Ice mode solution?

ChrisSlicks

It's the pavement there, concrete patch on one side and asphalt on the other. One side has more traction than the other and it pulls as a result. Fortunately it pulls you towards the corner so it's not all bad and it is after the initial braking application.

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SPOHN

I run on XP 8's at all four corners with sport brakes and haven't had this issue at all. That's why I'm so interested in this thread. I've only done three track days. Two at Road Atlanta which has about three hard brake zones which none have bumps or anything that would upset the car as you said. I do brake hard and late and thats all in a straight line myself but no trail braking as of yet. Haven't reach that skill level yet.

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cossie1600

Mike, what did u run on your c6 for brakes?

for me, ice mode usually happena at the initial brake contact, not under trail braking.

I run the same compound on the 350 rx8 370 and c6, I think the xp10 have too mich bote for non slicks

wstar

For comparison with the icing I was seeing this past weekend (also XP8x4 and stock calipers, can't be far from Spohn's overall setup, except perhaps in rotor heat capacity / cooling), my most common (only actually) track surface is in fact quite ripply and bumpy, and notably so in the one section where I first had the major ice-mode problem.

In that section the weight transfer is not only heavy to the front from the braking itself, but is also heavy to the right from having just barely completely a fast left sweep before getting into the brakes. There's also a decent chance that during that initial problem stop, I hadn't quite finished rotating the car to its new straight-line direction before jumping into the brakes, by a scant few degrees. I'll probably know better once I have all the video processed.

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SPOHN

Also my LSD helps aid in slowing being it locks at 50% during braking. Might not be a factor but I thought I'd throw that in there.

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ChrisSlicks

Doesn't make much difference, just means that the rear wheels are tied together to the drive shaft and engine braking effect will be distributed more evenly to the rear wheels. The stock VLSD unit will have a similar effect just not as strong, but in a straight line this isn't a huge factor.

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SPOHN

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wstar

And Spohn, if I could offer any advice from this past weekend, it's this: if you ever do feel like the brakes just didn't work when when you asked them to, lift and reapply/modulate to regain power, don't panic and keep your foot in the brake pedal hard like I did

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SPOHN

Yea I did know that. That's why I'm so into this problem with you guys. That way if it ever happens it will be in my head. I know a lot of you guys have this issue not sure Mike and myself haven't experienced it before. Especially Mike. He has lots of track days and on about three different brake setups at that.

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clintfocus

alright, so do you guys think me running DTC60 up front and stock compound in back on a street tired stock suspension 370 is a ok idea, or just bad to begin with? Im running buttonwillow this sunday, if you guys think i should get a pad for the back with a little more bite, ill figure out how in the next few days, but if not im going to leave the stocks in the rear. This is the first time tracking my 370, so thats why im asking you guys, but i do have alot of track experience, so my pace will most likely not be slow. let me know what you guys think

Mike

Just a thought I had that I posted in another thread. It could be total BS though, I really don't know, just kicking around an idea.


OK, its been in my head stewing for a bit, but I think I know why I am against a lower compound in the rear and why a proportioning valve won't work.

The car has EFBD. it senses each wheel and applies more brake as needed. I'm not 100% sure on this, but I do think, even with a proportioning valve, it will still direct more braking to the rear or front as needed, so with a valve, you may actually decrease brake performance, as it will be reacting to the lower or higher rear brake pressure.

Even with different pads, its still reacting, which is why I use the same compound all around.

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cossie1600

Interesting, never thought that would make a difference. It was nerve wrecking the car kept pulling to the right

ChrisSlicks

Yeah it can definitely throw you off. There are concrete patches everywhere at WGI, some of them are grippier than the asphalt and some are polished smooth and less grippy. Some are grippy in the dry and then slick in the wet, so you have to learn multiple lines.

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clintfocus

Drove buttonwillow raceway park config #13 clockwise(dubbed the time attack config ) Sunday. Ran dtc 60s front, Oem rear pads, bridgestone Re11 street tires._No ice mode all day even over the brake zones that were bumpy. Ran 2.04:140 best lap time, oil temps hit 230 max just a few times with the Nissan motorsports oil cooler

wstar

Hmm, for my next event, I'm seriously considering leaving my front XP8's in place and using my Bobcat (CT street pad) on the rear and seeing what happens. Worst case I burn up my rear street pads over the course of one weekend and have to get new ones. I'm also planning to making some ducting improvements in the front before then, but I don't think I'll have a solution that brings air fully into the spindle, just into the wheel well for now.

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