Art Morrison Max G Chassis under a 1st Gen Camaro

[Nutsy]

Just got this months PHR and read the AD from Art Morrison.

"Simply drop your car's body over the frame and build a new floorboard. Its a project that do-it-yourself home builders can do! Call now on details on giving your Camaro, Challenger, Chevelle, Dart, Demon, GTO, Nova (or ???) contemporary chassis technology performance."

Ok. Time for some discussion. Questions:

1. Realistically how much work is this?

2. Is this a better all around solution (performance wise) for a 700hp+ Camaro than an aftermarket front clip (WD, DSE, AM, etc.), frame connectors, and a well designed rear suspension?

3. How much would this be in comparison to a completely built DSE or WD front clip and custom rear setup such as a 3 link or IRS?

4. Has anybody actually looked into this at all? If so, please post your findings.

5. If you were planning a ground up build on your car, what would you do?

Talk amoungst yourselves!! :smoke:

[Marcus SC&C]

I talked with Don from the Art Morrison booth at a recent trade show about the MaxG chassis. Since on one else has said anything yet and I do this kind of thing for a living I`ll take a quick stab at your questions. ;)
1) Let`s not kid anyone,it`s a huge amount of work.
2) Better is a tricky word. The front suspension and R&P look to have pretty good geometry. The rear suspension they recoment for ProTouring use is their triangulated 4 link. That has it`s geometry problems but they`ve done some work to correct them by lowering the roll center and reducing torsional binding to at least some extent. I`d rather see it with a road race style 3 link with watts linkage or panhard but for a tri4link it looks decent. The one BIG advantage would be chassis rigidity and overall strength. Not only would you have a full box section frame but the method of installation welds the unibody/floor right to the frame throughout the car.
3) Just an educated guess but probably more than a custom front clip and 3 link,less than custom front and *good* IRS. That is if you`re paying someone to do it.
4) Just looking at pics and talking to Don.
5) I`d build my own chassis and suspension from scratch. But then as I said,I do this stuff for a living. YYMV Marcus SC&C

[ViperBlue68]

I had posted this earlier under the new 69 Camaro Body thread and asked what kinda ballpark figure am I lookin at for the max g under a new 69 minitubbed body?? Prodigy there you go it is designed for the Camaro should make it somewhat easier

[ProdigyCustoms]

I'll have to scope it out. Have not seen the issue yet. As stated above, I bet it is some work as I have built some full chassis in these cars. Where it seems best suited could very well be in rotted undercarriage cars. I have a Michigan 69 coupe that fits the bill nice, I was looking at doing a full tube chassis in it, this AM chassis might be an interesting solution.

[Steve Chryssos]

One big advantage to a full frame is that it becomes easier to channel the body over the frame for an extremely lowered look without giving up suspension travel.

I think the fundamental Max-G chassis was designed by our Katz Tsubai. Also it is the only aftermarket design that has been tested and published. I'm sure it works just fine for all except the snooty rocket scientist types.

As far as the ad's statement is concerned--Ibelieve that is how JP started out. "I'll just drop the body over the new chassis and build a new floor............................................. ................................... .................................................. ...........................................
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[Mean 69]

Snooty?! Now, who would you be referring to with that statement? :smoke:

Mark

[Salt Racer]

Snooty?! Now, who would you be referring to with that statement? :smoke:

Mark

You, Marcus, me, among few others.

LOL.


Seriously, this chassis would be a good way to go if you...
1) would be happy with performance similar to Morrison's 55 Chev (see video clip on their website) - and don't kid yourself on your intended use of your car. You wouldn't need much better performance if you never go to road courses.
2) can cough up $10K+ for a rolling chassis
3) are willing to do TONS of work or can pay someone else to do the job

[BRIAN]

