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      05-06-2018, 08:23 PM   #1
dre99gsx
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High speed track braking - wheel locking up

Looking for some opinions...

I went from PFC08 to FPC11 up front, kept PFC08 in the rear. Pocono today, braking from about 160 down to 60ish coming into the South course, I was constantly getting front squirm and an "active" brake pedal - meaning I was always fighting front brake lockup.

Could I have too much brake for these R888Rs? They are 255 up front as well. I wonder if these pads are better suited for slicks.

Also, I didn't seem to feel any better bit from these vs the 08s. Odd, but I may revert to 08s my next time out.
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      05-10-2018, 11:49 AM   #2
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Running the 11’s up front combined with bbk probably shifted too much bias to front (and your tires aren’t up to the task). That combined with motor swap (iirc more nose heavy than before?), plus the already short wheel base is a lot of forward momentum shift/bias.

Did you try braking earlier instead of dropping the hammer last second? You might be faster around the corner if going slower (lift a little and braking earlier) and carrying a higher entry speed then coming in so hot and having to drop that anchor....

Re squirm, what shape are your rtabs in? And what’s your toe settings?
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      05-10-2018, 11:22 PM   #3
dre99gsx
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Re bias...possible, as I did not have this issue on the 08s. Mind you, the track was damp all day, no sun, and cool. Previous weight balance was 49R/51F, I'm now at 48R/52F.

As far as braking is concerned, I'm not hammering it down, but am providing more progressive brake. But, as soon as it gets towards the peak of braking, it will start doing this.

I will try the 08s again next track out and see how it goes. The 08s performed pretty well, I just wanted more bite right at the initial application. I think I got it haha... These 11s may be better suited for slicks.

I'm at -3 front, -2 rear (camber), and maxed out toe-in in the rear (not much unfortunately, probably 1/8"), and 0 toe front.

Rtabs are <1 year old upgrades to Rogue Engineering. I did just find out my front-passenger FCAB (AKG 95a) now has slop. Wondering if this contributed to some of that squirm.

You are correct thought, these cars have such short wheelbase, that there is only so much we can probably throw at them.
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      05-11-2018, 08:50 AM   #4
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FCABs would definitely cause squirm under braking, but assumed it was alignment settings because I recall you just replaced those poly bushings not too long ago. Full metal bushings is no fun, maybe these are good compromise (paired with blue option):

http://www.rogueengineering.com/Rogu...E46_p_100.html

Honestly you may as well get 11’s for the rear since at very least you’ll want a balanced setup or perhaps even shift more bite to the rear. And it won’t be a total waste because those 11’s you have now won’t last nearly as long as the 08’s so you can keep the 08’s as a backup at the track.

To your point, if you’re not getting heat in those tires then I can see how the brakes are overpowering the tires. Hope you get this figured out though, solving for brake issues is the worst. Plus I think this is potentially one of the best oe brake upgrades for non-M owners.
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      05-12-2018, 01:16 AM   #5
dre99gsx
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I'll shoot for 11s out in the rear then, thanks for the tip. I can then mix and match a bit next time out.

Those rogueengineering are almost similar to my AKGs. The issue with my AKGs is the inner insert has some side-to-side play. I suspect I would get the same with those rogue units?

I also considered these:

https://www.turnermotorsport.com/p-3...e-e46-m3-pair/

and

https://www.ecstuning.com/b-turner-m...020321tms01~a/

I'll figure something out.
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      05-12-2018, 10:53 AM   #6
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Quote:
Originally Posted by dre99gsx View Post
Rtabs are <1 year old upgrades to Rogue Engineering. I did just find out my front-passenger FCAB (AKG 95a) now has slop. Wondering if this contributed to some of that squirm.
If you've got any lateral play in the FCABs or the control arm ball joints you'll feel it the most under hard braking since toe will be changing all over the place. I think I'd get this corrected before I'd push the panic button on the pad compound change. I just replaced control arms and FCABs for the 2nd time in two years to fix this same issue.
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