Brake Failure & Wreck in E36 M3 at VIR

[D_Eclipse9916]

DJ - Have you heard any discussion on ways to prevent this from happening? Sounds like an annual cleaning of the wheel speed sensors might be a good thing to add to the off-season checklist. What else could cause this?

To be honest, this is very rare. And there have been discussions all around because it is simply built into most ABS cars. Everything from Porsche to Camaros have this problem, and nobody really has "solved" the issue. E46 M3s has the option of swpaping in the motorsports ABS ECUs, and report in that they don't have it. But it happens very rarely, so who knows? Even Porsche's venerable 997 GT3 has problems with it, and if Porsche's GT3 ABS has it and hasnt been solved, I doubt the E36s will be at this point.

There are theories, but many beleive cleaning the wheel speed sensors helps, but to fix "ice mode" you have to let off the brakes, and get back into it. (just as you would without ABS). I encounter it braking on the backstraight since I am hard braking over the curbing on the left and pop 1/2 wheels in the air. I momentarily pop completely off the brakes and then back in to settle it if it occurs. (once in a blue moon even driving like that).

I have spun out (I got lucky and didnt hit anything) because of it. Many racers have hit walls because of it. Eric Wong in his m3 hit an HPDE guy, multiple GTS Porsches, and now one of our own :/

Link to other's problems: <!-- m --><a class="postlink" href="http://forums.rennlist.com/rennforums/997-gt2-gt3-forum/534934-well-abs-ice-mode-finally-got-me.html">http://forums.rennlist.com/rennforums/9 ... ot-me.html</a><!-- m -->

[Apoc]

The more I read, the more I realize I don't want computers in my track car(s).

The idea of a machine effing me because it felt like it is a little too War Games for me.

[D_Eclipse9916]

The more I read, the more I realize I don't want computers in my track car(s).

The idea of a machine effing me because it felt like it is a little too War Games for me.

Apoc, this isnt directed at you, but before people start freaking out and say remove ABS)

If you think of all the times you hit the brakes at threshold braking and it DIDNT go into ice mode with ABS....

What, maybe 1 in 10,000 times you hit the brakes it messes up?

How many times hvae you locked up the brakes without ABS? (and flat-spotted a tire AND almost gone off track)

Tell me which has higher failure points. I will take ABS anyday. Sorry, F1 drivers are much better than any of us, and they still lock up wheels without ABS. Hint: You are not better than an F1 driver.

Unfortunately no one informs anyone or has practice with ICE mode (because its rare, unlike locking up a wheel without ABS), so it typically ends badly. A little information and more knowledge on the subject would help with these situations.

[Apoc]

Given the option of:
A) Flat spotting a tire 1 in every 1,000 brakes
B) Flying into a wall 1 in every 10,000 brakes

I choose A. :dunno:

Of course, I'm biased because I've never raced with it.

[BLINGMW]

I was unaware of this phenomenon, sounds like many others were too. hock: I'm very sorry you had to learn the hard way!

DJ, I get where you're coming from, you've decided to "manage it" and accept the risk as being lower than no ABS. That's logical(ish).
However, I think I'm the other way on this as well. I can't say I've ever had this happen, and if I did, I would refuse to use ABS on track. Now that I know it can and does happen, and I find the behavior believable from a controls perspective, I would take it out of a dedicated track car.
Personally I've never gotten myself into too much trouble managing non-ABS on track, the wheel lock-up is predictable. So I'm comparing a braking controls system with a 0-serious-failure track record (me) with one that has obviously caused some accidents. For w2w racing, the choice is a little harder, I wish I could comment.

Given the option of:
A) Flat spotting a tire 1 in every 1,000 brakes
B) Flying into a wall 1 in every 10,000 brakes

That's how I'm viewing it too. :dunno: And I'd rather run off the track with a wheel locked than run off with almost no brakes at all.
DJ you should take it out of your car before you get yourself killed. (only half kidding)

A little information and more knowledge on the subject would help with these situations.

We should start a PSA campaign!

[D_Eclipse9916]

DJ you should take it out of your car before you get yourself killed. (only half kidding)

I have driven on track both ABS and non-ABS.

I dont think you guys are realizing that all you have to do is pump the pedal in ICE mode to get it back (just like locking up a tire in non-ABS).

So between pumping the pedal because of "you messed up with non-ABS" and pumping the pedal because of "ABS messed up"; And the likelihood (humans mess up a lot more than computers do). I take ABS. It has saved my skin a few times from plowing into a spun car right in front of me.

[Apoc]

It has saved my skin a few times from plowing into a spun car right in front of me.

Learn to drive, kid!

[BLINGMW]

I dont think you guys are realizing that all you have to do is pump the pedal in ICE mode to get it back (just like locking up a tire in non-ABS).

No I get it and I'm glad you're sharing the "fix". I just don't like when a computer or machine behaves unpredictably. That's ONE THING THEY'RE SUPPOSED TO BE GOOD AT.
People aren't expected to be as reliable. But it's an expected and even correct response when driving an ABS car, that if/when you screwed up, stay on the brakes! And for non-ABS, hey, manage it pal! But if the "emergency" action for ABS on track is now stay-on-the-brakes-unless-that's-not-working-then-pretend-you-don't-have-ABS-and-start-managing-it... well that's just a little more for the brain to process when it's already working hard (or in panic mode), and more braking zone has passed while figuring it out. :dunno:

[Apoc]

Said another way, I'd rather have the muscle memory from learning to not flat spot my tires than try and remember to do something the first time if I'm that 1 in 10k.

[Eclipsor]

This ice mode shit pisses me off (obviously). I really wish I had known about it beforehand. I would definitely have fully lifted off the brake and reset the stupid ABS system. My car would still be in one piece, I wouldn't have this scar, and my ribs would feel fine. Fuck.

I don't want anything to do with ABS in my next race car. I'm absolutely going with a dual master cylinder setup.

[Eclipsor]

Here's the view from the car behind me. It definitely gives a better sense of the speed I was going when I hit the wall, but my car goes out of frame just before the impact.

<!-- m --><a class="postlink" href="http://www.youtube.com/watch?v=iKtbos7Uhas">http://www.youtube.com/watch?v=iKtbos7Uhas</a><!-- m -->

[Apoc]

Didn't see any brake lights.... camera trick or function of ICE mode?

[G.Irish]

Here's the view from the car behind me. It definitely gives a better sense of the speed I was going when I hit the wall, but my car goes out of frame just before the impact.

<!-- m --><a class="postlink" href="http://www.youtube.com/watch?v=iKtbos7Uhas">http://www.youtube.com/watch?v=iKtbos7Uhas</a><!-- m -->

That was a good case of target fixation there

[D_Eclipse9916]

Here's the view from the car behind me. It definitely gives a better sense of the speed I was going when I hit the wall, but my car goes out of frame just before the impact.

<!-- m --><a class="postlink" href="http://www.youtube.com/watch?v=iKtbos7Uhas">http://www.youtube.com/watch?v=iKtbos7Uhas</a><!-- m -->

That was a good case of target fixation there

Watch a Spec Miata race as one car goes off, multiple others follow :lol: