Printable Version of Topic

Posted by: J P Stein Mar 30 2003, 08:22 AM

Clear skies, a running car and AUTOCROSS !!

I'm going to go play, now.

Posted by: Jeroen Mar 30 2003, 08:51 AM

cool!!!
let us know how things went

cheers,

Jeroen

Posted by: Sammy Mar 30 2003, 04:21 PM

Where the hell is JP with the details?
They only run three lap us there, how long could it take? :-)

Posted by: ChrisReale Mar 30 2003, 04:38 PM

Im a little bummed I bitched out and didnt make the drive south. Sounds like fun.

Posted by: J P Stein Mar 30 2003, 05:29 PM

Well, the car is faster.

My co driver was a tenth off the TTOD Z06.
I was ...er...farther back....a life time of 2.5 sec. The ought6 is normally the fastest door slammer at the local SCCA events.

There's more in the car even with the old tires.
It was LOOSE. I have too much camber in the rear.
The inside of the rears was 20 deg hotter than the outside, the fronts were 20 deg cooler than the rears, but fairly even across. Gotta back off the front bar, me thinks.

Someone talk to me about tire pressures. On my 4th run (6 passes on the car) the car was really squirrely. After that run, the pressure had risen 6 psi at the rear. I dropped the pressure back to 28 at the rear and that seemed to help.

Feel free to offer advise, please.

How low can one go on Kumhos?.. and
Does dropping the pressure provide more grip or am I just imagining it.

Everyone got 5 passes and should have gotten more (we did get fun runs, tho). I took nearly an hour to break into the trailer
that holds all the goodies. Someone changed the lock.......keerist.

Nuthin' broke, so it was a good test. SCCA in 2 weeks. We'll be ready.

BTW, Boring Bruce was there with his digi camera, so I might have some pics to bore you all with....film at eleven.

Posted by: Bruce Allert Mar 30 2003, 08:16 PM

I'm downloading them thar pics now
I rode with JP on his first run & added 3 seconds to it. This was my first time at AX and (Lordy) I didn't know what to expect. (Jim Chambers said I'd get throw'n around alot) I din't fully understand by what alot was I found out! Geeze! JPs car is FAST... I couldn't recover fast enough from one turn before we were into another... head bumping against the back & the top.... shoulders hit'n the roll bar... and then, of all things, my camera went shoot'n out from betwix'd mah legs and under JPs throttle foot We're still fly'n around the corner & I'm hear'n JP "Grab the damn thang"!!
So, there ya have it... The whole extra 3 second story
Oh, and lastly.... I'm hooked. I'll be driv'n mine next time. Pics comin' yer way JP.
Thanks for the great time
bruce

Posted by: Porsche Rescue Mar 30 2003, 10:14 PM

I was there too but don't tell anybody. I'm hoping I beat the guy driving the full size Mercury 4 door (it will be close). Finished 5 seconds behind a stock 1.7 in my 2.5 six. 5 runs--spun out on #1 and screwed up the slalom after that. Hit a cone on #2, spun out again on #4. Two clean runs--both real slow! I added a race seat and 5 point harness since last year and it really helps to be held still in the car. I think my spins were partly caused by the fact that, since I wasn't being flung around as much, the car didn't feel out of control until it was! As JP said, "practice, practice, practice,......".

Posted by: Bruce Allert Mar 30 2003, 10:26 PM

Jim, send me your email address and I'll send your pics to ya.
bruce
bcaphoto at attbi dot com

Posted by: J P Stein Mar 30 2003, 11:09 PM

Bruce took some great shots....after retrieving his camera. Here's one.

Posted by: Brad Roberts Mar 30 2003, 11:21 PM

GREAT shot.

I love when people enjoy there 914 on the edge....

I'll revisit your questions above later JP.

Those Kuhmo's roll way over....


B

Posted by: rick 918-S Mar 30 2003, 11:23 PM

OMG! That's coool. I love when they cock one at the hydrant!

Posted by: Rob Ways Mar 30 2003, 11:28 PM

Nice pict. Looks like a good time!

