I'm just an intermediate wimp. But I'm in a relatively heavy cabrio... and I brake HARD... and me and my instructor weigh in at about 600 lbs total.... and the VIR south course has one corner that is a 115ish-to-40ish hammer on the brakes... 90 second laps, so doing that every 90 seconds for 20 minutes with two other 80ish-40ish corners in between... it was death to brakes. Oh well... I had to try the track pads before I could justify the BDM.... now I know what I really need... I have a buddy with a MCS coupe who is a GOOD and FAST driver at VIR who has no problem with the XP10/XP8 combo... lighter car and maybe a little easier on brakes than me, too. So your mileage may vary. But yeah... my XP10s are crumbling around the edges, and all the orange paint turned to gray ash. And my red caliper paint turned black. I cooked 'em. And my rotors are pulsing a little... hope it's just deposits and not warped rotors... I'll have them turned a tiny bit if they don't clear up in the next couple of weeks with the Bobcats. The XP8's look almost like new - they got some wear, but didn't overheat. It's weird that my AX6 pads did better at the track than the XP10's... but I was soloing all day so 300 lbs lighter, and they faded a little late in the day but never got cooked.
I can't say I caught myself wishing for gripper tires yet... The gripped enough for a kidney crushing 1.3Gs and enough to fade my Axxis ULT pads in during the last ~3 laps of the last 2 sessions (turn 1 at summit point was 115-50mph) Haven't gotten any chunking either. Once the psi was high enough the sidewalls lost some of the squish they are infamous for. Though that and the tread pattern makes them fantastic in the wet. I only have 2 sets of wheels (stock with winters and rotas with the goodyears) and i use the rotas for april to october including all my hpdes I found it to be a good comprise street and track capable tire I subscribe to the learn how to drive well before getting r-comps school of thought <-- mistakes are more obvious on street tires just imho of course sorry for rambling!
TRUTH :yesnod: I'm definitely not ready for R-comps... but I'm also not driving anything as sticky as the Goodyears... yet. But I'll fix that sometime.
This is such a helpful tip to anyone getting into HPDE. Learn to drive street tires off your car (at, and if you're unlucky, beyond the limit) before you take the step up to the massive grip of an r-comp. Taking this attitude a bit further, my dad had an instructor who stayed in the beginner group (by her choice) for years and years. She was content to go out there and learn quicker by going slower. Turns out she was/is as quick as anyone. - Marc
Yep... after a sobering (though very minor) off track excursion during my first session Monday, I made a conscious decision to "slow down to go faster'... and spent the next four sessions happy to give point-bys so I could concentrate on improving my form vs. trying to be the fastest guy in my group... and I got a TON of benefit from it... my lines and my exit throttle modulation are way, way better than they were at the beginning of the day.
I'm with you on that! I was always content to go my pace, then for some reason two Fridays ago at LRP, I started pushing and pushing the limits of my stock tires/suspension. I knew what I was doing was risky, but I couldn't stop (I suppose this is the "red mist" driving school regulars speak of). Eventually, I went off track, and I honestly feel like I had to in order to get my mind right. I made it three years and up to the advanced group before going off - it really was a ticking time bomb! I had an instructor last year who said, "It's between your 20th and 30th day that you'll find yourself trying to do too much and going off track..." Prophetic! Anyway, sorry to stray the thread away from its original purpose. Tire pressures! - Marc
I have the BDM going on Saturday for the track Monday (KW V2's aren't going to make it on though due to time constraints, but they'll be on in July...). Blimey, you're going about it the right way. I wish I was a bit more patient, I tend to push it too hard--and you definitely learn quicker and safer if you creep up to the edge slowly rather than go past it and try to come back to it, if that makes sense... I've had three agricultural excursions to date--one was due to brakes gone (By gone I mean completely, totally, slam to the pedal to the floor and nothing gone--those were JCW brakes/JCW pads, and they came off immediately thereafter--instructor thought it was the dreaded gas between the pads/rotor deal; gave me the advice that I'd progressed farther than those brakes could handle, so off they came) at turn 5 at Road America. Over gators that seemed like 2 feet high (they've since filed them down a bit). And two others that were my own fault, and I've learned you don't necessarily need the stiffest sway bar setting, depending on your setup. You live and learn. Some say that you don't truly understand the limits until you've passed them; I honestly don't believe that though and if I can go the rest of the way without ever spinning or going off the track again that would be fine by me....
