probably due to your pad choice; which brand pads did you use?

I was switching back and forth from the OEM ones and Hawk HP+

Hawk HP+
StopTech slotted
No
Steering wheel shimmey under hard braking
No
Yes

Too easy to warp stock rotors. Haven't had that problem with slotted ones.

To me I can brake harder over more laps with the slots. I tell the cooling affect. there's less brake fad. But then again I brake hard and deep.

Also, go with Cermaic brakes from Poterfield racing. They've been in racing for years and make a quality pad.

Stock rotors should not warp. None should, really... IF your wheel lugs are properly torqued! The concern with drilled rotors (especially) is cracking due to lack of resistance to extreme temperature fluctuation (without going into the actual physical materials reasons).

I've never liked the Hawk HP Plus and won't use them; way too grabby especially for autox, their HPS and motorsport racing pads I love though

I don't autocross, so the grabbiness isnt a huge deal for me, but i love their grip coming down into hard braking zones

as long as you're braking in a straight line it's no problem

yep, like turn 5 at Road America, or coming down into 10 a/b at Road Atlanta :)

added clarification; ... or not at ten/tenths adhesion

I'm coming down into those turns pretty hard, prob close to ABS in both situations

I use the carbo tech panther 8's(on the front) and bobcats on the back( so I dont have to switch those out for street use). They are more expensive than the Hawks but not nearly as grabby and have much more rapid progression. Makes trailbraking much easier.
If you run on a hard braking track such as Road Atlanta i suggest strongly that you fabercate some front brake ducts no matter what pad you use. They do get hot.
olddragger

What would you use to make those ducts?

RacingBrake says no need for ducts on theirs, simply removing the OE brake shield is all their BBK requires for Road Hotlanta, etc.

The brake shield HAS a duct, though. Maybe it gets in the way of their kit, but there is a big flare at the front of the shield to draw air into the rotor (and then out the veins).

The rx7store.net rotors (Brembo blanks, slotted) and Hawk HP+ pads worked AWESOME at Mid-Ohio this past weekend. I even have pad left! This is a first for me. I usually go through a full set in 1 weekend.
The track was just finished being repaved the week before we got there. It was super smooth. I'd never been there before and had a blast. Videos will be posted over the weekend, hopefully!:ylsuper:

it's a flair, not a duct, and it's contained fully within the inside of the wheel shell :rolleyes:. RacingBrake doesn't recommend ducting air to the rotor unless you design the ducting to feed both sidesof the rotor evenly, the reason is because if you feed to the backside only it creates a thermal imbalance on the rotor

SpeedSource makes a duct kit that feeds both sides of the OE front brakes, they are presently testing the RacingBrake 2-pc rotors ...

Both the standard and Enkei wheel RacingBrake BBK's require one very small corner on the brake shield to be trimmed for clearance of the caliper mount. The rotor sits much further inboard on the Enkei wheel BBK, this requires a small area of brake shield protrusion near the tierod to be knocked down slightly with a hammer. Otherwise the brake shield works fine with their BBK, they recommend taking the back shield off because for track use it actually traps more heat than it relieves.

As I understand it and see it, air is ducted (or "flaired" :p: ) to the inside of the rotor at the hub and it should go through the veins from the inside-out. This would cool BOTH sides of the rotor through the veins. If you noticed, our stock rotors, as well as the ones I replaced them with, have a thicker outer disk than inner disk. I agree that there would be some disparity in cooling on the inside and outside, so it seems that it's been accounted for (to some extent) by giving the outer disk greater heat capacity by increasing it's mass. This is done front AND rear.

the difference is the OE rotors have straight vanes whle the RacingBrake BBK rotors have curved vanes and their rotors are unique in that the attaching hubs are center-mounted, they generate their own flow through the rotor through both the inside and outside, and I just happened to have a BBK disc on my table, it is the same approx. thickness on both sides

However, like I said before, RacingBrake generally does not recommend ducting or brake shields on their BBK kits for general track use ... if you need ducts for say, a multi-hour endurance race, then make sure you have air feeding to both sides of the rotor


and of course, SpeedSource makes and sells a ducting kit for the OE brakes that feeds both sides of the rotor, it would be a lot easier and less costly to feed the inside only if that was sufficient ... but what do they know compared to me or you :hahano:

I couldnt find any info on the Speed Source site about the air ducts. Do you have a link?

Mainly curious if it will work with an intercooler in the way, and with the MS Bumper. I am thinking the MS Bumper shouldnt be an issue since thats what they use.

-hS

they don't advertise on the web, you have to call

Will do

Speed Source producsts are generally out of my price range at the moment... but i'll find out anway. This maybe more reasonable a year from now.

-hS

if you don't get it soon you'll only be able to get it through access to the MazdaSpeed racer program:


https://www.rx8club.com/series-i-aftermarket-performance-modifications-23/speedsource-parts-rx-8-a-83108/

apparently I didn't quite get it right, the RacingBrake link below goes through a number of rotor design features and discusses the differences. Mention is also made about the brake shield. I wasn't aware that RacingBrake uses more curved ventilating space vanes on the hotter outer diameter of the disc than the inner. I found it interesting ...

http://www.racingbrake.com/main/rotor_vane_design.asp

also I edited a correction in an earlier post, SpeedSource is testing the RacingBrake 2-pc rotors, not BBK. They are required to keep the OE calipers per the rules. Word is that their testing went very well ... :)