Project Chili Pepper

[TomT]

While we're waiting on frame jig parts we've been cleaning up the new frame. We were going to go with 335's in the rear but we've decided 295-35-18's will work better. A lot of the drag race guys section the frame rails and stuff 295 drag radials in Malibus and Regals. After a lot of careful measurement it's still going to take a lot of work to stuff the 295-18's under the rear end because they are so "square." This is even more necessary because we want to get the car pretty low. Right now we are planning to section each of the frame rails an inch and then move them in 1.5" per side (so the rear will be narrowed 2.5" per side). This is all subject to change but for now that's what we're thinking.

[andrewb70]

Tom, you know what else would be cool? Ever seen the 3 link suspension used on GNXs? You could do something similar by starting with a housing designed for f-bodies that have an integral torque arm mount. Just an idea...Kirban used to sell a kit to duplicate the GNX setup, but that was years ago.

Andrew

[TomT]

Tom, you know what else would be cool? Ever seen the 3 link suspension used on GNXs? You could do something similar by starting with a housing designed for f-bodies that have an integral torque arm mount. Just an idea...Kirban used to sell a kit to duplicate the GNX setup, but that was years ago.

Andrew

Andrew, You know you're right...that would be cool. I was actually looking at a GNX on eBay the other day and noticed what I thought was a torque arm that had been added on (I think the diff cover had a provision to hold at least part of it). I'll have to see if I can find any good photos of that setup. I didn't realize it was a 3-link - so they delete the upper control arms? I would think that if they did it would require a panhard bar.

[TomT]

Andrew, the GNX I was looking at is still on eBay (and quite a bargain at $75k). I see a panhard bar in the photo! I'm going to have to research this further.

[TomT]

Andrew, you're just a plethora of automotive knowledge. I found a couple illustrations of the GNX setup. Looks like it might add some weight though. Still a cool option.

[monteboy84]

The GNX setup is pretty cool, but it's got some inherent design flaws. For one, the torque arm is too short, so the antisquat is too high which causes wheel-hop under braking, and for another, the front pivot is fixed and cannot move from front to back which causes bind. Something like a BMR with a FAYS2 Watts link would be best, but may get rather expensive.

-matt

[Tony_SS]

I think Marcus offers a Watts setup.

Very cool project Tom. Can't wait to see how it goes.

[andrewb70]

Andrew, you're just a plethora of automotive knowledge. I found a couple illustrations of the GNX setup. Looks like it might add some weight though. Still a cool option.....

Well thanks Tom!!! I made an excellent product manager....

My original intent of mentioning the GNX set-up was for it to serve as inspiration, and not to be directly copied. As others have mentioned, the GNX configuration had issues, but those issues can be addressed with a more modern design. I would combine the excellent Watts arrangement that is currently being offered for g-bodies, with a long torque arm, such as the one used on 4th gen f-bodies. I would start with either a 9" or a 12 bolt housing which has the torque arm mounts incorporated into the center section. I would then have the stock g-body lower control arm mounts attached along with the Watts link mounts. While the frame is exposed I would also add a bar to facilitate the use of coilovers in the rear.

Andrew

[TomT]

The GNX setup is pretty cool, but it's got some inherent design flaws. For one, the torque arm is too short, so the antisquat is too high which causes wheel-hop under braking, and for another, the front pivot is fixed and cannot move from front to back which causes bind. Something like a BMR with a FAYS2 Watts link would be best, but may get rather expensive.

-matt

I noticed that the GNX torque arm was too short as well. I guess it was a compromise necessary to fit it to a platform that was never designed for a torque arm. Even the lowly Vega had a torque arm that ran all the way up to the trans tailshaft!

[TomT]

Well thanks Tom!!! I made an excellent product manager....

My original intent of mentioning the GNX set-up was for it to serve as inspiration, and not to be directly copied. As others have mentioned, the GNX configuration had issues, but those issues can be addressed with a more modern design. I would combine the excellent Watts arrangement that is currently being offered for g-bodies, with a long torque arm, such as the one used on 4th gen f-bodies. I would start with either a 9" or a 12 bolt housing which has the torque arm mounts incorporated into the center section. I would then have the stock g-body lower control arm mounts attached along with the Watts link mounts. While the frame is exposed I would also add a bar to facilitate the use of coilovers in the rear.

