadster frame has 150 lb over the stock frame, which would make the car about 4% heavier. 4% heavier means 4% slower as well, so you'll want to consider the tradeoff carefully. After all, you bought a big engine to go faster. More weight would be taking you in the opposite direction.

I know a unibody conversion is lots of work, but it's unbeatable for stiffness in relation to weight. It would probably save you huge coin as well. If anything, just buy the front end as an assembly with R&P steering. Maybe the rear as an assembly too. (Art Morrision? Detroit Speed?) Of course, in saying all this, one must have very solid mechanical engineering and fabrication smarts to bring it all together successfully...

About binding: the factory C4L doesn't geometrically bind. I could be wrong, but a parallel-link rear with shorter arms on the top could bind in roll. In your shoes, I'd build a scale model first to be sure.




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Mark,

I would have the rear control arms made with a pivot joint. As fare as the weight I would have some of the bulk trimmed out. I know exactly where I would take it as you mentioned.

As fare as making a unibody out of this thing, no way, I have F bodies for that. Yes I could do this, but I have too many other cars and property to take care of. I'm getting old and this car is another project that I really shouldn't be diving into. But I have committed too both sons and my mother of getting this car back to it's former glory plus some. That's the main reason I will consider opening the check book. I could build the stock frame and let it roll boxed with a complete Speedtech suspension. If I do that it's major flaws won't be so bad. And I can say if I had Lance or Bernie driving it, I'm sure it would be as fast as any G body out there in that form given they had some seat time dialing it in. In all honesty I don't see that much performance to be had with any set up over what these cars can bring worked over. The gains are more for bragging rights with marginal improvements following IMO. I look at times, cornering pictures and much better unibody, IRS engineered cars still fall victim to the G body. A top contender would be a 150 - 200 K build and I'm not doing that either. This car was bought new and all options checked by me with my father. We liked the MCSS because it was a cheap resemblance of older muscle cars of the day and very good looking.

Regards.
Ron

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OK, I get all that, but a 4% weight savings can only help you. Now what that 4% is worth to you is your call to make, naturally. Maybe you can negotiate with the Roadster shop to save some weight and coin by removing all that fat? And no matter what you do to modify that frame, it will move your COM rearwardly compared to the stock frame, which will certainly be a plus. Btw, can you use your stock bumper mounts with that frame by deleting or modifying the end caps?

IRSs on a flat road course buy you essentially nothing. In fact, you'll probably lose because IRSs give you little anti-squat compared to a live axle. It's in street driving with irregular surfaces where they shine, but even there, for RWD, the car should be rear-heavy if the engine has strong output.

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Originally Posted by MAP
OK, I get all that, but a 4% weight savings can only help you. Now what that 4% is worth to you is your call to make, naturally. Maybe you can negotiate with the Roadster shop to save some weight and coin by removing all that fat? And no matter what you do to modify that frame, it will move your COM rearwardly compared to the stock frame, which will certainly be a plus. Btw, can you use your stock bumper mounts with that frame by deleting or modifying the end caps?



As fare as weight goes, I would have to inquire the actual number. I'm not sure if they're focused on factory comparisons to promote sales.

Yes, all you have to do is open the capped ends to allow the shock body to enter the rail.

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Outside of this conversation, I never cease to be amazed at hotrodders who fret over every last atom of HP and torque from the motor, but ignore mass almost as if it didn't count. For them, Newton's second law would read F ~ a*m^0.001 (Yes, that's a mathematical joke.) For the OEMs, however, not only do they sweat the atoms, but the grams of excess mass as well.

But it's not just 0-60 or 1/4-mile times. Mass hurts handling too. It has to do with how tires don't obey the Coulombic laws of friction (I go into detail about this in the block-buster Front sway bar project thread.) That's why lighter cars tend to yield better times on the course.

I wouldn't be surprised if the vendor didn't know the weight of the bare frame. And even if they did, it wouldn't be meaningful unless you could compare it to the OE frame in the same trim (250 lb?? Wild guess only,) and the odds of them knowing that are lower still. IOW, good luck (!)
__________________________
Ron, btw, one more thing - and maybe you'll want to answer this in the lounge forum. I only rode once in an F-body (1986 IROC-Z,) so I know almost nothing about them. Care to comment on their ride and handling, NVH, and anything else you'd think would be noteworthy? MCSSs nowadays are crazy expensive, but F-bodies are relatively cheap. Thx.

