therealdave

I have been wondering about something and am hoping that someone here can clear it up for me...

My car is lowered, with coilovers. When you lower a car, doesn't it pre load the sway bars? Wouldn't the proper procedure be to have adustable ends, loosen them, put the car on the ground...then attach the bars ends at the proper length?

I am having some trouble dialing the car in and I am wondering if this is a possible source....

In my prior Porsche life, it seems like that's how I used to do it.

TedDBere

If you want to eliminate pre-load then adjustable endlinks are the way to go.

ipuig

What exactly do you mean by dialing in?

therealdave

When I bought the car it was slammed to the ground. Looked great. Ok for smooooooth roads. My roads are not perfect so it had to come up a bit.

I have been raising the car via the coilovers, playing with the rebound and preload, but it still seems to rebound too hard over bumps. Now I do have really thin sidewalls in the rear (25), which I know is a contributing factor for the rough ride, but it still seems a little off. That brings me to the sway bars. I think the preload on the swaybars may be "bouncing" the car back up...

I am going to take the sway bars loose and compare the connecting point distances to the length of the fixed sway bar ends. I suspect the loose measurement will be less.

Does that make sense?

davidfarmer

lowering it symmetrically will not preload the bars. They move together in this motion. If you slammed each corner independently, and for some reason your car isn't symmetric, you could have some preload. I doubt it is enough to cause a serious issue though. There is nothing in the MOUNT that loads the bar....they are loaded against each control arm only.

Is the car's lack of performance the same turning both ways?????? If so, that would eliminate the possibility of it being a preload issue.

rustyguns

coil overs are stiff and normally rebound hard excellent for the track,,,tough with potholes!

rustyguns

the amount of preload would be insignificant

Crepitus

Lowered car. Rough road. I think what he is trying to describe is hitting the bottom stops then bouncing to a top out.
first thing that comes to my mind;
more ride hight
more spring rate
more dampening
Is this car used for autocross or road racing? You will probly find more help with a comfortable over road ride in the correct tech section for your car. The guys in this section feel steam roolers need more spring rate.
Most people consider sway bar pre load as putting a twist in the sway bar to manipulate cross weight.

hope this helps, btw I am a recovering porsche abuser myself.

therealdave

Thanks for the input Rusty and David.

I think I see what you mean David. When you say "MOUNTS" you mean the 2 U clamps that the bar passes thru. These clamps are lubed up and are not a source of preload.
And I also understand that the sway bar creates its own load from the attachments via the end links...one side loading against the other.

The part that I can't get clear is the length of the end links. Certainly the length has to affect preload... To exagerate, what if the links were 12" long? The only way you could even attach them would be to move the control arm significantly, thus loading the coilover. Right?

When I replaced end links (they were shot at 4000 miles!) I remember that it was difficult to even get them in because of the length. And that was with the control arms unloaded. The arms of the links that attach to the control arm and sway bar were at a severe angle.

My thought was that if I let the car sit on the ground, under its own weight, then measure the distance between the connecting points of the end links, then install adjustable links to that measurement. This should result in no preload.

Rusty

I have read on this forum that the Pfadt's are notoriously hard and difficult to adjust. I think I can confirm that. Although, I feel that I am making progress. This winter I discovered that the bump stops were SHOT!!!. I think the massive rebounding that I was feeling was the shocks bottoming out (at the old ride height). I raised the car almost an inch, by tightening the spring perches a couple of turns, twisting the shock body out of the base, and cut off half of the bump stop. That helped ALOT...

Sorry to be so long winded. Really appreciate the comments. Please confirm or squash my shorter end link theory...

therealdave

I do miss my Carrera's surefootedness, but not the lack of power, or repair bills!

therealdave

Crepitus

I was rereading your post and wanted to add, I agree with your assesment of bottoming out then bouncing back...

I know that my car is going to ride a little rough, I do not want it to be a marshmallow Just trying to figure out if I can tame it...a little. Thanks again for your ideas

Crepitus

We were typing at the same time. I think your on the right track. Be sure the car is on a flat surface. Make sure air psi is spot on. sway bar links need to be set so they position the the sway bar arms at a point in the travel that will prevent the bar from binding or contacting other components as the a arms move through their travel. connect one side. move to the other side. adjust the link to allow the link to connect with out putting any up or down pressure on the bar arm. This will eliminate any bar preload.

therealdave

Thanks. That's what I was thinking

Crepitus

OK I am starting to understand better. No adjustable end links are not a show stopper. if the car is on a flat surface, good tire psi, no cross weight, loose frame brackets. Shim as necessary to prevent any pre load. The one thing that I didnt think of till now is cross weight jacked in with the coil overs. The only way I know of to set that is to scale the car. A race shop or maby your friendly neighbor hood oval tracker. Gotta make sure nothing is bent as well.

I spent a stupid amount of money on a 951. I considered a LS1 swap, then started lookin at Vetts. A little bit heaver, a lot more robust, easy HP/TQ. Oh yeah, I really miss all the brand snobs.

therealdave

I might have to look at getting the car weight balanced.

I have spent alot of time "calibrating" the coilovers. Started by setting them back to factory specs (lengths) per their drawings. Then carefully roatated shock out of base to raise the ride height, keeping track of the amount of turns. Then after calling Pfadt for advise, tightened spring perches 1.5 turns. Just to get the slop out.

At this point, I feel that the coilovers are uniform from side to side. But of course, that doesn't mean that the car is balanced...

Where are you Pfadt guys.....there was a post here, now it's dissapeared?

Pfadt Racing

hey there,

We were trying to keep up with the info being posted so we need to get some things clear.

Do me a favor and give me (Blair) a call in 45 minutes so we can get you straightened out? Does that work?

therealdave

Just spoke with Blair at Pfadt and he gave me a couple of things to check and try. Back the spring perch off from 1-1/2 turns to 1/4 turn past snug, and disconnect the rear sway bar to see if there is any improvement in ride quality.

Will do. Thanks for taking the time Blair.

davidfarmer

the length of the ends is not significant if it's within a REASONABLE range. You want them to be rather perpendicular, and the adjustment will not change that very much. If you were to have ridiculously long/short links, such that the ends were extremely angled, it would change the characteristics of the bar.

Anyway, lowering your car should not effect the angles enough to cause a problem. T1 end links are longer than OEM, but still close enough to keep the geometry withing the proper range. Sometimes I'll mix and OEM solid link on one end, and an adjustable on the other, and you have to cut the adjustable to get it close enough. Regardless, you'd have to have an extremely short/long link to cause a problem if the preload is "neutral" when installed.

therealdave

Appreciate your feedback David. I was concerned or surprised when I replaced mine with (metal OEM) that the angles of the attachment bolts was SO severe. Leading me to believe that they might be too long.