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Scary Brake Fade With New Rotors And Pads!

Iron Mike
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Iron Mike Proficient

Iron Mike

Posted
Posted (edited)

Ok, so I just bought a brand spanking new set of project mu SCR rotors front and back and also a set of project mu M-spec (not available in Aus) pads all round too. I thought this brake set up would be pretty damn good for a road car, having slotted rotors and all......but boy was i wrong. I've had it on the car (which has only seen street use) for a month now, and recently partook in some spirited driving with some other GTR boys. After 15/20 mins of moderately hard driving, picking up speed then wiping it off, I really started to feel the brakes fade. Not a little bit, but a LOT. At one stage I had to brake very hard and almost drove off the side of a hill....When I eventually slowed down to park (moving at 5-10 kmh) I could not even stop the car. It kept rolling forward until it stopped almost on its own. I got out of the car and inspected the brakes which were billowing smoke, and were EXTREMELY hot. I have never shat myself so hard, nor have I been so disappointed in a purchase (that wasn't cheap) I was genuinely expecting more from. This was supposedly one of the best street/sport setups you could get for a GTR without an increase in rotor size/bigger calipers. What are your thoughts? I've considered upgrading to braided brake lines as well but that wont solve the fade or heating problems...

Edited by Iron Mike
34GeeTeeTee Grand Master

34GeeTeeTee

Posted
Posted

If you have old shitty brake fluid that is then undergoing higher temps them before then you are probably boiling it and getting a soft spongy pedal yeah? I'd be doing that and making sure the pads are sliding freely then re-check before worrying about the new hardware

MrStabby Grand Master

MrStabby

Posted
Posted

The rotors will be lighter than stockers, but will offer SFA difference in stopping power. Dont know anything about your pads, but you could try some A1RMs which are fine for me track work (on the G4 330mm kit) so should be more than enough for spirited street driving. I prefer not to use them for regular street driving, but many do.

Is the factory brake ducting in place?

Moodles2 Grand Master

Moodles2

Posted
Posted

Brake fluid is hygroscopic (except DOT 5 which is silicon based), the older it is, the higher the water content. Standard DOT 4 boils at around 220C, good fluids boil at around ~270C, the top end Motul RBF600 boils at around 315C while water boils at 100C. Once brake fluid boils it's completely useless as air is introduced in the lines, and putting the brake pedal flat to the floor won't do anything.

Moral of story, change brake fluid when you do a big change like change rotors/pads, and especially change it before a track day.

ichi-go Rising Star

ichi-go

Posted
Posted

You're probably using the wrong pad more than anything

http://project-mu.co.jp/en/products/pad_mspec.html

Rated to 500C - this would be sufficient on a moderate hard driving around the street, definately wouldn't survive track abuse

You need to go to something more track focus such has HC+ or even Club Racer or MAX700/900i

Hadouken Grand Master

Hadouken

Posted
Posted

Its got to be your fluid. No new pad/rotor setup will give up like it did with you. Even running old jap spec pads i could stop the car. So logically thinking whats the most important thing between your pedal and calipers? Brake fluid!

Im using dba 4000's with remsa pads and it stops on a dime.

MrStabby Grand Master

MrStabby

Posted
Posted

Its got to be your fluid. No new pad/rotor setup will give up like it did with you.

The fluid could be stuffed, but the billowing smoke is definitely overheated pads. 500 deg C is a pretty low temp rating, they're not even "sports" pads IMO.

levinboy Grand Master

levinboy

Posted
Posted

Most likely boiled the fluid at the same time as over heating your pads.

The Mspecs look more like a street pad, i use Project Mu Bspec pads for the street in my GTR and have had the odd spirited drive and never had them fade.

I have even used them on the track, i did over heat them on the track but in saying that the brake pedal never hit the floor i just noticed that braking power had decreased.

Would definitely recommend Bspecs for the street or step up th HC+ but that might be a tad over kill as they tend to be noisy and dusty.

The club racers are not suited for the street at all, i use these for track duties and are fantastic once at temperature

Iron Mike Proficient

Iron Mike

Posted
  • Author
Posted

Ye I somehow missed the 500 deg C rating when I bought them, and just read the street/sport part :I .... Load of BS if they claim they're good for anything close to sports driving. In my opinion theyre only good for cruising around town and even then, they're noisy as hell... So I've decided to do 3 things. 1.install nismo braided brake lines, 2. replace the brake fluid with something high performance, 3. upgrade the pads to project mu max700. I'll keep you posted on how things turn out :D

djr81 Grand Master

djr81

Posted
Posted

Just be careful with pads on street cars. They MUST work from cold otherwise you will have the shittest accident in the world when you run into the back of a car at 30km/h because the pads havent warmed yet.

Alot of pads (not saying this of the Project Mu ones you mentioned because I dont know) don't work worth a shit when they are cold.

Also Motul make good brake fluid.

MrStabby Grand Master

MrStabby

Posted
Posted

FYI last time i checked motul is around $25 for 500ml and is rated at 310 deg C. Nulon Xtreme performance is $10 for 500ml and rated to 280 deg C.

For me the Nulon is good enough, and available everywhere.

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

Just be careful with pads on street cars. They MUST work from cold otherwise you will have the shittest accident in the world when you run into the back of a car at 30km/h because the pads havent warmed yet.

Exactly.

It's what a lot of people don't realise. My Ferrodo DS3000 would take a food 4-5kms of stop/start to become moderately useful - before that, if I needed to stop in a hurry, wasn't going to happen and it's worse than a your average streer car by comparison.

To the OP - 15-20mins of hills run, it comes as no surprise you are having brake fade issues. Fluid aside, you simply do now have the heat dissipation capacity with stock sized rotors for that kinda work. If you do go again, expect to boil the fluid again would be my guess of how it will go down.

They wouldn't last 3 laps on a circuit (5mins), so going for 15-20mins on a hill run will be very hard on brakes.

You should've upgraded the rotor size/kit rather than buying new rotors/pads if thats the kinda driving you want to do.

The Bogan Grand Master

The Bogan

Posted
Posted

Did you clean the rotors with brake clean before instalation, mine had a heap of protective "stuff" on them which needs to be cleaned off.

If that stuff has got into the pad it will wreck them fairly soon I believe.

As with most things it is possible that Im totaly wrong !!!!!!

Iron Mike Proficient

Iron Mike

Posted
  • Author
Posted

Ash, even a quick 5 minute spirited drive causes this problem.

Exactly.

It's what a lot of people don't realise. My Ferrodo DS3000 would take a food 4-5kms of stop/start to become moderately useful - before that, if I needed to stop in a hurry, wasn't going to happen and it's worse than a your average streer car by comparison.

To the OP - 15-20mins of hills run, it comes as no surprise you are having brake fade issues. Fluid aside, you simply do now have the heat dissipation capacity with stock sized rotors for that kinda work. If you do go again, expect to boil the fluid again would be my guess of how it will go down.

They wouldn't last 3 laps on a circuit (5mins), so going for 15-20mins on a hill run will be very hard on brakes.

You should've upgraded the rotor size/kit rather than buying new rotors/pads if thats the kinda driving you want to do.

Even a quick 5 minute spirted drive causes this problem. Serious serious brake fade. I've heard of plenty of people using project mu SCR rotors on the track and having no such issue, so I've got my money on the probem being inferior pad choice and boiling brake fluid. Having said that I've just ordered nismo braided lines and uprated project mu HC+ pads, so we'll see how it all turns out :)

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