I've been researching suspension options and found bump steer kits which appear to be tie rod upgrades and toe steer kits which I suspect are different so can someone explain the difference? I also see that mono ball bushings look like a good upgrade but is it too much for a street car with 60k miles? Are these the bushings that replace the stock bushings in the lower control arms?

I picked up a set of KW V3's and want to upgrade whatever else might be worth replacing. It looks like the rear dog bones (control arms) are a good upgrade and there are quite a few manufacturers; is there a big difference between brands? I appreciate any input. I just picked up a 996tt, love the car, and want to start upgrading things slowly. It's probably bad form to not post pics so I better get on that right away!

 

Upgraded toe steer kits are just that. Toe arms that replace the factory arms with new ends which are usually harden steel heim joint with bushings and stock or upgraded ball joint. Adjust-ability can be done on the arm itself instead of the eccentric bolt. Which then can be removed and in place use a bolt with lock plate to eliminate movement.

A toe arm with bump steer not only adjust the toe settings but also aids in correcting bump steer angle. Which is usually more present on lowered suspension cars. Wheel travel angle gets affected when suspension compress, bump steer will be present. These bump steer kits aid the limit of steering angle change.

I think this made sense!

Here's a good article expelling bump steer and how it affects handling

Bump Steer explained

 

That helps - thanks,

 

Bump steer kit goes on the front
Toe steer kit goes on the rear

 

It looks like most are running the adjustable rear control arms and toe links. I don't see as many references to bump steer kits though. Are bump steer kits on these cars really needed when lowered?

 

When you lower the car it will induce a bump steer effect. I have pss9's on my car which is quite low. There is a definate bump steer, not horrible like earlier 911's were but still there.
Kw v3's set the car quite low. Your better off with gt3 rear lower arms and a quality toe steer kit then the dog bones, either way you will need more adjustable toe at the rear.
As for the solid bushings i wouldnt do it to a street car, replace the thrust bushings with adjustable ones and try that, will be a huge improvement over stock with all those changes.

 

That helps. Thanks for the info.

 

Very interesting

 

Find this quite interesting as well. I am looking for a set of PSS9/10 and was wondering what other suspension upgrades would be worth while while doing the coilovers to ensure great handling. Doesn't camber get affected as well when lowering the car? Don't need tires wearing more on the inside than they already do. How do you counteract that? Love to hear what all the good suspension upgrades are for a great handling street car and possibly some track too.

 

I'm no expert with these cars, I'm a driver instructor with local club and have driven on the track various 996TT, 996GT3, 997, 997GT3, my own 996TT and a friends 996TT which has KW V3.

My car has PSS9 and the rest of the suspension is stock, I wanted to baseline my car as I bought it (came with the PSS9's). So this year I tracked it 10+ times with various groups.

I have since come up with a upgrade path for the suspension which I'll share. Again I have not driven with the upgrades I have chosen, hopefully others will chime in on their experiences. I have scoured the online forums and filtered through those I feel are knowledgeable and come up with this setup for a street/track compromise (big emphasis on compromise)

GMG WC anti-sway bars
GMG WC rear toe steer kit
Rear GT3 lower adjustable control arms with factory rubber bushings
GMG WC front bump steer kit
GMG adjustable thrust arm kit
Revalving my PSS9 leaving spring rate as stock
Quality alignment

Choose the vendor for the anti-sway bars and since I'm ordering I'll get as much from them as possible to cut down shipping and duty.

Camber/toe/caster all are effected by lowering the car, also excessive lowering can be detrimental to handling. Alignment is critical, also my understanding is the factory pieces can't adjust for much lowering, the rear toe can and does change at the track, the adjustment point loosens and moves. Which is why people end up with too much toe and can't adjust the camber, most of the reason the adjustable parts in my list are needed.

It also depends greatly on the tires you plan on running, the stickier the stiffer your suspension needs to be to handle the grip (very simple way of looking at a very complicated topic)

 

I recently had H&R springs installed on my '03 TT and it did drop my car a full inch.
So while I am happy with the way the car looks, I was told I should add a set of rear toe arms ? that if I don't the inside of my 315/25/19 inch tires will wear out to quickly ?

Any thoughts or advice ?

THKS - JIM

 

Porsche's (especially 996's) Bump Steer on both ends when lowered. And you can use a bumpsteer kit or toe kit on either end. In fact, if you have adjustable toe arms already from Porsche you can buy the same piece to fit the front or back as the bumpsteer correction is in the tie rod end which is what you put on the front.


What it does is allow the mounting point for the Toe Arm to be significantly higher like it is when it's stock even though your car is lowered. Obviously, only works to a certain extent.


It's really for tire wear issues and helping to keep the alignment more in tact while cornering.

 

Depends on how many miles you are trying to get out of your tires.


You should not need toe arms for only an inch lowered IMO. 996 TT's are almost 4x4 height stock. A good alignment and you should be good. A little toe in on the rear should help preserve the rear inside edges which tend to wear out first.

Camber will be another issue, but you still aren't low enough for that.