My coil overs should be here in a week or so. I'm not gonna track the car but still want to set it up right. Do I need to have the car corner balanced after the install? What are the added benifits? Thanks in advance.

 

i believe it's needed ^___^
i'm don't really know the reason... but i'm guessing that by lowering the car, you somehow change the weight distribution on the coilover at each corner. that's why you have to do corner balance to have the weight distributed properly.
i might be wrong... lets hope some experts can answer this for us...

 

For sure it is very important. When you are putting new adjustable shocks on everything is unknown. You can messure them to make sure the setting is the same side to side and assuming the car is square that will get you in the ballpark. However, now that you can adjust it why not get take full advantage and get a 100% from them.
If the cross weight is more than 2% off you can feel it when turning left verses right. If they scale your car there shoundn't be a porblem getting it within .1% of 50/50. 50/50 cross weighted cars are the easiest driving for most uses. Now, if you're only turning one direction all bets are off.

 

As expected, Cary is dead on. I will try to say what he said maybe in a simpler way. The coilovers have adjustable heights. If one is too high, it will be taking too much of weight of the car on that wheel, and that means the other wheels will be off also. So, you really need to do a corner balance because even if you are meticulous and measure everything, your frame or mounting points could be off. It is a relatively cheap way to be sure you’re optimal.

Upon rereading this, I’m not sure it helps at all. Hell never mind but I am going to post it anyway to build my post count.

 

Don't waste your money on the coil overs if you don't intend to corner balance.

 

I had H&R coilovers on my S4 for about one month and then had the car corner balanced and I felt a huge diff. Highly recomended

 

Harry:

As all have recommended, get the car corner balanced. That's one of the main reasons to get coil overs.

BTW, don't expect the left/right (side) ride height to be equal following the corner balancing.

 

PSS9 owners,

I am getting my car re-corner balanced tomorrow. I tried several settings on the shocks, latest was number 3 on 4 corners, front sway set at 2nd tightest hole and rear was 1 hole looser. I find that the car has bumpsteer when going ~200km/h or over especially when there are potholes/bumps on the road.
Went to the shop and got the springs tested, they suggested that springs were too soft (240pounds) and I should get a higher spring rate.
Is this right way to resolve the bumpsteer ?

What would be the weight distribution on the porsche ?

Thanks,

PN

 

Thanks guys....Sounds like a must and will be done.

 

PN,

Installing stiffer springs is not the correct way to resolve bumpsteer. Having the car properly aligned taking bumpsteer into account is. Independent of your possible bumpsteer issues, you may need stiffer springs...something like 300 lb springs for the front may work better. What are the rear spring rates?

 

PN,

To make sure we’re on the same page, I define bump steer as; “the amount of toe change per inch of suspension travel.” This is figured in some cases per axle but, the best way is per corner (each wheel independently.) Either way, the front overall is always separate from the rear overall. Typically, I (to each his own) want to get the front very close to zero change and the rear at a slight constant toe gain in compression throughout it’s range (bump thru droop).

Typically with 996’s the issue is more often in the rear than the front. Before you make any big changes you might want to have the car bump steered and it’s possible that you may have a situation where you are getting more gain on one side than the other which will cause the car to do some strange things. Another big issue could be if your cross weights are off. This will cause the car will get a high speed wiggle if the road isn’t perfectly flat.

Springs will only make the car stiffer which means less distance traveled lowering how quickly you notice the bump change but, doesn’t effect the overall change. You also introduce the possibility of other problems to chase. In my opinion, I would try to measure and define what you think the problem is before adding or changing parts.

One last thought are your tires, they can be the problem or be significantly amplifying it.

 

John and Cary,

I am not really mechanically inclined on these things, I just tell them what I feel going above that speed and they had someone test drove my car for a couple of days and I am just relaying what he told me. The driver is an ex-race car driver.

He is trying to resolve the problem corner balancing etc without changing parts or springs for the time being, but he suggested if that does work I should change spring rate or even change the valving on the PSS9's. The other option mentioned is using a higher end suspension system, which needs to be re-checked very frequently.

I thought I'd ask you experts before I continue on. Question is what happens if re-allignment does not work ? Should I move a step by changing the spring rate then the valving or do both at the same time ?

Thanks,

PN

 

I’m quite sure what you are experiencing is a geometry problem. Stiffer springs could/will help by limiting the amount suspension movement. The problem I see with doing it this way is your ride quality will suffer greatly and you’re not actually “eliminating” the problem, only “limiting” it. Let me know how the car feels after they work on it this time. If you’re not happy with the outcome, email me exactly what they checked and how they did it and I’d be happy to call them if I think I can help … that is, if they wouldn’t mind.

 

Cary,

email sent!

Thanks,

PN

 

PN - still waiting for that e-mail please