SUSPENSION AND STEERING UPGRADES A LITTLE AT A TIME

[HP2]

Take a middle of the road approach.  Use 6-8 jackstands to support the car, shim between the stands and car to verify its level, weight the car down anywhere its required to level it, weld in supports. This avoids locking in any wedge the chassis may have developed without going all out to push/pull it into perfect condition.

Yes, a body shop can put it on a frame machine and tweak everything to blueprint spec, if that is desired. However you probably would have to provide the blueprint, which are typically found in the FSM Body manual. The best most could do without that is verify everything is equal and not bent.

If you want to at least verify proper locations of major frame components, you can use the FSM Body Manual or the MP Chassis Manual to understand the plot points to check yourself. Again this is best done on 6-8 jack stands with heavy string, a plumb bob and tape measure. it isn't precise within a degree like a shop's laser system, but it is pretty close.

[brads70]

I just tacked mine in sitting on the wheels then jacked it up to finish weld it. Here is a frame drawing if it helps?

[challenger_affair]

Thanks for all this info guys    The installation is not something I would actually tackle myself, I don't weld and I'm not really set up at home to do that kind of project.  I might be able to check the frame positions myself, but I'm not sure it would help anything if I can't do the work...  But I'm at least hoping to be educated so I can choose what I want and understand what I should expect from a shop.  Your explanations are definitely helping towards that end.  As far as the torsion bars, should they be released during this process?   

[brads70]

"As far as the torsion bars, should they be released during this process?"
I didn't when I welded in the subframe connectors and torque boxes.     

[burdar]

Has anyone who has done the PS mod had trouble getting the valve apart in order to add spacers?  I've got a metric Saganaw pump from the early 80's.  I pulled the valve out in hopes that I could use the spacers in my Challenger.  The valve will NOT come apart.  I've got the vise grips as tight as I can squeeze them together and the valve just spins when I put a wrench on it.  This was supposed to be a quick and easy mod but it turned into a PITA.  I hope the Challenger's valve comes apart without any fuss.

[Mopar Mitch]

More on the ps mod... As most ppl know, the Federal ps pump cannot keep up with rapid back-forth steering, such as going through a series of successive pylons in autocrossing... ONLY the Saginaw pump can keep up with that rapid motion.

So, if someone does the washer mod, will it effect the ps assist to the point that it won't keep up with rapid autocross/pylon maneuvers (like the Federal ps pump is known for)?

I've never yet had my T/S fast-ratio ps gearbox rebuilt, am using the Saginaw ps pump... and a small competition 11.5" diameter steering wheel.  The car steers great and is very quick and responsive in autocross through pylons, etc.... but, the gearbox will eventually be rebuilt to something like the FF II or III.

Comments about the washer mod and quick response through pylons (also... this applies to typical high-rpms ~3500-6500 when the Federal ps pump becomes dead.. and the Saginaw pump is healthy and responsive as needed).

[CUDA JAS]

More on the ps mod... As most ppl know, the Federal ps pump cannot keep up with rapid back-forth steering, such as going through a series of successive pylons in autocrossing... ONLY the Saginaw pump can keep up with that rapid motion.

So, if someone does the washer mod, will it effect the ps assist to the point that it won't keep up with rapid autocross/pylon maneuvers (like the Federal ps pump is known for)?

I've never yet had my T/S fast-ratio ps gearbox rebuilt, am using the Saginaw ps pump... and a small competition 11.5" diameter steering wheel.  The car steers great and is very quick and responsive in autocross through pylons, etc.... but, the gearbox will eventually be rebuilt to something like the FF II or III.

Comments about the washer mod and quick response through pylons (also... this applies to typical high-rpms ~3500-6500 when the Federal ps pump becomes dead.. and the Saginaw pump is healthy and responsive as needed).

That's a great question, and I do not have a answer...but if it does affect in that way, you can always pull the valve back out and reverse things.

Jason

[john h]

Has anyone who has done the PS mod had trouble getting the valve apart in order to add spacers?  I've got a metric Saganaw pump from the early 80's.  I pulled the valve out in hopes that I could use the spacers in my Challenger.  The valve will NOT come apart.  I've got the vise grips as tight as I can squeeze them together and the valve just spins when I put a wrench on it.  This was supposed to be a quick and easy mod but it turned into a PITA.  I hope the Challenger's valve comes apart without any fuss.

I had just a little trouble with it twisting I used a shop towel in between the grip jays and the cylinder.  you could try a giant channel locks and have someone apply the pressure to the cylinder while you turn the nut.

[john h]

looking into the shocks.... I was at the all Mopar show in Mn this last weekend.  QA1 had a booth there. I spoke to them about upgrades and looked at their shock offerings.  Their single adjustable shock sells for about $150 and seems like a nice product.  18 valve clicks per shock they said make the clicks match each side front or back but they can be different front to back.  seems like you could easily count the turns stiffer or softer and change the setup as required.  I'm thinking that for the extra $200 over the cost of non adjust it may be worth it?  anyone have experience with this shock or similar single adjustable?  They also offer a non adjust with similar construction for around $100 per.

[HP2]

You wouldn't want the front and rear shock to be identically matched in dampening because the  springs have different frequencies that need controlled. Matching shock rates front to rear can lead to porpoising at take off or rocking when hitting bumps. Side to side, however, you would most like want to match.

Adjustable shocks are great if you use your car in different capacities, as a cruiser, drag racer, or autocrosser. They allow you to dial in additional dampening performance based on the usage on hand and you can easily dial them back for the ride home. They also are great if you want to tinker with dialing in ride characteristics to your ideal personal preference.

On the other hand, if you are a set it and forget it kind of driver, don't like to tinker or do maintenance, or don't keep records of your settings and results, adjustable shocks can be a lot of work that produce an uncomfortable ride.

[crash340]

I have QA1 single adjust on the front of my car, LOVE them, as a daily driver type car, i could set the shock to a setting that I liked, each click is very noticible, I do drag the car from time to time so I can run the clicks down for that and back for street driving, still, the ability to set it to what you like and forget made it simple for me to choose. I did change them from the mopar QA1 part number to a Camaro QA1 part number as I run the car low and the Camaro length shocks dont risk bottoming out the shock and wrecking it.

[burdar]

I had to heat the valve up and spray it with penetrating oil.  It finally broke loose.

[john h]

I had to heat the valve up and spray it with penetrating oil.  It finally broke loose.

have you reinstalled it and given it a try?  what thickness spacer/shim did you use?

[john h]

I have QA1 single adjust on the front of my car, LOVE them, as a daily driver type car, i could set the shock to a setting that I liked, each click is very noticible, I do drag the car from time to time so I can run the clicks down for that and back for street driving, still, the ability to set it to what you like and forget made it simple for me to choose. I did change them from the mopar QA1 part number to a Camaro QA1 part number as I run the car low and the Camaro length shocks dont risk bottoming out the shock and wrecking it.

Just the fronts?  I was wondering about that.  front or back first again, a little at a time. $300 one month then $300 another month sort of idea.  I did not know if it would make much difference if you did not do it all right away.  thinking about what HP2 said... I don't race the car except for an occasional stop light quick launch.  I can see myself messing with it constantly trying to get the right feel, when all I would really need is good performing non adjust.  HMMM..  tough choice.  but this is for sure my next step.  even before the larger wheels and tires.

Thanks for the opinions guys.
John

[burdar]

I added three shims that totaled just less then 1/16".  It didn't change the feel much at all.  I could easily add another 1/16" spacer.  I might try that at some point.