FormulaRedline

So it's when you first get on the throttle versus, say, half-way through through the sweeper, having been on the throttle, and all of a sudden the revs jump? Is that description consistent with what you were getting, Dave? Is there a difference between sudden application versus rolling onto the throttle?

daverx7

Hmm... pulling the cobwebs out as the surfaces have been too cool or tires too worn out to get the wheel spin problem this year. To be honest... I just can't remember other than being in the turn and wanting to accelerate out and it reving instead of speeding up.

However, this might be a good thread to read:
https://www.s2ki.com/forums/index.php?showt...45&hl=wheelspin

Sorry, but my memory sux and would not want to give you any misinfo.

-Dave

FormulaRedline

Thanks for the link Dave, good thread. Unfortunately it seems the OP ended up having the problem due to a loose bolt on his front ARB!

Oh well, there was still a lot of good info. It seems most people had the problems under condition where there would be an excessive amount of weight transfer off that wheel (abrupt transitions, crested or off-camber truns, slicks and other mods pulling g's above what I'm probably seeing). I'm wondering if yours was due to your stock shocks, though that wouldn't explain pedalfaster's problems with it.

Good link I got out of that thread to double check your adjustments:
Vehicle Dynamics Assistant

I tend to err on the side of smooth transitions, I'll have to keep an eye out when my co-driver, who is much quicker on the throttle than me, goes out for his runs.

krazik

yeah being smooth helps the problem but only so far. You are correct on the conditions that cause it. In auto-x it usually takes something that causes quick direction changes. The rear swaybar stops the inside rear from rebounding and that causes the wheel spin. When the torsen diff doesn't have both wheels on the ground it becomes an open diff.

FormulaRedline

Good information Krazik.

And by err on the smooth side, I really do mean err...too slow. I imagine as we pick up this pace this year (we are already doing fine in our region, but have our sights set higher) and with fresh A6's on their way, wheelspin could become an issue. Hopefully armed with this knowledge I can prevent this problem instead of trying to combat it on the track.

PedalFaster

Well, now that people are trying to wrap up the thread, let me chime in with a few more comments:

You'll know wheelspin when you get it. Basically you push in the gas and instead of the car accelerating... nothing happens. I tend to enter corners relatively conservatively and get on the gas pretty early while the car's still got a lot of sideways load. I'm also not very smooth. Both of these may have exacerbated the wheelspin for me.

Also, you make a point I was hoping to not have to broach by myself -- if you're not pushing the car hard enough in corners, you won't get wheelspin because you're not pulling enough Gs to pick up the inside rear.

Last but not least -- modifying my Saner bar turned out to be quite a production, as I also had to mill down the bar ends to lengthen the flat area that the endlink mates against. By the time I was done, it wasn't any cheaper than just buying a Gendron bar and selling the Saner. I had a thread on this ages ago, but I can't find it now.

Windscreen

I belive Greg Lee and someone from Florida ran 245/275 A6 at the 2006 Nationals. I really like the balance of my car with 245/245, but as previously mentioned, I have Penske shocks and a custom stepped center section Speedway/Gendron FSB.

This setup fits my driving style extremely well and really responds to left foot braking. Need the car to rotate a bit? Just drag the brake a touch without lifting all the way off the gas. Too much and it will end in a nice drift, but its still big fun

A Chicago Region guy (Aruch) started running 245/275 A6 this spring, and at the first event he was right on top of me. I may have to buy a pair of 275s to try out at a test & tune in June. I'll say one thing for certain - they make the car look really goofy and make the AP1 gearing even more "out there". Reminded me of highschool and cars with jacked up rear ends.

Steve

daverx7

Where would having 275/45-16 in the rear put the top 1st and 2nd gears?

I was going away from the 265/45's because the local events I'm constantly hunting between 1st and 2nd.

-D

shaggy

The best way I found to limit wheelspin was to underdrive the corner.

I had a Gendron that I ran full stiff and, on grippy lots, I could get wheelspin with the 225f / 265r V710 setup.

Man... I haven't been in here in soooo long. Its nice to see some things don't change.

Andy

Windscreen

By my numbers, rev limit speed in 1st/2nd:

245/45zr16 = 43/66
275/45zr16 = 45/69

So, the rev limit corner radius for 1st gear increases from 103 ft to 112 ft. I think the 275 is going to be between gears more often, but will depend on the course design.

Steve