E30 guys...

I'm running Carbotech XP10s in front and XP8's in the rear of my 325is. The XP10s are a bit overkill. They were actually overcooling and getting me into a lot of trouble at VIR.

I am about to try Hawk HT-10's and Blues (Front/Rear, respectively). Should I be expecting the same level of performance/balance as the Carbotechs I'm running now?

What differences should I expect?

Thanks

I used to run the Carbo's and found that they overheated too easily and I had full brake cooling components installed. I switched over to HT-10s all the way around and found that to be a winning combo. I have tried the blues before and they worked tremendously well in the rain, however in the dry, especially summer time, they gave up about 2/3rds of the way through our sprint races. Also, remember that the blues are hard to find and have highly abrasive dust.

Depending on what you are doing with the car, I would do the following:
HPDEs: Ht-10s all around.
Racing: DTC-60s front, HT-10 rear.

Thanks,
Jon

Most of the SpecE30 guys run HT10s all around or PFC01s all around. I don't understand the love with Blue's - the dust is a PITA (I know - it's a race car), the technology is old (and I know - that doesn't make it bad). But the HT-10 is so much better in just about every way.

From my understanding, Hawk keeps the Blues around because they were so popular for so long, even though they are 2 generations behind (the HT-10 is last generation, the DTC pads are the up and coming, but the pad layout is not available for many fitments yet).

I have PFC01s on now, and I'll probably go back to HT-10s all around next time.

HT-10s all around FTW.

I'm happy w/ HT10s all around also.

Another "HT-10 all round" here.

-Charlie

I'm running HT-10's up front and HPS out back, but I'm just doing Time Trials. Works great for me, but I'm a newb.

Tried the Blues, wore through a set in 2 days and destroyed my wheels with the dust. Never again.

I use Hawk HT-10's all the way around. I do have a few sets of Performance Friction or something else. They are in a blue box. I am going to use them until my rotors crack, and then go back to ht10's. My brake set up is also different and the spec guys.

Personally I started to have problems with HT-10s crumbling and not lasting.

Switched to PFC's 01 and haven't looked back. Some of this is subjective feel to an extent, but I find the PFC's easier to modulate and more progressive then the HT-10's. I also think they last longer. Just my experience though.

Personally I started to have problems with HT-10s crumbling and not lasting.

Switched to PFC's 01 and haven't looked back. Some of this is subjective feel to an extent, but I find the PFC's easier to modulate and more progressive then the HT-10's. I also think they last longer. Just my experience though.

I've heard good things about the PFC 01's. Do you have a good source to buy them from?

I got mine from Bimmerworld. Might not be the lowest price around (but maybe they are), but I like to support the vendors that support us (with the board, BMWCR and NASA). Bimmerworld does.

I'll second (or is it third?) the recommendation for the PFC-01 pads all around. I've used them and the HT-10's and I think modulation and pedal feel is better with the PFC's.

I'm not the most experienced guy around but I have trouble understanding the HT10 F and Blue R scheme. E30 braking is pretty front biased. If you put Blue's in the rear, an E30 will be even more front biased. Why throw away potential braking? Same deal with DTC60's in front and HT10's in the rear.

Near as I can tell, the most common solution is HT10's all around, followed by PFC01's all around. I'm experimenting with balancing brake bias a bit by putting pads in the rear with more bite. Current solution is HT10's in front and PFC01's in the rear. That is working out fine, but I'm not quite sure I'm ready to say that it's clearly a better solution than the same pads all around.

BHP makes a nice front pad too. A little more expensive tho. The BHP rep described them as similar in bite to HT10's, but they struck me as having a little more bite.

The reason for the shifting of pad material is because the rears do not necessarily maintain enough heat to ensure that a pad such as the PFC or DTC will be within their optimum temp range at all times. If the rear pad is no longer in the optimum range than the bias is further shifted forward causing an issue.
The fronts on the other hand do maintain enough heat to take a higher level pad so for longevity reasons, you place a DTC or PFC component there for overall wear and mid-race strength. The HT-10s will go away on you.

I've heard good things about the PFC 01's. Do you have a good source to buy them from?

Bimmerworld. Again not sure they're the cheapest but I stick with the guys that stick with me, and I know what I'm getting. Anytime I've experimented with other vendors I've had problems that offset the 'cheaper' price.

