333pg333

Just want to get an idea of what everyone is running for front and rear toe? Put in camber too if you'd like. I'd be interested to see what people have experienced. I was having some nervous moments on the track with the rear getting a bit jumpy under brakes. Currently running 1mm total toe in on the rear. So 1/2 mm either side.
We also found this morning that one of the rear ecentric bolts holding the sway bar had snapped so it was only attached on the left hand side and the bushings in the middle. Not sure when this happened though. We did a test day yesterday. I wonder if the sway was doing anything with one side loose? Would having the left side and the central bushings still connected have had an adverse effect or simply no effect at all? Writing this, it seems like it should. So this morning before the event we disconnected the left hand side and I ran all today without any rear sway. The car felt a bit understeery and we softened the front. Seemed to work better.

Any opinions or experience gladly accepted.

Potomac-Greg

You can check at 44cup.com where lots of 944 racers live. I've been told that a shade of toe IN in the rear is good as the dynamics of braking will toe the rears out (depending on bushing stiffness).

That said, if you're driving hard and at threshold lockup, you'll have tail end wiggle. That's part of the fun!

On the sway bar, if one side was disconnected and the others were not binding, then it should be the same as running without a sway bar. You might want to pull the sway bar, maybe replace the drop links and put it all back to make sure the bar is not binding. I just ordered a set of KLA drop links because I always felt that the rear links seemed klunky and too long when using an M030 bar on its firmest setting.

http://www.paragon-products.com/Swayl_Bar_p/kla_droplinkkit.htm"]http://www.paragon-products.com/Sway...roplinkkit.htm[/URL]

mikew968

A little bit out in the front and a little bit in in the rear. And yes I know that is big time technical.

67King

You are going to find a lot of opinions here. I've heard slight in in the front, out in the rear. I've heard the exact opposite. I went with zero in the rear, and slight out (1/16th total) in the front, and I wasn't happy with how the car felt starting around 115MPH. I talked to Karl from Racer's Edge this morning about it at his Cars and Coffee, he runs zero in the front, slight in in the rear.

333pg333

Hmm, ok well I'm not sure what this means in reality. I always heard out front, in rear but it still amazes me that 1.16th or a mm can make any significant difference...but it does. Got me beat.

Larry Herman

I never liked toe-out in the front. It only affects turn-in for an instant, masks other balance problems, makes the car darty and causes extra drag down the straights.

I'm a big fan of 0 front toe. If you need it to turn-in better, add camber or make a sway-bar/shock adjustment. We bumped our 951 from -2.5 to -3.2 and the improvement to turn-in was like night & day. And I felt that it didn't cause the overall balance to change.

As far as the difference 1/16" makes, if it keeps it from going positive, then that 1/16 makes a lot. Any more than that is unnecessary.

333pg333

Thanks for that input Larry. I think I'm pretty much in agreement with you. We kept the settings from our version of Auto X and just dialed them back a touch. Initial turn in was great but it was really darty under brakes. I'm going to try knocking it back next time. I wonder if the darty front was making the rear feel unstable too? Even with no rear swaybar it feels like it wants to rotate in some corners under heavy braking.

I am liking the Nittos though. Not quite Hoosiers but not too far away.

SundayDriver

Every pure race/track car that I have done is slight (1-2mm) toe out in front and similar, or more toe in rear. Most, but not all, were purpose built cars and the front toe out really helps turn in. A car that has bushings may require very different settings as what you care about is what the setting is under load and that can change a lot with rubber bushings, some with harder bushings and not-at-all with hiem joints.

Also, double or even triple that for cold conditions to help get heat in the tires.

shiners780

When I was experimenting with different toe settings this surprised me too. 1/16 is such a seemingly minute change, yet absolutely transforms the car's ability to turn in.

Larry Herman

Interesting Mark. I can certainly see it for light-weight Formula cars & Sports Racers. Do you feel that it applies to 2800 lb+ Sedans and Sports cars equally?

SundayDriver

I tried it on my 993TT and it helped turn-in. But that was a dual purpose car - I never intended to leave it that way and it sucked on the highway - made the car wander as I expected. (I also played around with pretty extreme alignment specs to make it tail happy, but that is another subject.)

Back on the topic - my concern about toe out on a production car is if the bushings are soft (still rubber), then the forces could well turn a small toe out into large toe out and really mess things up. If the suspension has little compliance, then I feel toe out will help - just has to be tried on each car.

Even with a touch of toe out, the turn in difference between a sports racer and production car is immense. I would have to start the turn in on a production car 1-2 car lengths earlier than the Stohr.

67King

One of the reasons to run an ever-so-slight amount of toe-out is that it pre-tensions the rack. There is no such thing as a zero tolerance anything (or else, it wouldn't move!), so the slight bit of toe-out will take all of the "slop" (sorry for the overly technical term!) out of the system.

Larry Herman

If you look at the geometry of the steering arms on our Porsches, you will see that the alignment immediately goes to toe-out as soon as the wheel is turned even the slightest amount. I can see Mark trying to have additonal scrub to heat up the tires, and in that instance I would prefer toe-out over toe in (in the front) to do so. Other than that, I really feel that the darty nature that toe-out produces is being confused with enhaced turn-in capability. If I have to turn the wheel a few more degrees of initial input to get the car to take the same turn-in line, have I really lost any capability? IMHO no.

Dubai944

I run 0 to 6 minutes out on the fronts and 6 minutes in on each rear.

The rest of the setup makes a difference. I used to run more toe out on the front when I ran staggered tyre sizes to get the car to turn in better. Now I run a much wider square tire setup I usually run 0 toe on the front.

The diff makes a difference. I once borrowed a 968 box with factory LSD for a couple of races while my box was being fixed and needed to run a lot more toe in on the rear compared to my usual GT diff which locks the car down nice and straight.

Camber I generally run 3.3-3.5 front, 2.2-2.4 rear. Depends on tire temps. I often run less camber on the inside wheels on track configurations with predominantly one direction of turn.

333pg333

Just to clarify my current setup. Car is approx 3050lbs with driver and 1/2 tank. It has KW race oriented suspension w/ 630lb f and 710lb r spring before effective calcs. Racer's Edged all rubber bushings to metal or spherical, A Arms, and hubs. Big Reds / pfc 01's front Mo30 / 97's rear. 928 5/33 brake proportioning valve. It does have Tarret sways front and rear (although as mentioned it wasn't running any rear bar last meeting). So while it's no lightweight sports racer, it's not exactly a limo either.

I often had turn in issues and that led us to more and more camber and the toe out front setup. Now the turn in is generally great but there is definitely the dartiness under heavy braking. The car is also sitting higher than I'd like. We had to raise it up after it was getting into the bump stops too much. Now I think it's too high and this is also adding to a feeling of uneasiness during the heavy braking moments, or at least when washing off speed on less than straight braking. Not explaining this well but there is a RH kink at the end of the main straight which throws you to the right. Turn 2 is about a 100 degree corner and you really win or lose speed here with how you come through the kink and into/out of 2. When the car is darting around and feeling a little 'high' you really have to concentrate too much on just not spinning and stuff up turn 2.
http://wakefieldpark.com.au/index.ph...d=37&Itemid=55

I also happened to get a passenger ride in a 2004 GT3 on slicks. Wow what an eye opener! So much grip, balance, power out of corners, BRAKES! Loved it. Still, on R specs he was turning 1.05-1.06 and I got into 1.08 flat and can see where there is still plenty left out there so all is not lost. lol.