OK thanks for posting that

(1) the front caster is well off on the left side - caster should be within 0.2 of each other if everything is in good shape.
(2) toe at the front should sit between 0.00 and 0.02' left and right and total toe (left plus right) should be between 0.00-0.04'
(3) the stock camber range for the 991.2 GT3 RS is -1.33 to -1.27 at front (I believe on the Series 1 the camber may have been upped due to rubbing)

rear
(4) rear toe - left and right should sit between 0.08' and 0.12' and total toe should sit between 0.16' and 0.24'
(5) rear camber left and right should be between -1.35' and -1.25' for the series 2 GT3 RS (again the camber may be slightly different/ higher for the series 1)
(6) thrust angle should be as close to zero as possible and below 0.02 and -0.02'

The issue I notice is the front caster - I would expect these to be near identical. As it currently stands the difference in caster is quite large which means one side of the car (at the front) is slightly more "upright" than the other. I would expect caster to be within 0.2 with a good alignment and assuming everything is straight. This can cause a vehicle to feel like it is pulling to one side and effect the steering wheel return to center position.

Also your alignment isn't reporting the key secondary angles.

Specifically the SAI, the included angle, toe out turns, max turn inside, set back and track width difference. The machine that your alignment was done on can do what is known as a collision report, the data is automatically collected but not reported on the standard proforma. If the SAI is different left and right it may indicate something is bent - usually a strut or component in the steering and or a strut top.

If your car is correctly maintained the subframe should not move - most track car owners do routine spanner checks on all the nuts and bolts beneath the car prior to an event. The only time I have seen a subframe shift noticeably is if the car has been hit or not maintained well if track driven.

Key point - before you do an alignment make sure you are running the same brand of tires front and back, they are the correct sizes and are correctly inflated and check for damage or differential wear.

 

so adjusting the subframe may not fix? car never tracked, has been shipped by truck, driven on relatively smooth roads, tires in good shape

 

I’m saying to you it’s easy fix had the same problem on the front caster you need to align the subframe also can you measure the each side from center lock to center lock you will see the difference and post it here.

 

hard to tell, maybe the same, maybe off by 1/8 of inch or 1/4, used tape measure, was wildly different then used string, seems pretty much identical left and right

 

Do your car has any damage before ?

 

definitely undamaged, has been shipped by truck cross country, pretty sure wheelbase is same both sides now

 

Ok let me explain my situation more detailed and you can go from there.

When i felt the weirdness of the car we found out my right rear tire is sits more close to fender then opposite side and alignment showed the caster is wrong like yours.

We fixed the rear subframe as i said but never consider the front subframe shift. I couldn’t find it my front alignment values looked like yours and my wheelbase came out clean like yours as well.

Front subframe looked solid and we didn’t consider the shift and i thought may be the caster arm is bent because on service record it didn’t showed any changes on that part and i ordered the E-Motion Engineering caster arms hoping to end this mess and unfortunately issue not solved.

On my way back to shop to pick up the car and having anxiety on some possible chassis damage i got a call from my mechanic that they loosen the front subframe and shake it with claw bar and everything is fix which is a very relief moment for me because i know the car very well and the damage is very very minor because i have the video of the accident on couple of angels.

So i think you have some sort of the same problem but your car is clean as you said i can’t say why did happen but i can say that it can’t be done by driving on track trust me i beat the *** out of my car like bending the stock suspension, broken lower control arm and aggressive use of curbs which are homologated of F1 racing (Istanbul Park F1 Circuit) they stress the car very well. Don’t get me wrong I’m explaining this to you because thats my experience.

My suggestion for you is unbolt the front subframe and check for the bolt marks if its shifted you can clearly see the shifted bolt marks and then you know what to do i hope you fixed it sooner and if you have any further questions please PM me I’m more than happy to help you.

 

^^thanks so much for the advice, I just obsess about my car a lot, oddly the steering has been off by a degree to the right, ever since I got her. the car felt fine, I actually wanted them to move the steering wheel one notch to the left then it would have been perfect, its gonna be a few weeks before I can get it done, fingers crossed they figure it our, the dealership is impeccable, the tech well respected, GT cars serviced there all the time

 

they were unable tom align in the time they had, so they explained the issue, plus being an obsessive, I wanted to know as much as possible. I try noodles in soup with chopsticks and a bowl!! thanks for the help

 

Get it put back to the stock alignment range before attempting anything else - the ranges I provided are for the .2 RS.

step 1 ensure wheels and tires are correct and inflated to placard pressures

step 2 ensure car is put back to the stock alignment numbers

Importantly caster should be 8.5 +\- 0.2 both sides. Adjust camber and toe within the OEM ranges.

If this doesn’t fix the problem then investigate other possible problems. As a reference point my last three Pcars have been exclusively used for various forms of Motorsport - I have never had to adjust a subframe - not discounting it but do the basics properly first and then work from there.

The ranges in your alignment printout are not the same as mine which are direct from Porsche - make sure the wheel tech is using the specs for the series 2 GT3 RS and not the series 1. They are different.

Get the basics right make sure the tech is using the right info.

I fully appreciate your anxiety here - it is warranted for a car that can go beyond 300kmh. If the alignment is poorly adjusted braking from high speed can be a shocking experience with you literally fighting the wheel.

specifically if the strut position is out relative to another strut position eg caster or SAI.

 

+1 That is extremely well said....Don't take any shortcuts and make sure you have a solid basis for making any decisions going forward.

 

In addition to the wheel alignment angle numbers check to see how these numbers are achieved. Too often I see people use uneven number of shims from side to side causing whacky adjustments at front strut tower slots and rear eccentrics. Some don't even bother to check for symmetry of shims nor even know check, and go right to town with the other adjustments. It is totally possible to have final numbers that look perfect on paper yet the car drives not great. This is not new, same story since 993 with kinematic rear. I wrote about this in 997 forums. Car will pull if control arms are different length from having different number of shims even when camber and toe numbers match. Caster will be uneven as a result for the fore. I think the problem is our cars have too many different ways to adjust and most routine mechanics are only taught one way for mainstream non-GT cars. Not saying this is the case here but should check shims, slots, and eccentrics for symmetry before adjusting subframe.

 

Maybe this will help 😂

https://www.instagram.com/reel/CRYVx...dium=copy_link

 

thats exactly what Im afraid of!!!!!!!!! it looks so scary and how does it precisely adjust like that?

 

This is gonna sound funny but this is how i fixed it 😂😂😂