Posted by: J P Stein Mar 30 2003, 11:34 PM

Bruce was nice enuff not to get any of my more lurid
slides....he,he. here's another

Posted by: Brad Roberts Mar 30 2003, 11:53 PM

Way too much body roll.

Give the suspension low down...

I know the front bar.

It appears you need to run some stiffer rear springs.

B

Posted by: Bruce Allert Mar 31 2003, 12:00 AM

Geeze man! any stiffer springs & JP will need to install a shock seat! I'm sure I'm gonna be bruised in the morning but it sure was fun!
bruce

Posted by: Brad Roberts Mar 31 2003, 12:05 AM

Bruce,


I'm actually semi pissed at JP for allowing you to bring a flying object into the car. I have almost killed people on the race track that where hand holding a video camera and trying to drive while filming.

I'm done now. Glad you had fun. 90% of 914 owners have NO idea what their car is capable of.


B

Posted by: J P Stein Mar 31 2003, 12:29 AM

21 mm front t bars, 180 lb rear springs, 2lb digital camera... OOPS.....what can I tell ya, I screwed up.
I WAS almost kilt....or worse, slow.


I'm reluctant to do stiffer t bars at the front.
The stiffer rears will make the car looser, right?
The second pic is a little deceptive. That corner is off camber.

Posted by: Brad Roberts Mar 31 2003, 12:34 AM

Where did you have the bar set ??

Your forgiven (dad) next time I'm up there... I'll slap the person who was running grid.


B

Posted by: J P Stein Mar 31 2003, 12:39 AM

ERRR....I was running the grid. he,he

I set the bar just a little passed mid point towards the bar....for lack of a better idea.....now I have a better idea

Posted by: Brad Roberts Mar 31 2003, 12:48 AM

You have to tighten the front to make the rear stick or transfer weight back there (drop the rear end 1/4 inch)

Did you have the car corner weighted ??

Last weekend when Jeroen and I ran the Orange 3.0 six... I had the 31mm bar set on full SOFT and the back end was still GLUED. I felt the front end was understeering like a pig for my liking. I had 4 options:

1. raise the rear and dump weight forward (easy to do with threaded adjusters)
2. raise the rear tire pressure
3. lower the front tire pressure
4. blow it off because I dont run AutoX in zone7 for points.

I left to get food and Jeroen dropped the front tire pressure. This helped when I made another run. The car is on narrow Hoosiers with 250 rear springs and 22 front Torsion bars.

B

Posted by: Dave Cawdrey Mar 31 2003, 12:49 AM

DANG !! My new desktop pic Guess I missed out, too

Posted by: J P Stein Mar 31 2003, 01:25 AM

Korijo it was sunny & 71 deg....you screwed up

Bad:

No corner balance.
By "tighten" the front, do you mean increase the roll stiffness? That is not "conventional wisdom", but if you say so......There are 2 SAAC AXs (sat & sun) in a couple of weeks. I can do some.......tuning.

The front is really stuck nicely. It's no longer skittering all over the place at inopertune moments. Muellers bearings were worth every penny and bead of sweat. My thinking on big front tires is on hold. Now, if I just can make the back end to get with the program.

I asked my co-driver what he thought. Old Chuck says " I dunno, I just drive".... WTF, he does it very well.

Posted by: Brad Roberts Mar 31 2003, 01:31 AM

Tighten the front:

Stiffen the bar or:
install larger torsion bars

Dont use so much gas pedal. You may be inducing the oversteer.

Can you get me some fenderwell measurements ?? SHIT. You tweaked your fenderwells. I cant give you measurements that will get the car close to balanced without scales.

Do you have the threaded collars on the rear ?? or just the stock Bilstein adjustable "clip" ??

B

Posted by: Brad Roberts Mar 31 2003, 01:33 AM

Oh..

conventional wisdom is:

Tighten the opposite end that is loose.

If the rear tires are hotter than the front... your sliding the ass end around. Tighten the front or transfer weight back there.

B

Posted by: J P Stein Mar 31 2003, 01:46 AM

Just the Bilstein "clips".

The car is dead nuts even ....ride height at all 4 doughnuts to the ground ....4.5 inches...not very precise, but it's all we gots.

