STX Rules and Setup Questions

[CoolHandMoss]

Originally Posted by ka-t_240

any tire should be scrubbed/heat cycled before compition use to help clear the mold release off the tire.

They do get scrubbed on the first two runs for sure! I was just wondering whether there is any notable improvement in grip after they've been scrubbed and allowed to rest again.

[strat61caster]

Originally Posted by smg1138

For those of you guys running RE-71R's this season, how much camber are you running? I'm currently at -2.8 front -2 rear and think I need more.

I'm no benchmark but -4 & -3 right now, fronts were showing outer edge wear but I'll be stiffening the front before increasing camber.
Rear I'm likely dropping to -2.5

Suspension setup and site will have a notable impact, maybe to the tune of half a degree? (super soft like off the shelf KW vs. super stiff Tein SRC, slick asphalt vs. grippy concrete) Not sure, but figured I'd pitch in some numbers. I've heard as high as more than -5 up front a few years ago. I stopped using the pyrometer, it was leading me to think that I was doing ok when I wasn't, I've borked tire pressures and camber because 'the pyrometer is where I want it'

[cjd]

Originally Posted by tony_r

There is no reason to spray the BFG.

Two drivers and near 100F on a small crowd needed spraying. Not 3 minutes between runs. I think it was the sixth run that started to go. And we went to ten each heat that day.

[tony_r]

Originally Posted by cjd

Two drivers and near 100F on a small crowd needed spraying. Not 3 minutes between runs. I think it was the sixth run that started to go. And we went to ten each heat that day.

Had two drivers and 95-100 this past weekend on high grip concrete. Zero issues. Dropped time every run. Tires are down to the wear bars.

[cjd]

Originally Posted by tony_r

Had two drivers and 95-100 this past weekend on high grip concrete. Zero issues. Dropped time every run. Tires are down to the wear bars.

Honestly not surprised.

I had near full tread. At a guess it was the really short intervals and the number of runs, and more squirm probably adds heat. I wish I had a codriver this year for the tires, but can't bring myself to hand over the keys on the new car after losing the last one that way.

[ka-t_240]

Originally Posted by CoolHandMoss

They do get scrubbed on the first two runs for sure! I was just wondering whether there is any notable improvement in grip after they've been scrubbed and allowed to rest again.

A propper scrubbing/heat cycle should be done prior to competitive driving. It allows the tire to be brought up to temp, get cleaned off, and then fully cooled. This results in happy tires!

[BR-ZED]

Originally Posted by ka-t_240

A propper scrubbing/heat cycle should be done prior to competitive driving. It allows the tire to be brought up to temp, get cleaned off, and then fully cooled. This results in happy tires!

Any particular procedure that you use for this?

[BE4VER]

My diff is toast and I'm leaning towards purchasing the Quaife ATB. Done a few days of searching for info and there isn't much feedback on it. Does it really perform as well as the advertisement claims or is there something I'm missing? Any downsides to this I haven't read about?

https://shop.quaife.co.uk/subaru-br-...d-differential

[CoolHandMoss]

What kind of use did you put it through to kill the diff? Just curious.

[BE4VER]

Originally Posted by CoolHandMoss

What kind of use did you put it through to kill the diff? Just curious.

Not too much, zero power added.. hard launching for a Pro Solo back in 2015, running whiteline diff kit lock out, and having 235 wide 200 treadwear tires on the car since 2014.

[kinghurl]

First diff death I've heard of. Fluid change interval?

Sent from my SM-G930V using Tapatalk

[BE4VER]

Originally Posted by kinghurl

First diff death I've heard of. Fluid change interval?

Sent from my SM-G930V using Tapatalk

Just swapped in Motul gear 300 at 18k for the first change.

but now im a little more knowledgable and now realize my original question was kind of dumb. I realize the drawbacks to this quaife atb would be the exact same as the original torsen in the car, but now Im wondering what benefits you'd see from one of these quaife atb diffs v.s. just rebuilding my stock torsen? I know its a tq bias system but wondering if it had any mechanical advantages as in... are you paying for a better tq biasing system than stock? Also asking if this unit would be a strength upgrade handling abuse better than the stock torsen?

I know all about why I should just buy a clutch type and why I shouldn't, but it's not something I really want for this car being just a pleasure vehicle that hits a bunch of autocross each summer.

TL;DR if i was already in need of a diff would this quaife atb plug and play replacement be worth the extra money?

[BE4VER]

Originally Posted by BR-ZED

Any particular procedure that you use for this?

Find a parking lot with enough room to safely slalom about or a lightly traveled road to get some heat in the tires. no need for anything overly aggressive or sliding about. just keep the temps up for a half hour or more. then let it sit for 24hrs to cure.

[CoolHandMoss]

Originally Posted by BE4VER

I know all about why I should just buy a clutch type and why I shouldn't, but it's not something I really want for this car being just a pleasure vehicle that hits a bunch of autocross each summer.

TL;DR if i was already in need of a diff would this quaife atb plug and play replacement be worth the extra money?

I'm curious about this as well. I have no doubt that there is room for improvement but I have had no problems with inside wheel spin or anything with the factory diff. I find it hard to believe that there's enough improvement to justify the cost of an upgrade. So I'm curious to hear from someone who has one.