Best aftermarket suspension kit for pro touring 1970 Challenger

[anlauto]

You can't go half way on a "pro touring" car....you need to cut everything out and install a full Art Morrison chassis...anything less would just be a "resto-mod" in my opinion...

[7212Mopar]

If going the frame route, might as well look at SP that has Mopar specific solution.

https://www.schwartzperformance.com/chassis/1970-1974-e-body-challenger-cuda-chassis/

[70 Challenger Lover]

If you don't want to go with an entirely new chassis but want some improvements, you might consider chassis stiffening options first and go from there. As mentioned, US Cartools makes a kit that has torque boxes, sub frame connectors, lower radiator support crossbar, and inner fender panel to cowl braces. I got this kit for my car to tighten everything up and from what I hear, the improvement is remarkable without any suspension changes. It seemed like a good starting point before I upgraded suspension stuff. I have a feeling that doing heavy duty suspension upgrades without significant chassis stiffening would produce very disappointing results.

I think Aniauto does have a point that if you are looking for high end Pro Touring, you get into a different category that really requires you go back to square one and custom build a car from the ground up.

[HP2]

Frame conversions to present a cleaner slate of changes but also come with any benefits and drawbacks that other body on frame designs have. You also have the evolving geometry wars that begs the question about how often are you going to update your frame car to keep it consistent with or ahead of the performance curve with that genre of vehicle? These frame conversion also require modification to the uni-body structure that can make it very difficult to go back to an OEM configuration and may impact its value longer term, if that is a consideration.

I look at it this way, the refined OEM systems of the 1970 Trans Am series were more capable than the majority of drivers out there and in that time we have had significant advances in shock and tire technology that can make more average drivers look better than they may actually be. Odds are very good that if you are actually competing in  pro-touring events, you could get 95% or more of the way there with a highly refined stock set up. If you plan on  really pushing the envelope of competition, which is tough to define since there is no universal set of pro-touring rules to apply to the approach, then you will need a range of adjustability that simply can't be found in the stock stuff and you would need to go high end and understand that there is probably always someone out there willing to outspend you for the latest gizmos.

[cordodge]

Just by looking at the pics, it seems to me that the Art Morrison chassis is way beefier than the S.P it looks like 2" square tubing? And a weak point just before the rear frame? Could be wrong but just looks flimsy to me.

[7212Mopar]

Bruce, I think it has do with if the car was originally uni-body or if full body bolted on frame. Schwartz frame chassis for Mopar is meant to supplement the unibody and not replacing it to keep weight down. He has frame chassis that is designed to replaced the original frame and you can see those are beefier. Just search Youtube and you will see he has discussions on different type of chassis designs for GM, Ford and Mopar. I like the fact that he offers choice for four links with a live axle and independent rear suspension. I think they had a Charger build to around 800 to 1000 hp awhile back.

[7212Mopar]

Art Morrison frame chassis requires the unibody floor board removed. Once new frame is installed and body mounted, new floor boards will need to be installed. The Schwartz chassis does not need new floor board and if needed makes it easier to revert back to stock (still quite a bit of work).

[Chryco Psycho]

A full frame generally is weaker than a unibody .
Simple really , the full frame is basically just on one plain & needs to be a lot stiffer
While the Unibody is 3d with triangulation in every direction , much better solution . Enhance a unibody & it will work very well .
Using a tube frame with 10 pt or more cage is a different story again [think pro stock or pro mod chassis] , good luck finding any significant flex

[7212Mopar]

Unlike modern unibodies, I doubt that any finite element analysis were done back in the 60's and 70's. The weld points were probably never calculated and located exactly during manufacturing. Any add on will help a lot to stiffen it up I think.

[HP2]

While there was not enough computing horsepower to do FEA in the early years, there was plenty of engineering analysis done to these cars in the old fashioned, slide rule method.  Also, each  pre-production body line was run through an extensive stress analysis by a separate department. It was because of these factors that Chrysler discovered how to make unit unitized construction that was very robust and not dependent upon the exterior skin of the cars for its support.

In this century I've seen further modern analysis, on both the chassis design and the suspension analysis, that has made a very favorable impression upon modern engineers for the robustness of the designs.

That isn't to say it can't be improved further and there are quite a few available pieces out there to make the Mopar unibody design a very, very stout foundation.

[70 Challenger Lover]

Not sure if this conversation is at its end but lately I've been wondering if there is a benefit to upgrading the rear leaf spring suspension to a four link system. They look fairly easy to weld in and you could use the original 8 3/4 rear housing so the cost is mainly the kit. It seems like the car would ride nicer as well as perform a little tighter. Maybe provide a little more wheel clearance?

I have a 70 Challenger (non RT) that I'm putting fresh metal in and while I'm at it, I've been beefing it all up with the US Car Tool frame stiffening kit. While I don't plan to change out the front suspension system, I did weld up the k frame and I plan to use better upper control arms with more caster, better shocks all around, stiffer torsion bars and sway bar, brakes, wheels, etc.

Is the four link rear end upgrade beneficial or just for looks?

[7212Mopar]

XV Motorsport stage 1 was upgrade stock setup. Stage 2 was coil overs and multi link at the rear. Stage 2 supposed to give better handling over stage 1. In both cases, the rear still have a live axle.

[70Barracuda]

I put all the good firmfeel stuff in front,1.03 bars, and the RMS 4 link.  Car handles so good I have no idea which end works better. Every time I go around a corner it's like, I could have gone faster.  I need new seats!

Love it, the car is fun to drive now  Installing the 4 link was pretty easy.    I went w the Ridetech shocks in back and Bilsteins up front.

[ledphoot]

Overall I'd stick to something fairly stock that you can undo in the future. I was not overly impressed with the rack & pinion / coilover conversions out there, there are some serious flaws with the mustang II (PINTO!) based designs these originate from. I pieced something together myself that on paper makes sense to me... QA1 front suspension kit, borgeson steering box, ride tech adjustable shocks, Hotchkiss leaf springs, 1.14" torsion bars, Dr. Diff Cobra Brake kit... Will it be the ultimate pro-touring ride or Auto-X car? No... Will it lay spank on it's former self in terms of handling? Yes.... I believe I will strike a good balance of performance / handling with the small block stroker / tremec tko 5 speed and this suspension for the money that I spent. I will know soon enough.

[70 Challenger Lover]

I'm still a ways off on this car but as I repair the rust and finish putting in frame stiffeners, it's become clear that there is no reason for me to fret over originality or even maintaining the ability to bring it back to original. While the panel replacements are coming out nice, they are not spot welded like the factory and therefore noticeable to purists. Obviously sub frame connectors and other stiffeners are not removable so I figured why not make the car what I want with color and options different than the fender tag and then why not enhance the suspension somewhat.

I'm not going to race the car but it would be fun to improve the suspension so it rides nicer and tighten things up so it handles better. I was just wondering if the rear end suspension upgrades offered a big improvement for the money.