Andrew

I think you're right on the money Andrew. In theory this is a "simple" project though (simple being a relative term). I am intrigued by the swivel link arrangement that Detroit Speed uses which should pretty much eliminate any suspension bind and allow the springs, shocks, and swaybar all to do their respective jobs. I'm pretty sure my next personal project will have a torque arm but I'm getting ahead of myself...must focus on the Chili Pepper...

We do plan to run coil overs so we will most likely be adding a bar to serve as the upper coil over mounts (with some triangulated bracing). We haven't decided how much of the stamped spring pockets to leave in place yet (still noodling over that).

[TomT]

I think Marcus offers a Watts setup.

Very cool project Tom. Can't wait to see how it goes.

Thanks Tony. I checked out your garage - I love wagons! Yours is really cool. Your Monte looks great too - they have really swoopy lines. If I didn't have too many projects already I'd be chasing your wagon.

[TomT]

Since we will be cutting and welding on the frame, I decided to build a frame jig to keep everything straight and true. We picked up some I-beams and are bolting them together.

I had a local machine shop make a drilling jig from a square piece of one inch thick steel that we clamped to the I-beams and drilled thru so all of the holes would be exactly the same.


I needed a way to level everything up (since the floor in my garage isn't very level) so I designed up some stands and had them laser cut. I also had a piece of DOM tubing threaded and partially drilled.


I designed the stands so the parts would be self-indexing and the welds wouldn't be visible once the stands were mounted on the jig.

[TomT]

The stands were designed to work with some leveling feet that I purchased from Carr Lane.


Here a stand is loosely fastened to the jig.


Everything leveled up nicely using a digital level I picked up from Sears.


Next step - stations (crossmembers) to attach the frame to.

[desids]

Wow, those adjustable feet are a work of art - nice design!

Desi

[TomT]

Wow, those adjustable feet are a work of art - nice design!

Desi

Thanks Desi!

[tommycomfort]

The frame jig is amazing and a great idea. You can always use it as a heavy duty bed frame when you're done...

[monteboy84]

Great work!! I love your frame table.

-matt

[Norm Peterson]

I was actually looking at a GNX on eBay the other day and noticed what I thought was a torque arm that had been added on (I think the diff cover had a provision to hold at least part of it). I'll have to see if I can find any good photos of that setup. I didn't realize it was a 3-link - so they delete the upper control arms? I would think that if they did it would require a panhard bar.

Strictly speaking, the GNX arrangement isn't either a torque arm or a 3-link due to the fact that the center longitudinal piece is fixed on the axle and pinned (piece 14 in the diagram gives the arm no capability to 'plunge' fore/aft like a true torque arm). Think of it as a single center-mounted ladder bar, with the chassis side location carefully chosen to minimize bind vs the LCAs in bump.

Kirban at least used to offer a copy of the GNX suspension, and you could certainly use the diff insert plate from which to work up a true torque arm. It might even be possible able to just use the upper hole for the axle side pivot for a real third link, depending on how strong those ears are.

I think there's another option, at least I've seen where some work was being done about swapping in a Ford 8.8". Somewhere over on maliburacing.com, I think.


(there are at least two '79 Malibus that came without A/C and no antenna in the windshield. )


Norm

[Norm Peterson]

Everything leveled up nicely using a digital level I picked up from Sears.

I'd rather see the height adjusters screwed down to the minimum heights that still give you a level plane to work from. There will be horizontal forces applied to it from time to time, which will try to bend the bolts. When you can't avoid loading threaded fasteners in bending you should at least minimize it. I am assuming that the frame will be sitting on the I-beams when you drop the body on it and jockey it into position . . .


Norm

[Tony_SS]

That is a wonderful frame jig!

Thanks Tony. I checked out your garage - I love wagons! Yours is really cool. Your Monte looks great too - they have really swoopy lines. If I didn't have too many projects already I'd be chasing your wagon.

Tom I would love to see someone like you get this Wagon. When/if you are ever ready for it just say the word.