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One thing I noted was the front sway bar, looks so familiar to Bob's. laugh Or I should say Bob's look familiar to this one??

The 1993 - 2002 model F body handles great out of the box in stock form with optional shock and spring upgrades of the day. NVH, NV is awesome, the H a little harsh if you nail a bad northern pothole. The cars are very solid in stock form. With some light mods they're leaps ahead of most anything I have driven. They're torque arm set ups from the factory and accommodate rear exit exhaust.

The weight, for every 100 pounds I add in chassis weight I'll throw and additional 10HP to neutral the gains. I'm sending the heads off the new LS7 to Texas speed to be CNC ported with new longer valve guides installed, and stainless exhaust valves which adds 30hp they say. Eliminating the valve failure issues some read about. I have 300 pounds I can gain plus whatever I lost already from factory cast iron and heavy suspension parts. But honestly this chassis might not be as fat as you think? Depending on the gauge and material composition it can be misleading. These guys are serious designers and I'm certain they have reasons for each action.

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Hi Bob,

Thanks for all that. Let's hope I'm wrong about the weight of that frame. Numbers are always nice to have instead of opinions. You have two factors working in your favor: first, the lighter LS-7 compared to the old iron-blocked SBC in the front, and second this frame, which is clearly much more rear-weight biased than the factory frame. Hopefully, you can cut 50 lb of fat from that frame so the lighter motor more or less cancels the additional frame weight.

We know that acceleration maps better to TQ than HP, but both can misleading. Every extra 100 pounds represents about 2.7% of the car's base weight. From experience you'll need more than 2.7% more hp from the motor to compensate: I'd say more like 4-5%. So 500 hp would need to go to roughly 520-525 hp just for the extra 100 lb. Reduced weight pays off big time.

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This engine is 570 hp from GM, the heads bring it to 600.


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I'm guessing the crate motor is tuned quite differently from the factory-installed LS-7. So I had a long talk with Gerry about the tuning of the LS-7 cam: why such a crazy-wide LSA, for example? This came at a time when he and I were debating the merits of a 383 SBC cam David Vizard and I were working on for good economy. The short answer for the LS-7 was good economy, low emissions, and good tranny stability on the low end, and reasonable power at the top. But it came at the cost of midrange torque. My modeling and the testimony of several aftermarket tuners confirmed it's very easy to change the cam for big midrange and HP gains. But as usual, economy and bottom-end grunt take a dive. With ICEs, you can never have it all at the same time. (With electric, you can, but that's another conversation.)

And what is the "all" that ICEs deny? It boils down to high peak HP and a wide engine torque bandwidth. You can have one or the other but never both.

The crate LS-7 might be dynoed to different standards as well. But all the arguments based on percentages still hold.

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Hi Mark,

GM makes a LS7 570 HP engine with an upgraded more egressive cam shaft. This is a wet sump engine verses dry sump also.

Regards
Ron


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Hi Ron,

Thanks - exactly my suspicion.

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With a LS7 it’s a mindless job to belt out upwards of 700hp NA. The engine is a race bread machine that made its way into pedestrian vehicles. I was looking to finish a project quick with some short cuts. Honestly it might be best for me to stop this build thread and just post the car finished. I'm not that interested in all the theory and design work of building a G body. I can build a 200K V code Mopar or a 50K F body and I don't need to run software modeling, those folks over there just like clean cool cars that work. For me this was a project to get away from my work stress and most importantly life's stress. I almost lost my wife this year to covid, she was in the hospital for 48 days and wasn't predicted to survive. This event has given me a reality check on what's important, and cars aren't. They're fun toys to enjoy while we have our health. If it makes you feel good or empowered flaunting education and or theory maybe be a professor, but honestly I think it's all BS! I have a long standing GM engineering heritage in my family and listened to debates over dinner as a child though out my whole life. It all means nothing to me because I can, at the drop of a dime build a car to run with any jack azz out there.

Mark, it's not personal and I apologize if you take it as a jab, which it's not.

https://www.corvetteforum.com/articles/chevrolet-performance-ls427-570/


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I was only trying to help. Next time I suggest you do that by PM. (I'm very happy your wife pulled through, Ron, and I'm sure I speak for everyone here too.)

