brakes and trans breather

#1

Hello all,
2 questions. Im in the prosess of building a Spec e30, I have attended one HPDE so far. I experienced brake fade! That was scarry. My first question is what pads would be the best for a daily driver and that are good for HPDE. I plan to install some cooling ducts to the back of the rotors before the next one. And the 2nd question, how do you attach a tube to the trans, breather? (any one have photos) i cut a hole in the trans tunnel to look at it. I cant see how to attach a tube and what diameter tube to use. Can this be done with the trans in the car? Ok more than 2 question.
Thanks for any help
Kelly

#2

What pads to use is a strong function of your skills. For a beginner, Hawk HP+ pads would probably be okay and can be used on the street, albeit with some noise. That’s about as good of a pad as there is for street/track use. Past that you need to have two sets of pads, one for the street and another for the track (Hawk HT-10’s PFC-01’s, etc). It isn’t hard to change the pads at the track.

Also make sure to use a brake fluid suitable for track use (dry boiling point of at least 530F) and change it no more than three months before a track weekend. Cooling ducts for the fronts are a great help. Factory 3 performance has a very nice kit (http://www.factory3performance.com).

Are you having a problem with fluid venting from the transmission breather? If not don’t worry about.

#3

Thanks for the info.
The trans is wet arround the breather so I am assuming thats were its comming out of. I didnt take the tran out of the car. How do you get the dust cap off to attach a hose?
Right now i am running Hawk HSP pads and vavoline Synth brake fluid(dry boiling 500f)

#4

jlevie wrote:

[quote]
Are you having a problem with fluid venting from the transmission breather? If not don’t worry about.[/quote]

I’m losing almost a quart every race weekend and I know other guys in our region who are having the same problem.

#5

Okay, so you have the problem. The cap of the breather pops off and it can be removed with the transmission in the car. I’d have to go look at my spare tranny to see how you’d connect a hose to the breather. Ill try to do that later this evening.

Some folks seem to have the problem and some don’t. I have two transmissions, one of unknown mileage that pushes fluid out the breather and a 40k’sh transmission that doesn’t (both filled with Redline MTL). My guess, and it is only that, is that a higher mileage tranny generates more heat/froth and causes the overflow.

I think you mean Hawk HPS pads. They are a good street pad (better than OE) but aren’t really up to track requirements. There’s nothing wrong with Valvoline SynPower fluid. The original spec listed it’s dry boiling point at 530F, but that was later changed to 500F. I was told that the fluid didn’t change, only the published data, and that the fluid (when fresh) still met the original specs. So you should be okay in that respect. one of these days I’m gonna see what the dry boiling point is… SynPower is attractive because it is readily available, reasonably priced, and (per the original specs) has a reasonable dry boiling point. I’ve not had a problem with it yet.

Technique, skill, and the tracks run matters a lot in what pads will work. Paradoxically, a beginner may need better pads than an advanced student. That’s because the advanced student tends to use the brakes harder and for shorter durations than the beginner and carries more speed through a corner. And some tracks are just harder on brakes than others.

Try a set of HP+ pads and work on reducing your braking zone.

#6

+1 on the Hawk HP Plus pads, but as jlevie said they are a little noisy on the street.

I take that back, they are VERY noisy on the street after the first 1000 miles or so, but a great pad for street/HPDE use.

#7

So you can just pry it off with a screwdriver?
Thanks

#8

Just have two sets of pads. It takes only a few minutes to change them once you get used to it. I run the Spec pads and they work extremely well. ATE fluid but your choice should be fine also. I have no ducting and have not had a problem with brake fade.

Use your brakes less. B)

#9

I’m considering a brake pad change.
I use HT10 and I am hard on brakes :slight_smile:
The issue is fade at certain tracks, not feel or one-lap performace. Tire rack shows DTC ($$$) has a higher operating temparature.
It would be nice to worry less about fade in longer races.
Thoughts or opinions from those who have gone this route?(besides brake less)

#10

Robert, DTCs up front for me with ducting, HT10s in back. No complaints except the HT10 dust glueing itself to the wheels in the rain. Could last longer up front (5-6 races I think).

#11

allenr wrote:

[quote]I’m considering a brake pad change.
I use HT10 and I am hard on brakes :slight_smile:
The issue is fade at certain tracks, not feel or one-lap performace. Tire rack shows DTC ($$$) has a higher operating temparature.
It would be nice to worry less about fade in longer races.
Thoughts or opinions from those who have gone this route?(besides brake less)[/quote]

The DTC60 has higher braking torque then the HT10. If you put a higher brake torque pad in front you will shift brake bias forward. Some people choose to do that. Given how our bias valve works tho, shifting brake bias forward wouldn’t be my choice.