If you are building full tilt car it is in some ways easier to do full frame. Most Camaro's of that vintage have rear rail damages, rusted floors, etc. Most guys hear swear by the front clips. You will need subframe connectors anyway. Art Morrison stuff is usually pretty close to orig pan demensions so I do not see the huge additional work. Actually in some ways it is easier as you are not dealing with old parts. Simply build inner supports and cut floor off at rockers from firewall back. The frame is in one piece, fit to body at height you want. Buy floor pieces as you would have anyway and fit to new frame. I have done both and if you are building full frame off type deal I would go the full frame route. As for the suspension dynamics I am no engineer but their 55 probably has laid down some of the best numbers I ever seen in a magazine from a drivable car. There will always be somebody that disagrees with the suspension setup but it works, plain and simple. Good luck and add up parts seperate, then place your order for the frame. By the way they have made those rails for years they are just now advertising for different Pro Touring set ups. GOOD LUCK!!

[jeffandre]

Some nut is going to place a 2nd Gen fiberglass body on one of these frames a have a 2000# car...wish it was me!

[Marcus SC&C]

Snooty rocket scientist types?
Hey I resemble that remark! Nyuk,nyuk,nyuk. :lmao: Marcus SC&C

[1976SR71]

Some nut is going to place a 2nd Gen fiberglass body on one of these frames a have a 2000# car...wish it was me!

Now thats what i'm talkin about!!!

[Mean 69]

A 2nd Gen glass body? Where would someone get one of those? THAT! could be a very interesting car.

M

[parsonsj]

Yep, that's exactly what I was gonna do.

It is a LOT of work. Years of it if you do it as a hobby. Would I do it again? You bet. Morrison's stuff is top quality for street use, but it may be a bit wanting if you are one of them snooty types.

jp

[ProdigyCustoms]

I will be talking to them Monday. I am very interested in doing something with AM a project I have waiting. One of the issues with full framing a Camaro and channeling the body very much is the frame rails running through the floor. Even if the floor is rebuilt, the seating and flooring ends up too high for anyone over 5' tall.
A perimeter frame can solve this problem, but usually needs a pair of inner rails for additional support. With a perimeter base frame and properly located inner rails (Ala Prodigy), you can get a channeled lowered body, proper seating and floor height. I do not see this in the frames in the catalog. but possibly they do not have the Camaro frame pictured.
One thing is for certain. A full frame will easily outperform a subframe / frame connector / unibody any day assuming both are properly tuned. Making the body one with a rigid frame removes most, if not all deflection.
If Morrison has a frame for a Camaro,I would like to work with them as I have the perfect 69 coupe for it. it could make a cool project that might very well save some of these rusty undercarriage cars, and ultimately make a better car.

[Marcus SC&C]

They make them for just about all the popular muscle cars. I love the glass body idea! I just wish there were some glass bodys with street car fit and finish and provisions for proper glass,weather seals etc. Those are pretty hard to come by. I had the chance some years ago to buy an SCCA GT1 C4 Corvette we did all of the aluminum work on. I had plans to turn it into a street car,it would have been awesome since the car had already seen close to 200mph. But when I started looking at all the details it turned out that it would have amounted to practically building a whole new car. Doh. Marcus

[parsonsj]

Frank,
My frame is a ProFile version, which means it bends out and is welded to the car at the rockers. I don't have frame rails running through the middle of the car, resulting in lots of foot room. Katz can probably give you better information, but Kevin at AME told me that they didn't make that version of the frame anymore. Perhaps Art changed his mind?

jp

[ProdigyCustoms]

I will be curious to see what they say about the frame with no center rails. If is strong enough to hold some power it will be killer.
On Prodigy, Michael did welded rails to the rockers and also ran a center set of rails, basically framed the trans tunnel, for additional support. Right now out only compromise so far is foot well space is a bit narrow, but tolerable, as he made the tunnel wide enough for the 3" exhaust to go through.
I am siked about the possibility of using the frame without center rails. Sticking one under a new convertible shell would make for a badass roller. If it welds to the rockers only, the floor modifications would be minimal. Or at least what guy's like us would call minimal.

