I bought these for a lapping day and used them yesterday and I have to say I'm a big fan of them. Carbotech advertises them as a track only pad and I'd pretty much agree with that because they do make some noise at light braking pressures and are a little weak at cold temps but not nearly as bad as I was expecting - not so bad that you couldn't drive them on the street, just not ideal.

My setup in front consists of Z32 rotors, J30 calipers (twin piston), Maxima torque member (caliper bracket as some may call it), Goodridge Stainless Steel lines. Rear setup is stock everything with Hawk HPS pads. Valvoline SynPower fluid. Tires were Kumho MX in the front and Hankook RS2 in the rear.

Pedal feel was firm and never left me unsure of if my brakes were going to be there at the end of the next straight. I ran in Intermediate II run group (the higher of the intermediate groups) initially because I haven't been on a road course since 03 or 04, and I was eating people alive in that group. I moved up to advanced I (the lower of the advanced groups) and ran probably in the middle of the pack and in both groups I noticed that most of my advantage over people was under braking. I of course had way more brake power than tires, and next time I go to a road course I'm going to be on R compounds.

So anyways, Carbotech XP8s are highly recommended by me if you like to track your car. They would not be a good choice for street or autoX though, need to get too much heat in them for them to really shine.

 

huh, i was just planning on getting the hawk HPS up front. i don't get the opportunity to track much but i auto-x almost once a month.

how are those kumho MX's by the way. i was looking into them but considered not getting them cause they don't seem that great for treadwear for daily use. right now i'm planning on getting the SPT's all around.

 

you would not want XP8s for auto x as i said, you'd never get them up to temp. they'd make you slower.

MXs are not a great autoX tire. the Falken Azenis is the ubiquitous autoX tire. it is stickier at autoX temps than the MX is and has a stiffer sidewall. The MX is stickier when hot than the Azenis is though, which is why I got it. you put so much more heat in a tire when lapping than autoXing that the azenis start to lose their grip.

I have ridden on SPTs in another car - my buddy's Volvo S60R AWD and it seems to be a pretty good tire, but it's definitely no contender for dry autoX. I'm not sure if you're looking more towards it for it's treadlife and streetability than it's autoX ability though.

 

right, i wouldn't get the xp8's since i don't track that often.
basically for the tires, i want a decent all rounder thats still within my budget. more towards the treadlife and streetability. i thought about the general exclaim UHP's but a friend of mine just got them and auto-crossed on them. said they were pretty slushy even with the tires inflated @ 45 psi... so i'm staying away from those.

 

I've been using the carbotechs for a while now. If you plan on using the R compound tires (Hoosier/BFG/Hankook etc) I would seriously recommend using the XP10 or 12. The 10 should probably be fine. I couldn't use the 8 on my SSC car. I'd get fade within 3 laps. The 12 was my pad of choice. They do take a lap or so to get warmed up though.

Cheers.