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View Full Version : my car pulling to the left at the drag strip


AutoMods
08-10-2011, 10:05 PM
meant to ask this sooner but back at the rob shootout my car with all bias tires went straight down the track but as soon as I let off at the traps it would pull to the left requiring a decent amount of counter steer. Never really swayed or got out of hand but just a steady pull until I slowed it down to under 100.

15psi tire pressure and 135ish trap speeds. this normal?
Deimos
08-11-2011, 04:24 AM
alignment, radial pull or tire pressure being off.
c_mart_28
08-11-2011, 08:02 AM
What are your front runners?
Drifte
08-11-2011, 08:17 AM
Its probably that massive amount of tread on those fronts. You let off weight transfers and then you have to steer out of it.

Everything on the front end is tight, it probably does need aligned but drives straight, and tire pressures should have been perfectly even.

SO does seem like it would be the tires.
Scott
08-11-2011, 08:18 AM
I will venture a guess and say your bumpsteer is off...
AutoMods
08-11-2011, 08:40 AM
I run these because 16" bias skinnies aren't common http://store.cokertire.com/tire-styles/bias-ply-tires/blackwall/500-525-16-excelsior-blackwall-tire.html?___SID=U . I was guessing it was something to do with the bias tires coming down from their expansion but not sure. I'll pay more attention to it next time at the track
AutoMods
08-11-2011, 08:41 AM
also that above tire says requires tube but i don't run tubes. i also don't run tubes on the MT's
Scott
08-11-2011, 12:52 PM
also that above tire says requires tube but i don't run tubes. i also don't run tubes on the MT's

Sorry for my ignorance, that is a solid rear end right?? Have you ever checked bumpsteer? that can cause it to swerve/pull when the front suspension moves "like when you let off", and its way more noticable at higher speeds. Check to make sure the rear end housing is not bent? should be able to have all this checked on a alignment machine with the right communication to the tech doing it. Easy thing to check is measure the runout of the rear tires and see how close they are, make sure you set the pressure exactly the same before mesuring
AutoMods
08-11-2011, 01:21 PM
its the stock mazda IRS rear but next year I hope to have a ford 8.8 solid. Haven't had it aligned ever since I owned it.

I do have coilovers on the car front and back and I noticed that the rear drivers side of the car sits about an 1/4" lower then the passenger side with the coilovers set exactly the same. So I tried to compensate for it and made the drivers side coilover a bit higher and remeasured and drivers side was still about 1/8" lower then the pass side. Just left it at that for now. And those measurements were just taken by the tire to fender gap, I didn't actually measure from the ground to the fender or ground to frame.
Scott
08-11-2011, 01:30 PM
its the stock mazda IRS rear but next year I hope to have a ford 8.8 solid. Haven't had it aligned ever since I owned it.

I do have coilovers on the car front and back and I noticed that the rear drivers side of the car sits about an 1/4" lower then the passenger side with the coilovers set exactly the same. So I tried to compensate for it and made the drivers side coilover a bit higher and remeasured and drivers side was still about 1/8" lower then the pass side. Just left it at that for now. And those measurements were just taken by the tire to fender gap, I didn't actually measure from the ground to the fender or ground to frame.

I would measure the tires first, I've had a pair that was over 1" difference in circumference, not good. and unless you are on a flat ground "measured" the ride height measurements probably arent going to mean much, and you should be sitting in the car as well. The area in my garage I thought was flat needs 1.25" worth of shims on 1 corner to actually make it flat and level. Anyway you should have it aligned for sure and check the bump steer fr and rear and correct it if need be, I would almost put money on it being bump steer issue if the tires are the same rollout.
Deimos
08-11-2011, 05:30 PM
zero toe tierods would be a great improvement
Domestic Disturbance
08-11-2011, 11:24 PM
I run these because 16" bias skinnies aren't common http://store.cokertire.com/tire-styles/bias-ply-tires/blackwall/500-525-16-excelsior-blackwall-tire.html?___SID=U . I was guessing it was something to do with the bias tires coming down from their expansion but not sure. I'll pay more attention to it next time at the track

you got them for that classic european styling didnt you