I just got back from the autox. I am a bit disapointed. Now I am definetly very new to the car but this just doesn't seem right. To me it seems that the rear comes out or over steers just way to easy. A slight blip of the throttle and out it goes. Quick transitions thru the slaloms also does it.

Did put larger width rear tires on and figured that would solve it. I also stiffened the front sway bar a bit. Although I am starting to wonder if that was right or not.

At this point what would be the best wat to remedy this. Stiffer rear springs? Lower front or lower rear? Add a rear sway bar? Begining to think I just don't understand mid engine rear drive setups

I'm kinda leaning towards lowering the front a 1/2 inch but want to here some opinions of people who actualy know what they are doing.

choke up on that front sway bar even more.

in general:

tighten the front = make rear stick
tighten the rear = make front stick

what's your setup? (spring rates, tire sizes, torsion bars, sways, etc.)

Yes, more info on your total set-up, including tire brand and pressures.

KT

bridestone potenza s02a front are brand new rear are just about to the wear bar

17x7 205/50
17x9 255/40

bilstein shocks

weltmeister front sway bar and no rear sway bar.

I'll have to get under the car to see what the torsion bar and springs are.

Well, you don't talk about tire pressures but it could be that the worn rear tires are just about done giving lateral grip. The 17X9 225/40 profile tire has almost no sidewall to flex which is one way of absorbing the lateral g force.

A rear sway bar will make this worse.

I would suggest some tire pressure changes but what you are describing is happening much too easily. Just how much power are you packing? Your screen name implies turbo. Is it even a type 4 or a Porsche 6?

More information needed.

a 6 with 240hp 190 lbs torque

The tire pressure is 31 all around

True on power.

I had to learn how to drive all over again after the SIX went in.
I was experiencing "snap oversteer" out of corners where I was driving flatfooted with the FOUR.


KT

Wow... You must be one happy guy. Given what you have just said, I would say you need better tires (not worn) and more negative camber.
Negative camber will cause the tire to flatten out and stick in corners.
I would start with new rear tires and then have a four wheel alignment and corner weight done and get as much negative camber as you can in the front and rear. Usually we are talking about 2 to 2.5 degrees. Not counting the tires this should be around + or - $200.00 With the right settings the car should feel like it is connected to your brain synapses. You think turn and the car does it.

Just a thought here, I have no experience with those tires but I believe them to not be R rated DOT tires. Given that, those pressures seem a little low. 35 - 40 would seem more in the autocross ballpark.

You have got a lot of power for a 2000# car. I bet you are just overwhelming your grip.
Given your power to weight ratio, I think the simpler solutions like those involving tire pressure are going to be too little for you.

Rob gives you good advice.

You will need to modulate throttle in and out of the turns.
Once you straighten the car out, then GO!


KT

would you pm me your suspension set up, and I agree that some gentle throttle application may help. But with that amount of rubber on the road, I really doubt the oversteer problem is ALL throttle application.

Erik Madsen

I have it around 2 degrees in the front. The back I don't know how to adjust but you are probably right there. I'm gonna order some new rear tires tonight. Some falkens since I have been happy with them in the past.


I would really like to give more setup information but I just don't know the car that well.

Any links to how to adjust the rear camber?

Erik is right. That is a lot of tire. I am just thinking that the combo of worn tire and high power to weight ratio is going to cause the snap oversteer. You should be able to get at least 2 degrees negative out of the back with yours. I got it in mine without any tricks or spacer magic.

I have Falkens on my 240Z. I know of lots of guys autocrossing with them in SCCA. Temperature is an issue. These tires do not like getting hot. They can lose their grip when hot. A trick I see the SCCA guys using is a pump water spray after each run to cool them.

Trekkor,

I cannot wait to autocross the Bumble Bee. I am going to embarrass the snot out of myself spinning around and around!!!

I think I will bring the 4 to your party next week though... Depends on the good Doctor at IPB and what his prognosis is after the Bumble Bee tune, valve adjust, and weber adjustment... If he says the Bee can fly, who am I to keep her down?

You adjust the rear camber by adding shims to the trailing arm end cap to decrease neg. camber, and you remove shims to increase neg. camber.
This is the end cap behind the rocker cover, with 3 bolts in it, pointing up towards the sky. The toe is adjusted in the same place, by prying the cap forward for more toe in, and towards the back of the car for toe out.
If you have the proper shims, you only need to remove one bolt to add or remove shims, the other 2 holes in the shims are slotted.

Yea tires. you would have problems with any street tire and that much horspower.
However learning how to drive the car (no offense) but braking in a straight line and mashing the gas when you are pointed right is very important.
Also to keep the rear planted to the surface through judicious applications of throttle. Acceleration will transfer weight to the rear and make the rear tires stick.

Joe speaks volumes! You may need to slow down to go faster. Momentum momentum momentum!

