I need a suspension game plan

[Mopar Mitch]

RCCDREW -- How did you "lower" the car?   Torsion bar adjustment?  Dropped spindles?   Leaf spring mounts or lowering blocks, or de-arched leafs?

What are you riding on for tires?... sizes?  Air pressure in the tires?   60-50-45-40-35-30 series side wall tires?   High PSI and short sidewalls welcomes increased harshness. harshness.

I run 1.24" dia torsion bars, Koni shocks, etc., 225#/5"-arch fiberglass mono leafs, urethane bshgs, etc etc.   Yes very stiff, but not unbearable to drive on the streets... and when driven, certainly I avoid rough roads etc or drive slower over them... smooth roads and highway driving (and AX/HSAX/HPDE track events car handles on rails!)... all still drivable and not so severe as many ppl think.  For routine street/hwy cruising, I prefer my BFG T/As 255-60-15 front (~28-30psi), BFG T/A 275-60-15 rear (~26-28psi);  for AX/HSAX/HPDE, I have different rims/tires with shorter sidewalls.. 50-45 series.   

I agree with ppl suggesting adjustable shocks (dbl-adj best, such as QA1 or Viking, as well as Strange and a cpl others out there).  Viking are same as QA1, (same technology and past employees, but less expensive than QA1... although QA1 may favor better service if/when needed.. TBD... can't go wrong with either).   

[burdar]

No one has addressed his concerns about the rear shock x-member.   So, how much more stress is there with an adjustable shock and does the upper shock x-member need to be reinforced?

[CUDA JAS]

No one has addressed his concerns about the rear shock x-member.   So, how much more stress is there with an adjustable shock and does the upper shock x-member need to be reinforced?

not sure how and adjustable shock would impact the x-member as compared to a regular shock.

Air shocks I can see the problem, but adjustable, not sure.

Jason

 

[RCCDrew]

RCCDREW -- How did you "lower" the car?   Torsion bar adjustment?  Dropped spindles?   Leaf spring mounts or lowering blocks, or de-arched leafs?

What are you riding on for tires?... sizes?  Air pressure in the tires?   60-50-45-40-35-30 series side wall tires?   High PSI and short sidewalls welcomes increased harshness. harshness.

Car is lowered with torsion bar adjustment in the front and de arching the rear springs. I'm also running 17" rims all around. Running about 30 psi at all corners.

Thanks for all the replies. There is a lot to consider when it comes to shocks, for sure. Sounds like I need shorter shocks than stock, bilstein, QA1, or Viking. I'll do some more research for sure. And I will check out shorter bump stops, and bigger torsion bars.

[HP2]

No one has addressed his concerns about the rear shock x-member.   So, how much more stress is there with an adjustable shock and does the upper shock x-member need to be reinforced?

No more stress than a normal shock and no, it doesn't need reinforced. The issue with air shocks is that they may be pumped up so much  so as to take on  a percentage of weight support from the leafs. This is is when mounts get hammered. Under normal conditions with a standard or adjustable shock, they only need enough support to mange the motion of the leafs, not support the weight of the car.


Still wondering if the rough ride is suspension bottoming out ( inadequate springs) or cycling too much (inadequate shocks).  Those 35-40 aspect ratio sidewalls certainly don't help either. To make it all better will most likely require a step up in both  springs and shocks.

[RCCDrew]

It is definitely bottoming out. I installed new bumpstops a couple years ago on the lower control arm, and they are already damaged. I can also see nice shiny steel where the pinion Bumper hits the floor. The car is dropped 2" all around. On the freeway it's great. It's our crappy neighborhood streets that kills me.
I believe my aspect ratios are 45 and 55. Can't remember right off the bat.
How about espo HD springs for the rear, stock height or 1"lower?
The upgrade from stock torsion bars to .93" helped. Maybe I should go to the 1.12".

My other option is air ride. I'd rather spend that money on other upgrades, but this crappy ride is priority #1. Raising the car back to stock height is my last option if all else fails.

[HP2]

Bottoming front and rear both? And if the rear is bottoming, is it the housing hitting its stops or just the snubber contacting the floor? What type of bumper/tower is on your snubber? 

If you have the MP adjustable snubber unit in its delivered height, is, IMO,  too tall for a lowered car and you may need to trim it to fit better. If you are actually bottoming the housing to the  sub-frame, then yes, you need new leafs.

Another option for the front is drop spindles. These would provide the drop you want but allow you to crank up the t-bars more to provide more suspension travel and avoid the bottoming while retaining your current torsion bars.

Stepping up rates will provide more support for the vehicle  so the suspension is less likely to bottom out.  Bigger rates will require better shocks to control the  motion.  Its entirely possible to have much higher rates with more control and better ride comfort provided the shocks can control the motion, than what can be achieved with lower rates and marginal shocks.

All of this can be done without going to an air bag system. You can price out all teh options, analyze the time involved,  and the goals each achieve, and decide which approach may be best for you.

