brakes and trans breather

#21

allenr wrote:

[quote]
Is the HT14 to the DTC70 what the HT10 is to the DTC60?

:silly: (a spinning head)[/quote]

The DTC70 is not available for our cars.

#22

I tried the DTC60 this weekend in the 1.5 hr enduro and they were… awesome! They warmed up almost as quickly as the HT10 and the stayed strong with almost no fade over the corse of the entire race (with brake management).
When we finished I couldnt believe how they looked. There was none of that white crusty stuff crumbling around the edges. The DTCs looked like the HT10’s after they have just been bed in.
The downside was a major sacrifice on brake bias. The car would just not rotate under braking very well. This forced me to be harder on the front tires so they eventually started to go away faster than I would have liked.
Went back to the HT10’s for the sunday sprint and they felt like bicylcle brakes. If I have the choice, I will never use them again.
I am ordering a set of HT14’s for the rear to run with the DTC’s per ranger’s suggestion.
Thanks for the guidance in this thread!

#23

I’ll also give a thumbs up on the DTC-60, while I’m just a HPDE wanker at the moment, the DTC’s had way more bite and felt great all the way down to the backing plate vs the HT-10’s that turned to mush and started to crumble once they got below half way. I’ve also used the PFC 01’s but couldn’t get enough heat in them (I was at Watkins Glen, which has some rather long stretches w/o using the brakes) to get them to work consistently, when they were hot they were fabulous but felt a little spooky cold and wore quicker than I liked (that and they were by far the most expensive pad of the group)… That being said when weighing the cost/performance factor the DTC’s get my vote.

#24

allenr wrote:

I’d love to hear how those '14s work out for you.

allenr wrote:[quote]Thanks for the guidance in this thread![/quote]
Ditto.

#25

As promised heres an update on my ongoing search for the perfect brake pad combo.
Having found that the DTC60 is the way to go as far as hawks, I ordered a set of rear HT14s for nationals. I am not as familiar with Mid ohio and the rain screwed up most of what I should have found out during the week. But I did have a chance to use them on Thursday with mixed impressions.
The car definately has more rear bite which is what I wanted, but it just doesnt feel right. It seems that when I brake the fronts “engage” before the rears. Its the same with release, which I found was more of an on/off feeling with the 14s in the rear. I’m guessing this is a result of having different compounds in the front and rear. It would be nice if hawk would make the 60s for the rear. Also I’ve heard somewhere that they have discontinued the HT14 rears for our cars :huh: .

Basically I found that the DTC requires something more than an HT10 in the rear, I’m just not sure the 14 is the solution.
I liked the feel of HT10s all around but they just faded too quickly.

I’m looking foward to testing it out on familiar ground at summit.

#26

Welcome to our site
From BHP’s web site…

We are sorry to announce that due to circumstances beyond out control, Brake Horsepower Inc has permanently ceased operations and has started liquidating our assets. We appreciate all of the support we have received from our customers and we wish all of you much success in your future.

#27

I also experimented with brake pads at Nationals. I ran DTC60’s front and HT-10’s rear. I must say I really like the new setup. I used to run HT-10’s front and blues rear.

#28

jblack wrote:

[quote]Welcome to our site
From BHP’s web site…

We are sorry to announce that due to circumstances beyond out control, Brake Horsepower Inc has permanently ceased operations and has started liquidating our assets. We appreciate all of the support we have received from our customers and we wish all of you much success in your future.[/quote]

I have a set of BHP PR1’s that I would sell if someone really wants them.

#29

I liked the BHP pads when I tried them, but the friction material on the rear pads is tiny and they wear out quickly.

Most of the season I have run HT10s all around, but the rears do almost nothing. At Summit, I decided to try the Carbotech XP12s, and just did the fronts (leaving the Hawks out back). I liked them, but decided I had to try something different in the back.

For Nationals, I decided to try Carbotech XP16s all the way around and so far I really like this setup. It might be interesting to try 12s or 14s up front with the 16s in the back (and I might do that because I still have the 12s that were used one day).