[ProdigyCustoms]

I talked with Art Morrison today. Basically the frame will require x bracing and center rails, especially in a convertible. I am intriged with the possibilities, and am going to share my bracing I did on Prodigy, including the roll bar, and let them have a look at it. I think it would be OK. If it will work, it would solve the floor height issues, and prevent having to build a seat pocket with a high funny feeling floor. I would like to do one and be able to offer it as a roller. If it looks like it will work, I will probably use my coupe body first instead of cutting up a $10k+ new body.
Stay tuned.

[parsonsj]

Frank,

I'm not sure I agree you need center bracing. That bracing is in the same plane as the framerails, right? I'm not an ME, but additional bracing in the same plane is not very efficient at increasing torsional stability.

I think all you need is a rigid crossmember for the transmission, and properly placed tubes for the seat. A center brace is just gonna make tranny and exhaust packaging harder: it's just extra weight without a corresponding increase in strength.

jp

[Mean 69]

One thing is for certain. A full frame will easily outperform a subframe / frame connector / unibody any day assuming both are properly tuned. Making the body one with a rigid frame removes most, if not all deflection.

Snooty Rocket Scientist Voice ON:

I have to disagree with you on this one. It is really going to depend upon how the subframe connectors are integrated into the overall car. While I don't discount the ease of a full frame deal for a project, one can't make the blanket statement that the car will be "better." In particular, either a full frame car, or a subframed unit body (tub) car will suffer from the same thing: torsional rigidity. As JP hinted at, the way the frame rail are oriented makes ALL the difference in establishing a torsionally rigid structure. Unfortunately, it isn't a really easy nut to crack without doing a really well executed cage. You need to distinguish between what "type" of deflection you are talking about.

In and of themselves, I would guess that a full frame car has better longitudinal bending resistance, and certainly a lot more torsional rigidity, than a non-SFC'd unit body car. However, a well done set of SFC's, specifically a through floor type such as the DSE first gen units, probably exceed the bending resistance (in both aspects), because they take advantage of the floor sheet metal as a psuedo-sheer plate. Still not good enough for full tilt performance applications, but something to consider.

Consider this, an I Beam has really, really good longitudinal bending resistance, this is why they are used on huge load bearing structures, like a sky scraper. But, they have horrible torsional rigidity, if you made a frame out of them, it would flex torsionally like mad. Certain applications take advantage of this, most specifically to our hobby, the truck arm suspension system basically wouldn't work if the T/A's couldn't bend torsionally.

I think if the AM chassis deal was a bolt in affair, such as it basically is for the tri-fives (which it clearly works very well with), it would be a great option. Otherwise, I don't see the benefit of using one on a unit body car, especially due some of the compromises in the overall approach. Damn great setup, no doubt, but the "best?"

Snooty OFF.
Mark

[ProdigyCustoms]

I will send you some pics tomorrow John. It has torque boxes and also is tied with a crossmember / roll bar hoop. It is also tied across the center with smaller bracing. The seating position is still stock height, and the floors are reasonably normal height also.
We just finshed running full 3" exhaust through the tunnel, but keep in mind, it is a independent rear.
As far as weight, it is only forty pounds or so, it is good weight. Kind of like magnets on a slot car, LOL!

Mean, I guess I am talking about the best possible rigidity without installing a full Jungle Jim for a cage.

[Norm Peterson]

. . . I'm not sure I agree you need center bracing. That bracing is in the same plane as the framerails, right? I'm not an ME, but additional bracing in the same plane is not very efficient at increasing torsional stability. Actually, diagonal bracing in the same plane as and at 45* to any pair of longitudinal rails is pretty effective, particularly if it's in an "X" configuration. There are formulas for estimating the equivalent torsional resistances of single diagonal bracing and the "X" type. Roughly, and from memory, a pair of rails with single 45* bracing of the same cross-section as the rails generates a total torsional R (resistance) of about 3.5 times the out-of-plane bending moment of inertia (Ixx) of one cross section. R for "X" bracing is more than 10 times Ixx (10.6 times is suggested, IIRC). Not as good as a properly designed 3-D space frame (cage), true. But for single-plane comparison, the R for a single circular tube is only 2 times its Ixx (two tubular rails would have an R of 4 times the Ixx of a single tube). There are a few other considerations that have some effect, but that's the general idea.

