G-body Roll Call

[Norm Peterson]

Jorge from maliburacing, right?

How's the car coming along/doing?




Norm

[krakabash]

'85 Monte Carlo w/350

[whitess]

I keep forgetting to put up pictures of mine. (sadly I'm going to sell it):

http://s530.photobucket.com/home/whitess1

[ArtosDracon]

I'm pretty sure it's just been GM- G-bodies up till now, but heck, why not let the mopar guys in too.

[malihoochie]

I'm pretty sure it's just been GM- G-bodies up till now, but heck, why not let the mopar guys in too.

Haha

[MAP]

Greetings,

Somcamaross and John S - many thanks for the welcome. Posting on different web sites can be an incredible time sink, so I frequent extremely few.

Question for Craig Morrison/AME: if you wouldn't view it in the realm of proprietary information, would you please share any stiffness measurements on the stock chassis? Torsional stiffness about the car's CL longitudinal axis, and between the front and rear axle locations, would be of key interest. My opinion is that the stock chassis is woefully limp, and mostly because of those flimsy C-channel side rails in the mid section of the frame. Also, as I recall, the fundamental vertical resonance of the body mass on the frame (lambda/2 deflection mode,) was down in the 15-18Hz range. Again, a woefully low number for anything other than a cushy boulevard cruiser.

Best,
MAP

[CraigMorrison]

Greetings,

Somcamaross and John S - many thanks for the welcome. Posting on different web sites can be an incredible time sink, so I frequent extremely few.

Question for Craig Morrison/AME: if you wouldn't view it in the realm of proprietary information, would you please share any stiffness measurements on the stock chassis? Torsional stiffness about the car's CL longitudinal axis, and between the front and rear axle locations, would be of key interest. My opinion is that the stock chassis is woefully limp, and mostly because of those flimsy C-channel side rails in the mid section of the frame. Also, as I recall, the fundamental vertical resonance of the body mass on the frame (lambda/2 deflection mode,) was down in the 15-18Hz range. Again, a woefully low number for anything other than a cushy boulevard cruiser.

Best,
MAP

MAP- Thanks for the question! No, it's not proprietary info, but to be honest we haven't done any calculations on the stock chassis because it is so horrible. When we were measuring the chassis with the Faro arm, just mounting the arm onto the chassis was causing it to deflect. We had to add extra supports under the frame to keep the 30# of the Faro arm from deflecting the chassis and creating errors in the measurement data!

With the chassis supported by jack stands under the housing you can hold the rear passenger rail in one hand and lift and visually see the deflection all the way up to the front suspension crossmember. I know that this is pretty anecdotal evidence but we've never seen a chassis that has been this weak.

It is pretty apparent that it's sole purpose is to locate the bumpers and suspension points and the body is providing the chassis strength.

You are extremely correct when you say that the chassis is woefully limp!

[Norm Peterson]

We did have some discussion on the chassis stiffness topic a while back and a few crude-ish numbers came out of it but no confirmation.

Linky


And welcome to visibility (took ya long enough to start posting )


Norm

[MAP]

Thanks, Norm!

I don't know my way around here at all, so that link is a good inducement for me not to take this thread too far adrift.

Best,
MAP

[Doober]

I can't wait to see the frame... I'd asked if it's going to be along the same lines of the MaxG style chassis, but I'm not sure if you'd responded yet. Regardless I'm sure it will be way beyond the capacity of any stock G-Body frame! I'd love to be able to fit wide tires at all 4 corners (definitely not easy in the front), do you think it may be possible with this new frame?

[Samckitt]

Craig, what type front suspension are you putting on this?

[67rstbkt]

I just picked up a g-body for a daily driver and mini-project. I guess my Firebird build just wasn't enough. I think I have a sickness.......
Anyway, here it is in all it's glory; a 1983 Grand Prix
I took the rollers off of my firebird and threw them on there. I'm thinking 275/60/15 rears and 235/60/15 fronts and paint the thing hot rod black. What do you guys think?

[CraigMorrison]

Craig, what type front suspension are you putting on this?

They wanted a 3-link in the rear and we are using our "Sport IFS" up front.


I haven't seen the chassis design yet, so I'm not sure if it is a MaxG style or not. As soon as I see it I will let you know.

