non racer question: what happens past the point of screaching tires?

[car_nu_b]

Hey

I'm not a racer by any means, but i do like to take turns. The point I stop is when I can hear my tires screaching over my radio...once this happens i just maintain the spead i'm going. But i've always been curious, what happens if I gun it just a little bit more? My imagination says that my tires will castistrophically loose grip and i'll go flying off the turn ramp. Does this happen? Or is it more maintanable then that?

Thanks, I wont go off and try it. Just curious. I know this is a site for 240's so you guys would know! Also, sorry if i insulted anyone with my ignorance

[MeanGreenS13]

you username says it all nu_b... no hating here you'll just end up slinging the rear end out sideways, if it goes too sideways, yeah, if you dont know what your doing, you'll end up in a ditch or something, but if you start off small, and work your way up, you can control it. go have fun in an open parking lot, start with donuts and work your way up to taking sharp turns screetching the tires, then bust it sideways, best way i know to learn teh limits of your vehicle.

[cdlong]

go to your local autocross, http://www.SCCA.com. there you can explore the limits of your car and your ability in a controled, safe environment. and there are plenty of people that would be happy to give you tips and help you improve.

some more links for you.http://www.calclub.com/http://www.solo2.com/

[DjPantsSpecR]

Too bad its hard to tell exactly which tires are screetching, because either you will just take off straight ina path tangent to your travel, or you'll just spin out. when you hear your tires screaching they are maxing out on static friction. Co-efficients of static friction are always higher than co-efficients of kinetic friction (aka sliding). So you always have more grip when your your tires aren't sliding or spinning or screaching, well duh right?

so depending on what tires your have, and tire companies do have graphs you can get for some tires of slip angle vs grip (i cant remember what the other axis of the graph is, i dont think its grip, but thats what it equates to).

anyways, just as long as we're talking about slip angles....

tire pressure has a lot to do with the slip angle of your tires (slip angle being the angle the contact patch shifts with respect to the tire. Rarely does your car travel where the tires are pointed during hard turns.

so a low tire pressure should give you a big nasty contact patch and thus more grip right?

it will give you a big contact patch, but you will gain so much slip angle its ridiculous. The material severely loses elasticity while its not in much tension, aka a lower tire pressure.

so i like to have 40-45 up front and 35-40 in the rear. 240s have a lotta understeer built into em, so to help increase oversteer you can drop a little pressure in the rear, and up front pump up the psi to correct a little understeer.

but thats somethin you'll learn at the track...

[masticatingcow]

Yeah, if ever you're going to take in some "spirited driving" (you know, at night, no one around, kind-of-dumb-but-we-all-do-it type stuff), I would recommend that you KILL your radio. Depending on how loud your tires are screeching, you have have already lost a lot of grip, and are turning ineffectively.

In all likelihood, your front tires are the ones screaming at you. Gunning it when they're already losing grip will cause understeer, sending you off the ramp at a wider angle than the one you were turning at.

Just a tip to keep in mind... Always keep a tight line on an onramp and pay VERY close attention to how much noise your tires are making. If you hit gravel or a slick spot, having the extra space in the lane is good... you never know when you need to make a last minute correction. When your tires start screeching, you know you've got about the tightest angle you want at the speed you're going. As the turn opens up, aim for the outside of the turn and ease into the straight, at which point you can pour on the gas.

Now, this is a fundamental road racing technique applied on public road. I would not recommend LEARNING these types of things outside of the sanctioned events that SCCA and other autocross organizations hold. Yes, they can get pricey, but so can tickets and medical bills.

[cdlong]

they can get pricey, but so can tickets and medical bills.

$30 a month isn't too bad (for an autoX), and money is best spent on the driver (tires are second). $200 spent on classes and track time will make your car a lot faster than lowering springs ever could.

some tires make more noise than others. i've had tires that squeal well before starting to slide and some that won't even squeal in a full slide. it's better to go off of how the car behaves and feedback in the steering wheel. if you feel the effort drop off and the car doesn't turn as much, the front wheels are slipping, or starting to.

[vvaffle]

From what I have heard, R rated tyres stay pretty quiet even while sliding. Either way, just go easy on every control. In other words, never stab the gas, roll into it. If you think you are at a point that you could have slammed the gas, it most likely means you could have rolled into it earlier. Also, keep two hands on the wheel except for the half second you are shifting.