Two questions:

1) Recommendations on running the same or different pads in front/rear brakes? Typically I put a good track pad in the front and leave the rear's alone with street pads. Is this a bad idea? Factory brake bias nonwithstanding I figure the worst this can do is make the fronts work a little harder and also reduce the change of the rears locking up first and upsetting the car under hard braking. I could be all wet though.

2) Recommendations on pads for lapping days. Assume factory power/weight (FD), stock brakes and street tires for 20-30 minute sessions. I was using Porterfield R4-S pads last year which never faded on me and would easily cause the ABS to engage with the tires I was running. They did, however, leave nasty deposits on my rotors when they got hot after the sessions were over which caused vibrations when braking till the material got worn off. I was thinking just to upgrade to the real R4s this year, but they have this new R11 compound which looks to be superior to the R4 in every way including rotor wear, temperature range, etc. Suggestions? I'd like to stick with Porterfield for no other reason than I've had pretty good experience with their products and 20% discount on pads for NASA members.

Thanks!

 

Check this thread for a discussion on some FD track pads:

https://www.rx7club.com/suspension-wheels-tires-brakes-20/n-tech-competition-compound-440657/

 

I have a couple friends that i attend open track events with and they both were running the Porterfield RS-4 pads, and they both complained of the same things you did, and one actually had chunking of the pad in the front driver side caliper. One switched to Hawk Blues and the other switched to Carbotec XP-8's. The friend that has the carbotech pads actually runs them on the street, and loves them, except the dust that he has to clean off the wheels every two weeks or so, and he told me that he hasn't had any fade at all on the track day we last went to. Carbotech also says their pads are much more friendly on rotors than hawk pads. I'm not a huge fan of Porterfield pads, and i have never run the R4s or R11's, so i don't know how they would treat you on the street and track if you didn't want to switch pads every track event. I'm not skilled enough to have different pads in the front and rear, but when i play GT4 i love the rear Bias.....lol
Check out Carbotech and look at their XP-8 and XP-10 they might have what your looking for.

 

most guys in SCCA use Hawk Blues front and rear....as do I, and am extreamly happy with the brakes....only time I stand a chance against the Porsches.

 

On my spec 7 I used hawk blues on the front stock on the rear, on the racetrack,with no ill effects. The EBC's look like a good race pad,but never used them

 

With street tires, the Hawk Blues are probably overkill. You'll run out of tire long before you warm them up enough to work well. When they are cold, they will eat rotors up. And then there is the somewhat corrosive brake dust issue.

Having said all that, I do run them on my track FC. But that's with DOT track tires on the car (Toyos, Kuhmos, et. al.) and I am a lot more agressive on the brakes in this car over the FD.

I've run Hawk HP+ pads without any problems on my fairly stock FD. This was at VIR in the summer with mid-90's air temps. Fresh brake fluid is, of course, a must. Hawk Blacks are another option for a track pad.

I have a friend who experienced really uneven pad wear and bad rotor deposits with the Carbotechs on his FD. But I've seen other people run them without issue, so YMMV.

Good luck,

-bill

 

On stock power, and stock-sized street tires, you could probably run Nick's N-tech lapping day pads w/ decent street upgrade rears, like Axxis Ultimates.

You could almost run Nicks al of the time, except you'd replace them often.

 

Our SE weights about 2200 with fuel and driver. We have all stock rotors, calipers and master cylinder. We have a proportioning valve in the rear brake line. We don't have any cooling on the brakes. We use the stock SE wheels and stock fenders so our tire choice is limited. Last year we were running 195 55 14 Hoosier R3S05 which are no longer available. We race tracks like PIR in Portland and Pacific Raceway in Seattle as well as the very small Bremmerton Motorsports Park.
We've gone thru a few sets of Hawk Blues and are very happy with them. They come in quickly and brake HARD. They do eat through the stock front rotors pretty quickly but with the strength issues with those rotors we replace them before they have a chance to wear out anyhow. However the only way we can get the brakes ballanced is to run one stock pad and one Hawk pad in each side of the rear.

 

Just a quick update on the Porterfields. I've been running R4s in the front again and at the last event (on Shenandoah no less), I managed to melt those as well. Just like the problem with the R4-S I used to have. This is still with stock power and 235f/255r Azenis RT615's. There's pad material deposited all over the rotors now and it really messes up the works. Any suggestions on how to get rid of it in a hurry? I guess I could get the rotors turned. Anyway, looks like I'll be trying a new pad for '09.

 

It's too bad you're on stock brakes, or I'd recommend PFCs.

You could try some of the new Hawk DTM compounds. I wouldn't let Blues anywhere near my car.

 

My friend uses the blues on his 240 and they destroy his rotors in 2 or 3 events. His rotors are cheaper to replace than the pads though. I won't be doing that.

 

I've always liked Carbotechs and they make them for the stock brakes. I'd consider XP8, maybe XP10 but they're pretty aggressive for street tires in my experience. Lots of dust but they wear well and don't come apart.

They have a NASA discount as well.