The reason for the shifting of pad material is because the rears do not necessarily maintain enough heat to ensure that a pad such as the PFC or DTC will be within their optimum temp range at all times. If the rear pad is no longer in the optimum range than the bias is further shifted forward causing an issue.
The fronts on the other hand do maintain enough heat to take a higher level pad so for longevity reasons, you place a DTC or PFC component there for overall wear and mid-race strength. The HT-10s will go away on you.

The concept that you might not keep your rear brakes hot enough is no reason to add more bias to the front by putting higher torque pads in the front. Make the rear do the more work and the rear will get hotter. And since it has a single rotor (vs. 2 layer vented) and no air ducts, it will stay hotter.

The bottom temp range for these pads is ~500deg. Our tire operating temp is around 200deg, so it's not that hard to imagine our rotors being able to stay 300deg hotter. With crappy air flow and limited surface area, rear brakes can't possibly cool well. So once they reach operating temperature, staying at operating temp doesn't seem too unreasonable.

It's hard to say anything with any certainty without seeing test results. But E30's are not unique in this problem of OEM forward bias. 911's have the same issue. And those folks put higher bite pads in the rear to create more balanced braking. I'm not saying that they have the lock on the truth, but if they are addressing a similar situation in an opposite manner, we should ask ourselves why.

I think that it would be hasty to say that, without question, unbalancing the bias more forward is better then balancing the bias more to the rear.

Last month I was experimenting with Ferodo 2500's and 3000's. The higher torque pad was in the rear. My braking was pretty darn good. Until I burned thru the rear pads in a couple hrs.

I infer that 1) You can get E30 rear brakes to work. 2) Rear rotors stay reasonably hot. 3) Ferodo pads suck.

It goes without saying that changing your car's brake bias creates significant changes in trailbraking behavior. "Hey, how did I get backwards?"

The concept that you might not keep your rear brakes hot enough is no reason to add more bias to the front by putting higher torque pads in the front. Make the rear do the more work and the rear will get hotter. And since it has a single rotor (vs. 2 layer vented) and no air ducts, it will stay hotter.

The bottom temp range for these pads is ~500deg. Our tire operating temp is around 200deg, so it's not that hard to imagine our rotors being able to stay 300deg. With crappy air flow and limited surface area, rear brakes can't possibly cool well. So once they reach operating temperature, staying at operating temp doesn't seem too unreasonable.

It's hard to say anything with any certainty without seeing test results. But E30's are not unique in this problem of OEM forward bias. 911's have the same issue. And those folks put higher bite pads in the rear to create more balanced braking. I'm not saying that they have the lock on the truth, but if they are addressing a similar situation in an opposite manner, we should ask ourselves why.

I think that it would be hasty to say that, without question, unbalancing the bias more forward is better then balancing the bias more to the rear.

Last month I was experimenting with Ferodo 2500's and 3000's. The higher torque pad was in the rear. My braking was pretty darn good. Until I burned thru the rear pads in a couple hrs.

I infer that 1) You can get E30 rear brakes to work. 2) Rear rotors stay reasonably hot. 3) Ferodo pads suck.

It goes without saying that changing your car's brake bias creates significant changes in trailbraking behavior. "Hey, how did I get backwards?"

Not saying that your problem is mechanical, it may be a preference or driving style, but ensure that all of your brake and suspension related components are in top shape. Worn rotors, wheels not torqued properly, bad bearings, crimped brake line, tired/deteriorated bushings, and even improper tire pressures can cause a cars braking characteristics to change or feel "flawed". Cooling may be an issue as well, over cooling or uneven cooling can cause a pad to wear funny and not perform well.

Some people feel that running a lower friction pad in the rear will help because it's not up to the rigors of track duty and will begin to heat up quickly (especially if it were a front pad, seeing the bulk of the responsibility of slowing the car). This will keep the pad hotter and closer to the optimal operating range.

Having said that, I've never run mixed compounds in any track car I've driven. I'll be trying the PFC01's front and rear this weekend at Watkins Glen.

Not saying that your problem is mechanical, it may be a preference or driving style, but ensure that all of your brake and suspension related components are in top shape. Worn rotors, wheels not torqued properly, bad bearings, crimped brake line, tired/deteriorated bushings, and even improper tire pressures can cause a cars braking characteristics to change or feel "flawed". Cooling may be an issue as well, over cooling or uneven cooling can cause a pad to wear funny and not perform well.

Some people feel that running a lower friction pad in the rear will help because it's not up to the rigors of track duty and will begin to heat up quickly (especially if it were a front pad, seeing the bulk of the responsibility of slowing the car). This will keep the pad hotter and closer to the optimal operating range.

