Question for auto x-ers and such

[tobluforu]

Bringing car in (72) on monday for 4 wheel alignment. What are the setups that have worked for any of you in reguards to front, rear toe and rear camber. Also caster. I'm bringing it to a race shop that specializes in porsches but, just wondering what is working for you.
Thanks

[rscupper]

I don't know. Big help I am, huh?

What I do know is that somebody here will help you, but you need to give more info. What tire brand and compound will you run? Any mods to your suspension? Has your car been corner balanced?

There's probably ALOT more involved but that's about what I know to consider. The experts will let you know soon enough.

Cheers

[tobluforu]

Lowered to the hilt. 22, 28 torsion bars. 22 mm sway bars, r compound tires-205\50\15. Sway away spring plates, adj koni's. Monoball rear trailing arm bushings. turbo tie rods, strut bar.

[tobluforu]

Pink floyd anyone: "Is there anybody out there"...

[rattlsnak]

Youre sure to get mixed answers on this, depending on how much you drive it on the street. Go with -1 front, -1.5 rear camber for a good start. Most use between -1.5 and -2.0 for the front, and up to -3.5 rear more for race cars. Caster not adjustable, rear toe 0, front between .15 and .25 total.

[Tyson Schmidt]

Rattlsnak, caster is most definitely adjustable. It is adjusted by moving the upper strut mount forward for less caster and rearward for more +caster.

I am not sure though where the ideal caster setting is for auto-cross. Most people, I believe, move it to full rear for maximum caster. I'd be interested to hear from some auto-cross Guru's as to what the best caster setting is.

Rattlsnak is right on about camber settings. Judging by the mods you've done to your car, I'd go with the serious negative settings, since it seems to be set-up primarily for auto-X. Like -2 front and -2.5 rear. Front toe at 0 and rear at +.15 per side for a total of +.30 rear toe.

[rattlsnak]

Depends which model year and which strut mounts you have on the caster. No way to move mine anyway but side to side.

[Tyson Schmidt]

Which model do you have? 65-89 911's all have moveable upper strut mounts in all directions. 90 and newer have an eccentric on the lower ball joint to adjust caster.

You must have aftermarket camber plates on your car.

[SRT356/911]

The degrees given are good. The corner weighting is the most important. It requires adustable drop links on the swaybars. Preload must be taken out.
Stay with the car. Hope you are going to someone like Roger Kraus Racing. Brandon does the work and he knows Porsches.

[masraum]

Todd Serota on the email list preaches equal camber front and rear with neg 1-1.5 degrees for street driven cars. It's my understanding that more than 1.5 is usually pretty difficult to achieve in the front of most stock 911's at least the pre 964 models. Also max caster and for toe he goes with either 1/16" toe for front and rear or 1/32" frt and 1/16" rr. Again these are street driven car #'s. If your car is almost all track then you may want to go a little wilder. Most of the recommendations that I've heard don't go with 0 toe for a street driven car because it is "too skittish/darty."

[Z-man]

Question: have you autocrossed before? How much?

I would say go with the -1 or -1.5 all around. That's not too agressive, but bear in mind that you will wear out your tires quicker. (Inside tread will wear a lot faster that outer: so make sure you're checking your tires frequently!)

Funny no one mentioned rubber: if you get autox rubber, it will derfinately improve your cornering grip. They say good autox tires (Kumho Victorracers, Hoosiers, Bridgestone Autox tires...etc) can shave 2-3 seconds off your time. Plus, you're not wearing down your street tires as quickly!

Also: be careful with your changes to the suspension: Getting into lowering/adjustable shocks...etc. will quite likely bump you up into higher classes (ex: SCCA street prep classses). And in these highter classes, you'd be competing with people who have done a lot more changes to their suspension, so most likely, you'd be at a disadvantage.

My biggest suggestion is this: if you are starting out autocrossing, LEAVE YOUR CAR BONE STOCK. Work on improving the driver, not the car. Then, once you have improved your driving ability (say 2-3 years down the road), you will be able to make the adjustments to your vehicle that suits your driving the best. (ex: some people like a stiffer rear, other's like it loose.) While most adjustments mentioned above should help in most cases, why bother with the settings until you can fully benefit from that setup? If you're just starting out, believe me, even in stock form, you're not using your car to it's full potential! Wait until you're able to push your car to it's limits before modifying it!

Just my $0.42
-Zoltan. (autox junkie, running a bone stock 944S2)
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1989 944S2
PCA NNJR
Click for more:

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[rscupper]

A small bit of advice. If you really want to see how you and your machine are performing, religiously maintain a log book. Start NOW with your baseline data - suspension settings, tire brand/type/compound, tire pressures, your hours of seat time. Always log your seat time and any changes made to your vehicle. Besides the technical gains, it's really fun looking back on where you've been and encouraging to see the progress you've made.

Try not to make major changes to more than one thing on your car at any time so you can recognize if that particular change made any difference, positive or negative. Seemingly minor changes such as tire pressures may be made often at one event so you might want a separate format for tracking that.

The best advice ... go to auto-x events, drive, and talk to as many people as you can. Especially those that go fast.

Oh, and have fun

[Randy W]

I can't give away the settings of my suspension guru, Greg Fordahl, but O toe for an autocrossing car is a pretty well known number. As noted, tires will make all the difference in what alignment settings you may choose. Good advice also from many here about weight balance - you will feel the difference, and the differences will get smaller.

I've been on vacation or I would have answered sooner. Good luck, and keep us posted of your progress!

