Rick GT3

if you're just going to track the GT3RS, then use a more aggressive camber set up, but remember is not recommended for daily driving due to fast tire wear.
For aggressive settings -3.0 front and -2.6 rear is better use slick tires. Remember then you will probably need more caster in front and is better to lower 1.5cm all around.


if you want more front camber, you have 2 options:

Front monoball camber plate
https://tarett.com/collections/monob...81-991-991fsmt

Front lower control arms shims
https://tarett.com/products/gt3-lowe...-shims-lcashim

Rear lower control arms shims
https://tarett.com/products/991-gt3-...b5722b53&_ss=r

***there's other manufactures with similar parts***

I had read all the post regarding track alignment settings in this forum and copy all of them, but prior to make lots of alignment changes better ask to those who run similar cars in your local track.
also is always recommended to do corner balance at the same time.

Maxi_z

Anyone on here that have the top mounts switched ?

Also does anyone know if MR is actually still recommending to switch the mounts and what parts do they replace when doing their OEM suspension upgrade kit other than shims and adjustments ?

Maxi_z

Thanks for your reply

This is my second 991.2 GT3 RS and I used to own a 991.1 GT3 , the GT3 was adjusted at Manthey Racing with similar camber , and then on my first 991.2 GT3 RS I did my adjustments locally with switched top mounts and about -3.1 front and - 2.7 rear camber and very slightly lower.

The car was going really well and I already perfectly know how it should be with those settings on road and track.

But I also noted that other Porsche specialists seem to get similar aggressive camber leaving the top mounts as OEM but with just lower arms shims , so I was curious to get opinions or reviews on both ways of doing this , if there is enough thread for enough shims and if the wider track is

usually better or if there are other things that could make the steering feel worst etc...

Maxi_z

Anyone with some Manthey Racing setup knows if they recommend to swithc the top mounts ?

tgibrit

I'd be interested in this too, I was told that using shims with the lower arms changes the castor angle, which you avoid if you switch top mounts?

Imperium

I have a 19 RS Weissach and have switched the top mounts as per Manthey, to gain additional camber in front (more than -3,0) and have added 8 mm shims per side in the back to also gain additional camber (more than -2,5). Mind, if you switch top mounts you can not go less than -3,0 camber in front…

It is true that caster also changes but it is within Porsche spec. Nevertheless, I had quite a lot of rubbing with Pirelli Trofeo Rs which has completely gone away now that I am running Nankang AR-1 with same alignment.

I took Manthey alignment as baseline and tweaked to my liking after numerous laps on the tracks that I frequent. Current setup numbers are below, tire wear is perfect and car handles like a dream. I usually beat the field of same cars on any given track.

Front camber: -3,3
Front toe: +1,0 mm per side
Front height: 103 mm
Caster: 8,26

Rear camber: -3,0
Rear toe: + 2,0 mm per side
Rear height: 260 mm

Anti-roll bars (2 holes only on WP): front and rear middle/medium

Maxi_z

Thanks for the interesting reply

I did something similar on my previous 991.2 RS

Do you know approximately how much you ride height is lowered compared to OEM or can you measure from floor to fender just to get a rough idea ( I know that the correct measurement is under the car )

The camber is really close front to rear but it s well possible that it works well that way with the huge front tyres and the rear steering

I was using trofeo R but don t think it was rubbing and then also switched to nankang but only used them on a partially wet track so can t compare lap times

Do you know how the lap times compare between the trofeo r and nankang ?

FourT6and2

Stock ride height for 991.2 GT3RS is, I believe:

Front: 120mm
Rear: 275mm

TRAKCAR

Depends on the track, but at Sebring I found that lowering the car too much and more than 2.5Camber cost me too much time under braking, I couldn't get the time back with better turn in.
Even static load on a bumpy track is better a little higher. I've never taken it off the factory setup and no matter how much chassis tuning we did with different sway bars and springs, we couldn't make it go faster.

Now the 991.1RS is an entirely different story.

Imperium

Original ride height was 113 mm front and 268 mm back. Initially I lowered to 103 mm front (can’t go lower because of FAL) and 257 mm back, but had quite a lot fender rubbing in the back when tires were new so had to raise to 260 mm. That way original rake was somewhat maintained.