You're reminding me that hot-rodding has evolved from cubic inches to cubic dollars. Maybe I should say cubic hedge funds counting recent inflation.

And of course, as you wish, over and out.

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I hope your thread continues, I don't post much but do keep up with it. A guy close to me in knoxville had Roadster Shop build a frame for a c10 a couple of years ago and I can tell you that the frame and craftsman ship on that frame was A+.

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No, I won't stop the build thread. I shouldn't be that way and send apology to all members. I just get a bit frustrated with things "life" and vent at the wrong folks at the wrong time. Mark is a very smart fella, I respect his angles and knowledge.


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Hi Ron,

Thanks. OK, I'll just say this before (really!) shutting up. First, glad to hear you'll be continuing the thread. I'll continue to watch from the background and root you on. Second, I've got to say again, that I was only trying to help.

So I hope you enjoy this to the full. But if I could submit an encouraging word to someone who is my senior, I would only say that when we think we're too old to be inquisitive and learn, and think we know it all, then we are - too old. Speaking for myself, I've barely scratched the surface. I wish you a happy return to a youthful attitude of inquisitiveness and discovery.

Btw, you've hinted you've made many interesting car builds. It would be great if you shared them in the lounge forum!

Best,
MAP

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I have been in contact with Patrick at the roadster shop, the frame the way I want it rolling is just south of 30K. It will hold a 345 tire out back, Bear brakes and several other upgrades. The chassis is 10 months out for production.

I will have many very nice chassis parts, frame and a near new 12 bolt Moser rear for sale soon.

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Might be interested in a few things.

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This build will take another turn. I was going to tub the rear and throw meats on the back and had an alternative thought. I have inquired about stretching the quarters and fenders, not flaring only the wheel well lip but leaving that intact and pulling the whole body panel out on a gradual taper with a 62.500 track width all the way around on a widened chassis. The doors will be recessed similar to a new Camaro. Only live once and what the heck, lets see what we can do here?? Pat should have some budgetary numbers next week, then I can bust the piggy bank open!

BTW, I copied Marks drawing and sent it to the roadster shop. Marks 17 year old drawing will come to life in the next year with a killer factory style custom paint job!

This should emulate the sketch MAP has posted. Mark could you post your drawing below?

Regards,
Ron

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Hi Ron,

Here's the thumbnail:

[Linked Image]

The sketch kind of hints that the flaring in the body in front of the front wheel well, up to the joint with the front fascia, isn't straight but curved concavely. It's simple cosmetics but I think it looks much better this way.
Also, Ron, are you going to move the front wheel well forward (and thus stretch the frame) by 4"? I later found that 3" is innocuous but 4" starts to look a little funky.

Also, you'll probably want to go wider with the flares because you're proposing roughly 4.7" more track width than stock. Btw, you'll like the extra space this makes for the engine. Miles of clearance for headers...

You're broaching new territory here, Ron! I think you'll love the results, and you will definitely have one truly unique Monte!


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Originally Posted by MAP
Hi Ron,

Ron, are you going to move the front wheel well forward (and thus stretch the frame) by 4"? I later found that 3" is innocuous but 4" starts to look a little funky.

This won't happen, I can't afford to make the car longer.

Also, you'll probably want to go wider with the flares because you're proposing roughly 4.7" more track width than stock. Btw, you'll like the extra space this makes for the engine. Miles of clearance for headers..

I'm actually going to add 4" of additional track width over factory @ 62.5 if that's correct? I'll know the numbers soon I would say.

You're broaching new territory here, Ron! I think you'll love the results, and you will definitely have one truly unique Monte!

Yes this is exciting too say the least, I'm very motivated as I'm so impressed by the level of skill I've seen on their builds.



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Sorry - I should have clarified that when I said moving the front wheels 3" or 4" more forward, it was while keeping the car at its existing length. The idea is to move only the front wheels and the front wheel-well openings that amount forward. Everything else stays put. Here's how 3" more forward would look courtesy of MS paint (from back in the day when it actually did some useful things):
[Linked Image]



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My late friend Greg Weld put a Roadster Shop chassis under this 40 Ford Pickup and he was beyond pleased with it. I've seen cell phone pics of the Speedometer at 140 mph during the Good Guys Road trip taken with one hand on the wheel and one hand on the phone...it's that smooth and predictable. He loved that truck and his daughter has it now and still loves it to this day.