As to the sway bar. I think we talked about this when you were up here (you, me and DD). What you say is the opposite of CW and DD said so....I just listened

No shit the ass is sliding around. I never totaly lost it, but came damn close to one of my pattented tank slappers

Posted by: Brad Roberts Mar 31 2003, 02:06 AM

Are you on the lowest clip setting for the rear Bilsteins ??

Who was CW ?? Chuxster ??

I'll let you know the next time DaveD gets a 914 over 40mph.. LOL


B

Posted by: J P Stein Mar 31 2003, 03:13 AM

Various things I have read over the years (including sway bar instructions) say to soften the front sway bar to reduce oversteer. This is what I mean by Conventional Wisdom...or raise the front spring rate.

Since we don't run the rear sway bar on these cars, I wonder what is right.

My experience tells me that higher rate springs in the rear make the car loose (oversteer). My experience with the old set up showed that softening the front sway bar decreased oversteer.

I really don't want to add more body roll. I'm hoping that dicking around with tire pressures will get me where I wanna go. I do like it to oversteer a bit and I may not be that far off......

I'm on one clip from the bottom on the rear shox.

Posted by: Brad Roberts Mar 31 2003, 03:30 AM

Your contradicting yourself:

"soften the front sway bar "

"or raise the front spring rate" to reduce oversteer.

Stiffening the front bar gives you the same response as adding bigger torsion bars. Its just a very fine control over the "amount" you ad versus the big jump a larger torsion bar has. Sway bars have a range that you can ad. Something like this: Set on full soft it has a effective range of: 0-150lbs. Full stiff might be: 200-350lbs.

Just FYI: the person at the AutoX who told me to do the 4 things... is a Indy Car team engineer. I should have jumped when he told me what to do... but again it wasnt for end of year points.

Oh.. most the instructions I read are for 911's.

B

Posted by: J P Stein Mar 31 2003, 03:49 AM

That's you're not "your", damnit.

To keep this simple, I'll do what you say....and report back, of course.

Gotta think on that sway bar as springs thing a bit, but now it's time to shut off my brain.

It was a gud day tho.

Posted by: Brad Roberts Mar 31 2003, 03:52 AM

Sounds like a great day. You have nothing to lose by setting the bar on full stiff and driving the car around. Then set it on full soft and drive the car around. Should only take about 15 minutes to adjust the bar.

B

Posted by: Racer Chris Mar 31 2003, 06:09 AM

We had a significant snowfall last night. F you all in sunny CA.



JP, put a ty-wrap on all four of your shock absorber pistons to check if you are bottoming them out.

Posted by: Jeroen Mar 31 2003, 07:08 AM

Hey JP,

The end that you tighten (either by swaybar or springrate) is the end that's gonna loose grip.
The end that you soften is the end that gets more grip...
(so if you want more grip in the rear, either tighten the front, or loosen the rear. And vice versa)

Since you got the rear tire temps way hotter on the inside, I'd suggest you lower the rear pressure first

One of the pics shows you lifting the inner front wheel, but that you're still having quite a bit of bodyroll at the same time.
That would make me think you have too much swaybar for the t-bars you're running (= get bigger t-bars in front)

I'll post some pics on of the orange car we took out last weekend when I get back home tonight.
It had nearly no body roll (22mm front t's and 250 rear springs and a big 31mm front swaybar set to full soft)

I was pretty amazed how "comfy" the orange car still was. It was definatly not oversprung or bouncing all over the place.

Where did you suffer from oversteer? On corner entry or corner exit?

cheers,

Jeroen

Posted by: Bruce Allert Mar 31 2003, 08:43 AM

Brad, you have good reason to be and so does JP. THAT will never happen again. The energy & force created by the constant slingshot effect when reversing direction puts so much G force on everything not strapped in including the light camers.

Sorry JP for mentioning it, din't wanna get ya slapped I'll take it fer ya
bruce

Posted by: Sammy Mar 31 2003, 09:33 AM

I think we are missing the point to this thread big time.
Most of the posts so far have been about dialing in the suspension on ULF. Maybe if he gets it dialed in perfect he might pick up a few tenths, I want him to go after the 2 1/2 seconds left in the car as it sits.