Couple of things to consider, do you have a limited slip, if not with that much power one wheel can't handle it well. When I was auto-xing with the six I ran about 24 to 25# air pressure cold front and rear. Many of the 914s I see use same size front and rear tires as the larger rear tires will force oversteer. Whenever I replaced tires for racing, I replaced all 4 at one time so tire wear as a factor is eliminated.

Thanks for the replys. I am more then a bit disapointed so far. But I will get it sorted out. I'm gonna stiffen the front sway a bit more, add more camber to the rear and ordered new rear tires but they won't be here until next week I am sure.

I'm also gonna take a driving course this friday and hopefully get some of it all sorted out. This time I will bring the tire temperature gauge with me and adjust pressure where needed

So your saying the larger rear tires force it into a spin HUH? I could kinda see that. I swear though I feel like I am barely touching the throttle.


Yeah I just picked up the wheels on ebay and this is how they came. I've only put a few hundred miles on the front which were brand new. The rear definetly need to be replaced soon.

Last time I swear

I'm ordering a set of falkens for the rear right now. Gonna get the alignment done in the morning. But I just had a quick tire question

I'm using 255/40 right now and Falken has that size. They also have a 275/40 with looks to be about .5 inch wider and bigger in diameter. It will fit for sure. The question is will that be safe or even work good on a 17x9 wheel. Here is a link to the information on the tires.

http://www.falkentire.com/rt615_sizes.html

It says a 17x9 is within spec but just thought I would make sure here first.

brilliant...

just ignore the manufactures recommended info and listen to some total strangers on the internet

you will get more sidewall flex with the 275's, but sometimes that is not a bad thing...when my 255/40/17 Kuhmos need replacing (which is really soon), I'll be going with the 275's as well.........

Well they can say it works. Doesn't mean it works well. Hopefully a few others have an opinion on this. I'll wait a few hours before ordering. Ain't no way they will be here before Friday anyways.

If i rememember correctly, you weren't spinning as bad the first time you autocrossed the car a few weeks ago. I'd switch back to the wheels and tires you had for the first AX for friday if you still have them. As fast as the car came out on you, I'd say it's a tire issue.
If you think it's the driver, I could always take it for a spin for you! Seriously though, see ya Fri and be awake! Long day ahead of you.

Ya know your right I should switch tires for friday. Why the heck didn't I think of that

The new wheels just look meaner though. I was hoping it would intimidate the cones

BTW, your fastest time was pretty impressive for not having a handle on the car. Now get some tires and give those GT3 drivers a bellyache!!!

Hey Dominic I found this page with photos from yesterday. This guy musta liked my car because he took alot of pictures of it. I think I got a stalker

Photos are great. Wish I could take photos like that.

http://www.plaftaphoto.com/gallery/album343?page=1

Get the Falkens on all four corners and tear it up.

Set the pressures high, too.


KT

Yup agree with KT (once again)
adding new Azenis to the rear will now cause the front to push..

Go big or stay on the porch with the cats.

You got a lot to learn about AX & photags.
Ya gotta give em' some sideways stuff that looks semi under control.
Then they'll follow ya anywhere.
I didn't get away with this.....but it looks gud.

I am going to have to disagree at this juncture....

Until you know exactly what you have as far as suspension components and what you alignment specs and ride height you have....this is all speculation.

I also do not necessarily go along with the notion that your tires have to match to get good performance front to rear.

Just like my 914-4 calipers on the rear of a track car (wouldn't work), accomodations can be made with your set up to make it work quite nicely.

I have AXed a couple of Porsches of various types over the years which, for several reasons, had mismatched tires front to rear.....and things worked out just fine.
Not dangerous, not uncontrolable....just different from the norm. Being able to adapt your driving style to the conditions of the track and the car is a learned skill.

Find out exactly what you got and then come back for some more specific and helpful information.

I like that pic JP....

Kind of like this one

Turboman808,

in order to get rear negative camber...
you really need to take it to someone that knows what they are doing.
unless you are familiar with strings and have experience, I highly recommend taking it to a pro.

you can't just adjust the number of shims/camber without changing other things ( IE: TOE)

talk about tail happy..
if you screw up your toe, you will really have a problem to keep it going straight... or else it will be slow.

it can be done at home, but if this is your first time on a teener and you are trying to chase a handling problem, I would recommend having a pro do the alignment and then at least one variable is eliminated.

brant

with Brant..

Yeah I am taking to a shop that came recommended in Hackensack in the morning. Don't think they have much experience with 914s though. I don't have alot to do at work so I will probably hang around and make sure everything is going right.

2 in front and back is the plan or somewhere close to that.

Apologies to Nate for this one:

Click to view attachment

Check this out!!

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I've been there, too!!