But on the other hand, you are a heck of a lot faster then I am.

#12

Good point on the bias issue.
Jeremy- do you run HT10 in the rear b/c cost or to adjust bias?
EDIT: it appears they dont make DTC’s for the rear???
Have you guys run both in the front? What difference in feel/ performance did you notice? I may try DTC for the first time in the enduro this weekend if there’s no big difference in feel.

Thanks,
R

#13

I thought that conventional e30 wisdom was to run a more aggressive pad in the front? I know I do on my e30 M3. Too much pad in the rear would induce premature lockup I would expect.
What say the more experienced?
bruce

#14

HT10s don’t do crap in the back. I liked the BHP pads all the way around b/c it gave better (more) rear bias, but that’s the only other pad I’ve tried so far. I went back to HT10s b/c of cost though.

#15

Hmmm…
I dont want any less rear bias than I do now w/ HT10’s all around.
BHP? I had never heard of those. They appear to have a MUCH higher operating temp than the DTC. Did you use the “PR1”?
Big question is what did they cost you? (dont show price on the net)
http://www.bhpbrakes.com/HTML/blank/Pads.html

Found a nice quote by Carter the site is using to advertise:
“I found the BHP PR1 brake pads to be more effective than the pads I had been using. I could brake later, while still under complete control. I found no increase in rotor wear. During the NASA National Championship race, one competitor mentioned how surprised he was when I out-braked him. In Spec E30 racing, a driver needs every legal advantage. I plan to use BHP brakes for sure.” - Carter Hunt, Spec E30 Founder and Series Administrator.
:laugh:

#16

This page has some prices although they don’t show PR1 compound for the rear.

From what I hear, BHP company was started by someone who use to formulate at Carbotech.

I really like Carbotech pads but they are just too expensive for me. It looks like BHP pads are up there in price too.

#17

I had several conversations with the BHP guys a while back. They use manufacturing technology similar to Hawk DTC60 so the pad behaves better at high temps than earlier technology pads like the HT series. Apparently they helped Hawk develop the DTC60. This pressure molding manufacturing technology means less torque ramping at engage, a more linear release, and less pad crumbling and breaking apart as it wears.

The BHP PR1 compound is similar to the DTC60 in brake torque. BHP has a PR3 compound that is similar to the HT10 in brake torque.

The PR1 is not made for the E30 rear.

There are a lot of strong opinions on pads and I don’t want to get in a fight. With that in mind…The E30 brake bias valve shuts off pressure to the rear pretty early. So putting high bite pads in front just reduces the contribution of the rear brakes even more. And I can’t see how that would help.

I’ve put some pretty aggressive pads in the rear and the data indicates that it doesn’t make much difference. That is to say that the bias valve limits pressure to the rear so significantly that high bite pads in the rear didn’t matter much.

A good arguement can be made for the same pads all around. That would lead to equal brake torque behavior all around, until the bias valve kicked in.

Ultimately folks need to experiment a bit until they find a solution that they like.

#18

Wow. Great inside info. If its similar to the DTC I think I’ll use the DTC in front and HT10’s in the rear (they don’t make DTC’s for the rear of an E30 right?). Hopefully it doesn’t screw up the bias too much.

#19

allenr wrote:

6 months ago Hawk said that they would be coming out with a DTC60 E30 rear. Last month they said that they’d backburnered the project because they’re not convinced that there is enough market for it.

If your intent is to move bias forward, while having a new generation pad up front, then your solution is entirely workable from what I’ve learned. A BHP PR1 up front and HT10 rear would create similar results.

If you are interested in moving brake bias to the rear, the high bite pads available to us is the Hawk HT14 and the PFC01.

An interesting experiment that I’ve not yet tried would be the BHP PR3 front and PFC01 rear.

It can be hard to get info on relative brake torque specs between different companies. After numerous conversations with various reps, this is what evolved:

DTC60=PR1>PFC01>HT14>HT10=PR3

It would be interesting if folks that were aware of test data chimed in on that heirarchy. I talked to reps from each company to get that order, but that doesn’t mean that each of them had good scoop on other company’s products.

No anecdotes. It’s hard data or nothing.

#20

I’m liking Hawk mostly b/c price and once in a while I get some help from contingency stuff.

Is the DTC70 (not 60) too much pad for us?

I definately want more rear bias… or at least not any less.
Is the HT14 to the DTC70 what the HT10 is to the DTC60?

:silly: (a spinning head)