[MAP]

Hi Craig,

Amazing! My plan is quasi unibody conversion, bulged quarters and fenders for wider tires, front wheels 1.7-4" more forward, and 3-link at the rear with a Watt's link. The Monte Carlo body style accommodates the bulging and the front-wheel relocation surprisingly well, as renditions show: you have to look at before and after pictures two or three times, and even then, the differences are difficult to detect - the car simply looks like it came that way from the factory, since the stock crease lines in the body suggest a reality waiting to happen...

Previous measurements showed the body to be a good deal more rigid than the frame - agree here - I think that frame probably ran well down the production lines GM had at the time, and maybe that's why they used a bare minimum of a connection between the front and rear halves of that frame.

Not to try to pull too much attention from this thread, but a lively discussion of your frame is happening here:

http://www.montecarloss.com/communit...441#Post829441

On edit: I've got a 1981 Monte Carlo minus suspension, and up on jack stands, as I write this. The car is completely stock, and without even a trace of rust. The condition of the OE frame/body bushings is TBD, however. I'll try to take a torsional stiffness measurement on the frame in this condition over the next several days and report back. Edit 10/17/10: Got it. Without suspension, drivetrain, nor hood, the frame with all 14 OE body bushings attachment to body, measures 2,490 ft-lb/deg. I'd assign about a +/-5% tolerance to this measurement. If the car had all missing components installed, I suppose this number would have been a tad higher - maybe 2,600 ft-lb/deg? The frame, body, and even the bushings look essentially as-new (with 100% of the car's life lived in eastern San Diego, I suppose I shouldn't be surprised.)

Best,
MAP

[mc84_zz4]

Well, this week there was an update on AME's facebook page.
There may still be some details or changes later, but this does look REAL tasty.
The little magic I would like to see, is if they can package the tri-link rear to still retain some form of rear seat, or if a triangulated 4-link may follow later...
Still, very exciting to see this project coming to market.






You may need to login to see the album:
http://www.facebook.com/home.php?#!/...01846653183796

[Samckitt]

I am curious to know I'd they are narrowing the rear frame rails, what rear width tires will fit, what front suspension are they using, raer seat still usable? Are they going to sell this frame, how much?

[Doober]

I am curious to know I'd they are narrowing the rear frame rails, what rear width tires will fit, what front suspension are they using, raer seat still usable? Are they going to sell this frame, how much?

I was wondering about the rear seat myself with the 3-link. They did some test fitting yesterday/today it looks like.


I also had asked about the rear tire, the reply was 335s, the fronts he would have to check on.

[somcamaross]

I am curious to know I'd they are narrowing the rear frame rails, what rear width tires will fit, what front suspension are they using, raer seat still usable? Are they going to sell this frame, how much?

x2!

[CraigMorrison]

I am curious to know I'd they are narrowing the rear frame rails, what rear width tires will fit, what front suspension are they using, raer seat still usable? Are they going to sell this frame, how much?

The chassis is designed to fit 335's, as this was the tire spec'd by Holley. Because this is a track-day car, they weren't really concerned about the rear seat, but if some of the center seat springs are trimmed, the rear seat should be able to fit back down. However, you probably wouldn't want to be riding in the middle and hit a bump. This car is also getting a full cage, so accessability to the rear seat will be difficult.

The chassis originally was a one-off reverse-engineering job for Holley. To be honest, I've been pretty blown away by the response that this chassis is getting on our FB site as well as on the forums.

It is definitely something we can do again, but pricing hasn't been discussed for another chassis. Also, the spec on this chassis was pretty high - remote reservoir Penske's, splined sway bars, 3-link, Woodward rack + reverse engineering and design time.

Now that we have the specs, I'm pretty confident that we could offer this chassis with either 3-link or tri 4-bar in the back and a few IFS designs up front. The tri 4-bar would definitely minimize sheetmetal removal in the back seat area as well.

[mc84_zz4]

I would be real interested in seeing how the packaging turns out for the rear-seat area.
I conclude that tubbing is soon to follow, possibly some trimming to clear the UCA.
About the front end: I hope they offer a set of wheel wells. That would
allow fatter tires, and to run much lower than the stock plastic wells.