As one who doesn't have a clue about finese on the track, I think we should be trying to figure out how that other guy got within 1/10 of TTOD with the same set up.

I've read the books, watched others, and still don't know why some drivers are faster than me, JP's car is obviously faster than he is (and way way faster than I would be in it) so I be scratchin my haid wondering what the other guy was doing that we aint.
I don't want ot hear slow down to go fast, when I do that all I do is slow down.

Is it timing? is it too much throttle or aggressiveness?
This AX stuff is frustrating. It seems like the action comes so fast that i'm usually a tiny bit late setting up for the next corner, could that be part of it? I also slide my car more than most, maybe I need to be less aggressive and try not to slide at all, JP could that apply to your style also?

Maybe i need to ride with someone who is faster than me, but I'm scared to let someone else drive my car at the limit. JP, have yo ridden in your car with that hot shot driver? What does he do different?

Posted by: Porsche Rescue Mar 31 2003, 09:57 AM

I'm with Sammy. I'm not even in the same ballpark as JP (not even same league) but I too am frustrated. I know I did poorly but don't have much of an idea about how to get better. Probably time to read the books I have gathering dust on the shelf. Reading this thread helps too. The rear of my car was real loose. Turns out I had 32 lbs cold in rear tires, 28 front. If I understand correctly, probably should have been even or possibly reversed. I have stock (non-adjustable) front bar and 180 lb rear springs. It's real hard to anticipate the course when you're looking at it backwards!

Posted by: Part Pricer Mar 31 2003, 10:25 AM

Boy, this discussion should take an interesting turn.

It is really difficult to determine what your tire pressures should be based upon a limited amount of knowledge. More info is needed (tires, etc.) However, to me, your pressures seem low for an autocross. Remember that due to the limited amount of time, tire pressures will normally only increase by as much as 4 lbs. during an autocross.

For my car, with 195/60/15 street tires, I normally start with 40 lbs. hot pressure all around and adjust from there.

Posted by: Porsche Rescue Mar 31 2003, 10:38 AM

Paul, I have 205/45x16 on 7" Fuchs. Kuhmo Ecsta street tires.

Posted by: J P Stein Mar 31 2003, 11:16 AM

I agree with Sammy 100 %, but I'm working on 2 things at once. I want Chuck to beat everybody and I wanna learn to drive nearly as well.

I don't get a chance to really watch what he does, nor do I want to interupt his concentration by riding along....tho I should prolly do both.

I KNOW I'm sloppier than him. Tho he hit some cones, I never saw him get badly out of shape...I certainly did It IS frustrating....more butt time, I guess.

Maybe I have to face the fact that I'm a better crewchief than driver....but not yet.

Posted by: J P Stein Mar 31 2003, 11:21 AM

A couple more pics. Say hello to Chuck.

Posted by: J P Stein Mar 31 2003, 11:26 AM

And "the slow guy"

Posted by: J P Stein Mar 31 2003, 11:36 AM

The new trick magnetic number plates were prolly worth a second or so.

Posted by: Dave_Darling Mar 31 2003, 12:47 PM

OK, a few points here....

What B said in this thread is Conventional Wisdom. Make the front suspension stiffer, and the rear of the car will stick better. I recall B saying the opposite, back at the meet at your place. Could be the beer gettin' in the way of my memory--or of my understanding of the discussion up there. As I recall, we did make a bit of a dent in the supply in the workshop that day...


Now that one is easy to fix! At the driver's meeting, speak up and ask for an instructor. Have the instructor ride with you, and try to pay attention to what he or she is saying. Do this at every autoX for a year--you may be amazed at how much your times improve!! Also, after you've autoXed a handful of times, you will find that your brain actually starts working (a little bit, in my case) again through that adrenaline haze. At first, it is all just happening very much "NOW NOW NOW NOW NOW" and there's no time to think at all--but after a while, you can actually remember where you want to put the car, and how to get it there.


Sammy, one of the most important autoX skills (after throttle steering) is looking ahead. Always know where your next turn-in point, apex, or track-out point is. Look at it. Forget the apex just in front of you--you've already set the car up for it and you're gonna get it or you're not. Where's the track-out? Look at the thing! Once you start looking ahead--really looking ahead--you will not wind up "behind the car" so much.

