i would say bump for a slow guy -- but i'm not as fast you. Crap....

anyway, i will say when greg recommended i take a few pounds out the rear -- wound up going from 40 to 37 -- the rear was a lot more predictable.

Next time, i'm going to try higher front tire pressures. I don't think 42 is enough.

Oh, Greg -- what are the tire pressures you ran in those slicks i have in my basement -- sitting there gathering dust...*sigh*

 

What tires are you all running that you want such amazingly high tire pressures? Hoosiers, Kumhos, Toyos, etc. usually have a sweet spot under 40 hot (I start my Hoosiers for road racing at like 27-29 cold!). One of the reasons why the tires may have been more predictable dropping them 3 pounds from 40 is that at 40 they were probably heating up and getting outside of their range.

I could be wrong, as I don't know the exact tires you are on, but something to consider.

 

The OP is running stock Yoks. I ran hot pressures around 40-42 front and 36-38 rear depending on the weather and surface. I think they are running pressures too high also, but I didn't ride with any of them at the last event either so it's hard to tell *why* the car was so loose.

Brendan and Carter - I have a pyrometer we can use at the next event if I make it.

That's good to know about the Hoosiers, I'm running them for the first time on a road course this weekend and I was unsure where to start. Thanks!

 

I've run the stock Yokohamas at two track weekends (both at Sears) and ran them at stock recommended pressures. They were awesome right out of the box.

Definitely would think that they'd need a bump in pressure for autocross to not have them roll over too excessively, but jumping from 32 to 40 seems to be way too much. I personally would've started out at like 36/33 instead of the factory 32/29 and checked for wear on the shoulders. Maybe that's what you guys have done to find the right pressure, but I can see bringing them all the way up to 40+ cold as a way to lose grip once they get some real heat in them.

-p

 

That's what I was seeing peter. I had them cold at 40/38 and they heated up rather quick and the rear was all over the place (42f / 40r). Once I lowered the rear to 37 the rear end was more predictable but the front was still squirmy.

Turn-in wasn't nearly as predictable as I was waiting for the front to slide out -- the wear on the tires appeared to be ok. Nothing excessive but with the soft sidewalls I was attempting to get the car to feel more predictable.

Eh, more seat time... more seat time....

 

You don't have soft sidewalls, comparatively speaking. The squirm is likely the front diff looking for traction...

 

well next time, if you are there, i'd like you to ride along and tell me if that's what it is. Just feels like the car doesn't bite in the turns. Perhaps I am carrying too much speed and the diffs are looking for traction.

 

I'd be happy to.