Having said that, I've never run mixed compounds in any track car I've driven. I'll be trying the PFC01's front and rear this weekend at Watkins Glen.

What problem? I'm experimenting with brake bias and one of the experiments used pads that, by today's standards, are not up to par.

If a pad is not up to track duty, why would it get hotter? If a pad isn't stopping you, it's not generating as much heat as a pad that is stopping you.

The idea that rear pads don't generate enough heat to stay in the track pad operating temp range is a common idea. But that doesn't mean that the idea is correct. And even if it is correct, it doesn't mean that putting a lower friction lower temp range pad on the rear is the logical solution.

My point is that it is a mistake to dismiss a plausibly effective solution just because of herd instinct. Where's the data? Why are the 911 driver's going the opposite direction?

I've also hard very good luck with ht-10's going to try some PFC01's up front this weekend at WGI (my rear are almost brand new still). The other this I've heard with running split torque pads (more aggressive pads up front) is to aid in trail braking. The theory being that the less agressive rear pad allows less rear bias making it easer to "drag" the rear brakes in trail braking situations. I'll let you know how it works this weekend with a PFC01/HT-10 setup :)

I've also hard very good luck with ht-10's going to try some PFC01's up front this weekend at WGI (my rear are almost brand new still). The other this I've heard with running split torque pads (more aggressive pads up front) is to aid in trail braking. The theory being that the less agressive rear pad allows less rear bias making it easer to "drag" the rear brakes in trail braking situations. I'll let you know how it works this weekend with a PFC01/HT-10 setup :)

I've talked to other folks with the same idea, although not everyone chose that pad combo to get there. Let me play devil's advocate for a minute:

1) We already recognize that E30 brakes are biased forward. Do we really need to remove even more rear braking in order to trailbrake well?

2) Do Pro driver's use their cockpit biasing adjustment to balance their braking, or to intentionally imbalance?

3) Balanced braking will slow you down faster. Why are we so quick to sacrifice that?

I'm not asserting that you are wrong. This is as much art as science. Think of these as just discussion points.

I just ordered the Performance Friction 01's from Bimmerworld. Of course I'm buying from them as they saved my ass at Roebling last year and are generally around the club races a lot. Good... No, GREAT guys.

Good choice! I think you'll like them.

Scott - I haven't looked at this from a science point of view, but I can say that the PFC's are easier to trailbrake (for me) due to their progressive feel.

I can get into the brakes hard, start my turn in, feel the car take its set and the back rotate while I'm releasing pressure and adding more steering input.

The HT-10s felt too 'on/off'. I can still do it but it isn't as comfortable as with the PFC's. My two cents. What that has to do with the bias, etc. Not sure, but I've looked at the graphs and my car stops as quick or better as Skeen and other 'good' drivers that run different setups so I think from a performance standpoint they're at least equal and maybe better.

As always though your mileage may vary.

What problem? I'm experimenting with brake bias and one of the experiments used pads that, by today's standards, are not up to par.

If a pad is not up to track duty, why would it get hotter? If a pad isn't stopping you, it's not generating as much heat as a pad that is stopping you.

The idea that rear pads don't generate enough heat to stay in the track pad operating temp range is a common idea. But that doesn't mean that the idea is correct. And even if it is correct, it doesn't mean that putting a lower friction lower temp range pad on the rear is the logical solution.

My point is that it is a mistake to dismiss a plausibly effective solution just because of herd instinct. Where's the data? Why are the 911 driver's going the opposite direction?


I don't mean you have a "problem" necessarily. I'm implying that there is a chance you are unhappy with certain setups because of a mechanical issue, not the chemical adhesion of the brake pads. Any by "you", I mean anyone unhappy with their car's braking characteristics.

Have you ever driven street pads on the track and gotten them so hot they felt greasy? That is what I meant by having a lower friction compound in the back, if it's not a track pad, it will get hot quickly. Some people, not me, feel this gets the rear pad into it's desired temperature range. Or at least close.

I don't agree with "if it's not a track pad, it will get hot quickly". I would instead say, if it's not a track pad, it will quickly get outside of it's design heat range.

The couple of times I used street pads on the track...well, I'd use the word "scary" instead of "greasy". By lap 2 I knew I had a problem. And after a good scare in lap 3, I went in, took those pads off, and threw them in a dumpster.