Anecdote--I was a corner worker out in a long 180-degree sweeper. Tobias Olney came roaring through in his 914-6. He turned the car in, and I saw that he was looking all the way around the corner at the apex. Tobias is a credible TToD threat. (OK, part of it is the car. But he can use that car!) This is not a coincidence!

--DD

Posted by: J P Stein Mar 31 2003, 01:25 PM

I remember the disagreement, but as to who said what, I doan remember fer sure.....what I rememeber is not what you thought you said....got it?

I'm gonna stiffen fuckin' the front sway bar and find a fuckin' parking lot to terrorize, then I'll know that what you thought what you said was not what you meant.....that should clarify things

Posted by: ChrisReale Mar 31 2003, 01:40 PM

Let me know when you find the lot, Ill bring some pop and hot dogs, and we'll have a party.

The last AX, I had my front bar set to almost full stiff, and I was understeering slightly. I have street tires and stock torsion bars, so that prolly has something to do with it.

Posted by: Bruce Allert Mar 31 2003, 01:53 PM

Check this guy out. He's up on 2 wheels!!! Must be a stunt driver!!!
bruce

Posted by: J P Stein Mar 31 2003, 02:32 PM

There's a pic on the PP 911 list that I really wanna steal....anybody know how I do this?

Posted by: silver six Mar 31 2003, 02:42 PM

jp,

Sure. Just right-click on the photo and select "save picture as . . ." and then save the picture on your desktop or some other place where you know where to find it. Make sure it has the proper suffix (e.g., if its a jpeg call it 911photo.jpg, if it's a gif call it 911 photo.gif).

douglas

Posted by: J P Stein Mar 31 2003, 03:18 PM

Thanx, Douglas. I was screwing up the naming of the file. Here's the pic. Randy Wells at the Parade bring the inside wheel to new heights......prolly needs stiffer springs or sumthin'.

Posted by: TimT Mar 31 2003, 03:34 PM

Thats the old 911 "salute" I rmember watching a old 911 at Lime Rock going through big bend with a wheel about 1' off the ground. Funny thing is the guy was posting some respectable times ( for being on 3 wheels) On a 911 thats from to little rear spring and to much front anti roll bar

Posted by: Don Wohlfarth Mar 31 2003, 03:39 PM

Set the car up with torsion bars and springs, fine tune with sway bar.
JP, tire pressures too low. Taking tire temps at ax is almost waste of time as you'll never get them up to temp. Maybe with 2 drivers each getting 5-6 runs, back to back.
Car has too much body roll, needs heavier front torsion bar. As car sits stiffen front bar, keep making stiff until front plows, then back it off. When car is loose (oversteer) decrease front tire pressure, increase rear pressure.
Walk the course then walk it again. Sit in car with eyes closed and drive the course. You cannot think on course, you have to know what turns follow what turns. DD says ride with instructor. Hardest thing to learn is to be smooth and look ahead. Do not toss car around.
When rear is sliding by spinning tires you'll lose 1/2-1 second, maybe longer.
You must stay aggressive and attack. You are either accelerating or braking (in some form). If you are coasting because of indecision on increasing or decreasing speed you are losing time.
The fastest drivers can no more tell you how to go fast than I can. It's a seat of the pants feeling that comes from seat time, seat time, seat time.

Posted by: Brad Roberts Mar 31 2003, 04:46 PM

I need JP to take tire temps. I dont care what the number is. I need to know if the car has too much neg camber or not enough. He runs in the same place 90% of the time...so getting some numbers wont kill him. I agree they wont come up to temp. I just need the difference across the tire.

Oh.. I try to keep all 4 tires on the ground. 3 dont have the same traction as 4.

B

Posted by: Brad Roberts Mar 31 2003, 04:56 PM

Relating back to Sammy's post:

We the know the other guy is faster in JP's car. This guy (Chuck) will drive around any problem the car may have. If we help JP get the car a little more AX neutral..this guy will take top time of day. I have lots of "old guy" customers who will drive the wheels off of everything no matter how crappy the setup.... THEN help them out with the car and they flat out fly.

