Inrev

I'm currently getting suspension mods which are the following:

RSS Front toe links
TPC Rear toe links
RSS Shims
RSS Caster pucks

trying to achieve the following aligment specs:

FRONT
Camber -3.0
Toe neutral
Caster 9 degrees

Rear -2.5
Toe .30 degrees

My installer (dealer) tells me that once the stock bushing come out of the front LCA, it will be hard to bring it back to stock if I ever decide to sell the car as he needs to pressure the bushings out and odds are they'll get destroyed. Even if they do survive he won't be able to put them back in. Porsche doesn'T sell the bushings alone so if I ever need to bring it back to stock I will need to install buy new lower control arms at $1600 CAD a pop...

Can anyone chime in? I'm deciding whether I should just ditch the caster pucks and stick with OEM...

ShakeNBake

You can get the adjustable thrust arms instead of the bushings. They are more expensive.

I'm not sure anyone buying your car next will care about the bushings, they are functionally useful. They do indicate the intention to track the snot out of the car though...

Shandingo

You will not be able to achieve -3 degrees up front without either one or the other of adjustable caster pucks or adjustable thrust arms.

Bill Lehman

Not really, You can get the camber but not hold the desired caster without the pucks or thrust arms. A little extra caster is not a bad thing as it adds camber when the wheels are turned. I don't have any caster mods.

ExMB

+1

I don't have either. I'm not rubbing and I have track wheels with an increased offset compared to factory wheels.

Shandingo

What I mean is that if you dialed in -3 camber in front the wheels would be rubbing on the wheel well due to the extreme caster angle without the adjustable. Therefore -3.0 without the caster pucks is not possible. I know this because another member whom I know tried to get -2.75 without caster pucks and the wheel rubbed too much (due to the caster setting that resulted from dialing the -3 negative camber) so he ended up having to install the caster pucks. In addition, the OP should consider installing adjustable tie rods. At -3.0 camber the OE tie rods will start to run out of threads to achieve sufficient thread engagement.

Shandingo

Btw, my car is setup with the adjustable tie rods and castor pucks and I have about 10.2 caster and - 2.5 camber up front. The car is very stable at 10.2 and I believe the stock caster setting is about 10. I have not driven the car with a different castor setting so I cannot say how 9.0 would feel but 10.2 feels great to me.

Inrev

Well I had them do it, they got 11 degrees of caster however with -3.0 degrees of camber. Car feels solid and the ride doesn't feel harsh. A bit more direct than before. I just hope there's no rubbing at the track, I'm using the OZ 19in wheels with 245/40/19 RE-71Rs

Hams955

You may not be able to get to -3.0 camber on the front with stock LCA's and top plates.

Do you plan to run a wider wheel/tire combo or stock size/offset/width?

Achieving the camber you want on LCA's alone will widen track width.

I ended up a little more like -3.2 as I was only able to get to -2.8 on LCA's only. I am running Tarret camber plates with BBi LCA's.

I opted to run adjustable thrust arms to maintain caster at 10 degrees and neutral toe.

Also your rear toe is too much; you'll create snap oversteer.

The car responds more to almost zero toe in the rear and reduce ride height and set rake properly.

Just a suggestion.

- Chris.

Shandingo

You may be able to get away with no rubbing since you have 19" wheels, but I would imagine it will be very close. I don't have any data on the 19" setup so I cannot help, but you already had the work done so you will soon know.

Inrev

First time I hear about snap obersteer because of toe in. In what circumstances? Also .30 deg is total toe, not per wheel.

ExMB

Actually wheel OD does not come into place with the rubbing he is referring to. Its the overall wheel/tire OD that in conjunction with the caster could rub on the fender lining. Now one opens a can of worms with square shoulders versus rounded shoulders, actual tire tread width (which might differ between OEMs for the same claimed size), etc.

Inrev

Ok so a bit of an update: I drove the car around on the street and after a while noticed some rubbing so took it back to dealer. I tried to tell them to adjust caster to 9 but they said the quickest way is through ride height adjustments (I was in a hurry). So I got 13mm more in height all around and my camber went from -3 to -2.6 front, and -2.5 to -2.2 in the rear. Caster still around 11.

I drove it at the track today and it handles just beautifully, but even with the adjusted height there is rubbing, I suspect during hard braking.

Will adjusting caster prevent rubbing at this point? They tell me the strut is pushed in as far as possible and that adding more shims won't help.

Shandingo

^Get a set of adjustable thrust arm bushings (aka castor pucks) installed and that will enable you to dial back your castor without losing the desired level of negative camber. That should solve your rubbing issue. I would recommend going back to stock ride height as well.

Inrev

I got the RSS ones, I think my mechanic was struggling with them