[Linked Image]


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That’s a very nice truck, thanks for posting Lance.

I’m already getting flak from Mark on the cost, but the quality they put out I see as second to none.


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My good friend Chris Jacobs has had an IRS Roadster Shop chassis under his Chevelle for a long time. Was very competitive on course as well until everyone else just got so much faster. Still a great car that he loves to long haul and race in..

[Linked Image]

He's in Chicago and is real close with the guys at RS.


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I can say this about the Roadster Shop frame that I saw at the fall rod run in Pigeon Forge a few years back is that it stood out. All the frames from all the different manufacturers pretty much look the same as each other at all the booths and the Schwartz looks just like the rest after looking at it on their website. Pretty much just a basic fabbed frame, RS frame looked like a piece of art. I'm not speaking on functionality I'm speaking on looks alone the RS frame put the rest to shame all the way down to all the weld beads perfectly placed. All day there were crowds around the RS frame the others just people stopping to take a glance and moving on. On looks alone I would pick the Rs frame all day.

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Another sweet ride, that paint looks very slick too.

I'm not looking to build an auto cross car, but yet a great driving street car. Honestly the more I think about it I hate to cut the car up at all. I might just leave it a stock wheel base and run 17" N90 wheels? I'll see this week what kind of money were talking?

Regards,
Ron


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While I'm trying to spend Ron's money for him. Lol. Here is the RS 7.0L twin turbo grand national. Over 300 pictures in the build album link.

https://roadstershop.com/galleries/1987-grand-national/

[Linked Image]
[Linked Image]
[Linked Image]

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Those are two great-looking vehicles!

Well, Ron, you're in a good position with your background to take a step back and think through the scope of the project in realistic terms that will be right for you. Now is certainly the right time to do it. I think most folks, including myself quite possibly (!) would get into it halfway and realize we bit off a bunch more than we could chew. Going forward, I know I'm going to tell myself that despite the best forecasting possible for budget, double it, and it will probably be almost enough smile I know you won't make that mistake.

Best,
MAP

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Hi Brent,

Our posts crossed - that's an amazing GN! First-rate bodywork.

But here's the problem - outsized flares work great on a GN body, but look terrible on an MCSS. The visual problem is the cosmetic swooping creases in the body. Modest flares are OK, like that GM attempt. But big flares would clash because they would have to overrun the creases. I tried some sketches of that and it looked awful. You can have big flares or the factory crease lines, but not both at the same time. And that's why smooth, gradual fairing is the right approach for the MCSS, in my opinion. But no matter the approach, those front fenders are going to be a big challenge. There's not much height above the top of the wheel well opening and the top of the fender to work-in a lot of extra width. Even the front flares on that GN look a bit pushed in this regard, because the intersection of the conical shape of the flare and the convexity of the fender creates an upward-pulling elongation along the top of that intersection that looks a bit strange. (Btw, the shop made the same mistake as GM: the height of the front wheel well needs to be higher to avoid tire interference while turning and going over bumps. An inch would make a big difference.)

Anyway, point is, gradual fairing hides the visual problem for an MCSS.

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Hey Brent,

I did see that one on their web site, awesome build and thanks for sharing. I couldn't afford a GN when they were new hence the SS monte I have. I couldn't imagine paying the bill on that one either... LOL

Regards,
Ron


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Well, just a thought for others who might want to try this: I'm pretty good with body work. I think I could do as well as the Roadster shop on that GN, for example. So, for an MCSS, I'd start with a fender mockup in clay to get the right shape defined, then buy an extra used fender to translate that shape into steel and Bondo. That way I could perfect my technique without risking defacing the actual car. With the fender done right, then I'd take my chances on the quarter panel.

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It appears they use coordinate measurement equipment and software to build the modifications to after they have the rendering approved by the customer?

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They use a CMM? That's impressive.

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CMM as in a Faro Arm or similar? I see some 3D scans but nothing like a Faro. I've been looking into 3D scanners casually. You can get a decent one for less than a grand now. It's come a long way in the last couple of years.

