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Interesting...so did you ever run the car with your new motor on road tyres?

Im interested to hear from more people whether semis are harder on brakes or easier? My car doesnt really hurt brakes irrespective of tyres so cant really tell.

I found I definitely hurt the brakes a lot more using semis. The extra grip afforded means holding much more speed into corners and much more 'available braking' before you can lock a tyre. So I guess you can wipe off far more speed (even though you go through the corner faster on semis of course - I think you still disperse more energy/heat as the overall increased speeds and later breaking)

I had no trouble at Wakefield in my 1500kg Porsche running EBC greens - cant say the same about my GTR with DS2500s... but you'll need to careful when drawing any conclusions from that. (Porsche 1:18, GTR 1:17)

Maybe the Porsche had much bigger pads/rotors which would mean you didn't generate as much heat? Its only the heat developed which ultimately kills the pads - so perhaps the DS2500 just had to put up with more rotor temperature?

what model porsche are you referring to? (i Love porsches and work on them for a living) i bedded in the maxistops and already they have faded on bedding in (maybe i cooked them) i jsut hope i didnt cook the new discs

Its was an 1984 (so the big single piston jobbies, not the "hand of God"'s) 928S auto. Even with the greens they brakes felt nicer than the GTR's dual pistons + DS2500s, which as stated by others should be a much better track pad.

Rgs,

Kot

Maybe the Porsche had much bigger pads/rotors which would mean you didn't generate as much heat? Its only the heat developed which ultimately kills the pads - so perhaps the DS2500 just had to put up with more rotor temperature?

The porsche was running 16inch rims so the rotors couldnt have been as big as the 324mm's i have on the GTR now (with the sumitomo calipers and extention brackets). I think the pad surface area would have been about the same size. The 324s seem a lot better than the 296s, but i still got some wobble.

I also measured the rotor temp with the 324's and it was only about 300 deg by the time i measured (so it would have been a bit more on the track itself. None of the DBA4000 thermal paint stripes had gone off tho, so they couldnt have been that hot.

Maybe i just remember the porsche better than it really was... maybe porsche use better material in the rotors...??

  • 2 weeks later...

Have just bought myself a set of RB74's and am going to use thm allong with the stock rotors.

Their judgement day is @ wakefeild next week.I have a feeling that they will be ample enough for my needs.

As far as the bedding in proceedure goes i was told to do 4 runs at 70kph down to 10kph using med braking force.Then drive easy for a couple of mins then do it again.then just drive normal.

Was also told to never brake hard,drive over 100kph and brake or hold the accelerator down while holding brake down when bedding in new brakes.all no no's :(

Interesting...so did you ever run the car with your new motor on road tyres?

Im interested to hear from more people whether semis are harder on brakes or easier? My car doesnt really hurt brakes irrespective of tyres so cant really tell.

I would have thought with the semis you are on the brakes for a shorter period of time as your corner speed is higher and brakign distances shorter. The heat input is going to depend on grip levels but i would think the duration of braking time being longer with road tyres, combined with less corner speed will mean your brakes would be getting hotter.

Interesting to see how you go now with the pads and rotors sorted...are you sure the dead pads/run of little probs were all related to running semis?

Yep i did one track day with the new power at philip island on street tyres, brakes didn't give me any hint of issue, traction did tho :(

On street tyres, the brakes lock up easier, so i guess theres less friction there before lock up on streets, compared to semis, there would be more friction which could be part of what causes it... Went to winton with RB74's thats where i killed my discs/pads on semis.. then went to PI with DS3000 and new fluid, and had soft pedal pretty much straight away... very annoying.... which just means heat is being put into the lines/fluid i guess, so hoping getting rid of the heat before it gets that far will work. Ie DBA5000 + get rid of stone guards, plus look at ducting.... Works for chris, gotta work for me right?

Also ben says semis make brakes work way harder, and we all know he's never wrong :happy:

Besides that you can jsut feel semis putting more strain on the whole car, suspension, brakes etc....

Has anyone had an experience with Project Mu rotors and pads? I'm looking at starting to do track days and want to upgrade. The are one option I'm looking at but I haven't heard anyone talk about them.

http://www.mackinindustries.com/md/projectmu/projectmu.html

Also, does anyone run have experience with Nismo S Tune or R Tune pads?

FYI, here are the two options I'm looking at:

Item Brand Model Cost Source

Greenline $1,406.86

Brake Rotors, Front Project Mu SCR Rotor $435.68 Greenline

Brake Rotors, Rear Project Mu SCR Rotor $392.18 Greenline

Brake Pads, Front Project Mu HC+ $202.11 Greenline

Brake Pads, Rear Project Mu HC+ $185.17 Greenline

Braided Brake Lines Nismo $191.73 Greenline

UAS $1,720.00

Brake Rotors, Front DBA 4000 $490.00 UAS

Brake Rotors, Rear DBA 4000 $490.00 UAS

Brake Pads, Front Ferodo DS 2500 $275.00 UAS

Brake Pads, Rear Ferodo DS 2500 $170.00 UAS

Braided Brake Lines Goodridge $295.00 UAS

if your not going up in disc size. your wasting your money on slotted etc etc rotors.

brakes are a leaver. if there the same diameter there going to ofer the same force.

just get the best pads you can oford. that is if your ones arnt had it.

if your not going up in disc size. your wasting your money on slotted etc etc rotors.

brakes are a leaver. if there the same diameter there going to ofer the same force.

just get the best pads you can oford. that is if your ones arnt had it.

There is also heat dissipation to worry about... after market rotors can get rid of heat better than stock ones.

I used the project Mu level 900 padsa and they were great but ended up killing the RDA discs. I still reckon that the disc cracked while it was siting in the pits thought as i read later that a car should be moved a few inches every few minutes when returned to the pits to stop heat transfer and cracking discs. They were great though never faded once.

I used Bendix Ultimates with RDA rotors and Jaguar DOT4 Brake fluid. Brakes were awesome, stopping was consistant but pedal started to get soft as the day progressed, ill do another flush this week and now my brakes squeal like a pig. Oh well all in good fun!

I used Bendix Ultimates with RDA rotors and Jaguar DOT4 Brake fluid. Brakes were awesome, stopping was consistant but pedal started to get soft as the day progressed, ill do another flush this week and now my brakes squeal like a pig. Oh well all in good fun!

Good to hear it went well. If you're doing another flush go for the Motul RBF600. It seems to stand up to the punishment well - i dont feel like i need to bleed my brakes after track days since i've been using that.

BTW, i suspect my brake problems may have been contributed to by completely stuffed upper control arm bushes...

Rgs,

Kot

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