Amen... Mine was just a nice straight understeer skid over the curbing until two went off into the dirt... and I pulled right back on... Looking at the in-car video, it's almost laughably trivial, but it scared the BEJEEZUS outta me when it happened. I've seen too many videos of spins into the armco...
Some quick, worthless input from me: I've generally found 40 PSI just a bit too high FOR ME. I end up greasing the tires up. It is fine on the rears if you want more rotation, but front's I prefer at around 38. That holds fairly true for some street tires and different R compounds I've had. The key is to constantly check the tire pressure throughout the day as the ambient temp rises and falls. Cabrios: I would say run it with the top down. I've had mine corner weighted and I believe (don't have the paper in front of me) the ratio is 61-39 front to rear. The more of that weight you can transfer to the back, the better. Brakes: I run JCW brakes on my JCW '06 Mini with stock pads. I've yet to experience brake fade or any other issues and I am fast behind the wheel. Most of the time I run the car with the wife co-driving so the brakes are pulling double duty with less time to cool down. I get a feeling (and a feeling is all it is) is that a lot of the drivers are falling into the trap of getting that one fast lap at the expense of their equipment causing the overcooked brakes and deteriorating tires. I woulld say shooting for consistant lap times and learning how to maintain your equipment on the track will net you faster times in the end with a lot less wear and tear on your gear.
Good stuff. Top down wasn't an option for me at this venue... or I might have done that. Brakes - I hear ya. I KNOW I could make lesser brakes work on my car - I've done it. I KNOW I was abusing the heck outta my brakes at this event and coulda been much easier on them with little or no impact on lap times. I just didn't have the self control to do that... and probably won't in the near future... so a kit like the BDM gets me a lot of headroom to be a braking idiot. :devil:
The brakes are so track dependent too. At RA, there is plenty of time between turns, and the Wilwood's were just fine there. At Blackhawk, where it seems you're on the brakes as much as the gas, they're toast....
Good thoughts. Tracks and driving style are huge factors in how you and your car perform. I am going to over compensate with my brakes on our new track (HPR). It appears to be a deceptive little beast with 14 corners over 2.55 miles. Here is a graphic of the track. Thoughts? Fun track! Don
No, but I can see Aardvark. That little picture dos not do the track justice. Some of the pictures posted here really highlight the track. :cornut: Don
I run my Dunlop Direzza Sport Z1 Star Specs at 44 hot - the wear goes right to the edge of the tread, but not onto the sidewall. I agree with the idea that stickier tires need more pressure. I started off a track day at 38 hot, and the ride was not as crisp as I prefer. I pumped them up at lunch time and wheeeee! - much better. I've seen a few places where people run more pressure in the Star Specs, so YMMV. I used to run my Potenza RE050A's at 38-40 hot, no problem, but I wasn't as good a driver back when I had those tires. An instructor I respect runs 38 hot in his R-comps. I think he has some Kumho R-comps, not sure which ones, but I think the V710s. Alignment specs: -2.0 fr, -1.5 rear, 0 toe.
just back from njmsp-lightning course. i found that the re-01's heat up more quickly than star specs. started at 35 all around and was at 48 after first run! i don't recall that happening last year with the star specs. ideal hot pressure seemed 40. i had a very wet day. the bridgestone's didn't seem to hold quite as well as the star specs, but were very predictable.....and i like them more now that i've tracked them. in the second and third runs i was much faster and i imagine more comfortable than my colleagues in the wet intermediate group (just the place for a cabrio i think). i still have those star specs with 3/32 tread left for the next dry day (and start them at 33-35, higher just didn't land me in my happy place):cornut:.
Tim, Did you adjust down from the 48 after the other runs or did the wetness cool them down. The 40 was on the RE-01s? I take it you run high in the rear so your turn-in is crisp and rear rotates better in sharp turns on track? When is your next track day? Don