I took my own advice and left the rear bar alone-<br>The weekend was great and I (and most everyone else) will have pix up before too long.<p>The slotted disks never faded, but I need to upgrade the lines. The black coating has turned white from the heat...<p>I'll have more info once the film is developed, scanned and dumped to the ftp site.
10-05-1998, 10:12 AM
Jason, I caught myself on two turns....and made the correction before anything got hairy. Good feeling to catch it and make the adjustment.<p>Felt my brakes fading on several occasions...got to get the Brembos, lines, and ATE Super Blue in there for next time.<p>Steve S.<br>97 2.8QM<br>
10-05-1998, 10:55 AM
At the end of sessions, I felt my brakes starting to fade pretty badly. On the up side, it did get me to actually take one turn better by having to wait longer.<p>I think I boiled the fluid once too, at least that's what some people suspect. I found some brake fluid around the cap for the brake fluid reservoir. The cap was a little loose too.<p>Contemplating discs, lines, and a brake flush,<br>98.5 Wett RamAir'ed Santorin Blue 2.8QMS
10-05-1998, 11:17 AM
My cap comes loose occasionally after driving gravel roads. I'm a little suprised you guys are getting so much fade.<p>Are you getting deep into the abs?<p>Doing a lot of late braking?<p>Are you pads really worn? Disk?<p>Can you touch your front rims after a session (very hot)?<p>Do you have aftermarket rims?<p> Are they an open "airy" or closed design?<br> <br> Are they 17"?<p>The slotting doesn't really make a difference in dry racing. So, I would assume that the new full mass disk helped here. There are a bunch of superb aftermarket pads out there that grip even better at very high temperatures. I like the Porterfield R4S's for on off track use. A good pad has a ceramic insulating layer to keep the heat off the caliper.<p>If the brake lines near the caliper are very warm (too hot to touch), then I would definitely get some better fluid (Castrol SRP anyone?).
10-05-1998, 02:15 PM
10-05-1998, 02:48 PM
10-05-1998, 07:38 PM
Re: ABS<br>After a few laps, ABS starts to kick in when I brake heavily. This is with BFG R1's too. The track was a bit bumpy at those braking points though.<p>Re: Late braking<br>Yep...<p>Re: Pad/disk wear<br>Not too bad. The disks are a bit grooved from the weekend, but no big deal.<p>Re: Touching rims after a session<br>This would just be a bad thing. I know, I tried.<p>I use the factory sport rims for the track (with BFG R1's on them). I've never noticed brake fade off the track.<p>98.5 Wett RamAir'ed Santorin Blue 2.8QMS
10-06-1998, 05:55 AM
10-06-1998, 06:38 AM
I have one roll to get developed, the second I still have a few shots left.<br>Maybe I'll burn them and get them posted by the weekend?
10-06-1998, 06:54 AM
10-06-1998, 09:06 AM
10-06-1998, 10:18 AM
10-06-1998, 04:55 PM
Warren-<p>I was browsing TireRack today to learn about R-1's and I read their information about heat cycling the R-1's and letting them rest for 24 to 48 hours to enhance longevity. Did you have your new tires heat cycled before you mounted them?
10-07-1998, 06:26 AM
The old standby for stock class cars is now dead. They have been replaced by the GForce for better or worse.<p>R rated tires should be heat-cycled once before racing, then let sit. You can have them do it for a charge, or just drive them yourself for free.
10-07-1998, 04:38 PM
Yeah, I saw the g forces on the tire rack web site. <p>Back to heat cycling--it's the bit about waiting 24 to 48 hours if you do it yourself that I wondered about.<p>Warren W. had just bought his R-1's prior to the TWS event, but he did comment that he had 50 miles on them, I think. Maybe it was 5o miles on his bars.<p>Cheers
10-07-1998, 07:41 PM
Howdy Drew. Yeah, I had about 50 miles on the R1's to heat cycle them. The worst wear was when I ran 2 sessions back to back. On the outside tires, I have what I can only describe as a "melt line". It looks like the inside edge of the shoulder block (uh, that's like 50% of an R1), is slightly "melted".<p>I've still got plenty of tread though, and they're worth every damn penny IMO. Better them than my Toyo Proxes T1's...<p>98.5 Wett RamAir'ed Santorin Blue 2.8QMS
10-07-1998, 08:19 PM
It's a chemistry thing. Heat cycling them up to full race hot temps, and then allowing them to cool and contemplate their navels for at least 24-48 hours allows all the compounds in the tire to "cure", just like bathtub caulk or silicon sealant. Once the rubber molecules have formed permanent, romantic attachements with all the other molecules, you'll have a much more consistant, longer wearing tire. Ever wonder what the TV guys mean when they say that "Joe Blow Racer has just changed to scuffs" ??? Scuffs are new tires that have been on the track just long enough to heat them up to operating temp, scuff the lables off, and then allowed to do that navel thing for a couple of days. If you're trying to rip off one fast lap, use a new tire. If you're trying to last all 500 miles, use a tire that's been heat cycled.<p>Groove of Death ? Watch out for R1's wearing the center out faster than the outside edges. If you see this starting to happen, RAISE the pressure by 3+ lbs. R1's are really touchy about pressure, and the Groove of Death is a sure sign that you're under-inflated. That melting you described is normal (if I understood your description) in a tire that has been up to operating temps (160-210 deg. F.)<p>
10-08-1998, 07:54 AM
The outside of the center tread is indeed wearing faster than the inside. I tried 38/36 on the first day, but the car ran better with 34/34 on the second day. Maybe I'll compromise next time and do 35/35. Does this sound about right for an A4?<p>As for the melt line, thanks. I wasn't sure if that meant that I overheated them or that it was normal. Like I said, I love the tires, and the only time that I felt them start to slip a little was on a back to back session. I had to take some of the road course with less power, otherwise I'd just slide.
10-08-1998, 08:45 AM
R1's, due to their contruction, are a lower pressure tire than most other race tires. <p>2700 lb. RWD Volvo race car - solid rear axle, coil-overs and BIG bars, 2x normal spring rates - 25-28 front, 21-24 rear.<p>2200 lbs. GTI race car - FWD, coil-overs, 2x normal spring rates all around, front lower bar, 246-30 front, 28-35 rear. <p>I don't run R1's on the rest of the fleet, so this is the only good data I have...<p>Toyo Proxes RA-1's, Hoosiers and Kumho's (especially Kumho's) run 5-15 lbs. higher in all four corners. <p>Call a good BFG tire rep (not Tire Rack, they just have good prices but not necessarily good data) and ask him about 3300 lb. A4's. My guess is that you'll end up in the high 20's or low 30's on R1's.
10-08-1998, 03:25 PM
Buy a pyrometer adjust your temps. as close to equal as possible. You can raise and lower the <br>inside,middle,and outside temps of the tire with an air gauge...neat.