Up here in the frozen north, its getting, well, closer to frozen, which means wrench time. Now that we have a "motorsports" forum, I was wondering, what allignment do the rest of the auto crossing 914's use, why, and how does it work?

Not like it matters to this thread alot, but got the rears pulled to clear the 7" keizers and 205 50 710's, and found some good values for wot throttle response across the rev range for the SDS, and had a total blast at our last event of the season yesterday...

Well there was (or is) a wise old man that told me how to set up my car to go fast in tight Autocross courses.
Pretty much worked exactly like he said.

1/8" total toe out front
1/16 total toe in rear
as much caster as you can get keeping them equal.
Camber is tire dependant. Hoosier A3S05 liked -2 degrees. Tune with pyrometer.

Attitude of car or "rake" 1/4 lower by the front lift donuts.

What he said.. except for this:



This is driver dependant. Some people need -1.5 and some need -4. Yes some tires work better with more or less but it all comes down to how hard the owner of said tires pushes them.

Carrera Cup cars show up over here after being driven by a pro driver with -5.0-5.5. Very FEW people in the states can drive that car on our tracks.

1/8 toe out in the front works if you have new plastic bushings or bronze.. or roller.. the only time I use zero is if the stock bushings are in place. It will toe out this much on the stock worn out rubber crap..LOL

B

(toe out in front - makes it "twitchier" no?
that makes it great for AX

i street my car too... but my specs
are 1 1/8 or 1/16 toe in front (cant remember)
1/16 toe in rear
-1.6 Camber front
-2.0 - 2.1 camber rear
max caster up front (being equal)

a little toe in upfront makes it a bit more stable in a straight line (good on the street)

oh yeah.. and my AO32R apparently like lots of camber

Correct on the toe out. Great for turn in, not so good on the street. The car will follow EVERY groove it encounters.

I have found I dont need to run toe in in the front with 914's. They always turn in well if the cross weights are good. I also dont like to scrub all 4 tires as the car goes straight. The 4cyl cars have a hard enough time dragging the two rears with toe in!!


B

I agree on the toe in and toe out numbers most folks have mentioned.

Keep in mind that what's good for dodging cones is not always good for the track. Brad's comment about draggin tires is valid on the big track, where every fraction of a pony is valuable. Reduce the rolling resisitance as much as you reasonably can without sacrificing lateral grip.

I run around 1/16" toe out in front and around 1/16" toe in at the rear. As much caster as I can while keeping the camber equal. I don't remember the camber numbers though, something like -1.25 F, -1.5 R.

-Josh2

all those toe numbers sound like good AX baselines. camber is something that I never had enough of in the front, but often had a bit too much of in the rear. At -3.5 front, I was still looking at decambered balljoints.

It's hard to get too much caster on a stock 914.

all of this is dependent on your setup and driving style. experiment often.

Nathan's post proves my theory.

Everyones needs are different. What works for one person may not work for another.

Take these numbers and "start" somewhere. Adjust accordingly.

Running on the same Hoosiers Nathan ran on.. I use -3.0 to -3.25 in the front. he may push the front tires harder than I do.

I cannot emphasize how important individual alignments are. I learned this ages and ages ago with Pro drivers. I got tired of "generic" alignment shops throwing whatever the "last guy" had on the car. I was performing "out of the box" alignments at age 18 when I had access to a the "latest" Bear ACE equipment (Sears/Park Mall/Arlington TX..lol)


B

Yup camber is driver dependant. rim size also affect the profile of the tire.
225/45-15 A3S05 on an 8 inch rim makes for pretty square sidewall 35 PSI makes for great grip and very quick response.

Driving style is a biggy. I am more twitchy and prefer to slide the car a bit to change direction rather than turn and "hang on" the turn leaning on the tire that is just scrubbing speed.
Hey it's what I have been taught and it is pretty competative in a fairly big fish pond.
Yes Aaron toe out makes the car a handfull on the road. I usually drive 80-90 MPH going home from and event with both hands on the wheel 100% concentration.

PS. now I run bias ply slicks and this is a totally different animal.

Golly, must be even slower than I thought....I only run -.5 camber at both ends.
You must be right again, Brad

has anyone done anything with redesigning the front end to create significant positive ackerman in an AX-914? if you're running super wide/sticky tires (enough to get into scrub radius issues), i think it would be a major benefit. you could run the static toe straight up and get good positive ackerman to swing the car around the tight stuff.

(maybe i'm thinking too much about karts here....)

Yes, Porsche did....by divorcing the strut tube from the ball joint & spindle.
They're still all attached (thank God ) but the strut has been moved inboard thus allowing more backspace on the wheel to get rid of scrub radius problems.

The 914 setup is hopeless, me thinks. Adapting a post 89 strut setup to a 914 A arm
would be a possibility....and prolly the best bet. More backspace could then lead to a clearance issue to the inner fender at full lock. I haven't looked into the dimensional aspects of this. Got a late model strut assy laying around?

What is anyones experience with rear camber? We seem to agree that front camber is driver specific, and that with tire "A" a different drivers might end up being faster with different settings. How about camber in the rear? My mind goes both ways on this, one thought is to match maximum front camber to the rear, perhaps to try to make both ends handle the same, this will maximse cornering grip. The other side of the coin is that with the limited power of our 4 cyl cars, keep the back tire flat on the ground, but as much power down as is availible.