#30

Update to the brake torque Order of March.
XP is Carbotech
DTC & HT is Hawk
PFC is Performance Friction
BHP is gone so no more PR1 or PR3

XP16>XP12>DTC60>PFC01>HT14>HT10=XP10>XP8=PFC97

#31

allenr wrote:

Kind of thinking out loud here…but I’m wondering if there could be some sort of bedding issue with the rears. If Ranger is correct about the rear bias being shut down rather quickly, maybe with an even higher bite pad in the front, the rears don’t bed in correctly and/or don’t get hot enough during use. If so, might have to throw some street pads/rotors on the front and go bed in the rear pads.
I could be totally off base though :laugh:

#32

secu wrote:

[quote]
Kind of thinking out loud here…but I’m wondering if there could be some sort of bedding issue with the rears. If Ranger is correct about the rear bias being shut down rather quickly, maybe with an even higher bite pad in the front, the rears don’t bed in correctly and/or don’t get hot enough during use. If so, might have to throw some street pads/rotors on the front and go bed in the rear pads.
I could be totally off base though :laugh:[/quote]

As usual, there is no consensus. There are folks that beleive that keeping rear brake temps up is a problem that has to be addressed. I’m not one of them tho. Sure the rear brakes do less and therefore generate less heat, but the rear brakes also don’t cool for shit. The single unvented rear rotor would get hot much faster then the vented front that has 2 rotor disks. Once hot the lack of rotor venting, lack of brake ducting and the dust shield would keep it hot.

Finally, temp change is proportional to temp difference. So 1000deg brakes cool fast, but 300deg brakes cool slowly.

When I tried Ferodo pads last winter I went thru the rear pads in <2 track hours. I had nothing left but twisted backing plates. That taught me that you can get the rear brakes to work and getting heat into the rear brakes isn’t a worry. It also taught me to avoid Ferodo pads.

Note that there are good arguements AGAINST running different brake compounds F/R in order to increase threshold braking. One might increase total stopping power but end up with evil light braking characteristics in the first 3rd of a turn. So just because it’s an interesting experiment doesn’t make it a good idea.

911’s often put higher bite pads in the rear. But they have different porportioning systems and different weight distributions.

Bedding. Being obsessive by nature I was careful about bedding, right up until SpecE30. That’s when I figured out that few others seem to pay any attention to the issue. The SpecE30 bedding process seems to be:

  1. Put new pads and/or rotors on.
  2. Retrieve beer and chicken leg.
  3. In the morning methodically apply homogenous boundary layer of pad material by driving fast and braking hard.
  4. Crawl out of the car drenched with sweat and laugh at the rival who ended up backwards on the last lap.
#33

Great info.
I also sometimes get cracking on rear rotors so I dont think lack of heat is an issue because of lack of cooling.
I always bed the old school way… although I’ve almost been kicked out of more than one track for “reckless driving on access roads” :laugh: .
Again, dont take my observations too seriously until I get to try it out at a familiar track (summit) next month.
I’m thinking if I have the same problems as I described at mid-o, I will try carbotechs. If hawk doesnt care enough to make 60 rears for our cars than I wont use them at all.

#34

I just bought some Carbotech XP10’s for the front. The idea was to get a pad with similar brake torque to the Hawk HT10, but would resist cracking apart better. I’ll be using PFC01’s in the rear so the bias experiment continues. Next I’ll try XP12’s in the rear and see what the data shows.

Carbotech seems to have a nice range of pads for us, but they ain’t cheap.

#35

Carbotech prices:

325 E30 XP10 XP12
F: CT493 $149 $166
R: CT279 $172 $181

Definately expensive but if they really work then maybe its worth it…

Carbotech descriptions:

[quote]Carbotech™ XP10™ (1110™): When Carbotech unleashed the XP10™ to the general public, and it was an instant success, gathering multiple regional, divisional, and national championships. The XP10™ is a very high initial bite friction material, with a coefficient of friction and rotor friendliness unmatched in the industry. Fade resistance is in excess of 1650°F. Due to the high level of friction and bite, this material is recommended for cars weighing around 2,000lbs or more, not including formula cars and cars with brake bias bars weighing less than 2,000lbs. This is the preferred compound for the front of Spec Miata racers, SSC,SSB, T3, SRF, ITS, ITE, H1,H2, H3, H4, 944 Cup, ST, GS, Factory Five Cobra’s and many more Grand-Am/ALMS/SCCA/NASA classes. XP10™ is also ideal for advanced/instructor level HPDE drivers. XP10™ still maintains the highly praised release and excellent modulation, rotor friendliness, and 100% non-corrosive dust that have made all Carbotech compounds so successful. XP10™ is not recommended as a daily-driven street pad due to possible elevated levels of dust and noise.

Carbotech™ XP12™ (1112™): The latest iteration of the highly successful XP™ series of compounds with an extremely high initial bite, torque and fade resistance than compound XP10™. XP12™ is a world leading friction compound that is unmatched as a Ceramic racing compound, with a temperature range of 250°F to 2000°F+. The XP12™ still has that excellent Carbotech release and modulation that has made all other Carbotech compounds so successful. The XP12™ is the most rotor aggressive compound Carbotech offers, but compared to the competition the XP12™ is still very rotor friendly and contains 100% non-corrosive dust. XP12™ is recommended only for expert/very advanced drivers. XP12™ is found to be most affective on race cars weighing 2,400lbs or more using R-Compound tires; or street cars weighing 3,200lbs or more for track use only. Ideal for LMP1, LMP2, DP, T1, T2, T3, H1, H2, GT1, GT2, GT3, TC, GT, ST, GS, MX-5 Cup, etc… XP12™ is NOT recommended for use as a daily driven street pad due to possible elevated levels of dust and noise. [/quote]

Looks like the xp12 is ideal for our cars

#36

Be sure to bed in the Carbotechs with a new rotor for the best result.

Also, watch out for the rivet heads - They leave nice circles on your rotors.

#37

BrakeSwap.com told me that those prices(from Carbotech.com) were old and no longer accurate. So if you are getting pads for those prices I’d like to hear about it.

Re. XP12 being ideal. Not necessarily. Brake torque characteristics are a matter of personal preference. If the most common pad in SpecE30 is the HT10, it would be hasty to assert that a far more aggressive pad is clearly better. Some folks will ultimately like it and others won’t.

There’s been lots of pads available for years that were more aggressive then the HT10.

It would be nice if we could see some test data that shows brake torque curves relative to pad pressure and temperature.

One of the interesting things about Spec3 is that there is a spec pad. Is kinda a bummer.

#38

For me its simple: which one will not fade and offer acceptable brake bias.

I have to admit I like the idea of a spec pad. I think anything that can be spec’d should be. It keeps guys from having to spend twice as much as neccessary just to keep up. Although we would probably go with the ht10 which I am not a huge fan of.

#39

I also like the idea of a spec pad. Being a Spec series I think there should be a spec pad. This will also open opportunities for contingency money if they were spec’d. Kind of like we have now for the sixth place award in the SE with the Bimmerworld support which is great.

We find a manufacturer that is willing to offer some deal, run one more sticker and we are all on a level playing field.

I personally like the HT10’s. I think its a good pad, good life. Crumbling is a bit of an issue but not too serious in my opinion. I have not run PFC01’s but people seem to like them as well.

I have run the carbotech XP10’s and 12’s and liked them both but they are expensive. In my opinion, not worth the extra money for our application.

I have only experienced a brake bias issue while running XP12’s front and rear. I had to switch to XP10 in rear to get a nice solid feel on the brakes. The XP12 has great bite and high torque. I think they were a little much for the rear system. It certainly made trail braking interesting.

#40

Brian-
Good to hear another perspective.

I am now considering going back to the trusty ht10 all around for summit. I would hate to find when I got there that the combo I have now is a bust. Ive got a track day in the winter i can use to test pads.

note: the spec pad would probably have to be a hawk b/c nasa’s relationship with them. Rule enforcement could also be an issue. I havent looked very closely but a DTC and an HT10 look pretty identical to me inside a caliper.