Astockboxta

Im checking to see if anyone else has had this problem. I a-x my S car and have the normal anti-lock stopping power,you know where you have to push thru the lack of stopping ability with excessive pedal pressure.But this past weekend at the SCCA Pro-Solo I ran completely thru 2 walls of cones because the brakes went into "ICE" mode. No matter how HARD I pushed on the pedal,the car did ZERO slowing down...it felt as if it sped up.The tires did not slide to my knowledge.

I have 25 years of experience in all kinds of cars,so I think I have enough talent to correct driver error (maybe)... I run Double adj LEDA shocks,R-compound tires,stock bars front and rear.M030 springs. I drove a WRX that scared me half to death a month ago that did the same thing....I told that guy to sell it before it killed him !! He said he just got used to it... Now I have the same problem !! Is this a reprogramming issue? or will different pads help?

I have just started running this car by the way...

If not....its for sale !! in whole or parts.....
John B

Drew_K

I've never heard of this problem, but is it possible that the issue is cause by running different diameter tires? I don't know much about ABS systems, but I wonder if the car gets confused if you run different diameters then OEM, or different diameters front to rear.

A less than ideal solution might be to disable the ABS by pulling the fuse/relay, if there is one.

Astockboxta

And that method is Illegal... =( in stock class.

Actually the tires are same as stock in diameter... front and rear.

Leeds Gulick

I occasionally (two or three times) had this happen with my 1992 911 RS America and 1995 993, but neveer with my 1999 Boxster, 1999 996 or 2003 Boxster S. It happened in the earlier cars when getting hard on the brakes as the front end suddenly got light as the pavement angled away such as when the course is going up hill and the pavement suddenly flattens out. I autocrossed these cars a lot, including SCCA National Tours and Pros, and never had a problem on the later models.

Leeds

grey ghost

hello John

When I ran Roberts 00/S we never had that happen, what I am thinking is that you
might have way to much bump/orcompression on the front shock. this would not let
the front get the weight transfer on to the front wheels. give this a thought also could
the shock held the inside tire in the air or gotten it too light.

the only other idea is you have some kind of electrical problem, or a bad wheel sensorthat reads under duress.

hoping to run with you at the Atlanta Divisional.

Thanks Rob Falkner

2004 Boxster S 550 se

Abe Anderson

This problem usually only occurs on the track with new pads, as the gases come out of the pads you can press as hard as you like and they will not stop the rotors. This is why it is necessary to break in certain types of pads. I AX a 03 S with stock pads and have never experianced what you have.

Good Luck!
Abe

Astockboxta

GeeZ...this is not sounding good....
Rob,I took all the front compression out previously to get better initial turn-in. G H thought I may have to much rebound on the rear and during turning dive in...the inside rear was losing contact....any thoughts on this.?

Man..I musta looked like a complete noobe in Walnut Ridge when Id blow clean thru the outside turn walls !!! But I am at best..an agressive driver and it would have nuthin to do with that!!! But if I slowed down to not have this happen...as you could see by the results,I was almost 4 seconds off pace !!

Rob..I am lookin forward as well to runnig with you in Atlanta. (we'll swap cars) hehehe
John Brown

grey ghost

Hi John

that was a good laugh, maybe for fun runs. looking at what Gh has said it might be.I run the GT-3 frnt bar and it helps keep things planted. we have pictures with one of front tires about 3" to 4" off the ground in a big sweeper. John I know you have alot of slick experience of late. they tend to let you go in deeper and trail brake better.

One other thought , I was reading on another forum that the 350Z guys were having the exact same problem at Walnut Ridge. I was not there so this is hind sight from other drivers I have spoken with. the surface was concrete with exposed agragate that had been polished smooth over the years. this could be a major factor as a unloaded tire is going to slide quicker with the less friction on the surface, as the surface is almost like glass as was decribed by Mike Jr. Johnson in his asp Zo6. he could not put any power down. enough of my rambling. have you had any Ice mode on any other surface.

John, I have been told that my driving style as controlled fury:0 very aggresive
from my years in the smaller cars such as 85 Mr2 and early Miata's.
the Mr2 allowed alot of trail braking. but when i drove the Miata I had too change my brake style as i tended to lock the fronts all the time. what I did
was do a straight line brake with a "the Miata Two Step" that is you stroked
of the brake had a breif pause while the weight tranfer onto the front tires
brought the nose down then you could apply alot more pressue. I still use this
style all on all the cars i drive.

thanks Rob.

Irishdriver

Happened to me once on a slalom, basically I had the ABS pumping when I got very sideways and the traction control brain and the ABS brain seemed to get in each others way.

It had a funny hard brake pedal and practically no brakes. I kept going and gave the brakes a sharp (left foot) kick as I drove to the next marker cone and it seemed to sort itself out.

Never managed to repeat the experience.

Astockboxta

My condition is repeatable....all 12 runs at the Pro-Solo..
But...I do remember after checking my set-up notes,that I dialed in a lot more rebound in the rear to help on the launch..(WHEEL- HOP) I think the added rear dampining is carrying the rear wheel off the ground. So I ll check that at the next event.........

So.........lets talk about that wheel hop on hard take-off....... LOL
motor/trans mounts or suspension ???????????????????

John Brown

ps thanks a lot guys for your input !!!!!
Rob..see ya in a couple o weeks

Irishdriver

Axel tramp on take off can be controlled by the right foot !!!

I'm running totally stock suspension as I decided to see how far I could get without spending money on the car. We won class 1 of the German Porsche slalom championship last year.

Now I find the car is a little loose and it probably needs a set of bushes all round.

Check your tyre pressures as well....whatever you do the effective setting here for both standard and modified suspension seems to be hte same pressure fromt and back. Depending on your personal preferences this could be 2.0 to 2.5 bar.

Have fun

grey ghost

So.........lets talk about that wheel hop on hard take-off....... LOL
motor/trans mounts or suspension ???????????????????

Hi John

we never were able to get a set up that let us get away from the wheel hop. what
we would do was try to get enough wheel spin not to get the hop. we general pulled
1.9 to 2.0 60" times using the prosolo lights(which are different from drag lights.
Robert always had more than me. it must be a diffrence in how we launch.

we did not have ajustables for any of the Pro's. when we had the Moton's we never
did try to duplicate the Pro launch.

thanks Rob

KenJ

My 03 S has had a couple of malfunctions during AX. BUT, there are other times I can blame myself and it wasn't the cars fault. I wasn't all the way on the brake pedal and inadvertently was squeezing the throttle too! That'll cause the same problem. Do you have big feet like me?

kj

Brian_77_3.6

I have friends with 996 cars that have experienced the ice effect from ABS. They all say that by releasing the pedal and reactivating the brakes the condiditon went away for that brake zone. But they all have had repeatable experiences with ice and ABS. I have had it with a Chevy Tahoe. Now thats a scary experience trying to stop a tank.