I have also measured floor to fender for your convenience, it’s 69,5 cm front and 70,5 cm back.

I suspect there is some sound reason why Manthey don’t just add shims in the front and widen the track width and instead go through with more tedious job switching top mounts. As another user replied in your other thread, and I agree, it probably has to do with caster going out of spec.

I went through 8 sets of Trofeo R’s and now with third set of Nankang AR-1’s I can say that Nankang tire is around 0,7 second faster per 1 track minute.

Nizer

Regarding maintaining caster, best solution is to get adjustable thrust arms. These provide plenty of adjustment to correct camber changes regardless of how you go about accomplishing (shims vs rotating top plates). Also, don't bother with multi-hole pucks, which many aftermarket suppliers will try to sell you. They don't offer anywhere near the range of adjustment vs adj thrust arms and they're prone to moving.

FourT6and2

I'm at 115mm front and 275mm rear and my tires are tucked...

mipcar

Hello, Looking for confirmation / guidance on alignment. 999.1 RS MSPC2's. Have just installed BBI swift spring kit and tarett drop links F/R. I did have my rear fenders rolled as had previous rubbing.

Running more track days than roads. Really no complaints on previous alignment, but hoping for some improved grip with the spring upgrade. I do get wear on outside of tires as others have reported.

Drop links installed in middle position sway bar F/R. These came from a fellow Rennlister off same car. I did not adjust as I believe his alignment was performed at BBI. Appeared to be pretty close to stock length.

Looking for good track specification.

Settings prior to work:

Ride height measured floor to fender.
FL 69.7 FR 70.0
RL 72.5 RR 72.0

Camber LF -1.33 RF -1.31
Toe LF 0.01 RF 0.01
Total toe 0.02
Steer Ahead 0.00

Camber LR -1.29 RR -1.31
Toe LR 0.10 RR 0.11
Total toe 0.21
Thrust angle -0.01

My research so far.

Front camber -2.6
Front toe 0
Rear camber -2.4
Rear toe 2.5mm (not sure if this is total or per side or should be degree?)

Front camber -2.2
Front toe 0
Rear camber -2.5
Rear toe -2

Thanks!

Maxi_z

Geometry and alignment is really dependant on many different combinations of things and also a personal preference and for example will of course depends on the tyres you use , the track etc...

If you are an intermediate driver and are not at full attack all the time of course some mild settings can be even better as often the more aggressive settings work well when the car is close to it s limit

But I would say that if you want to go fast on most tracks and get correct tyre wear you should at least use - 2.0 camber ( that s also what pirelli recommends as a minimum for the trofeo r )

I would also say that usually the car works better with something as - 0.5 more front camber at the front to make it less underteering and with more turn in so that would in theory makes a miniumum of - 2.5 front and -2.0 rear

If you look at what kind of settings are usually suggested by many Porsche specialists as Manthey on similar cars as 991 GT3 etc they are usually closer to - 3.0 front and - 2.6 rear

The rear toe is usually ok close to standard spec and I think you would want to stard with 2mm toe in each side ( toe in as oem )

On the 991 gt3 rs there is rear weel steering so at the front maybe it s better to use a little of toe in as 1mm or 1.5mm total toe in but then adjust to your preference

I would of course not suggest at all to use rear toe out as thin could make the rear reall oversteering and difficult to control especially with the rear wheel steering and without slick tyres

Of course all of this is just some advice and be sure to ask the advice of some professional shop or Porsche specialist to confirm that whatever settings you use are ok

When doing the alignment leave the key turned on to make sure that the RWS is on it s center setting

Maxi_z

BTW I just did some Nordschleife laps and I wanted to use some oem MPSC2 tyres that were looking as new but old from 2018 or older

The car had some weird reactions at the rear and I went to manthey and they suggested that the reactions where caused by the age of the tyres so they fitted some new trofeo R

They were completely right the old tyres were causing that problem but that made also me think how it s possible that many on the forums that track the car are not convinced by the Trofeo R tyres

They are so much better in everything ( on a dry track ) compared to the MPSC2 ( that is an excellent all around tyre of course but still not as track focused ) and even if not at the grip level of MPSC2 R they are cheaper and last much longer