wheel hop

Mr Kleen · Post by **Mr Kleen** » Thu Jun 15, 2006 9:32 am

at the autoX class I noticed a LOT of wheel hop when powering out of turns, maybe a little as I approached a turn. there was some talk that it was probably the KD-W tires, but I'm not so sure the springs don't have something to do with it as well.

I had the same tires at the Summit Point HPDE and never noticed any hop, at least not as pronounced as it was at Tuesday. since that time I've added the h-tech springs and a progress rear sway (medium setting).

if it's the tires, I'm OK with that. they're fine on the street, great in the rain, and they'll wear out and I'll replace them. if it's the springs, that opens a can of worms... I really hope it isn't the rear sway. I wanted to get some opinions from Brian and Eric (was that the other instructor's name?

) but we ran out of time and I ran out of energy.

thoughts?

zaxrex · Post by **zaxrex** » Thu Jun 15, 2006 10:03 am

maybe the tire pressure was too high? more or less camber?

Did you notice it more from the front or the rear?

Post by **complacent** » Thu Jun 15, 2006 10:08 am

wheel hop in front, or out back? it's pretty common to lift an inside rear wheel when turning in an autox, esp when you have replaced the rear sway. have you swapped out the front sway as well? that would be my next step. Our cars really seem to love a beefy front sway.

Personally with those H-Techs in my old WRX, I didn't experience wheel hop at all. How much of your bumpstops did you cut?

Post by **Sabre** » Thu Jun 15, 2006 11:22 am

I can give you two bits of advice based on experience: When I had my winter tires on during one of the lvl 1/2 classes, I had the exact same problem. I ended up doing two things to correct it: Hit the gas sharply to get the ass end out or turn smoother. Hitting the gas made me rotate to get the wheels back under traction and pointing more in a straight fasion so that I did not have to have the wheels at too harsh a angle in the turn. Turning smoother made them less likely to break traction in the first place. I would get it A LOT if I entered the corner too fast and put the tires at too steep an angle.

With the new tires that I was running, I only experienced it once this past class and that was because I went too hot into the corner.

What setting did you have your rear sway on?

Mr Kleen · Post by **Mr Kleen** » Thu Jun 15, 2006 11:53 am

it felt like the entire car was bucking, not terrifying but not a good feeling either. really distracting...

the bump stops were cut according to the Tien directions (something like 1/4" in the front, none in the rear?). the front sway is stock. the camber should be stock (or close) as I had an alignment done at Don Beyer a couple weeks ago.

Post by **Sabre** » Thu Jun 15, 2006 2:23 pm

Was it like the tires were continually chirping/sliding/bucking very quickly? lol, maybe we should just go out to a parking lot one night and drive around a bit. I highly doubt you were hitting the stops.

Mr Kleen · Post by **Mr Kleen** » Thu Jun 15, 2006 2:27 pm

felt like all the wheels where hopping, that's the best way I can describe it. Brian's dad said it was the KD-Ws. maybe it took the rear sway and springs (and the tight AutoX course) to bring out that behavior?

I'm down for a parking lot thrashing again.

Post by **complacent** » Thu Jun 15, 2006 2:43 pm

I'd be inclined to trust BG's papa... The two of them reeeely know their ish when it comes to suspension and tires.

...but we should still thrash a parking lot to "investigate" anywho

Mr Kleen · Post by **Mr Kleen** » Thu Jun 15, 2006 2:55 pm

if something's worth doing... it's worth doing right

Post by **Sabre** » Thu Jun 15, 2006 3:04 pm

Post by **complacent** » Thu Jun 15, 2006 3:22 pm

drwrx · Post by **drwrx** » Fri Jun 16, 2006 4:51 pm

Mr Kleen wrote:Brian's dad said it was the KD-Ws. maybe it took the rear sway and springs (and the tight AutoX course) to bring out that behavior?

How many miles were on the KD-Ws before you hit the track?
How did the shoulders look before, and after the class.

New tires can behave rather oddly when they have not been broken in, or heated up enough. Also, if the shoulders had never seen any hard cornering prior to this day they could also be the culprit, unless they had been shaved prior to that day.

Mr Kleen · Post by **Mr Kleen** » Fri Jun 16, 2006 4:58 pm

not sure of the exact mileage, but I would say they were broken in. after the class the sidewalls were chamfered pretty good, but not nearly as much as they were after Summit Point.