And there's more. Placed at 45*, the general torsional load on the chassis largely resolves into bending loads, suggesting that open sections can be used without giving up too much overall R. I'd think that this little piece of structural trivia could come in handy in certain carefully-defined situations where the use of closed cross sections is impractical.

Source: "Design of Welded Structures", Blodgett, Lincoln Arc Welding Association

Norm

[nancejd]

I think it would be pretty hard to duplicate the rigidity of a three dimensional structural system with a system that was two dimensional, regardless of how you braced it. You would have to make up for it with shear mass of material. That's why trusses in buildings work so well compared to a solid beam.

[parsonsj]

Norm,
I am having a hard time following your math. Can you give us the same information again but do a direct comparison between a cage and a brace? Something like; assuming a 40 inch cage height, and 48 inch long framerails we would get the following torsional resistance numbers:
Framerails = 1
Framerails plus brace = 1.5
Framerails plus cage = 2

Or something like that. Please?

thanks!
jp

[Norm Peterson]

Let me try.

First off, it's not possible to put as hard a comparison up going between the frame only and braced frame to the 3-D space frame. If bending were the only issue, nancejd has already provided the comparison. To put a number up for overall bending stiffnesses only, your basic cage could be several hundred times as stiff as a pair of 4" deep rails. That's assuming there's enough light bracing present to keep the cage from flopping out of its vertical plane under load but not enough to add much general stiffness to the chassis as a whole.

Bending isn't the only stiffness of importance, though. There's torsional and axial (tension/compression) stiffnesses that also matter, plus lateral bending (think side-impact crash protection) and a couple of shear stiffnesses (that aren't significant in any reasonably well-designed automotive chassis and will be ignored). Might as well mention this here - it's the torsional stiffness that's usually implied when chassis stiffness is mentioned, since that's the one that has the greatest effect on chassis/suspension tuning.

For the cage dimensions provided, your torsional stiffness is another matter entirely, as you've perhaps only doubled it (assuming for the moment that the tubes and the rails are of the same cross section and that the light bracing does not provide much stiffness help here either). You do get some help from the laterals and the crossmembers, so let's say a bit more than double. How much? Well, 'it depends' . . .

Torsion is the most difficult load to provide stiffness against, so usually if you can achieve a high torsional stiffness in your design, you will have built in more than enough bending stiffness. The way most cages go about adding torsional stiffness is to triangulate it. This works by putting all the added diagonal tubes in tension or compression, as tubes are pretty rigid against those loads and have good resistance to buckling (if allowed to buckle, their structural value is about zero).

Not all diagonal bracing is created equal, though. And 'intuitively' adding diagonals can have surprisingly less effect than it 'appears' that they should. That's the big reason for my not putting any better comparative numbers on this. It's why you run these analytically using a 3-D space frame program (something called 'GRAPE' at least used to be available free online, and I have access to a couple others). Or build a scale model and put it through a program of "let's try bracing it from here to here and test it" (either Circle Track or Stock Car Racing magazine ran a feature article describing this approach sometime within about the last year or so, and I can look for it later).

Please understand that I'm not trying to weasel out of providing an answer here, it really is because the issue of torsional stiffness is not nearly as straightforward as bending stiffness. This is about as complete (while being somewhat simplified) as I can make any discussion of relative stiffnesses that does not require me to perform a couple of space frame analyses so I can refer to more rigorously determined answers.

If anybody tells me that they find this a bit confusing, I won't be too surprised. But it's not too bad as the whole spectrum of 3-D structural analysis goes - let's just say that an explanation of how the chassis of David Pozzi's Lola provides its torsional stiffness ends up going to a whole 'nother level.

