MonteCarloSS.com
MonteCarloSS.com

CELEBRATING 20 YEARS!

Previous Thread
Next Thread
Print Thread
Page 4 of 5 1 2 3 4 5
Joined: May 2002
Posts: 4,550
M
MAP Offline
20+ Year
Member
Offline
20+ Year
Member
M
Joined: May 2002
Posts: 4,550
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.

Last edited by MAP; 09/11/22 10:09 PM.
Joined: Sep 2007
Posts: 3,325
Likes: 4
15+ Year
Member
OP Offline
15+ Year
Member
Joined: Sep 2007
Posts: 3,325
Likes: 4
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


Enjoy life, family first!
Joined: May 2002
Posts: 4,550
M
MAP Offline
20+ Year
Member
Offline
20+ Year
Member
M
Joined: May 2002
Posts: 4,550
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.

Last edited by MAP; 09/11/22 10:15 PM.
Joined: Sep 2007
Posts: 3,325
Likes: 4
15+ Year
Member
OP Offline
15+ Year
Member
Joined: Sep 2007
Posts: 3,325
Likes: 4
It appears they use coordinate measurement equipment and software to build the modifications to after they have the rendering approved by the customer?

Last edited by 1 Slow SS; 09/11/22 11:31 PM.

Enjoy life, family first!
Joined: May 2002
Posts: 4,550
M
MAP Offline
20+ Year
Member
Offline
20+ Year
Member
M
Joined: May 2002
Posts: 4,550
They use a CMM? That's impressive.

Joined: Jul 2003
Posts: 9,279
S
15+ Year
Member
Offline
15+ Year
Member
S
Joined: Jul 2003
Posts: 9,279
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.

Joined: Sep 2007
Posts: 3,325
Likes: 4
15+ Year
Member
OP Offline
15+ Year
Member
Joined: Sep 2007
Posts: 3,325
Likes: 4
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

Last edited by 1 Slow SS; 09/12/22 05:23 PM.

Enjoy life, family first!
Joined: Jul 2003
Posts: 9,279
S
15+ Year
Member
Offline
15+ Year
Member
S
Joined: Jul 2003
Posts: 9,279
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.

Joined: Sep 2007
Posts: 3,325
Likes: 4
15+ Year
Member
OP Offline
15+ Year
Member
Joined: Sep 2007
Posts: 3,325
Likes: 4
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


Enjoy life, family first!
Joined: May 2002
Posts: 4,550
M
MAP Offline
20+ Year
Member
Offline
20+ Year
Member
M
Joined: May 2002
Posts: 4,550
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?

Last edited by MAP; 09/12/22 10:44 PM.
MAP #1075116 09/12/22 11:02 PM
Joined: Sep 2007
Posts: 3,325
Likes: 4
15+ Year
Member
OP Offline
15+ Year
Member
Joined: Sep 2007
Posts: 3,325
Likes: 4
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

Last edited by 1 Slow SS; 09/12/22 11:47 PM.

Enjoy life, family first!
Joined: May 2002
Posts: 4,550
M
MAP Offline
20+ Year
Member
Offline
20+ Year
Member
M
Joined: May 2002
Posts: 4,550
Hi Ron - sure makes 100% sense. With your background, I don't doubt that you can spot imperfections that 99% of people wouldn't.

Joined: Jul 2003
Posts: 9,279
S
15+ Year
Member
Offline
15+ Year
Member
S
Joined: Jul 2003
Posts: 9,279
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!

Joined: Apr 2011
Posts: 1,270
10+ Year
Member
Online Content
10+ Year
Member
Joined: Apr 2011
Posts: 1,270
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

'85 MC with budget 5.3L swap, TH350 with stock 2.14 rear end
It ain't much off the line, but it's nice on the highway
Joined: May 2002
Posts: 4,550
M
MAP Offline
20+ Year
Member
Offline
20+ Year
Member
M
Joined: May 2002
Posts: 4,550
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.



Last edited by MAP; 09/14/22 08:42 PM.
Joined: Sep 2007
Posts: 3,325
Likes: 4
15+ Year
Member
OP Offline
15+ Year
Member
Joined: Sep 2007
Posts: 3,325
Likes: 4
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


Enjoy life, family first!
Joined: Feb 2020
Posts: 782
Likes: 1
Member
Online Content
Member
Joined: Feb 2020
Posts: 782
Likes: 1
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]

Joined: Sep 2007
Posts: 3,325
Likes: 4
15+ Year
Member
OP Offline
15+ Year
Member
Joined: Sep 2007
Posts: 3,325
Likes: 4
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.

Enjoy life, family first!
Joined: Feb 2005
Posts: 180
R
15+ Year
Member
Offline
15+ Year
Member
R
Joined: Feb 2005
Posts: 180
Beautiful build sir


1979 Monte Carlo
1986 Monte Carlo
Joined: Feb 2005
Posts: 180
R
15+ Year
Member
Offline
15+ Year
Member
R
Joined: Feb 2005
Posts: 180
Hey map I'm curious what do you do for a living if you don't mind me asking


1979 Monte Carlo
1986 Monte Carlo
Joined: May 2002
Posts: 4,550
M
MAP Offline
20+ Year
Member
Offline
20+ Year
Member
M
Joined: May 2002
Posts: 4,550
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.)

Last edited by MAP; 09/15/22 06:39 AM.
Joined: Jan 2000
Posts: 5,750
Likes: 4
M
20+ Year
Member
Offline
20+ Year
Member
M
Joined: Jan 2000
Posts: 5,750
Likes: 4
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

Joined: Sep 2007
Posts: 3,325
Likes: 4
15+ Year
Member
OP Offline
15+ Year
Member
Joined: Sep 2007
Posts: 3,325
Likes: 4
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.

Enjoy life, family first!
Joined: May 2002
Posts: 4,550
M
MAP Offline
20+ Year
Member
Offline
20+ Year
Member
M
Joined: May 2002
Posts: 4,550
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.

MAP #1075166 09/15/22 11:25 PM
Joined: Sep 2007
Posts: 3,325
Likes: 4
15+ Year
Member
OP Offline
15+ Year
Member
Joined: Sep 2007
Posts: 3,325
Likes: 4
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

Last edited by 1 Slow SS; 09/15/22 11:27 PM.

Enjoy life, family first!
Page 4 of 5 1 2 3 4 5

Link Copied to Clipboard
Help MonteCarloSS.com


Recent Contributors
86BlackSuperSport
Authorized Vendors
Tell them you saw it
on MonteCarloSS.com!


Dixie Monte Carlo Depot
Mikes Montes
Powered by UBB.threads™ PHP Forum Software 7.7.5