Randy Wells

[tobluforu]

Car is done. Mechanic asked me a bunch of questions about how I drive the car, where i drive the car, how much I drive the car, what i want to do with it, etc.. Told him all info plus the fact that my car understeers. First thing he said was I should corner balence it-I knew this but with x-mas coming up, that was not going to happen. Then he took me for a ride in it and drove car hard trying to induce understeer and oversteer, which he did. It's fun having someone else drive your car to the limits who is not afraid. He put it on rack, checked height, checked pre-load.
Front toe: 0. Rear toe: 1\8th in. Front camber: -2.9. Rear: -2.6.
We then went for another ride and the car handles better than it ever has. Car is a little skittish in a straight line but, my understeer is now gone. His next comment after i was smiling was "wait till you corner balence it"

[SRT356/911]

Where are your swaybar settings? For good balance on that car I recommend foward of center at the rear and reward of center at the front for a start. Then you have to work at it by noting what the car is doing.
If it is pushing, move the rear forward. If it starts to oversteer, move the front rearward. You are looking for neutral balance. The corner balancing is very important though.
You can get close yourself by putting your weight in the front seat area. Use someone or 'stuff' to get your weight.
Undo the swaybar droplinks and set the car to the desired ride height. You need adjustable springplates for this. Measure to the lip of fender. It should be the same all of the way around.
Adjust swaybar drop links and reconnect.
Allowing the car to settle is very important. When you take the weight out of the front seat, the left side should come up about 1/8". Car will look 'leaning to one side' when it is sitting, but correct when you are driving it.
That should allow you to have fun till you get it corner balanced. Recommend Roger Kraus in Castro Valley.

[tobluforu]

Rear swaybar clamp is about 1 1\2" from end of bar . Front clamp is about an inch from end of bar. I tried all adjusments with the front bar to see if i could get rid of understeer. Found this to be the best setting(before alignment). That took me about 3 days. I then started on the rear bar and found after a couple of days that this setting was good enough. It's tough adjusting the bars with out a rack. So. I should stiffen the rear bar to induce more oversteer? I'll give it a shot.
I did exactley what you said when adj the height and pre-load. Took my weight set and added 200lbs to the seat and floor board.
Are you going to sears this weekend for the racers group tour. If so, I'll see you there.

[StuttgartDavid]

Thoughts on Caster and Toe:
1) Don't over-toe a race car.
Toe-in promotes stability, which is not necessarily good when the whole point in the first place is to get the damn thing to turn quickly! (Kind of like the intentional dynamic instability of a modern fly-by-wire fighter jet - an airframe that constantly wants to veer off-course but is held in check by the computer (think driver here) will naturally transition to a turning state more quickly than is possible with an inherently stable airframe, once you take out the constant corrections that keep you going straight in the first place).
An old San Diego PCA guru and former IMSA champion, Wayne Baker, used to set up autocross cars with slight TOE OUT a the front to promote turn in. I really liked it on my 914 - it was incredibly responsive for autocrossing, but it did hurt straight line stability on a big track like Willow Springs. However, as he said "Don't worry, you'll be paying attention! Besides, if you're driving in a strait line for more than 20% of the time on most big tracks, you aren't taking the right line to begin with."
Toe in at the rear is much more critical to stability - which is why it is important to keep the rear bushings in good shape to minimize toe change due to suspension play. Some brave souls go with zero or even positive toe at the rear for intentional dartiness in a dedicated autocross car, but I believe that is too risky for the street, much less a high speed track. Rapid steering response is one thing, squirreliness in response to every one of the numerous minor corrections required in a high speed sweeper is different!
2) Say yes to caster:
The nice thing about lots of caster is the self-centering effect on the steering wheel. This is very useful on an autocross course to begin with, because the car wants to help you transition to opposite lock for the next turn or for skid control. It also helps if, God forbid, you lose your grip on the wheel. You know just what the wheel is going to do - go back to center - so you can plan accordingly in your recovery efforts.
I have always run max possible caster on both my 914 and 911, for every type of track. I see no downside - anybody know otherwise?
Always remember - "it's not the equipment that counts, but how you use it!"

[SRT356/911]

A lot in the last one.
I agree with what David said for the most part. The car will be darty down the straight of a high spped track, but the turn in is great. Downside if you drive it on the street and have front toe out is SEVERE tire wear. Took a set of $200 tires each to the wearbars in 4K miles. Took out the toe out. Wear good. Driver needs to pay more attention.
I am grappling with 'equipment vs driver'. There is a point where one meets the other. There is no way that a 2.4S with all the suspension in the world can compete against a well set up 3.2 or larger engined car with all the tricks and goodies and weight saving stuff done to it and an experienced driver. Or for that matter with a well driven 996. What I am trying to say is there is a point where you squeeze everything you can from a certain car and there is no more.
Go to GGR/PCA web page and look at class JP at the various tracks and compare those times to the other classes and cars. TT series.
I have had relatively new students that have blown the doors off lower classed cars due to sheer HP and preparation and low weight and fair driving. Put them in an older car and the curve will be way steep and the times down.
I will be at the 'meet' in Fremont and then on to the event at the Racers Group. Am going to Castro Valley first to pick someone up and give them a lift to Sears.

[Don Wohlfarth]

2blu, how much ax experience?
Absolute best advice on this thread so far is to start a log and keep it up to date.
Your car sounds like it's set up fairly aggressive. You may want to keep a real close eye on tire wear. 2.9 on the front and 2.5 on the rear may be too much for the tires and won't allow a full foot print. Damn sure chew the inside tred on the street.
With the changes you've made you may want to find one of the better drivers at your next ax and have him drive your car a couple times to see how it handles.
If your car handles reasonably well the next step is to do nothing but learn to drive the car. Quit trying to improve the car, start trying to improve the driver.
Ax is one of the most intense 60 seconds you can spend in a car, at least by yourself.

[SRT356/911]

2blu
I agree with Don 100%. The car is there for now. It will grow with you as you have more seat time.