[RCCDrew]

It's the stock type pinion snubber.
I was thinking about drop spindles. The only thing to think about there is I have the PST torsion bars that are clocked for lowered cars.
So is the better setup dropped spindles or bigger bars?

[RCCDrew]

I couldn't use the  TD901 like in the catalogue, I used TD801 due to the lowered ride height as per QA1's recommendations. ( I e-mailed QA1 my ride heights and this is what they suggested)   If you go on QA1's web site they tell you how to measure and then email them the results and they will give you part numbers.

Hey Brad, those TD 801s are for the rear, correct? What did you use for the  front?

[brads70]

Hey Brad, those TD 801s are for the rear, correct? What did you use for the  front?

Yes for the rears I believe, can't remember the front part #'s .... I suggest to measure your car as QA1 wants and get them to tell you what part #'s to get as your car may be different from mine. 

[73440]

TD501 per catalog, but as mentioned call QA1 for best fitment.
They are on my list.

[72bluNblu]

A 2" drop with .93" bars is too much, that's why the suspension is bottoming and that's why the ride is harsh. Not enough available suspension travel for the wheel rate you have with those bars.

You don't need drop spindles if you're willing to go larger on the torsion bars to reduce the amount of suspension travel to match the new lowered ride height. But, you will need better shocks if you want a decent ride with the larger bars.

I run Firm Feel 1.12" bars on my Challenger with Bilstein RCD's. The ride is great in my opinion, and my car sits pretty darn low. I actually raised it up a bit to keep from dragging my headers so often. It's about 25" to the top of the front wheel opening, and all of the lowering was done with the adjusters.  The Bilsteins work pretty well, I think the Hotchkis Fox shocks are a little better for ride quality and handling when the torsion bars get really big. I run the Hotchkis shocks on my Duster with 1.12" bars, which have a higher wheel rate than the E body 1.12's. But they're more expensive too. Both the Bilstein RCD's and the Hotchkis Fox's that I have are non-adjustable, so, no messing with the adjustment to worry about. I didn't get the adjustable version of the Hotchkis shocks because I'm cheap, not because the adjustable version isn't better though.

If you're dropped a full 2" I would suggest going larger than 1.03". The PST 1.03's are good bars, but, you have to match the amount of available suspension travel you have with the wheel rate, and I don't think the 1.03's will have enough wheel rate to keep you from bottoming out too frequently if you're dropped that much. Just my opinion.

[HP2]

I was hoping  72blueNblu would chime in since he has a well thought out set up with drop spindles.

Are drop spindles better than bigger bars...it depends on  your vehicle weight, engine, road condition, driving style and applications, tires, shocks, and a number of other nuances.

If you have a cruiser, with a small block, and your roads are kind of wavy, drop spindles may work best. $500 for spindles, control the motion of $100 with of  Monroe gas magnums, and an alignment for $100 and  you down the road after a weekends worth of work.

If you drive aggressively, have a big block and you roads are full of pot holes, bigger spring rates and improved shocks may work best. $300 for t-bars, $200 for new leaves,  and $400 for shocks and a weekend worth of work may be the solution. I'm including  replacement leafs here because if you step up the front rate, you will need to step up the rear rate to  match.

You still have the snubber hitting issue to deal with. If you have the stock unit and you don't change the leaf springs, you may need to manipulate your pinion angle some to turn the nose down, lift the rear slightly, or use a  shorter bumper. This makes for another argument for changing to a stepped up rate in back, or  adding some clamps or half leaves to the front segment to reduce the  twist allow the  housing to rotate.

[72bluNblu]

Not anymore actually. I got rid of the drop spindles a few years ago. I found that I could lower the car just as much with the torsion bar adjusters with the 1.12" bars and not have a problem with bottoming out the suspension using shorter .375" tall poly button style lower bumpstops. I also had to use taller upper bump stops to limit the suspension extension to keep the torsion bar adjusters loaded at that ride height and at full extension.

But seriously, the limiting factor was the ground. I had my header flanges at 3.5" off the pavement without drop spindles, which was a little too low for the roads around here.

So really I don't see a need for the drop spindles if you want a good handling car. They just add bump steer and suspension travel you won't use with larger bars. If all you want to do is slam the car on the ground for cosmetic reasons, keeping the torsion bars under 1" you'll need the drop spindles. But you'll have other issues with that set up. If you're willing to go up to even 1.03 or 1.06" bars you'll be able to lower the car substantially. If you go up to 1.12" bars like I run you can drop the LCA bumpstops to frame clearance to 1". And if you run headers they'll be the issue. With the larger bars you need the better shocks, but your suspension geometry will be better too. Less bump steer, better roll centers, and a more beneficial camber curve. 

[RCCDrew]

I know what you mean. My Dougs headers are kissing speed bumps unless I go REALLY slow.

I have a decent game plan now.
Energy suspension bumpstops
1.12" T bars
Espo HD Springs

Still up in the air on the shocks. Leaning toward the QA1s, because they accommodate for ride height. But will the Bilsteins do the job? And will the Bilsteins bottom out like the stock length QA1s?
Also, has anyone run the 1.18 T bars?