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Hi Bernie, a Faro that I’m used to using for large OEM machine installation and alignment is 250k, starters. I would say they don’t have that from what I’ve seen. I will talk with them later today and follow up with the equipment they use.

You don't need a faro "arm" for precision measurements, things have move much in the last years for CMM. Faro has a laser tower with a hand held mirror reflector "the size of a pin pong ball" that catches it's view locking on a beam, that will record anything you set it on with the push of a remote button. This is what I have spec'd on site for the last 10 years for machine installation alignment while mapping 3D roll maps holding .001" for customer validation records.

https://www.faro.com/en/Products/Hardware/Vantage-Laser-Trackers

Regards
Ron

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Wow, that's awesome!

The pictures of the GN - I saw a 3D scan in a picture of the computer screen. Is that what you were referring to when you mentioned coordinate measurement?

I was thinking about a stereo scanner for prototyping parts in Solidworks. For $800, I don't need a ton of work lined up to jusitfy it. Given the inconsistencies in production frames, I feel like even 1mm accuracy is enough.

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Hey Bernie,

Honestly I just seen all the monuments scattered on the car and automatically think CMM. I have no 3D scan experience, it has to run parallel to CMM to some extent I would think? And for sure they need some type of numeric feed back if they’re building frames. But who knows sometimes I get a bit out in the weeds over thinking stuff…

I’ll still plan to talk with Pat one day this week and get the scoop. I’ve been bit tied up building a bigger garage this year as I have too much junk to work on. This shop is has about 1400 square feet so it should help a little.

Regards
Ron


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Well, with respect to the level of bodywork I see in that GN as far as the photos convey it: one doesn't need a CMM for that. A good body man can do that as well, and even avoid the odd upward prolongation of the seam line between the front flare and the convex fender by using a slight departure from conicity with the flare. Or, English wheel it, and give the flare a bit of complex convexity as Chrysler does with some of their 300-series cars, I believe. I agree with Bernie that given production tolerances and how material variations cause stamped steel panels to come out with slightly varying shape from the factory, 1mm spatial tolerance is probably sufficient. For the frame, given its 1980s provenance, even 1mm is likely much too optimistic. Almost any CMM is far, far better than that...

As far as the CMMs we used, they were in receiving-inspection in my facility and I had only infrequent contact, and it was already several years ago. The ones I saw were definitely multi-linked arms; could have been Faro but I'm not sure. I was told they cost $$$, yet the staging table was only about a meter square. A quick look online suggests that stereo laser scanners as you're citing, Bernie, are the way to go in terms of value. More advanced laser doppler velocimetry has been around for decades now.

Ron, are you still thinking about widening your MCSS at the Roadster shop?

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Well, we all know something the other doesn't. For sure my use of CMM is miles ahead of automakers frame tolerances, principle was my point not tolerance.

Mark, I'm open to doing it. But nobody will cut on my car until I understand completely the quality control part. I want to walk side to side and see the same thing with repeatability and dimensional accuracy. I don't care what anybody has to say. I have an extremely well trained eye and can spot things most folks don't. I want the car perfect for that kind of money period! I honestly believe these guys want the same and will have a clear explanation. Once I'm satisfied with what I hear, I won't bother these guys unit I pick the car up if I can digest the cost. dunno If I do this I can't buy my new Camaro and that's a tough one.

Chassis = 30K plus
2023 LT1 Camaro 455HP 6 speed = 37K

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Hi Ron - sure makes 100% sense. With your background, I don't doubt that you can spot imperfections that 99% of people wouldn't.

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Originally Posted by 1 Slow SS
Hey Bernie,

Honestly I just seen all the monuments scattered on the car and automatically think CMM. I have no 3D scan experience, it has to run parallel to CMM to some extent I would think? And for sure they need some type of numeric feed back if they’re building frames. But who knows sometimes I get a bit out in the weeds over thinking stuff…

I’ll still plan to talk with Pat one day this week and get the scoop. I’ve been bit tied up building a bigger garage this year as I have too much junk to work on. This shop is has about 1400 square feet so it should help a little.

Regards
Ron


https://roadstershop.com/galleries/1987-grand-national/#&gid=1&pid=7

Taking a second look, I spotted this picture. The dust on the car probably serves the same purpose, to reduce reflections and make it easier for the scanner. Although I have no direct experience, my understanding is these scanners create a surface file (.stl ?) that can be imported into a CAD program and you go from there. In my case, I would be building solids of new parts based off of the scan. It looks like they did something similar, including building a jig for the fender flares. That capability means they should have no problem at all making both sides exactly the same. I can't wait to watch along!