When Chuck takes TToD (not if) JP will know in the back of his head that the car is "right". He can then focus on driving and not F-ing with the car. Chuck probably doesnt even know what the car is doing... he is just doing whatever it takes to compensate.

JP.. its your car. Ride with Chuck on one session. Dont think about what the car is doing... focus on what Chuck is doing.

B

Posted by: Porsche Rescue Mar 31 2003, 06:09 PM

Now back to the simple stuff: Isn't Don's advice (loose car, inflate rear tires) just the opposite of what Brad and DD said earlier in the thread? I'm pretty old and easily confused! Which is it? I won't change springs, t-bars or front sway bar soon. My car oversteers. If I can help the problem a bit by playing with tire pressures, I want to do that.

Posted by: ChrisReale Mar 31 2003, 06:23 PM

Jim, I had the same set up you have, 180# rears and stock sized front sway bar. My car over steered like crazy. I recently put a 22mm bar in and it is like night and day. I guess Ia mtrying to say that tire pressure is very important, but I doubt that it will have a massive effect while you car is un-even as it is.

Posted by: Brad Roberts Mar 31 2003, 06:25 PM

Jim,

Don is correct. You can dial in some understeer or dial out some oversteer by playing with the tire pressures. Basically you are balancing the car with a different method by raising and lowering the tire pressures. DD and I suggested making a bar adjustment. Both methods are correct. One takes more work than the other. Sometimes, you cant do enough with the tire pressures and a bar/spring adjustment has to be made.

I want JP to get the car corner weighted.

B

Posted by: Brad Roberts Mar 31 2003, 06:36 PM

Jim,

I need to go over what Don said: "When car is loose (oversteer) decrease front tire pressure, increase rear pressure"

This is counter what I normally do. If the car is loose I need more weight back there. To get more weight back there I would raise the front pressures or drop the rears. Don could be a 90 time SCCA AutoX winner.. I have no idea. But this goes against what I do.

Jeroen and I had a car that easily understeer'd. Jeroen dropped the front tire pressures. We could have made a even bigger change by pumping up the rears. This suggestion came from my Indy car guy who just bareley missed TTOD on the first and second day of the autoX. I told him I was going to raise the rear of car he said pump up the rears or drop the fronts.

B

Posted by: Dave_Darling Mar 31 2003, 06:38 PM

Like B said, either may work.

The interesting thing here--tires have a range of pressure where they stick the best. This range is different from tire model to tire model. Some tires (notably the very sticky "competition" tires) work best when they have relatively low pressures, like in the 20s. Other tires, such as many or most "normal" street-type tires, grip best with pressures around 40 PSI or above! Going to higher pressure can lead to a loss of grip, and going to a lower pressure can lead to a loss of grip. Depends on where you are relative to where the tire works best.

This is a long way of saying that raising the pressure in the rear tires will often take out some oversteer, but sometimes it can actually add more! It depends on the exact tire.

--DD

Posted by: r_towle Mar 31 2003, 06:41 PM

I would vote to lower the rear suspension a little and have it corner balances...

It is leaning alot more than mine
23 mm front bars
180 lbs rears
front tires used to leave the ground when the front sway bar was to stiff, I softened it up and as Brad says, the rear sticks better...I actually spun for the first time with the stiffer front sway bar setting, but I was learning all about sway bars that day...

Mine is now neutral with no pre-load, and the back sticks like glue.

Rich

Posted by: Mike T Mar 31 2003, 06:53 PM

Yes do that. I fought a random oversteer/understeer problem for 1/2 a season back when I first started autocrossing my 914. I finally discovered it had been riding on the front bumpstops. I had lowered the car before the first event and neglected to check for travel.


Mike T

Posted by: Mike T Mar 31 2003, 07:07 PM

This is the key to fast AX times. Seat time. Set your car up, leave it that way and drive it at as many events as you can.

Also smoothness is key to fast times. Look ahead on course, set yourself up for the next pin or gate. If you can't remember the course, walk it more times. draw your own map if you have to.

If the whole thing is just too overwhelming find a part of the course that you feel you are weak on and concentrate on just getting that right.