Norm

[ProdigyCustoms]

WHEW!! I will let you rocket scientist battle back and forth here. All I can tell anyone is Art Morrison said it needed center rails, and common sense tells me it does also. As I said, I'll let you know.

[CraigMorrison]

Hi guys, Craig Morrison here. I figured I would sign up to answer any questions about this chassis. While Katz will be able to answer some of the more hard core engineering questions, I'll hopefully be able to answer a few of the others. I figured I'd post a pic of the chassis in question:
This is a chassis we did just recently for Bobby Alloway's 69 'Stang project.

[dennis68]

Welcome Craig...nice looking chassis. When are you guys going to get away from that weenie Mustang II style suspension?

[CraigMorrison]

C5 front suspension is available for this chassis. It does require some engine setback due to the location of the R&P. We have been discussing what direction we would want to go with our own spindle design. I'll definitely keep you posted.

The only part that is MII is the spindle, the geometry is our own design and we've been able to make it work pretty good. If you haven't had a chance to see our GT55 project being tested, you can watch it here:
http://www.artmorrison.com/gallery/view_album.php?set_albumName=GT55testing

The same front and rear suspension that we used on the GT55 is what we have used on this chassis.

Thanks for the questions!

[ProdigyCustoms]

Thanks for the pic Craig. Here is what I was talking to your guy's about. Stock Camaro's are limited on head room even with relatively thin bottom cushions and with the seat mounts a couple inches lower then the top of the rockers. The floor on this frame will have to go on top of the frame. If the body is channeled over the frame like this group would want it to be for stance, the floor would be even with the top of the rocker. The floor to roof height will be reduced by 3" or so, which will make it difficult for even me at 6'.0".

I do however feel this can be eliminated if the center rails are run further forward before the bend that ties into the front clip allowing for a seat well and front floor space. As you know, it is very uncomfortable to have a seat in a low pocket and a floor that is almost even with the top of the seat. I've done drag cars this way and it is OK for 1/4 mile, but your legs will fall asleep if driven any miles.

The situation is not as critical for the rear seat as it is all ready designed to sit above the floor anyway.
My question is could the frame work without the center rails, and as your guy's said, probably not in a convertible, and in reality, probably not in a coupe either. I think some minor changes might cure all the issues and make it a really killer alternative for rusted undercarriage cars. Or just for someone that wants a full chassis.

I would love to work it out and find a way to do it.

[David Sloan]

Graig
Does the C-5 suspension have the same geometry as the vette. or has it changed?
We may be interested in a full frame w/ the c-5 front an no rear suspension.
The motor set back OK. How much does it set back (2-3''s)
Thanks !

[parsonsj]

All I can tell anyone is Art Morrison said it needed center rails, and common sense tells me it does also

Frank, I gotta disagree (nicely). My chassis was also designed by Art and it doesn't have the center X-brace section. I welded my rocker panels directly to the framerails and designed an "in-rigger" tube setup for the tranny crossmember and seat mounts.

Perhaps the difference is that my custom firewall, floor, package tray, and wheel tubs all retain their original intent. In other words, I welded steel panels back in place just like the originals:
1. roof, package tray, and trunk mounts welded to the wheel tubs
2. wheel tubs welded to the framerails, inner panels, and quarter panels
3. floor braces welded to the foot wells
4. bead rolling to stiffen flat sections
5. lots of cross-sectional dimension in the tranny and dirveline tunnels
etc.

Hopefully Craig can provide some more data, but I'll bet that center X-section is designed so that racers and car builders can make floors out of aluminum and simply rivet it in place. In other words the floor, firewall/cowl, package tray, and wheel tubs wouldn't need to be load-bearing.

jp

[Steve Chryssos]

Perhaps the difference is.......
jp

And you have a roof and full cage. I believe Frank is referring to the center rails and bracing required to reinforce his convertible--where a jungle gym would look like a uhhh....jungle gym.

