Track Rotor Temperatures

Magpie · Postby **Magpie** » Sat Jun 06, 2015 8:43 am

Nope MattR booster staying where it is!

In an email conversation with Keith from FM (I was enquiring about their rear brake with handbrake and if it would fit the NB8B OEM discs, and it does), Keith commented that I "may have an adjustment problem with the brake pedal. If all the free play is adjusted out, the return hole in the master cylinder gets covered up. Then, as the fluid heats up, it has nowhere to go when it expands. If it’s fully covered, the brakes will eventually come close to locking up. You may have it partially occlude."

The master cylinder is already being rebuilt by Automotive Plus so will see if this solves the problem, however worth checking on the brake pedal adjustment. Plus looking at putting a pressure sensor on the rear brakes so it can be monitored. If this does not solve the problem then (smile MattR) the booster will be REBUILT.

Whilst it would have been good to do track rotor temps again with the same rotors, the current ones are stuffed and will replaced with DBA 4000 T3 ones. Another bill....

madjak · Postby **madjak** » Sat Jun 06, 2015 9:31 pm

Magpie, the reason i went with the 11.75" willwood rotors was mostly due to the cheap replacement of the discs. At $30 US a rotor they become a cheap annual replacement item.

Its interesting what Keith was saying about the rears. I dont think I'm seeing this issue with mine but its good to know these issues. At some point I'd like to remove the brake booster all together. With the lumpy cams i can feel the pedal moving under my foot as i heel and toe through the gears under brakes. This can't be good for my brake control.

What pressure sensors are you using in the brake line for monitoring? I bet if I logged mine I'd see the pressure fluctuations under brakes.

Magpie · Postby **Magpie** » Sun Jun 07, 2015 6:10 am

Honeywell 0-2000 PSI (PS-2000G-OEM-LD05)

Not wanting to start a war on what is better, my researching on Willwood suggests that whilst cheap may not be the best option. The rotors are thinner hence temp control could be an issue and cracking. nitroDann posted a great link on a discussion on brakes, I will try and find it again.

I would expect a few pad changes with the DBR's.

Magpie · Postby **Magpie** » Sun Jun 07, 2015 7:17 am

http://www.miataturbo.net/general-miata-chat-9/anyone-have-any-brake-questions-81577/

Brake discussion thread on Miata Turbo, good reading.

madjak · Postby **madjak** » Sun Jun 07, 2015 10:29 am

I figure that with the rotor cracking issues with the Wilwoods and the rate I wear through rotors anyway regardless of the quality it's a part that I'd prefer to change yearly. You can buy the directional HD rotors for $100 a rotor which will last longer than the cheap non-directional $30 rotor but unless there is a difference in performance I don't need the longer life. My understanding is that both these rotors are made from the same material its just the straight vane is a simpler cast and is more a bulk item so the price is low.

I was running the DBA rotors last season and the upgrade to larger Wilwoods will be paid for over a few years because of the difference in rotor costs.

This is a an experiment though... which is why I find these discussions great. I check my rotors each event because it may be the case that these cheaper rotors aren't good enough. So far they are looking good.

Magpie · Postby **Magpie** » Sun Jun 07, 2015 10:32 am

Based on the price of the DBA Rotors I could be swayed to your thinking very soon...

Hellmun · Postby **Hellmun** » Sun Jun 07, 2015 8:30 pm

madjak wrote:I figure that with the rotor cracking issues with the Wilwoods and the rate I wear through rotors anyway regardless of the quality it's a part that I'd prefer to change yearly. You can buy the directional HD rotors for $100 a rotor which will last longer than the cheap non-directional $30 rotor but unless there is a difference in performance I don't need the longer life. My understanding is that both these rotors are made from the same material its just the straight vane is a simpler cast and is more a bulk item so the price is low.

I was running the DBA rotors last season and the upgrade to larger Wilwoods will be paid for over a few years because of the difference in rotor costs.

This is a an experiment though... which is why I find these discussions great. I check my rotors each event because it may be the case that these cheaper rotors aren't good enough. So far they are looking good.

Uh remember that's $100 USD. Add in postage and the exchange rate at the moment and those are nearly $160ea. You can get 11.75' Ultra Lites from VPW in Australia for $47 AUD without postage. The HD's can be ordered in as well but are $194ea. I haven't been able to test my 11.75' kit properly yet from trackspeed. I had a brakeduct which was torn which destroyed my first set quickly. Those HD's would have to be pretty amazing to be the same dimensions but last 4 times as long to make it worth it.

madjak · Postby **madjak** » Mon Jun 08, 2015 12:24 pm

actually looking on Summit Racing, you can get an ultralite with a directional vane.

http://www.summitracing.com/int/parts/wil-160-2899/overview/

which is $50.46 from VPW.com.au. Might be worth a shot for next year