I still contend that a rear pad that is doing more work (because it has more bite), will be a rear pad that stays hotter. The fact that I burned thru those Ferodo rear pads suggests that I had no problems keeping them hot.

Lets say that with equal pads E30 rear brakes do 1/3rd as much work. I'd bet that they get <1/3rd as much air flow. And I bet that the single rotor design cools <1/3rd as efficiently as the front vented design. Therefore it's at least within the realm of reason that they can stay around the same temp as the front.

All I'm saying is:
1) The goal of balanced brake bias is a reasonable thing to explore for stopping faster.
2) Putting pads with more bite in the rear is a reasonable idea to explore for balancing that bias.

So I'm not saying "This is the way it is". I'm saying, "hmm, we ought to experiment with this."

I don't agree with "if it's not a track pad, it will get hot quickly". I would instead say, if it's not a track pad, it will quickly get outside of it's design heat range.

The couple of times I used street pads on the track...well, I'd use the word "scary" instead of "greasy". By lap 2 I knew I had a problem. And after a good scare in lap 3, I went in, took those pads off, and threw them in a dumpster.

I still contend that a rear pad that is doing more work (because it has more bite), will be a rear pad that stays hotter. The fact that I burned thru those Ferodo rear pads suggests that I had no problems keeping them hot.

Lets say that E30 rear brakes do 1/3rd as much work. I'd bet that they get <1/3rd as much air flow. And I bet that the single rotor design cools <1/3rd as efficiently as the front vented design.

All I'm saying is:
1) The goal of balanced brake bias is a reasonable thing to explore for stopping faster.
2) Putting pads with more bite in the rear is a reasonable idea to explore for balancing that bias.

So I'm not saying "This is the way it is". I'm saying, "hmm, we ought to experiment with this."


And don't get me wrong, I'm not saying not to experiment with anything. It's like tire pressures, people run all sorts of combos to get what they feel is "perfect" for them. As far as running more aggressive rear pads, my biggest concern would be locking up the rear as the weight transfers to the front under heavy breaking. That may be an extreme case, and/or vary depending on car and setup, but I would assume (bad word) this is why more people don't try it.

We all agree that E30's are front biased. So currently the front locks up first. If we keep putting pads on the rear that have more and more bite, eventually we will have the rear locking up first. Which isn't necessarily bad.

Here's the most simple scenario where all we care about is straight line braking.....Lets assume that the standard E30 front locks up when the rear had 500 hp of braking capacity unused. When we have so much bite in the rear that the front has 500hp of brake capacity unused, then we've gone too far. Too far, because we've created a rear bias that is as inefficient as the current front bias.

Between the two is a big grey area that consists of additional braking potential. We need to explore that grey area where we don't leave 500hp of braking potential on the table, yet we have trailbraking characteristics that we like.

Bimmerworld. Again not sure they're the cheapest but I stick with the guys that stick with me, and I know what I'm getting. Anytime I've experimented with other vendors I've had problems that offset the 'cheaper' price.

I can't agree with that comment more.

Regarding the brake choice, I've had excellent luck with the HT-10s. For one race I had HT10 front and Blues in the rear...never again! In trail braking situations, the release characteristics of the Blues in back made for some interesting situations.

I have a set of PFC01s from Bimmerworld sitting in my trailer when my HT10s are done. From everything I've heard, I'm really looking forward to using them.

You may be considering this but the weight shift can effect lock up too. So just because a wheel is locking up mean that it is putting down effective braking force.

Watch the World Challenge cars, the Acuras and Mazdas lock up rear wheels all the time simply because there is no weight on that wheel and it is effectively doing nothing to slow the car.

I'm not sure there is a magic combination of brake pads that is going to make a significant difference in stopping our cars. I'd be looking for those that give you the most confidence under braking and allow you to manage the attitude of the car. If you figure something out though tell me first.

You may be considering this but the weight shift can effect lock up too. So just because a wheel is locking up mean that it is putting down effective braking force.

Watch the World Challenge cars, the Acuras and Mazdas lock up rear wheels all the time simply because there is no weight on that wheel and it is effectively doing nothing to slow the car.

I'm not sure there is a magic combination of brake pads that is going to make a significant difference in stopping our cars. I'd be looking for those that give you the most confidence under braking and allow you to manage the attitude of the car. If you figure something out though tell me first.

Ya, I agree that my analogy was simplistic. The car's weight distro at the onset of braking, in the braking zone, and trailing off of the brakes has an infinite # of variations. But if we absolutely know that the E30's are front biased, then we have to experiment with bringing that bias more into balance.

