cruiser

Damn... I was at track yesterday again and again experienced dead pedal (long travel, with poor braking power) after a few laps (5-6 laps). I have fairly new brake pads and few days old ATE Super Blue brake fluid.

What else do I need to change? To steel brake lines ? Brake cylinder (car has about 85k miles on it) ?

On one occasion I almost lost a control when braking hard for a turn and suddenly my front left blocked (FD has ABS mind you) completely...

So... there must be a problem somewhere in the system. Do you think stainless steel brake lines would solve my problem with brakes ?

Mahjik

iTrader: (1)

What pads are you using?

shawnk

The lines and fluid are not directly affected by 5-6 laps on a track. If you have a problem with them you would notice it all of the time.

The only difference I can think of is heat. Once you heat those rotors up you are going to lose your stopping power. I have seen this during a highway tuning session after only a few pulls. Have you tried ducting air to the rotors?

Shawn

maxcooper

You need brake pads designed for use on the track. Unfortunately, it is nearly impossible to find pads that work well on both the street and the track, so you'll need to get used to switching pads when you go to the track.

-Max

twistedriver

I am pretty new at racing or really high speed driving. But isn't it true that there is two kinds of brake fads? Hard pedal and poor brakeing power, and sinking pedal and poor pedal. And isn't sinking pedal a sign of air or water in the system? If someone can clean that up for me that would be great. Thank you in advance!

maxcooper

By "dead pedal" it sounds like fading the pads to me. You have to push harder to get braking force, so the travel is longer (firewall flex from the pedal pressure, etc.). With boiled fluid, the pedal gets spongy and you get VERY little braking force all of a sudden. Boiling can be caused by really thin pads (worn almost to the backing plates), lousy fluid, water in the system, etc. Air in the lines would feel lousy even with cold brakes. It doesn't sound like he is running track pads, so that was my best guess.

-Max

cruiser

I'm running Bönez Stage I brake pads. The brake pedal gets soft and I get very poor braking power, often I need to pump it in the 2 cool-down laps to get them to work at all, so I wouldn't blame it on the pads.

Maybe the mechanic did a lousy job in bleeding my brakes when he changed my brake fluid ?

It's NOT like that I would have same brake effort on the pedal and would get worse and worse stopping power, but the brake goes all the way down very easily and doesnt brake at all unless I give it a few pumps.

After 30-50mins or so, its back to normal.

Mahjik

iTrader: (1)

Nope, it's the pads. Those won't work for lapping (I know, I tried). You can run the Bonez on the rear, but you need some real lapping pads for the front.

cruiser

So its the pads...Oh well... Anyoine tried Axxis Ultimate ?
Or Hawks Blue ? EBC Red ?

I'll order along also some stainless steel lines...

But why would I get a dropping pedal with these pads ? In my understanding, if its the pads, then the force required to press the brake pedal fully is the same, just the stopping power detoriates. Is it not so ?

Mahjik

iTrader: (1)

It depends. Because the pads can't handle the heat from track driving, it may be cooking the fluid as well. Where as fixing the pads will fix the fluid (which was the fix in my case).

I've never run the Hawks pads, but I've not heard good thing about them. I've heard good things about EBC pads. I'm currently using the N-Tech lapping pads:

https://www.rx7club.com/showthread.p...hreadid=236544

The only problem with getting the N-Tech pads for you would be that Nick doesn't take credit cards so you would have to order by money order or some other means.

rynberg

The Hawk Blues are awesome but their dust is horrible. Cruiser, I would try some Porterfield R4-E.

My bet is your fade is a combination of a) not a perfect bleed, b) old rubber brake lines, and c) inadequate pads boiling the brake fluid.

Actually, in your other post, you stated that top speeds at your track were 100mph, I'm surprised you're getting such bad fade. How long a session do you typically run?

Mahjik

iTrader: (1)

When I tried running the Bonez pads, 100 MPH was about as fast as I could go without hitting fade. If I kept it under 100 on the straights, the pads were fine.

Now, running the N-Tech lapping pads is a whole different ballgame!

cruiser

I usually run 6-7laps, each about 1min15secs.
Its a track quite hard on the brakes. It has 3-4 straights in one lap where you go about 90-100mph and then brake down to 50mph.

I would assume its the combination of all things mentioned above also...

I wont rest in peace until I beat the new M3 on the track

Howard Coleman

iTrader: (6)

hey cruiser,

i love it that you are running out of brakes... it means you are driving hard. i recently started what turned out to be a pretty good discussion as to brakes... it was entitled: FD brakes. do a search... only a couple of weeks ago at most.

chances are if you are doing 1:15 laps and you have 3 straights the track is a brake eater. your most fundamental problem is the small fd front rotor. there are a bunch of easy fixes depending on what you want to spend.

start by making sure you have fresh brake fluid, try a set of EBC red pads. if they don't do it you will be needing some primary hardware upfront.

and don't sweat the M3, a little more camber, 30/27 air pressure cold and you will eat him for breakfast.

keep us updated.

howard coleman

cruiser

Ok, my front pads are gone after yesterdays track session. They only held for like 5k miles - Bönez Stage I. These pads simply suck - they dust as hell, their dust is also very corrosive and all they do on the track is boil the fuild
I will be getting some semi-track pads as my next set from a local manufacturer. If that fails I will get EBC Greens for street and EBC Red for track.

I have improved my time from last time for 1 full second, considering I was only running 9psi (was hot as hell outside, have had water temp gauge climb past middle after only like 3 hard laps but quickly settled on cool down laps - was also running fans on their full speed). Last time I ran 12psi (as it was much colder) and did 1m13.97sec.

I was running 35psi front and 30psi rear hot tires pressure on street tires. My alignment is way off, but due to rusted alignment bolts/screws and worn right toe-link we couldn't set it correctly (rear toe positive on one and negative on other side, positive camber in front, too much toe-in in front, etc...).


Anyway here are the results from top25:

Luka ; BMW Z3 M Coupe 1.11.92
Sinisa ; BMW E46 M3 1.12.20
Tadej ; MAZDA RX7 1.13.00
Ivica ; Mitsubishi EVO 6 1.13.03
Ziga ; PORSCHE 993 Carrera S 1.13.52
Miha; HONDA CIVIC 1.8 VTi (slicks) 1.13.70
Josip ; MERCEDES BENZ 1.13.97
Luka ; HONDA CIVIC 1.14.05
Milan ; PEUGEOT 205 (slicks) 1.14.17
Francesco ; FORD COSWORTH 1.14.17
David ; HONDA CIVIC 1.14.54
Sasa ; ITR 1.15.60
Vito ; HONDA CIVIC 1.16.25
Klemen ; SAXO 1.16.47
Andrej ; RENAULT CLIO 1.16.50
Ivica ; VW CORRADO 1.17.30
Hrvoje ; HONDA CRX 1.17.48
Tino ; ASTRA GSI 1.17.58
Tomislav ; SEAT LEON 1.8T 1.17.80
Nenad ; HONDA CIVIC 1.17.90
Mitja ; ALFA 155 1.18.50
Denis ; SEAT LEON 1.8T 1.18.61
Martin ; SUZUKI SWIFT GTi 1.18.70
Tomislav ; BMW 320i 1.19.40
Melita; MR2 Turbo 1.19.43

At next track event I should be on new pads, with full exhaust and correctly set alignment. I will also take Howard's advice and run a little lower tire pressures.

P.S.: I'm especially proud of beating that lovely 911 and Evo6 (modded, running track pads)