jmartpr

19x11 ET46, which do run very close to the end of the toe link. Some people just go with a 19x10.5 to eliminate the clearance problem. Front one is 19x9 51ET,

IPSA

In the absence of DSC or TPC links, increase rear static toe at least 50 % to reduce high speed braking wiggle. Changing the rear inner ball to a metal spherical bearing also helps.

Puggz

A touch over 3/8"... that would be as far as I would go from a practicality standpoint. How low will it go?

Inrev

Any update on your track setups? Is having the rear stiff and front soft still a must?

I did one track day and oddly my mechanic set the rear soft and front middle as a few of his customers didn't like rear at full stiff. I was consistently slower on a large portion of the track than a GT4 on stock alignment (middle/middle sway bars) He also was on Sport Maxx 2 though and seemed to have more grip whereas I was struggling to find grip on my MPSC2. He killed his front left tire though so that speed cost him $...

Will ask my mechanic to get me -2.5 front -2.0 rear, slightly open toe front and 2mm total toe in rear with full stiff front and full soft rear and report back.

jmartpr

Dealing with the understeer via sway bar is a band aid solution.....and usually ends on a car that some people don't like how it behaves. Ont he 981 GT4, once I had my alignment set with bigger tires up front I ended up with the sway bars both at the middle (stock).
I think your new alignment specs are perfect for double duty. Slightly toe out front is what I had but keep in mind the car at speed on the highway will wander/shim a bit...but turn in response is so good!

Croc999

Here is my story:
At the first track day that i did the understeer was obvious and the hard loaded side's front tire got overheated like crazy.
So more more camber is needed.
I went ahead and installed 4mm shims at the front + plus some coarse manual toe correction and this the way i've arrived to the alignment shop.



The rear camber was at 1'20" with a good toe in.
The front camber however was with big difference 1'30" vs 2'.
Caster is actually pretty usual for Porsche in 9+ range and almost equal between the sides. Since the caster can't be adjusted these were good news.
I was concerned about camber differences and thinking that we probably will need to play with shims - but actually front top mounts were NOT put to the max camber setting - so by moving them camber was equalized between sides and we reached 2'10".
This is a lot IMO with just 4mm extra shims.
If 8mm give about 30" (half degr) so whithout any extra shims i estimate we would get 1'50" - almost 2 degr which is fantastic.
Front toe set to 0 was easy (hard to reach though without removing front undertray)
Rear toe is a problem to get maximum with max rear camber - i mean we could add a bit more rear camber via adjusting bolt but toe would go to toe out.

What needs to be removed:
- central part of the rear diffuser - very easy, around 6 bolts
- rear undertay - easy, around 8 bolts
- rear cooling air guides - easy, 2 bolts each
- front undertray - we didn't remove it but it looks also like easy procedure with ~12 bolts
All in all nothing difficult but it takes time.
All in all it took 3 hours (shims were preinstalled).

This is the summary:



Results:
I'll be tracking this Friday so i would be able to tell.
Out of the shop with cold tires the car was oversteery like crazy. Really got my confidence ruined.
Later on the road it wasn't bad but i didn't push too much as i still was scared

Will see how it goes from here.
Perhaps no other way bu adding more rear camber and adjustable rear toe links...

jmartpr

Looks good. I think this is as far as you will be able to take it without some extra suspension parts. If you do track a lot go for -2.5 up front and -2 on the rear (try to keep front/rear camber diff at 0.5).
One thing about camber plates is that they do bring the caster back to specs...they will automatically add -1 degree.
If you later go for the wider tire up front you will need them as adding shims pushes the wheel out, which looks good but brings problem with inner fender clearance and caster.

Croc999

Since i want to keep car under warranty i can't do any changes.
Still thinking how make adjustable toe links "invisible"...

jmartpr

As long as you don't claim warranty for something in the suspension/tires you should be OK with warranty work on other non-related parts.
The thing is that you will need the toe links sooner or later. It also helps having a good relationship with your dealer.

lovetoturn

The car will likely be a bit unstable in high speed turns with those rear toe numbers. You need about 10-12 minutes of toe in the rear which is about 2 mm. Hence the need for aftermarket toe links. I will be using the TPC offset links which further stablized the toe changes under load.

jmartpr

Agreed....I used 3 mm with the TPC rear toe links on my 981.

ExMB

@ croc999

Is best in you list your location under your avatar pic. If not you'll continually get advice regarding mostly US dealers. Most don't understand that in ROW countries dealers play by different rules.which may include (by)yearly inspections to stay legal.

Croc999

i already stated my location in the settings.
but apparently there 2 different fields that needs to be updated.
Done.

mprog

Here's the alignment I've been running with ... so far 1 day at Laguna Seca, and 1 day at Thunderhill.
Tire wear has been pretty even, but I'm also not pushing TOO hard just yet. I'm coming from a 911, and on top of that this is my first manual car in about 7 years.
Hardware modifications to hit this are:
- TPC Offset toe links
- RSS Caster pucks
- Additional shims
I'm also running a DSC Sport Controller. I had my 991 DSC controller reprogrammed for 718, and I'm using the 981 GT4 w/ Offset Toe Link Calibration. I'm hoping to do some modifications to the calibration after I'm more familiar and comfortable with the car.
Aero set to track front and back.

So far it's pretty good! There's still a good amount of understeer, and so next time out I'll put the rear sway bar to full stiff. I'm going to keep the front bar on medium because the front springs in this car are pretty soft (257 if I recall). I also plan to lower the car just a bit (10mm?) and install a DBJ Front axel lift kit (sitting in my garage actually... just need to find the time to install it). I may also do spherical LCA inners on the rear, depending on how planted the rear end of the car is as I get a little faster driving it (just to match the solid bearings of the toe arm).

jmartpr

That looks good! this is a great setup for street / track use. I plan to purchase your same setup except will add the Tarrett camber plates (going for -3 deg up front) with the Porsche Motorsports front strut reinforcement plates.
My front track tire is a Pirelli DH in 265 at that takes care pretty much of all the understeer The problem is finding the rear in 305, is getting harder to get.