- with that front to rear spring rate difference, i highly suggest you "initially" try the rear sway on full soft and the front sway in the middle setting

- in terms of front (toe-out), "my" opinion is that the car really responds well to toe-out and that is why i run it (1/8th total toe-out in my case or 1.5mm per side)

- with that said, one of the reasons i run that much toe-out is that i started with the oe MPSC tires and then switched to r888s

- if i was running Hoosiers or slicks (much much better grip) i "might" dial the front toe-out a tiny bit to maybe 1mm per side but 1.5mm perside is fine in my opinion

- but, what i will do when i switch to Hoosiers next year is stiffen my front bar by one hole

- let us know how the car handles after your trackday as i'm very interested

- your spring rate rate setup is "similar" to how KW sets up the street 997 cars for the ring

 

I agree, big split on spring rates F/R and seems to me front and rear are both too light for a track car setup with Motons and Michelin race slicks assuming you're running fairly smooth tracks. If you plan to incorporate any substantial downforce, rates are definitely too light.

 

The car feels very very hard on the street (I only use the car in the street to go to the track) and in the track the car roll is very limited and handles very very good.

The alignment was done in a shop with a good Hunter aligner,but now that I want to make a more precise alignment I bought the strings and Smart Camber tool and the Hunter alignment is not good I noticed some differences Left and Right.I haven't done the alignment yet maybe tomorrow.

 

Today I started to align the RS,I spend some time installing the smart string tool and I think I made a good work then I used my scale levelers to make a flat floor.

FRONT CAMBER
I moved my FRONT camber to the max (with OEM camber plates) 2.3° and I wanted 3.0°

FRONT TOE OUT
5mm dif per side total 1cm


REAR CAMBER
Since I cant have the 3.0° in the front I moved my rear camber to 1.9°(I have GMG adjustable dog bones)

REAR TOE IN
2mm dif per side total 4mm


What do you guys think?

 

- give it a try and see how it feels
- probably too much toe-out in front (as was mentioned in earlier posts) but give it a try (likely a little too twitchie)
- you are going to need some more spacers to increase the front camber if you are not going to rotate the struts (these are 996gt3 part numbers so just go to the dealer and order some - they come in 1mm, 2mm, 3mm, 7mm - order a 7mm for each side (costs maybe $20) and you will have enough to get to -3.0 if you are currently at -2.3
- I run -2.7 with non rotated struts and just spacers but can get a tiny bit of rub at near full lock with compression in a corner
- rotating the struts and then using the shims will reduce the caster to avoid this problem

- what tire sizes (f,r) are you running?

 

Just rotate the strut tops, and you will get your 3 degrees. Relocate the spring plate studs to the other three holes. No need to remove the struts, just loose the strut upper nut, press down and to a side, remove the camber plate (3 13mm nuts) switch the studs.

I think you might have set the front toe out to 0.5mm per side (1mm total), rather than 5mm per side (insane and not recommended at all) or 10mm total (1 cm).

5mm is too much toe-in for the rear, 4mm is the ticket regardless of having full monoballs/solid bushings and stiffer springs. I have run 2mm total at the rear for autoX, but it's too twitchy at the track.

Get the dog bones back to original length. Never adjust camber with them, it messes up the thrust angle and cross alignment. To illustrate this, imagine two 1" long dog bones at one rear corner, and two 12" dog bones at the other corner. You can manage to get the same camber and toe from both corners, but the car would be a mess.

I run 2mm toe-out front and 4mm toe-in rear on the stock suspension, other than GMG bars (much better than stock, bye bye push), GMG upper dog bones and Tarret toe-links.

The 450/900 spring rates are fine, I'm not convinced yet on running close to even spring rates, these cars weigh twice as much on the rear axle (2200 lbs) compared to the front axle (1100 lbs). I ran Michelin Blue Cups at Cal Speedway on the stock springs, and a lowered car, and suspension travel was not a problem. I ran on PASM normal, I could have gone stiffer with PASM sport.

Cup slicks (yellow or blue) are 240/640R18 and 270/680R18 they should run on 9"/11" ideally.

 

I use rotated struts and 7mm shims, caster on the stock settings, minimum -2.7 even camber, maximum -3.5 camber. -2.7 is all I need.

 

Wow I am learning many things thanks.

-Ok will reduce Toe Out
-I don't know the spacers ,do you have a pic or part number?
-Tires I use Michelin CUP slicks 18" I don't know the size but they are the only allowed to be used in Porsche Cup series.

 

-Sounds interesting just rotating the upper plates to get more front camber will try this.
-I have 2mm Toe in rear ,my track has a very big strait.
-I adjust camber with the GMG Dog bones because I camber and Toe locking plates so I don't use the OEM Camber-toe bolt to adjust.

 

When I say 4mm Toe-in rear, I mean total toe-in (2mm per side).

Little toe-in at the back increases tire life (good) and helps rotation (good), but reduces high speed stability (not good), reduces usable power out of turns (not good), reduces braking stability (not good).

Adjusting camber and toe with the upper bones is like running a spacer on one side and not the other. The upper dog bones need to have the same length per pair. A pair is the two front upper links, or the two rear upper links, not the same side front and rear upper links.

To adjust camber at the rear, use camber shims. Tarret Engineering have plenty of them available on multiple sizes. Buy a couple of 7mm for the front axle, (6) 1mm, (2) 4mm for the rear axle. You don't need to touch the eccentric bolts for camber and toe adjustment at the rear. I assume you already have toe links, so adjust the toe with them.


Here is a link to the shims: (Ira's site) http://www.tarett.com/items/996-997-...him-detail.htm

 

Cool thanks I will order the camber shims to get the proper camber and will equalize the length of the dog bones.

This shims work in 997 GT3 and GT3rs correct?

 

shims work on the front control arms of the 7GT3 only, and the front and rear control arms of the GT3 RS.

 

I just shoot them a mail I hope they have the parts available I have a track day soon.

Very good info thanks for your support.

Now I need more power jiijiji what can I do?

 

Today I finished my alignment:

FRONT
TOE 0°
Cam 2.4°

REAR
TOE IN 2mm per side
Cam 2.1°

Next week I will receive Tarret camber shims and will use more front and rear camber.

 

I have another question,when adjusting the rear toe all the upright rotates a little bit it is necessary to readjust the upper MG dogbones to liberate some stress and that they move freely?