Click to view attachment


I'll be running Hoosier a's on the front and r's on the rear at Marina.
I've got a pair of 710's I may toss into the mix...On 5.5" rims

I'm really trying to save my new tires for the track.


KT

Well I got up early and came to work so I could bring it inside and put it on level floor.

Now at some point this car was corner weighted but I think at this point it has gone out the window. I've taken about 30 lbs out of the front anyways so screw it!!!


Well one thing I found was the drivers side was an inch lower then the passenger side. This was without me being in the car. For now I just evened it out. I didn't disconnect the sway bar when I did this so I may have screwed it up even more.

I did stiffen the front sway bar a bit and it may have helped. I did do some controled drifting in an empty lot around 5am. I think it feels a bit more predictable but I could certainly be fooling myself. I also got the front about 1/4 inch lower then before.


When I take it to the alignment shop I will disconnect the sway bar and see if things still are even or not.

The back was dead on even side to side.

Off to the alignment shop in a few hours.




Really got to get this sorted out properly over winter. But for now I will have fun with her I guess




Oh and here is Dominic autoxing



And here I am with smoke clouds as usual

Brant's advise is right on! Check the alignment and rear toe. For a calmer car I suggest 1/8" toe in. My 914 was at 0" toe at first and it was tail happy with my driving style at the track. I have 22mm front bars and 180 lbs rear springs. A 19mm front sway bar and no rear bar. The front bar is set about halfway to the stiffest. A good shop can corner balance and get you the negitive camber you need. My car without any cutting or grinding has -1.9 in front and rear without any shims. Spend the money at a good shop.
van914

everytime you change the ride height, you screw up the alignment.
I guess you knew this, but after the shop gets done with it... don't touch the ride height.

if you have changed the ride height since your purchase, this may account for the wacky handling.

also, depending upon rear suspension bearing/bushing material you can't get away with Zero Toe (except for braced bearings or monoballs)

the poly bushings still deflect under load and your zero toe then changes on you while cornering.

I run toe braces for just this reason

I just got back from the shop.

I never touched the ride height since I bought it so it was like this


It was a weird experience. The guy did the aligment in record time. But after telling him what I wanted I came back and they only charged me for the front and it was only $65. Guy said the back didn't need to be done. I didn't say anything but I am thinking "WTF why didn't this jerkoff do the rear like I said?"

I just kinda left annoyed...

Well It turns out he did do the rear or I have been taking some happy mushrooms. The back was definetly done and I guess I should have hooked the guy up now HAHA
But yeah it all looks good now and I should be ready for friday autox school.

What rear springs do you have? What bars are in the front?

But after telling him what I wanted I came back and they only charged me for the front and it was only $65.

Well It turns out he did do the rear or I have been taking some happy mushrooms. The back was definetly done and I guess I should have hooked the guy up now HAHA
But yeah it all looks good now and I should be ready for friday autox school.
[/quote]


$65 for a 4 wheel alignment....?no way....

That is not even an hours worth of mechanics time. A full alignment takes a good 1-2 hours minimum.

What kind of equipment does this shop use and do they have any Porsche experience, specifically 914 experience?

I did notice some front bias on your car Dan. Couple of times you came into corners with fronts in full lock up at Alameda. My car seems to have fairly balanced braking however I tend to lock up single wheel occasionaly which can be scary.

sorry about

Grant,
Both times that happened was due to me wanting to take a different line than everyone else and getting into the dust and tire shavings (marbles).
My mistake not the cars tendency to lock up the fronts.
Still adjusting my driving styles after driving a Boxster for the last several years with ABS.
Darned 914 won't threshold brake and turn at the same time like the Boxster

On the big track my brake balance has proven to be spot on so far.

I am going to a slightly more aggressive rear pad on my next set.

Right now I run Porterfield RS4Es up front on my M calipers and stock pads on the rear (914 fronts).
Will be going up one level on the rears to see how that works.

And I love my low car

Turboman,
Take a ride up to Manchester with that thing.
I don't have a full time alignment setup but I am occasionally able to use my racing alignment equipment for customers.
I think It is just as fast and accurate as the pro shops.

Yeah I totaly want to bring it up there. I was kinda thinking after summer though. Even though I want it to work I also just want to party and have fun and pickup chicks in my 914

If I get really annoyed with the car I will bring it up there sooner though.

One more question and then I hope this thread dies because I am ashamed of my bad driving

Also I really don't know the spring or torsion rates. I can't seem to find that information.

Would there be any benefit to switching to konis? It has bilsteins right now. What I did notice was alot of wiggle in the back when transitioning from side to side almost like the rear shocks are to soft.

What bad driving? Sorry, you walked right into that one! See ya friday.

Click to view attachment

I like Bilsteins.

BTW, I think I've driven your car once before.

I think half the people on this board have.

was this car once owned by a guy named mike out on the west coast?

maybe CA, but maybe WA or Oregon?

brant