Ed Newman

Mine is an X51.

Ed Newman

Are you running stock C2 brakes or GT3/Cup brakes? What pads? I upgraded to Cup front calipers with Brembo GT3R rotors and GT3 rear calipers and discs. I run Pagid RS29 Yellow front and RS14 Black rear. Great modulation and stopping power. With the Hoosier slicks, I can get on them very hard and not get into the ABS. I think the bigger discs give better control.

karlooz

i am running stoptech front brakes, pagid rs14 front and rear. they are GT3 sized rotors, or very similar. i can still oout brake a lot of cars on the track but i feel it can be even better without the stock ABS in the way.

Ed Newman

A few thoughts...

1. Try the RS19 or RS29 in front next time and see if it helps
2. Check your tire heights. The 996 ABS is VERY sensitive to different height tires. You must match front and back heigths within .2 or .3 inches or it will trip too early
3. Go to wider tires in front, you should be able to fit a 265.

karlooz

thx, i have not tried the RS29s with the slicks. it may work in that they have less bite than the rs14, thus not tripping the ABS.

tire heights are good. both front and rear yokos diameters are spot on, 25.6".
i would go with the 265 but that would mean a brand change as yoko do not come in that size. another thing though... wouldn't going to 265 not make a difference? the stock ABS is not used to this much deceleration Gs and will trip the ABS once it has passed it's G threshold. does the ABS have an accelerometer or does it purely measure by the toothed wheel on the hub?

Ed Newman

The RS14 is a VERY aggressive pad. The early bite may be too much. Once into the brakes, the RS29 should perform as well as the RS14. Is the ABS coming on as soon as you hit the brakes? I know it's very hard to tell but that might help decide if it is the early bite.

The ABS works off of the wheel speed difference as measured by the toothed wheel on the hub. No acceleraometer. Do you have a traqmate? I would be curious what kind of braking G's you are getting.

karlooz

it's not coming on as soon as i brake but later when i apply more pressure. i'll have to really think about it next time at the track.

my data logger shows a max of -1.4 Gs on braking. what kind of numbers are you getting?

Ed Newman

That would be interetsing. Do you have Cup brake cooling ducts?

I'll have to check my laptop tonight.

karlooz

yes on the cup ducts. my brakes have not faded at all in 30 minute races and 100+ degree heat.

eagerly awaiting your data.

jrgordonsenior

Great info Carlos and Ed on braking. In the 996 Spec class we're stuck with stock C2 brakes. I intended to run yellow (19's) and blacks as I did on my cup car but accidentially ordered oranges up front as I had them on my boxster. I've raced twice now including this past weekend at Cal Speedway which really uses your brakes. The combination worked well for me, though I will probably move to yellows up front for the next set to save my rotors. I have cup ducts below, and ducted tubing via the front bumper vented directly to the rotors. I'd love to have GT3 street or cup brakes....

As for the Yokes this weekend, I ran them all day Friday, and both races Sat & Sun starting DFL (no qualifying). They worked consistently well all weekend, my fastest lap was half-way thru Sunday's race 1:49:01. I did a time trial Sunday for the purpose if setting a new track record (which I did) running Hoosiers R6's 245/285. I did 1 hot lap and posted a 1:49:3, 2 tenths off the Yokes. I run the Yokes at 28 hot, the Hoosiers at 34...

I check my oil pressure several times in the banking and it never wavered below 4 bar. It was a quick glance, at 140 you don't want to take your eyes off that wall up there....

karlooz

the yokos were ONLY 2 tenths quicker? surprising
that was for only one lap, though. i don't think they would be as fast as the yokos for an entire race.

nice job on the track record.

jrgordonsenior

Thanks. Hoosiers were stickers, Yokes started the weekend with 3 HC's and finished with 8. They'll be my practice tires Friday at Miller....

Ed Newman

Ok, I have some issue with my Traqmate and can't download my last day at WGI which is the only time I have run full slicks. Looking at past events, it is interesting. The peak G's on braking seem to be in the 1.3-1.4 range. That is with Hoosier R6 "DOT" tires. I would assume the slicks would gain a little. The curious thing, is that the braking G's on my personal best lap at WGI never exceeded 1.25. Maybe it is true about less braking... go faster.

karlooz

true about less braking for lower lap times. my peak braking Gs came from a race, dive bombing someone in a corner.

thx for your data. very similar to mine even though i am on 230 wide slicks and you are on 265 DOTs. makes sense... grip of slicks vs. DOTS

jrgordonsenior

The compound of the slicks makes a difference too....