vandersmith

Thanks for chiming in, this is super helpful as I've been digging around in a lot of old threads.

My AWD alignment numbers are above. I've been running 2.6F/2.2R which made the car twitchy when converting to RWD.

Was researching your #s along with heavychevy's. Will look to stick with over -2F/1.5R. Toe needs to be reset so I'll have to take a look at your numbers further.

Am very used to the no PSM on track, it kicks in at strange points.

I'll have to give those numbers a shot on my next set. 235/315 has been working fine even though they are not perfect. My 9/12 CCWs in GT2 offsets allow a lot of options.




Would love to come down, first born in August might make that a little tough! I'm sure you all will have enough fun without me

vandersmith

New Alignment and Corner Balance with help from many here:

911mhawk

Look forward to hearing how you like it compared to old settings on the track Friday.
Where'd you have do the corner balance/alignment and dyno runs done in this area?

vandersmith

TruLine - Bellevue

Based on research here form similar RWD converts:

Car: Porsche 996 Carrera 4S
Notes: Recently converted from AWD to RWD since last Tru-Line (Seattle) Corner Balance
Use: Strictly to and from the Track
Driver Weight: 185

Suspension:
KW V3 Coilovers (400 lb springs Front/ 680 lbs rear)
Tarret Solid Camber Plates Front & Rear
Polyurethane Bushings in Thrust Arms Front/Rear
New Stock Lower Control Arms
Adjustable Toe/Caster Arms
H&R Front & Rear Sway Bars
Tarret Endlinks

Note: Rear Right Toe Link is slightly bent

Desired Settings:

Front:

Camber -2.5 – 2.56
Caster 7.5 – 7.56
Toe OUT -1/32in (-0.79mm)
Total Toe -1/16in (-1.58mm)
Steer Ahead = 0.00

Sway Bar: Softest
Ride Height: 4.5”

Rear:

Camber -2.25 – 2.3
Toe IN 1/32in (0.79mm)
Total Toe 1/16in (1.58mm)
Thrust Ahead = -0.03

Sway Bar: Middle
Ride Height: 5.1”

jumper5836

So that weight is rwd @ 3422 lbs with you in it and full tank of gas?

My Turbo corner weight, haven't got it balanced I just got it weight to see what they were. This is no driver, awd with full tank, all fluids, stock wheels, comfy sport seats, but with spare tire/tools and rear seats removed.

Seems my front is way off from one side to the other, but I was thinking it was due to no driver. Is it possible it would even out with driver or would it become worse?
FL: 679 FR: 592
RL: 1035 RR: 1079
Total 3385

vandersmith

The corner balance includes 185 lbs (me) in the drivers seat.

Full tank, half roll cage, seats, etc.

Interesting numbers. With how stiff the chassis is I really can't comment on whether it would balance out or not but I do highly recommend corner balancing. The car is night and day better

vandersmith

So I guess this is actually the really interesting part of the corner balance:

AWD Weight: 3513
RWD Weight: 3422

91 lbs.

Work since:
LWFW (less weight)
LSD (more weight)
RWD (less weight)
Me (more weight)

powdrhound

Your total weight is about right accounting for the removal of the spare wheel and rear seats. Stock 996TT is normally 3450-3500lbs. Your cross weight is off by 131lbs. Porsche specs the limit at 20kg, or 44lbs. on a GT2/3. Added driver balast may change that a little but not much.

For comparison, my cross weight with driver is 12lbs. My car with full fuel and no driver is 3198.

jumper5836

Thanks seems it's in need of a corner balance then. Does height effect corner balance. Just wondering if it is done if all the corner height come out differently?

vandersmith

Here's some track video from Friday's PCANW day at the Ridge:

Car was aligned, lowered and corner balanced at TruLine Bellevue to the GT2 Specs with new NT01s.

The car responded brilliantly but was a handful. Took an entire day to get the line dialed as the car favored much more oversteer versus the predictable throttle and push thru apex that existed with the previous alignment. Slow in fast out matters much more now as throttle application mid-turn requires much more finesse than before. Turn in was much improved. Entry, Mid, Exit speeds are all relatively the same but the car is much more lively.

I dig it and will need a few more days to adjust. Lap times we're similar 1:55s-1:56 on new NT01s that weren't broken in. They should drop a few ticks as I acclimate and they break in.

Anyway, here's the final session's video chasing a few instructors and my buddy in his 930 Turbo.


Interesting Note:
For the day, the car was only a half second off the fastest GT4 times...

white out

Thank you for posting updates. This is great.

vandersmith

Quick 5 month update:

RWD is amazing. Been daily driving through the winter and the car has been awesome. Added a few more go fast parts and maintenance items ahead of the upcoming track season.

I'm going to go through with the complete GT3 suspension conversion. More to come here once I can confirm parts etc.

Steve Theodore

Any updates vandersmith? Your signature would seem to indicate you threw in the towel on this setup and bought a 2005 GT3, but just curious.

vandersmith

The C4S has been handed over in complete track form to a new Rennlister where it'll see plenty of track/auto-x use!

More to come on the GT3

Steve Theodore

Very good...hoping to see you at some local PCA events bud.