THSCC Forums

Last session out this weekend I had an interesting experience. On the 2nd (3rd?) lap, as soon as I touched the brakes to slow for turn one the car spun (probably right at 100 mph or so). Not just a little sideways step, we're talking like a top.

Marty Howard tells me that it was a clock-wise spin. I'll be honest, it happened so fast I couldn't have even determined that without skid analysis.

The car had been braking straight all weekend, with no hint of anything but predictable braking (the best the car has ever been). I slowed from the usual 110-120 on the back straight just fine, the car rounded turn 17 just fine and it drove straight on the back straight just fine (no indication of a severely hung caliper or anything).

I did bleed the front brakes before heading out for the final session.

After the spin my drivers front tire was flat, so I thought maybe I had cut it down. I've since inflated it to re-seat the bead, and it holds air just fine (must have popped off the rim when I went of track sideways).

I've not had a chance to do a post event inspection of the car, so maybe there will be an obvious mechanical problem. What I'm looking for here are some ideas of mechanical problems that result in SNAP spins as soon as the brakes are hit (or as soon as the front end starts to load). This should be a problem that can develop in the matter of a few turns?

I've not driven the car hard since the spin, but I still seem to have a firm brake pedal, etc (I have contemplated a bleeder screw coming loose).

My first thought was fluid on the track, and the driver of the Z car in front of me reported being low on water/coolant at the end of the session, however, if that were the case, I'd expect that Marty Howard would have been more than a very uncomfortable witness to the whole thing. I was close enough to the leading Z car (I had recently pointed him by) that I almost caught him in mid-spin (he was braking, I wasn't anymore), so we were close together. I looked at my windshield immediately following the spin, and saw no indication of fluids.

Comments? Marty, do you recall anything obvious? Maybe a puff from a locked tire, etc?

Scott

Could be fluid, could be you were just a bit off line and the track was slick there, could be any number of things. Even if you did lock up a front brake you should just slide. Perhaps you locked up the rears and were not completely straight? Good that you didn't hit anything!!

Ron

Did Rice touch your car?


*ducks*

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02 Focus SVT
STF 9

Any chance you dropped a wheel off track? Track is curved and a little bumpy there - I have come very close to doing that myself!

Now, if you had rallycross experience, then dropping a wheel off track wouldn't be a big deal. Hahahaha! Maybe rallycross should be mandatory for all TT drivers so you know what to do when you hit the dirt Oh, wait, then the trackers would be going off all the time just for fun!

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Mike Whitney
whit32@gmail.com, 919-454-5445
V10, V8, V8t, I6, I6, V6, F4t, I4, I4, I4, I4, I2, 1, 1

Isn't one of your rear calipers different from the other thus a bias towards one side?

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Has no responsibility whatsoever.

They are both Toyota calipers, just rebuilt by different companies. Same pads, etc, shouldn't bias things one bit. Certainly didn't bias things to one side or the other for the 90+ minutes on track leading up to the spin.

AFAIK, I didn't drop a wheel off before braking.

Maybe Ron is right, and it falls into the "stuff happens" category?

Scott

I had this happen when the studs/bolts holding the brake disk to the hub all sheared. If it was a clockwise spin check the bolts on the left front hub.

Tom Herbert

Interesting. I could certainly see this as an option (that wouldn't be obvious on a quick inspection).

Stuff you'd never imagine would break....

Scott

Maybe a piece of debris got caught in your RR brake & caused it to lock when you hit the pedal?

Car is on jack stands now. Nothing seems out of the ordinary. All rotors are still bolted where they belong, etc. All the pads show even wear (inboard and outboard, front and rear).

I'm starting to think it's just a freak incident. Seems like a good reason to do a light brake check before all the hard braking zones. I've got to remind myself that it's an HPDE, not a race...

Scott

Yeah, Matt Nicholson clued me in to that one when I rode with him at Full Course last year - that's why I was doing that so much in front of you at Patriot.

Me: why do you keep tapping the brake pedal before the braking zones?

Matt: so I'll know whether I still have brakes or not. (at this point, we're about to be braking from 110 or so for turn 1)

Me: uh... ok.

Scott, occasionally I too have had one of those "Hey, WTH just happened" moments on the track. Could be anything.

As to the brake check...this saved Oscar and me from throwing away the Integra at VIR one year. At the end of the straight approaching rollercoaster, the Integra is going over 120mph so it's wise to check them well before the brake markers. I did, and found nobody home.



Right rear bleed screw had somehow backed out - it had been fine all weekend, hadn't touched it. Managed to get the thing reeled in and obviously pitted.

Scared the hell out of both of us. Now I even tap when I'm in a race.

Have you ever uttered the words "fishing boat" in the presence of the Corolla? Cars are people too.

Celica, not Corolla.

Yes, I utter it all the time. As a matter of fact, while I was spinning like a top I'm sure I screamed, "Damn you, I'm trading you for a fishing boat!"

We all know that cars (and people) respond better to fear and threats than they do to positive reinforcement. Just ask my employer.

Scott

Being right behind you I had a great view of the whole event. You did spin clockwise, and with a lot of smoke. It almost appeared the right front locked up right before. I didn't see a tire down or any other definate reason for the spin.

I did get a good look of your "oh shoot" (well, maybe not shoot) face, and the other Z driver looking wide eye in his mirror.

As far as you line and such, it appeared you were right where you had been in the previous lap and braking where you had before, maybe a touch later.

The Z was off line a bit though and braking harder. Maybe he put just enough fluid on track to disturb that one wheel. His Overflow pipe was lined up right at your right front.

Too bad my camera was turned off.