Ask questions of the fast guys, watch their runs, car placement etc. Pretty soon those 2.5 seconds will melt away.

Mike T

Posted by: Racer Chris Mar 31 2003, 07:51 PM

I have a few suggestions about how to succeed at autocrossing.

1) Don't fuck with the car at the event. Learn to drive what you have, and work around the shortcomings. When you are concerned about what needs to be changed you aren't concerned enough with your driving. Obviously the problem is not the car if someone else can get in and beat you by 2 seconds. The most you should change at the AX is the tire pressures, but definitely not after only one run.

2) Use the first run for familiarization, not for time. If you try too hard you will lock up the brakes by going in too deep, and lose track of where the course goes. Figure out where the most time is to be gained, where the longest fastest parts are, and plan to maximize them. Most importantly you need to memorize the course without mistakes during the first run. If you were paying attention during your walk throughs (3 or more) then the first run should go smoothly. Also, the first two runs are to heat up the tires to operating temps, not to set FTD. During the second run you can begin to test the limits, but don't go for broke yet.

3) Don't use third gear unless the course is real fast. Time lost on the rev limiter will be made up by not shifting up and down. Make a couple of good runs, then try a different combination to see if something can be gained.

4) Don't try to corner on the limits until you have the course nailed. It's much more important to be able to go fast on the straights, which requires full control at corner exit.

5) Sometimes going wide to enter or exit a corner takes longer because of the greater distance travelled. Using all the road only works in the fastest sections. Make sure you can hit the apex cone with the tires, but don't.

6) Make sure you can apply all the power without wheel spin when entering a long straight. Give up something on the entry if necessary in order to straighten out the wheels early at the exit.

7) 914s can make up a lot of time in a slalom if you get the timing right. You want to already be pointed toward the next turn in point as you go by the previous cone. If you are still turning as you go by the cone, you are too late, and will have to turn more, which is slower.

I'm sure there is more. I'll think about it some.

As far a setting up the suspension, the 914 is pretty well balanced from the start. If only 3 tires are touching the ground you are clearly giving up some cornering traction. Don't compare it to a 911 on 3 wheels. I agree with whoever said to increase the front torsion bars. Then you can rebalance the car with the sway bar. With the way your car appears in the pictures, if you are getting oversteer it is either from trailing throttle or excessive throttle, not balance.

Posted by: ChrisReale Apr 1 2003, 01:02 AM

So...JP...if ya wanna get rid of those 21mm torsion bars, let me know......

Posted by: J P Stein Apr 1 2003, 04:38 AM

AXers around here have been gunning for Mr. Kotzian
ever since he got that '06 workin'. He had an off day at Topeka last year and finished 12th (IIRC) in SS. I went back and looked at 2 years of local SCCA results. Nobody in any Porsche has come within 1.5 sec of him in that time period (weather being equal) Maybe he was having an off day, but I don't think so. Another of his Corvette buddies was there keeping him honest. It was not a horsepower course, tho.


So, OK, I asked for advice.
Brad hit the nail on the head. Chuck drives thru difficulties that leave me lost.....maybe that's why I asked him to share the car ..and I was lookin' to get the car balanced a bit better...but

When any 914 is running equal with a FAST Z06 it ain't that far off.

He has 385 hp, monster Hoosiers, ABS and years of experience. ulf has 800 lbs less weight, season old Kumhos, a home builtonthecheep motor, a WAG at the suspension settings, and that's about it....it's really kinda funny.

I will take some selected advice and try it....then maybe, try some more.
As for my driving, I'll go for a ride or 2 with Chuck, but not take a camera.

Don't hold your breath on them t-bars, Chris.

Posted by: Jeroen Apr 1 2003, 04:52 AM

General concensus (wow fancy word!)...

The end that you tighten is the end that looses grip (and the other end will get more) and vice versa.

Judging from JP's report and the pics, my gut feeling says the front bar is too tight (even though that contradicts the above).
Why? Because it lifts the inner front wheel... (which makes me guess that the car understeers as well).
The swaybar alone won't fix the bodyroll. To take care of that JP would need bigger t-bars (and maybe bigger rear springs).