[Mean 69]

Perhaps the difference is that my custom firewall, floor, package tray, and wheel tubs all retain their original intent. In other words, I welded steel panels back in place just like the originals:

Which was exactly the point I made earlier, all of the "sheet metal" becomes very, very effective at increasing stiffness, especially in the shear plane. While this alone won't address torsional rigidity (which I completely agree with Norm as the hardest part to nail, this is well documented in the literature), it will go leaps and bounds towards improving rigidity overall. Hence my previous post regarding full frame versus SFC'd unit body cars, and this is completely independent of the "Jungle Jim" cage. Now, a contiguous full frame, sunk into the sheet metal and welded directly to it, ala II Much, is terrific, but I'd take my through floor SFC'd Camaro with the front subframe (welded securely to the SFC's), and the rear frame rails welded directly to rear of the car as it came from the factory, over a full frame that is bolted in a handful of locations to the body. Any day, and twice on Sunday. And on this one, your mileage "won't" vary.

Mark

[parsonsj]

Fair enough about the roof. That makes a big difference in torsional stability.

The roll cage was something I added later (so it wasn't assumed when the frame was designed), and Art's literature at the time said the 2x4 frame rails didn't require a cage.

jp

[parsonsj]

Mark,

Agreed. You could look at the frame rails in II Much as big-ass SFCs.

jp

[Q ship]

I don't want to hijack this thread, could you guys please take a look at my thread here? (https://www.pro-touring.com/forum/showthread.php?p=47300#post47300post47300) Thanks!

[upacreek]

I called Don Today and he said they didnt have the max-g for
67-69 camaro's. Kind of broke my heart there are several pro street project just setting around that this would be perfect for.

[CraigMorrison]

upacreek- We do in fact make a Max-G chassis for the 1st Gen Camaro. See the photo attached above to see what it would look like.

[ProdigyCustoms]

Craig, you are the one that can settle this difference of opinion. John feels the frame will work without center rails, I feel it needs them in a Camaro, even in a coupe. The frame pictured above clearly has center rails and a bit of an x bracing.

I guess the question Craig is............

Will the frame work without the center rails as pictured above in a coupe without a full mutli point cage?

Will the frame work without the center rails as pictured above in a coupe with a full multi point cage?

Will the frame work without the center rails as pictured above in a convertible without a multi point cage? A multi point cage (Jungle Jim) is not even an option in a convertible.

[CraigMorrison]

Frank, Katz and I were talking about this yesterday. It would be very difficult to build this frame w/o the center "X" in it. We could do a custom build a chassis similar to JP's or one of your own design. We have been able to build some pretty wild chassis for people over the years, and if you have an idea for building a better mousetrap, we would be more than happy to draw it up, bend it and weld it. If you eliminated the "X" in a chassis like this, I would definitely recommend running a cage or something else to prevent flex. If you didn't want to have a full cage in the car you could go about it a couple of different ways: structual console or belly pan. The console could either be out of 1/8" sheet metal and be about 10"-12" tall or you could make it out of tubing. While not a PT car, here is what one of our employees did to his Caddy frame:
https://static1.pt-content.com/images/pt/2005/04/MyPictures0004vi-1.jpg
This chassis is for a 58 Cad that will become a roadster. There is a lot of extra rails on the floor, but the console "spine" is what I am talking about.

The next idea is to use a 1/4" aluminum bellypan that is securely bolted to the bottom of the chassis. This would also help stiffen the chassis without an "X". The only thing you would need to worry about then is heat management with the exhaust system.

I hope this answers your questions.

[daryn67]

Craig


Could this frame be used as a bolt in using the front mount location with a center and rear mount fabbed to bolt to the body. I am interested in using this chassis and talked to you about it a year or so ago, before it was available for the unibody cars. i may need to call to get all my questions answered.

Daryn

[CraigMorrison]

Daryn- check your PM

[ProdigyCustoms]

Thanks Craig, what you call a console is exactly what I did for Project Prodigy. I think I have a plan. It would make a cool project. Right now I am still waiting to get a body. I will be in touch next week.

[BigBlockOlds]

Does anyone know what the Max G chassis normally runs, price wise?