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We use a Faro for facility scans. Yeah, the dust is probably just to take the gloss out of the surface, we've done scans with puddled water that creates an "alternate universe" underneath due to reflections of the laser scans. The dots help the system make some anchor points to tie together multiple scans. We have used billiards balls that were drilled and threaded with a magnet base to be able to place them easily around a shop, but have since figured out that the software is good enough at matching it all up without them that we don't mess with it anymore. Occasionally you get an unintended match were the north end of the building gets copied to the south end, and you just have to manually orient it in the general direction, then it lines up the exact position from there.
Ours also does it as a point cloud, then more work turns it into a surface model. But for something like a 200,000 sq ft industrial facility, you don't want surfaces slowing the model down generally so we leave it out. It's also about 4 or 5 years old, tripod mounted, omni-directional, and scans large buildings to within 0.010" pretty quickly. I think we've played with some smaller pieces and longer/tighter scans and got better accuracy, but we just don't need it for our needs. Neat stuff though, cool to see it used on something like that.


Shawn

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Ditto on whatever that white stuff is - we needed to use a white spray-paint dust coat on our speaker cones to get a good, non-specular reflection for our laser velocimetry scans.

Looking at those GN photos, I have to say that shop does some very impressive fabrication. I don't agree necessarily with that trunk stiffening scheme, but I'm only aware of structural software that does analysis and very little, if anything at all, of synthesis. You still need the grey cells to figure that out. Overall, this looks good for you, Ron. It looks like you'll get top quality. Unfortunately, it also looks like you'll get a bill to match.



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Hi Mark,

Unfortunately, nothing I'm interested in comes too cheap, even if I do the work. Just a nice engine these days runs 10-20K and up depending, what we want? The good thing is if I do the build, I be happy with the end product, and you can remind me of the cost and lack of ROI of a G body... LOL

Seriously though, how much should it cost to build a rolling chassis that you deem as a top performer? I have 10k in parts laying around for a factory G body chassis build. I bet double adjustable remote reservoir shocks alone are 3K.

Regards,
Ron


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Out of curiosity what are you talking about trunk stiffening scheme? I wouldn't think you would need much stiffening of the trunk with the full frame with roll bars tied in at the back. I see early on they have some small tube tacked in to keep the body in place while removing and building new wheel tubs in the back but when finished I don't really see much back there.[Linked Image]
[Linked Image]

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Hi Brent,

You're correct, no trunk stiffening scheme here... laugh lmao

Mark,
I had to make a similar fixture when I moved my tubs in 5". The reason being is the trunk hinges mount to the inside wheel tubs. So to widen the tubs you need some support, I do agree that's a bit much to hold a deck lid up for a couple days. As fare as the finished product in the trunk, I like what I did better to my 1 slow SS back in the day.

You guys keep posting stuff like this I might just buy the Camaro... laugh

Regards,
Ron

Last edited by 1 Slow SS; 09/15/22 06:59 AM.

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Beautiful build sir


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Hey map I'm curious what do you do for a living if you don't mind me asking


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Hi Folks,

Well, first, my mistake about the trunk stiffening scheme - I thought it was going to be a permanent part of the build (!)

About the cost - Ron, you make a good point. The days of cheap hot rodding are long gone. That's why the hobby is dying fast and will eventually go (has gone?) the way of ham radios and home-built computers. I have to keep reminding myself of this when I see the price tag of that Roadster chassis. So I suppose in a 2022 context, adding an extra zero to many of the prices I remember from the 1990s is in order.

About how much I would expect to pay for a top-notch rolling chassis, I'd expect to spend more in time and less in money than the direction you're going, but that is by no means a slight on your approach. Time is money, after all. Unibody would be central to this to maximize stiffness in relation to weight, so lots of time-intensive design and fabrication. But that's probably the only way I'm going to get a 10x increase in torsional stiffness about x without making the car as heavy as a Sherman tank. My guess is that if you asked the Roadster shop to do it, your $30k(+) rolling chassis would look downright cheap by comparison. For me, it would have to be a labor of love or forget it.

