I'd like to. I'll need as much seat time as I can get before the Devens Tour but I'm not sure how many events I'll actually get to before then. I'm getting married in May so free weekends prior to that are almost non-existent...

Question: What tire pressures are you guys running on your bsp/sm cars with 285 30 18 Kumho 710's? We were at 30psi all the way around this past weekend and it didn' t feel so bad but I'm just wondering what everyone else is running.

 

We run 45psi all around - you should, too!!

 

Nelson,
Get out your pyro and do some testing, hell Kyle has a whole shop, he must have some stuff in there.

You are right about events between then and now. My only chance to run Devens before the NT I have a commitment to NYR. Oh well.

John

 

easy: HKS TRB02...done

 

What kinds of brake pads are you guys using? I have the Ferodo ds2500s, but they just dont seem to heat up until the very end of a run. I'm thinking about going back to stock pads...

Res

 

Much love from "Rusty". Nelson, be careful. Once you get bit by the AWD turbo setup, it tends to get pretty addicting.

Say hi to Travis for me next time you see him.

-Sean Caron
Ex-DSM Street Mod'er.

 

Just wondering how important it is to cornerweight your coilovers for autocross and what this service usually costs? Is this something that may get you that last tenth if you are a nationally competitive driver, or is this something that really has a noticeable impact on performance at autocross speeds?

Thanks.

 

i'd like to know this as well as i'd like to get my setup corner weighed, i also heard you need to do it w/ your race tires on and in you in the car or something like that, but i'm not sure....also, what tire pressure would you recommend for kuhmo V700's in 275x40x17

Thanks

 

with a half way decent driver, a decent corner weighted setup will be worth a few tenths at a minimum. the more precise you can make the alignment definately helps at any speed, especially in autocross where the cars agility is more important than raw speed.

 

I haven't done it myself (will be shortly after I get my suspension on) but common sense tells me it makes the handling more precise and predictable turning left and right as you try to equalize weight transfer.

 

I think I'll end up doing it, but I'm concerned about doing it before I've settled on a good ride height for both ends of the car. I would hate to get cornerweighted only to find out that I really need to raise the car up for tire clearance or you have handling issues that are likely attributable to rake, etc.

 

Paul considered it an extremely important step. The guys knew the ride height they wanted to use on my setup, so they went with those specs while ensuring a 50/50 cross-balance.

 

Let me give a somewhat (although mildly) dissenting opinion...

First of all, corner weighting is not a waste of time, and probably cannot hurt you.

That being said, unless your car is way off the mark with respect to its cross-balance, I suspect the benefit is minimal. It's a minor tweak, much less important than issues like alignment, rake, damper settings, etc.

Let's say that your car has more of its weight on the RF-LR diagonal compared to the LF-RR diagonal. In general, when such a car is turning right under deceleration or turning left under acceleration, it will have better grip than a 50-50 car. When it's turning left under deceleration or turning right under acceleration, it will have worse grip than a 50-50 car.

The thing is, what is the bias of the course? Most courses are biased either toward turning left or right. Is grip more important on entry or on exit? Are any of the corners significantly on-camber or off-camber?

My point is that the "optimal" cross-weight for any particular autoX course is almost certainly not 50-50. By having your car at 50-50, you're least likely to experience cross-weight issues at a particular autoX course (assuming that autoX courses are basically randomly distributed around a 50-50 average) -- so it's certainly a reasonable goal of course, but it's no guarantee of the fastest setup.

(Oval track racers don't run 50-50, for instance. Because they generally want to optimize grip on corner exit -- which means turning left under acceleration -- they want to run a weight bias toward the RF-LR diagonal.)

And also realize that once that inside rear tire lifts off the ground, it doesn't matter what your static cross-weights are.


I recall listening to one of the all-time great autoXers talk about setting a Street Prepared car up with different spring rates on all 4 corners. There's no way that car was "balanced" in any conventional sense. But it was also ridiculously quick.



If you're going to do it, you can go ahead and do it now. You can adjust the height yourself without screwing the cornerweighting up by more than 1 percent or so -- just be careful that when you adjust ride height, you adjust it evenly side-to-side to within millimeter precision. And keep a record of the original (50-50) bracket/spring-perch position so you can always use that as your baseline for adjustments.

 

One other thing about corner weighting. I have read that if you take tire temps and your diagonal averages are very close then your corner weight (cross weight) is also very close.

I haven't done anything to substantiate this (ie get good temps and then get cornerweighted).

I do however have diagonal temp averages within 1-2 degrees F and the car feels very good. This is only with setting ride height of the car equal L-R and getting a decent alignment.

 

Any new england guys planning on getting out to the CART event at Laz parking in Hartford, CT? I will be making the trip, supposed to be a large smooth lot.