I have 24 3/4 front and 25 1/16 rear. Mine is sitting a little lower than stock and I have smaller diameter tires than stock on there right now but the relative figures should be valid. In fact - the difference f/r might be even greater with stock tires on there because my current tires are a little taller in the front than rear IIRC.

 

Bob-D - I will check my GT3, The measurements I took were on my wife's car which is being track aligned tomorrow. Perhaps her ride height is off. The dealer was mucking around and changed an A arm to cure a clunk in the front suspension. I can't see that affecting the ride height though. The height in back is like yours but the front seems higher than you and Z06.

I'd say your rear toe is suspect. OEM is 13' per side and with neg 2.5 camber, Motorsports suggest 17' per side or, more than double what you have. Not enough toe leads to instability at high speeds even in a straight line and it can be a handful in corners. You don't seem to have that problem though. I am not confident about the effects while braking though. We set static toe in because the suspension tends to toe out under load either when cornering or accelerating in a straight line. As the load is reduced the suspension returns to a toe in stance. Under braking the rear of the car is pretty light and since you said hard braking, I assume you're doing it in a straight line.

I like your theory about the brakes being grabby especially since the rears are lightly loaded when braking hard. Could the instability be ABS trying to prevent lock up on individual wheels?

Rgds,

 

I agree about the rear toe - I'll probably go ahead and fix that issue since I'm fairly certain the car could use some more. That will allow me to narrow down things and determine if the brake bias is out of balance as well.

 

Bob - the RS19 Yellows are much better cold than the Oranges when cold (or when hot for that matter ) They do make more squeaks than the oranges though when cold...

 

I think everyone should try 0 toe front and rear and then tell me how good it is.

 

As a point of reference , on my Turbo , there is a 7mm less distance between the wheel well lip and the reference point on the front susp arm compared to the rear measurement delta . That's why factory specs measure at the susp arms.

 

Z06 - I measured my gt3 and got 25 1/4" in front and a shade less in the rear.

944CS - do you work for a body shop perhaps?

 

really? maybe the gt2 is different (?) but i've never noticed a change in power w/ the ac switched on in a 996. i've tracked my car at willow and fontana several times in 100+ degree heat and never felt a loss of power while blasting the ac...

 

With 13' of toe in, that should be enough to not have an issue in stability,
i would like to think that under braking there is not that much play (movement) where the rear wheels are going to toe out, which causes the car to dance under braking.

I would try slightly less brake pad on the rear.

 

Rob,

If you time your laps you will see an improvement with AC off. If you lap with someone who is a fast as you, turn off AC and you will suddenly be faster than he is. don't take my word on this, try it.

You might also try scientific method and ask yourself how much parasitic drag plus compressor drag the AC has. I measured it on a DYNO on my C4S a few years (6 actually) and measured a 14 HP difference. How much money does a gadget freak spend to get 14 wheel HP on a 911? Roll the windows down and save thousands! I tried it on the dyno because I was there anyway and my curiosity had been tweaked. My wife and I wee teaching at an event with a huge skidpad (where "Driven with Sly Stalone was made). We had an impromptu drag,her in a 993 and me in a 993 C4S. The first run was a tie. She smiled and said she had the AC on. Mine was off (no fool I). The second and subsequent runs she pulled away easily as soon as we hit 3d gear.

Best,

 

There is a reason for that:

"You are not driving fast enough".

Under light acceleration, there won't be a noticeable difference in power.

 

At full throttle doesn't the air con turn off?

 

no i dont work for a body shop why do you ask?

 

944 CS - If you run zero toe in the back of a 911 you are gonna have one evil handling car.

 

my experience with 996's is not with stock suspension......and I think everyone rules out 0 toe all around before they even try it......so if anyone wants to try an alignment spec do whatever caster/camber/sway bar/rear wing settings u want but try it with 0 toe.......anyone here ever driven at pocono or summit point last year?