About the oversteer that JP reports... lower the rear pressure to get the temps even across the thread. If needed dail out some neg.camber in the rear.

All said, a lot of it depends on the driver too...
Chris made some good points in his post above.

I'm not really good at AX. I usually start too gung-ho (=too agressive) so on my first few runs I'm focussing too much on keeping the car under control while I should learn the course (this way, it takes longer to learn the course).
Basically, too agressive is slow but too smooth is slow as well.
Like I said, I usually start too agressive and smoothen out as I learn the course (times get better). Up to a point where I'm too smooth and times start to get worse again. Which is my call to get more agressive again.

AX is quite a bit different from track driving and the "ideal line" that works on a track usually only works on the fast parts of an AX course.

Like Chris sayz... it's better to sacrifice a little on your corner entry speed so you have a good clean corner exit (=faster accelleration on your way out).
That specially helps in slow/tight corners where you will suffer understeer when going in too fast (which will definatly f-up your corner exit - waaaay wide).

Oversteer can be used to set the car. But if you have the idea that you suffer from oversteer, usually, you're just too much on the loud pedal too soon.

Ok, I'll shut up now and let the fast guys do the talking

cheers,

Jeroen

Posted by: 914Timo Apr 1 2003, 05:13 AM

Me tooo ..........

I have stock front bar and #140 rear springs. I may want some day a little stiffer ride.

Posted by: Bleyseng Apr 1 2003, 09:27 AM

I want it just to not f-ing rain at the autox so I can actually feel how my car handles now. I don't have the hp JP does but mine doesn't have the body roll or the tire lifting trick unless the rear bar is hooked up.
It sounds like the front sway bar needs to be looser then? Or bigger front t-bars to stop the front from digging in? How about stiffer front shocks setting, wouldn't that do the same thing if JP can adjust 'em?
I know very little about how to set up cars soo I am just trying to learn here.
Got the results from the last autox and my son took 2nd and I wuz 7th in GTU (I was atleast faster than E. Fry). Not too bad in the rain, Blair just drives the car and then flips me the keys saying "It goes alot faster now, Dad!"

We both are trying to figure out what the car is doing in kinda tough to do in the rain as I spun on every run except one slooow run.

22mm Front bar-set in the middle
22mm tbars
old Koni shocks set to firm
180lb rear springs
Bilstein gas rears
205 Kumho Victos on 7x15's
32lbs of air- WTF should a starting tire pressure be??

Still waitin for some 4mm shims from Brad so I can align the car.....
Geoff

Posted by: Jeroen Apr 1 2003, 09:44 AM

For rain settings, you could try to thighten the front bar to get rid of some oversteer
Beyond that you can raise the front tire pressure and/or lower the rear pressure
Do that untill you have more understeer than you like...
Still, you'll always need a "tender foot" in the rain to avoid oversteer

Dunno if JP has adj.Koni's or not... If he does, he could fiddle with those a little too. But I doubt it will take care of the bodyroll much though...
Same rules as on other parts (sways, springs, tire pressure)
Soft: add grip at the adjusting end, loose grip on the other end
Hard: loose grip at the adjusting end, loose grip on the other

cheers,

Jeroen

Posted by: Dave_Darling Apr 1 2003, 03:34 PM

Shocks will only help in the very-very short term. They mostly affect transient stuff, the longer-duration things will get past them. (Think low-pass filter if you're an engineer geek.) It might help if the wheel just hops up very briefly, but I'm pretty sure that's not what is happening.

Personally, I'd consider the stiffer front torsion bars on JP's car and softening the front sway bar. I'd also consider an LSD and a rear sway bar. (Maybe even give it a try without the limited-slip!) But I'm not sure I would actually do any of the above! It sounds like the car is doing quite well as it is, and focusing on the wheel-lift may not really help much in the long run. So I'd just try to get the alignment where I wanted it, work out the tire pressure issue, and drive drive drive drive drive!!!

Don't you worry, Chuck will beat that Vette one'a these days!

--DD

Posted by: Porsche Rescue Apr 1 2003, 05:10 PM

I'm bettin' JP will too, it'll just take a little longer.