Thanks, guys....this is what I'm talkin' about!!! It'll take a little while to read those links, Bfulmer, but they look very interesting.


Now...say I were to upgrade to decent pads that operate best at high temps...luv 'em on the track.....but what happens when a deer jumps in front of me after a 20 minute highway drive?? Same great stops or less stopping power since I haven't used the brakes...venison?

 

hmm... I think the stock brake is good enough for me.!! but like endless or bamboo's brake should perform better than stock brake.!! but actual what type I don't know a .!!

 

i have the rotora big brake kit & its PIMP!!!

 

It wouldn't be that bad unless you get a really radical brake pads. I've had track pads on my 8 while driving to the track and it was fine. As a general rule, the higher friction linings make more brake noise (squeal) so they may drive you crazy. Noise generation is another reason you don't find them on your stock RX-8 brakes.

 

Anyone have track day experience with their stock brakes? How do they do? Any fade? I'm planning to do a track day a Gingerman Raceway this spring and am interested in finding out, but not "the hard way".

Stew

 

They last pretty much all day long but feel like crap for about 2 weeks after the event. Your tires will also gum up a bit due to how hot they get and how much rubber is left on the track from people who use slicks. They will last the whole day though. Just dont plan on spending two days at the track...

 

On a car without ABS or EBD (such as my '94 Miata) I have found two ways to decrease stopping distances - fit stickier tires, or improve the brake bias. I did both, and it had a dramatic impact on the braking distances. But the '94 non-ABS Miata had too much front bias from the factory. Mazda has learned allot since then.

On a car like the RX-8 with ABS and EBD, it seems intuitive that mucking with the bias (intentionally or unintentionally) won't have much of an impact on braking distances. Yet I just recently read a report in Grassroots Motorsports where they did decrease the average braking distance of a C6 Corvette by fitting a BBK. It wasn't a huge difference, but it was repeatable.

Having said all that, I can think of three reasons why a BBK *might* decrease braking distances:

1. Lower unsprung weight (many BBKs are lighter than the factory setup) results in fractionally better mechanical grip.
2. Improvements to the bias. Again I think EBD would eleminate this effect, but I'm not 100% sure.
3. A more repsonsive pedal helps the driver put the car up against the threshold of lockup more quickly and/or more predictably, hence picking up a few feet. This would more likely be true of a car with just "average" brakes from the factory.

Of these three, I'd guess that the RX-8 would only benefit from reason 1, possibly 3.

George

 

I have done 2 track days in my 8 and although I am not the fastest guy on the track, both times I came away thinking that the stock brakes are unbelievable (in a good way). They repeatedly hauled the car down from speed - 120+ on the back straight for a 50 mph chicane and 110+ on the front straight for a 70mph sweeper. These 2 turns are less than 40 seconds apart so there isn't much cooling time in between. Each session was 30 minutes long so I feel the brakes were given quite a test of reliability and effectiveness at high temps/speed. At both track days we had half a dozen RX8s and everyone was similarly impressed.

Would I do a BBK? Sure but I would spend the 2500+ on coilovers first. I would also want to allocate money to lightweight 17" wheels with some R-Compound tires. Then I would experiment with new rotors and pads. Finally, I would think about a BBK.

I think my next mod is some braided steel brake lines and clutch line.

 