I hear the DTCs are very good too, but I've never used them.

 

I run Hawk HT-10s on the front, Blacks on the rear, and I get very good life out of the pad and the rotor. Of course, this is an FC...

 

This Stoptech whitepaper suggests using Hawk Blues to clean a rotor of pad deposits:

http://www.centricparts.com/Centric%...%20Removal.pdf

I think I read somewhere that Hawk Blues are an iron carbon compound that turns into iron carbide when it heats up. If true, this would explain why it is so hard on rotors (and so good at cleaning them). Hawk Blues are good to about 1000 deg F according to the Hawk catalog. I've never used them.



My experiences with different pad chemistries:

The Porterfield R4 is a carbon kevlar compound, good to around 1300 deg F. It beds easily, and is compatible with the R4-S street compound, so you don't need to swap the rotors between street and track.

The Carbotech XP series are carbon-ceramic, good to 1600 deg. The Carbotech compounds are sensitive to how the rotor and pad are bedded in. Never use carbotech pads on a rotor that has been used with another chemistry pad - it will leave uneven deposits and judder like crazy. Even bedding a new rotor with their street pad (Bobcat) will cause this problem - I know from personal experience. In other words, if you use Carbotech XPs at the track, use a dedicated set of rotors.

 

FWIW, I use Carbotech XP pads on my M3 and change them off for the OEM pads for the street. Never had an issue.

 

Which pad do you use to bed the rotors?

I used to mix and match the XP and Bobcat pads too, but always bedded the rotor with the XP. For one set of rotors I figured I'd just bed them with the Bobcat and save a little race pad. The XPs didn't like it, and it ruined the track day.

Rather than risk a recurrence, now I just use Porterfield R4S on the street and swap rotors and pads to XP for the track. Given the cost of a track day, two extra bolts per wheel isn't that much trouble.

 

Rotors were bedded with the OEM pads. It takes about a good 20 minute session to get the XP's working again after the switch (depending on the temp on the day). For the OEM pads, it usually takes a little bit to get their transfer lay back on after the XP's, but after about 3-4 days they are fine (fronts only).

I swap the N-Tech Lapping day pads and the Bonez pads on the FD with the same results.

 

Somebody recently asked me about my "bedding procedure", and I don't even have one. I slap on the race pads, and they're "bedded" in a lap or two. I put the streets back on, and they're set by the time I've finished driving home.

I used to go out and try to find empty road, and do all these "procedures" of multiple stops, etc. Don't bother anymore. At least with the combos of Axxis Ultimate streets, and PFC or NTECH race pads, it's been a non issue.

Maybe I'm just lucky or don't know the difference!

 

Gotta love the PFCs - no need to bed the pads at all. I just go out and hammer on them from the first lap and they work great. The 01s are the best pads I've ever used. They took some getting used to, but I think I've figured them out.

The Carbotechs need to be bedded. I start out with moderate force and increase it over a few laps until I get some fade, then go to the paddock and park it until the next session. I've tried to keep going after this point and the pads didn't work well at all. But after they've cooled, the pads are mostly up to their potential.

I don't swap pads so I can't comment on how any of these work with street pads.

 

I need a set of lapping day pads with more capability than my Hawk HP+'s.

I'm considering the Porterfield R4, Carbotech XP-8, PFC 01's, and N-Tech Lapping day pads. While this is a loaded question, I'd like good HPDE capability and I'd prefer that they be safe to drive to/from the event. Naturally, careful driving is part of the game. Has anyone used any of these pads in this manner with success?

Dave

 

I've used both the R4 and the XP8 this way, and they work fine on the street to-from the track. I had bad luck using them on the same rotor though - the XP8 leaves uneven deposits if the rotor is bedded with the R4.

Based on my experience, I'd try the R4 first since they are very compatible with the R4S. If you can get by with the R4 on the track, you can use the R4S as your street pad and not have to swap rotors. If you burn up the R4 on the track, then move to the XP8 after buying some new rotors, and swap rotors when you swap pads. If you are stock, a new set of four Centric rotors can be had for about $100 bucks.

It seems likely that chemistry compatibility is a function of temperature, which means if you are using the stock FD3S brake system you will be more likely to have the problem.

 

Try Nick's lapping days first—I thought they were pretty good on track (they'll certainly be better than HP's, which aren't really track pads), and you can definately drive on them. The only real downsie is that they seemed to wear quickly on track, but you've got to have a compromise someplace.

 

R4 is perfectly streetable at any temp. But as I said before, I managed to overheat them using street tires on a hot day, even on a relatively low-speed track.

 

+1 on N-Tech's track pads (either Lapping Day or Competition pads).

 

Thanks for the feedback.

Well I called Ntech and they don't have lapping day compound in stock but he has a set of competition compound.

He says they are safe to street a little bit and the difference between the competition and lapping is mostly initial bite / torque. The temp range for the lapping and competition pads are similar. $175 is a lot of money for front pads (in my mind) but I don't see a point in buying another brake pad that might not work.

Dave