I set mine medium front and firm rear since I will track the car. If DD then you could do soft front and medium rear. Either way it will help the car be more neutral in handling.

 

Thanks Doc, I'm going to order the springs and sways tomorrow. I haven't figured out exactly what the sways add by themselves but the consensus seems to be that the springs and sways are a worthwhile upgrade.

 

I had an alignment done on my car and after only 4500 miles (10,200 miles total on the tires) I had very bad wear on the inside of the rears. The outsides were not quite to the wear bars and probably would have another 1,000 miles left on them if the inside 2" wasn't almost to the cords.

My alignment was -1.5 rear and -0.41 front.

I have new tires now and wonder what I should do? The car drives great as a DD and the one track day I had was great too. Lots of squealing in the corners but nice grip and turn-in.

Any suggestions?

 

You need to check the rear toe. You want to be about .10-.14 toe in on each side.

 

Paul/Doc/Slawek/etc., very interesting and informative discussion on the camber issue. I had asked Ira at Tarett about a similar topic, camber plate versus GT3 lower control arm, and following was his reply:

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The camber plates will get you about 1.1 deg extra negative camber, while the GT3 control arms can get you up to about 2 deg. more. The main problem with the arms on a turbo car is that as you add shims, the axles get displaced in the CV joints and can fail. You can probably safely add about 5mm, but 10mm or more is very risky. You can use the camber plates together with the GT3 control arms to help reverse the effect. They will increase axle engagement. I also have a supplier that has just finished up a design for some CV spacers to increase axle engagement on cars with more than 5mm of shims. The camber plates will increase steering response with only a very small increase in road noise. They replace the OEM plate, but you will retain the OEM bearing and hat.
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Yep. We are doing the 5mm shim on the bottom and the Tarett camber plates on the top. That will wild us the -2.5 and be safe and not damage the the front axles. Car goes down today for the work.

 

when we compere gt2-gt3 suspension to the turbo cars we need to understated that Porsche design then on those cars differently.
Look at pictures below -the angle in witch suspension travel on turbo and on gt cars is compliantly different
gt- lower part of cailover is pushed foreword
turbo- lower part of strut is pushed back
That change alone make a big impact on how the car behave under breaking and acceleration on truck .
All we can do is to try to make our turbo cars handle better then the stock turbo-and this is a good thing
Cheers

 

Hi Can. Interesting how Tarett is aware of the problem yet so many that get involved in setting these turbo alignments have no idea. Scary. As an owner and paying customer you'd expect that the person setting your car up ought to know about any pitfalls before touching anything.
Could you please ask your contact at Tarett if he has any knowledge on the difference in length between the 996 and 997 cup arms, and if so what he specifies as the max shim on each arm type? It'd be great to have this info for future reference.

Doc it'd be great to hear all the detail on the recovery of your alignment re exact lower shim used etc. I'm guessing he's going to reset your car up for free.....given you've saved his bacon big time?

Thanks slawek. Interesting to see the differences side by side.

I'm assuming the grey car picture is the awd turbo....with the red calipers?

 

yes it is Poul , as you can see the turbo suspension geometry of the front is different to the gt cars .
One more picture showing coilover installed..

 

If you look at Tarett's web site for GT3 LCA http://www.tarett.com/items/996-997-...kit-detail.htm, it seems 996 LCA and 997 LCA are not identical because for 997, you need some "trailing arm adapter" kit??
I emailed Ira with some questions and will post when he answers.

I have just read this whole thread a few days ago and had a chuckle looking at your posts. Very sharp Paul.

 

Thanks for the very interesting picture! I was not aware there is such significant difference in geometry.

Do you know if the difference is "*merely*" from the Turbo being AWD and the front differential housing/mechanism necessitates the change in geometry?
(I would be somewhat heart-broken if it's for some other reason - like to "tame" the Turbo's response or whatever.)

 

Thanks again slawek. It shows the whole front strut set up angles are completely different between the 2wd and awd cars.

Thanks for the link Can. Those top camber plates do look good. Do you have them on your car at all? And i wonder why they don't just use the 997 LCA for 997's if a mod is needed to make the 996 LCA fit? There must be a reason why they went to the trouble of producing an adaptor kit....unless there is a benefit in using the 996 arm on a 997 over the 997 arm?

 

Can , Poul as you very well know for past forty years Porsche is improving 911's .
The rwd cars have big advantage because there suspension is based , developed and improved on racing experience.
Our 4wd turbos are a money making side project for them ,-out of that side project they manage to create one of the best cars in the world- that is not so bud -is it?

 

Paul, my questions to Ira of Tarett and his answers (in blue), in reference to http://www.tarett.com/items/996-997-...kit-detail.htm . It appears the difference between 996 and 997 LCA is not length, but the thickness of that thrust arm bushing (the round bushing on the LCA itself that connects to the trust arm in front of the LCA if I am not mistaken).
BTW for anyone reading this, if you have a favorite vendor already - never mind, otherwise I would most highly recommend Tarett stuffs. I learned of Tarett from guys on Rennlist's racing forum - it's the "real" thing and it's been around a long long long time (the key ), and Ira is a knowledgeable and superb help.

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1. On your web site, it appears you are offering 996 (**not** 997) GT3 LCA for 997. Why is it that there is no 997 GT3 LCA?
We carry the 996 GT3 LCA mostly because of price and availability. I sell them to 997 and 987 customers .... I’ve sold a few 997 cup LCA’s, but they are much more expensive.

2. And for 997, you need to use a "trailing arm adapter" kit? Why is this necessary please?
The thrust arm bushing of the front LCA on the 997 and 987 is thicker than the 996 one is. The rear is the same as on the 996. To make up the difference in thickness, we have an adaptor spacer kit that takes up the extra space. The other option is to change the thrust arms to the 996 ones, which is much more expensive.

3. Is the length of 996 GT3 LCA different from that of 997 GT3 LCA? Is this why the trailing arm adapter kit is necessary?
The cup arms come with a 10mm shim, and end up being about 20mm longer than the 996 arms overall. I don’t know how they compare with the 997 arms, but I’ve always based the shim quantity on the 997 and 996 arms being the same length, and it’s always worked out about right.
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The GT cars have different uprights in the front to allow for more caster, and even then many folks upgrade from the stock GT uprights to the Cup car uprights for even more caster. These won't fit our cars due to the front drive axles