I think you will get a full range of answers on this one. Much of it does depend on how hard you drive the car. I think if you have never been on the track before then you will probably be OK with stock brakes for your first time out. If you have been on the track before and a pretty fast driver (everyone thinks there fast until they get to the track) then you may have problems. I went to Gingerman twice last year and the track is pretty hard on brakes in general. The first time I was there I had the stock brakes with a front lining change (porterfield was the only pad available at the time) and I was more than fine. Mostly because I was pretty slow and learning the track. I then used the same setup for a two day session at Watkins Glen and again I was OK because I was slow and learning the track. The front porterfield linings and stock rears lasted the three days without much fade until the last sesion or two at the Glen. During these last two sessions I was experiencing some pretty bad fade mostly because I was starting to drive the car harder and faster. I would just take a cooling lap and the brakes would come back. After that I chose to install a front bbk from StopTech with PFC97 linings. I did another day at Gingerman and two more at the Glen and everythin is great. I'm actually driving much harder now with no signs of fade. I can go about two track days on a set of rear lining and the front PFC's wear like iron so I have many more t-days left on them. Oh yah, I also changed the brake fluid to Motul before my first track day. Side note: I really like the PFC97 material and if they make a pad now that fits the stock calipers that would be my lining choice. In fact, if they would have had a pad available when I was looking I may still have the stock calipers and rotors on. It is sort of a pain to change lining on the stock calipers if you have to switch with the backing plate shims to the new linings. I suggest ordering a replacement set of shims for your track linings. I tried running the porterfield lining without the backing plate shimes and I was getting alot of pad rattle.

Hope that helps

 

I have run 3 track days at Sears Point with the Mazdaspeed pads on my otherwise stock car. No fade on track, and no ill effects afterwards. Sears Point is not known for being hard on brakes, though.

Since this hasn't been addressed in simple terms in this thread, I'll do it.

There are two main reasons an F1 car stops from higher speeds in shorter distances than an RX-8. They're the same two reasons why an F1 car can corner with greater force than an RX-8. Those reasons are traction and mass.

If you're using brakes to decelerate a car, you can't brake with more force than the tires can apply to the road. You'll just lock up the tires. This is why everybody says big brake kits aren't really necessary for most RX-8s. You can lock up the tires fairly easily. Put stickier tires on the car and you have more traction, so you can apply more braking force to the road and stop the car in a shorter distance. F1 cars have tires that are 14 or 15 inches wide and are so sticky they don't last 500 miles. RX-8s have tires maybe 8 or 9" wide and last 25,000 miles or so. You can see that there is going to be a difference in the amount of deceleration that these cars are capable of just based on the tires alone, without even considering the additional traction from downforce generated by the F1 car's aerodynamics.

The other reason that F1 cars stop quicker is that they weigh less than half of what an RX-8 does. Less mass means lower inertia, which means that the brakes & tires slow the car down faster than a car with more mass (& thus higher inertia). This is easy to experience on the street - an unloaded pickup truck stops in a shorter distance than the same truck loaded with 1000lb worth of payload.

A legitimate reason for upgrading the brake package is for fade resistance. Brakes work by turning kinetic energy into heat energy. That is, brakes apply pads to discs, and the friction slows down the discs and generates heat. If you get too much heat buildup in the discs, the pads get outside their optimal operating conditions and don't work too well anymore. That's brake fade, and it happens when you stop many times from high speeds without enough time between stops for the brakes to cool. If you have a brake disc that has a larger mass, it can hold more heat. It also has more area with which to dissipate heat into the air. These factors mean a bigger brake setup (not just diameter, but thickness also) can handle the rigors of repeated stops better.

In general terms, if you can lock up your tires under braking, and you're not experiencing brake fade, your braking system is adequate. This is what bfulmer was saying early on in this thread. Accordingly, I have the Mazdaspeed pads on my car because I was concerned about fade on track, not because I was looking for shorter stopping distances. bfulmer has the Stoptechs on his car because he was experiencing fade on track.

I don't believe he said that all brakes were equal. He was saying that the RX-8's brake system doesn't need improvement for the circumstances that the majority of these cars see. And in the case of the Mustang BBK tests, keep in mind that Mustangs have some pretty sorry excuses for factory brake systems. 11.5" front rotors on a 3400-pound car? Not my idea of a good time. It's possible to fade those things with a single hard stop from high speeds.

 

Thankx for the input.. That makes better sense now.

 

Wiser words were seldom spoken. If you want to stop (or slow down) like a F1, replace your tires with racing slicks. Just be prepared to change your tires each time you go for a ride.

As for the EBC pads, I can't speak to their performance on an RX-8, but they're extremely popular on Saabs, to some extent for their stopping performance, but at least as much for the absence of brake dust.

 

Matt-man

I'm sure everyone appreciates you taking the time to explain everything. I've been studying for a final and I haven't had much time to reply. You did a better job than I could anyway.