But after the chassis, there's no way to avoid spending serious coin on the front and rear suspensions (R&P steering, of course.) The A/G body stock suspension is a relic from the 1960s and belongs in the dustbin of history. I know it can do good things with strenuous, heroic intervention (I'm thinking of Lance and mmc427ss,) but I think it makes a lot more sense to start with a fresh design. And of course, I'd make the car wider at the axles.

But after the front suspension, the comparison stops because that's when using an EV drivetrain would induce me to use an IRS in the rear - most likely a swap from a Tesla.

I know, I know. As if an EV conversion is cheap...

(On edit: Regulator, sorry I missed your question before: my profession is loudspeaker design. 23 patent records. Cars are just a hobby.)

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I think that GN being a frame off and cutting the rear wheel wells, trunk, and cutting the quarters to destroy the body lines of the car with flares would require lots of bracing to keep original sheetmetal from moving during fab time.

I akin those flares to seeing some of those wild 70's cars that blew the corners out to fit huge wheel/tires under the machines. I like the idea of pushing the sheetmetal out for bigger but it needs to be tastefully done. Not sure I really like that way out look on the GN.

At autox events you will see blown out corners to max tires sizes. Unfortunately for some the geometry of the suspension and wheel bearing loads are never considered. Notice how much offset the rear wheels on that GN have, lots.

One thing at looking at the RS "standard" front suspension is they do two track width up front on most all chassis. Then fit wheel offset to fit the car. I would think you can change front track width from "standard" but adds a few dollars more to a chassis.

I've been in Precision Chassis shop many times, a local high dollar mostly drag chassis builder. Last time Jimmy showed me a car built using Docol tubing, ouch, that will add a few dollars to a chassis build.
https://www.facebook.com/Precision-Chassis-Inc-160338450719439/
Bob

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I had my call today with the roadster shop. I can buy the 32K frame with what I need to fit under a stock body. I asked about doing body flaring with a widened track, that's not an option. They only do turn key cars at this time. Those jobs are 3 years out and BIG money. The money is serious, more so than I ever could imagine! I asked where I would be on the conservative side having them do the car as a survivor, no paint. With me providing a new interior, engine, trans, we were looking at 250K minimum. If I were to have it painted we could say 300K on the low end. I'm out, I was thinking 50k could get me in the ball park getting a frame and flaring the body panels. Quiet honesty I'm in the wrong business!

I'm building the car 100% myself, I need to pull out the Speedtech parts, donor frame next month and get to work. I'll keep my money buying my Camaro and have two cars for the price of a chassis.

Bob,

Precision is a very good chassis shop, I was looking to possibly have them do a frame also.

Regards,
Ron

Last edited by 1 Slow SS; 09/15/22 10:50 PM.

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Sorry to hear that news. Curious if you're building the car yourself, are you going to widen it also? With your standards of bodywork, I'd imagine the result would be excellent.

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I have done much metal work over the years, replacement panels and light mods moving frame rails in and over sized tubs. I don't have the tooling too fabricate a radiused panel, also I need the experience forming metal to that extent. I won't be doing any of that on this car, I'll move the frame rails in a bit and put some 325's on the rear at best. I'll build a real nice car, it won't be as unique as I would like though. frown

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Still sounds like a car that most of us can only dream of, and I'm sure you will love it. For absolute performance, I think there's other starting points that we can all agree would be better than a G (of course, none of us would agree which starting point is "Best"), but between the type of work you are doing, the quality standard it will be done to, and the story of the car, this will be an amazing build that I know I'm looking forward to.

Someday I'd love to be able to drop that kind of money on a car, but for pretty much all of us here, I doubt that's in the cards right now.


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Hi Hunter,

Thanks for the positive encouragement. The car will be very pretty when done, and your correct. I’m still very fortunate to have the resources to finish the build too a fairly high level. Age does have a couple benefits, time and a little money to play with. laugh

Regards,
Ron

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Looks like fun. Will you add Miracle-Gro to your frame (couldn't resist!)

TQ on that motor: the curve looks flat and broad, always a good sign. You're well beyond a 50% torque bandwidth.

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This week the frame comes in and the car moves to the shop where the rotisserie resides. Won't be long and we can see how pretty I can make her again. cool


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Great - congrats!

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