There are a number of variations to try:
Hawk Blue Front, HT10 Rear
HT10 Front, PFC01 Rear
HT10 Front, HT14 Rear
??? Front, HT14 Rear
BHP Front, ?? Rear

So we should be able to find something that compensates for the front bias, but not too much so.

Some folks talk about how the OEM designed the brake bias, as if that's the ideal carefully engineered solution. But that arguement is a nonstarter. OEM's have lots of design considerations, and performance is only one. For example, OEMs don't spec neutral front camber because of it's performance advantage...it's the lawyers.

all of you running HT-10s on a E30, is this with or without brake cooling ? i don't mean the stock cooling ducts, i mean the kits that run right up to to the rotor like this : http://www.factory3performance.com/shop/shopdisplayproducts.asp?id=42&cat=Brake+Cooling

Cooling SpecE30's is a whole 'nother issue. That one has a number of long threads both here and at SpecE30.com.

Most folks racing SpecE30 have air ducts/hoses bringing air to the front brakes. Most of these cooling their brakes are using one of a couple designs of backing plates to hold the hose near the rotor. Your link is one of those designs.

The guy behind Factory3 Performance is Chuck Taylor. He's one of those guys you want at your back when there's bad guys in the wire and final protective fires are called.

But back to brake cooling. As usual, I'm the problem child. After trying one type of backing plate and looking at numerous others, I decided that I didn't like any of them. So I ended up McGuyver-ing a solution that is so fabulous it will go down in the history of race car engineering. Go buy a couple Chef Boy R Dee cans and you too can walk down Ranger's path of brake cooling greatness.

The Chef Boy R Dee can reference will make sense when you read some of those threads.

Cooling SpecE30's is a whole 'nother issue. That one has a number of long threads both here and at SpecE30.com.

Most folks racing SpecE30 have air ducts/hoses bringing air to the front brakes. Most of these cooling their brakes are using one of a couple designs of backing plates to hold the hose near the rotor. Your link is one of those designs.

The guy behind Factory3 Performance is Chuck Taylor. He's one of those guys you want at your back when there's bad guys in the wire and final protective fires are called.

But back to brake cooling. As usual, I'm the problem child. After trying one type of backing plate and looking at numerous others, I decided that I didn't like any of them. So I ended up McGuyver-ing a solution that is so fabulous it will go down in the history of race car engineering. Go buy a couple Chef Boy R Dee cans and you too can walk down Ranger's path of brake cooling greatness.

The Chef Boy R Dee can reference will make sense when you read some of those threads.

thanks for the info but my question is specific to ht-10s and not cooling in general. what i'm asking is that since the ht-10s (and other compounds) need to build up heat to be effective is cooling going to be counter-productive on an e30?

The HT10 is by far the most popular SpecE30 brake pad. Therefore most SpecE30 braking issues are largely an HT10 issue.

Personally, I think that the issue of rotors having problems staying within the operating temp range is over-wrought. Our tires operate at 200deg so the rotors just have to stay 300deg higher to be within the pad operating range. The sheer volume of steel and aluminum in the wheel/hub will resist cooling off rapidly. Things cool off rapidly at high temp differentials, but as the rotor temp drops, cooling occurs slower and slower.

How often do we hit the brakes, at least every 20secs? And some air blows on them thru some 3" hoses? Doesn't seem like staying in the temp range would be that hard. This is especially true for the rear where there is no air flow and the rotors aren't vented. Yet all sorts of folks are anxious about rear brakes being too cool. I put on some high bite pads (Ferodo) on the rear for a race weekend the other months. After 2 quals and 2 sprint races I was on my rear backing plates. Keeping my rear pads hot was the least of my problems.

tks. i'm planning to switch to HT-10 all around and install the factory-3 kit. i was just worried that i'd over-cool the fronts. seems not to be an issue..

tks. i'm planning to switch to HT-10 all around and install the factory-3 kit. i was just worried that i'd over-cool the fronts. seems not to be an issue..

Don't take anything I say as gospel. I'm the rebel. You'll find lots of opinions, most from folks with more experience then I. But I admit that being a mechanical engineer is handy when the issue is heat xfer.

Don't take anything I say as gospel. I'm the rebel. You'll find lots of opinions, most from folks with more experience then I. But I admit that being a mechanical engineer is handy when the issue is heat xfer.

what you say makes sense but i will do some real world testing too. :)