 

I have had the EBC Red Stuff ceramics on my 8 for a little over 1000 miles now. I can say that they are GREAT. Hardly any brake dust is just a tease compared to the performance of the pads.

Granted, the Red Stuff are track quality pads so you get a little more noise. For instance, since the temp has gotten down into the 30s here I have had minor squealing until the brakes get up to temp.. But after that it goes away.

 

I have the MS pads. I think the pads are good for now.
But I want to find some slotted only rotors, and I want them to be light, and same as stock in diameter. Can anyone help me?

I 've seen the Autoexe, which are lighter, at japanparts.com. You shave about 2kg, but they are truly expensive: $700 the pair
Rotora has too, but don't know how much they weigh...

Philodox, do you have any tips about yours? Thanks

 

I bought my Cross Drilled & Slotted rotors from Vivid Racing. Rotora makes the ones they sell.

 

Do the EBC Red Stuff Brake pads squeal more than the pre-TSB Mazda pads? Thinking about changing out to these pads. And do they only squeal when cold?

 

My EBC Red Stuff pads don't squell until the temp drops below freezing. Above 30deg F or so you won't have any squealing. Of course, once the brakes warm up the squeal goes away. Hope that helps.

 

I got the Hawk HPS (street pads) brake pads. I like them. Not much different felt from the stock pads, but my braking feel was already pretty good from upgrading to the Goodridge stainless steel brakelines. There was a Powerslot/Hawk rep. at the Racing Beat event. He was talking brake pad thermal efficiency when we went by his table. It was quite interesting, talked about how each has a different rating that signifies operating temperature, and how the Hawks were like 2 letter grades higher, made to operate in substantially higher temperatures (tracking).

 

Hawk has a whole range of pad compounds for different levels of abuse. I used the HPS compound for street duty and the Black or Blue compounds for track events on my old Mustang (275RWHP, 3400-ish pounds) and I was happy with their performance. The Miata guys I've talked to could get away with the HP+ compound, but on the heavy Mustang they'd fade in a couple of laps even on street tires.

 

I messed around with different pads quite a bit on my previous car and I think they mainly made improvements in feel, they seemed to make the pedal a little more sensitive. But I doubt they actually shortened the distance much, especially from lower speeds, because they actually made it easier to lock the wheels. But different tires made a huge difference.

Another thing I heard is if you want to upgrade brakes, you have to do the whole system. If you have bigger rotors and pistons with the original master cylinder, the master cylinder isn't able to provide any more total force than before, so it is just spread out over the larger piston surface area, but with less force per square inch.

 

Thanks for posting this. I thought I'd wrecked my brakes at Laguna Seca. I was pushing it harder than I ever have. The brakes went from just fine to crunchy and pulsating in about 4 laps. I noticed it the first time in turn #1; 100+ mph to 30+ on the edge of the ABS.

When I read your post, I decided to wait a while before even having diags done. It is much better after 10 days, although it still feels like I warped the rotors.

Has anyone warped stock rotors? If so, did you replace them with reasonably-priced rotors and upgrade the pads, and have they performed well since then? These brakes test well, I just want to be able to drive hot laps all day without warping the rotors.

 

The symptoms you describe sound very much like uneven pad deposition. Check out these two articles which help explore the subject further

http://www.stoptech.com/faq/data/faq25.htm

http://www.stoptech.com/whitepapers/...otors_myth.htm

Although we are talking about two piece rotors, the phenomenon can also occur with one piece rotors, especially at the track where stock pads can't take the temperatures.


Also, the StopTech kits don't need you to replace the entire brake system. You don't even need to replace the master cylinder. All of our kits are meant to work with stock brake systems and abs systems.

 

Now we have Stop Tech on the forum? Crazy... That makes SSR Engineering, PTP Motorsports, Endless Rotaries, Mazda pro racer Lou S. , Tire Rack and now Stop Tech.... Awesome!

 

Glad to see StopTech here.
Hopefully we'll see some forum specials ...

Yea to StopTech!