Any thoughts on rear camber?

i was always happy with -2 to -2.5 in the rear...

On my mild little put put I have -2.5 front and -2.75 rear. Works nicely

Well, Brad agrees with Brad
The actual fact is that some tires like more camber than others....front & rear may vary and someone like Nate will like more camber as he liked to run radically low pressures. Course he chewed up tires rather quickly, right Nate?
As for Euro cup cars....maybe. Also maybe they run on glass smooth F1 tracks & maybeuse stiffer springs & lower ride heights that can't be used on an American track.
They also run class spec tires and can fool with pressures....lota maybes.

I run Hoosier bias ply slicks and they don't like near the camber that radial R-spec tires like.
Like Joe said, tire temps across the face tell the tale. Tread wear (or wear dots) also
are a clue to both camber & pressures.

.

righto. but i had similar experiences with other tires at other pressures. tires are a happy consumable, no biggie there.

Cough ...mild ....This link is for you Dan : Tribute to Dan's "put put"


Some of us with practical street cars who drive on the worst roads in the US could only get about -2 ...I tried going lower and kept bottoming out on the bumpy section of mountain road to my house.

That is tooooo funny Grant... Thanks for the sentiment.
Is it really that low? YES

I've been waiting for someone to use that word, "ackerman". Carroll Smith wrote a couple books back in the 80's on tuning and building race cars. At first he recommended zero ackerman. Then a couple books later he changed his mind and was recommending extra ackerman. I've spent the last 20 years or so playing with sailboats and have just got back into cars the last couple years. I was expecting everyone to be doing this and more. Seems like extra ackerman gives you the best of both worlds: Straight line speed and stability and then improved turn-in and possibly more cornering power. It's on my list of things to do. It's just way down there right now. I've got to get the thing painted and an engine back together over the winter.


Nathan: how's the karting going??

JP,

I said:

Does this not "agree" with what you said:

??

You also said Nate liked to run low pressures. I didnt/dont and still needed -3.0-3.25 on the same tire on the same width rim. I ran em 40 hot for AutoX.



B

Mine are -2 front -2.5 rear if I recall correctly. I have to look up my other settings because I don't like my turn in effort. It "feels" too heavy. My car is not as low as Dan. I have a perfect corner balance. After the last event of the year in November I will have it redone. Ron Kain at IPB does the set up for me. As far as tire pressure is concerned, I think it is as much a suspension setting as the others and tire brand dependent. I like more, but not as much as Brad. Maybe 36 hot.

On a slight hijack, is that a smile on Brad's face in the avatar? I don't think Brad has smiled in a couple of years... Life must be better.

check your toe. if at 0 toe it's still too heavy, you may consider taking some out some caster.

Took me awhile to figure out how to get more caster in the Boxster. It required pushing out a bushing on the lower control arm and re-clocking it so another control arm that comes into it, mounts and pushes the arm farther forward.

Net = more caster by pushing the bottom of the control arm forward.

GT3 arms have two bolt provisions for more caster. Both arms can have the bushing pushed out and re-clocked for more or less caster.


Brad smiling.. YES. Real job that challenges me daily and the bills are getting paid off as fast as I can. I found someone who is goofy like me and sarcastic like me. She has a type A personality that fits very well with me. She will be driving soon!! 5'10 130lb brown eyed blonde!!


B

Rob,

please tell Ron Kain I said hello. He is one of the fastest 914 drivers in NorCal. I missed a call from him a few weeks back and havent returned it. Ron and I used to be accused of being "brothers" when we ran track events up north. He is a stand up guy who does great work. I wish I could have seen his new building before I moved south.


B

he looks kinda goofy to me, actually.















can ya feel the love??

Sure! I can feel the love from my redneck brother from another mother

Let me know when you come down to run Buttonwillow kart track. I'll show up and help out.



B

Brad,
Will do. I see him probably twice a week or so. You two actually do sort of look alike. I plan on luring him out to an autocross this year if I can get him away from the wife for a day, maybe she would come too?
He turned me on to my new (old) taildragger. '84 Carrera with 55K miles from two obsessive PO's Every record and even a Rubbermaid tub full of parts that had been taken off and replaced. I guess they wanted me to have the originals? Factory sport wheel, Factory manuals, original suspension parts replaced with Turbo... Body 9.5 Interior 9.5 Mechanical 9.5. Yum yum... put 500 miles on her last weekend. What a ride.

He had his daughter in Karts for awhile, is she still doing that? Hard to balance a family and racing..and business.. and ecomm business... he had a lot going. Worse than me!!

The Carrera sounds nice! I'll be up soon for events.



B

Brad,
I spoke with Ron today. He was totally charged that I had spoken to you. He wants you to call or email... Let me know if you need digits or an email address. Your "brother" misses you. He has a ride in my car at any autocross event he wants to drive in. He just has no time.
Rob

Thanks Rob!

Ron and I have always gotten along very well. I'll give him a call before the weekend. I need to find out what he is up too.


B