Gee whiz. next time before i do something, i'll test it with scientific results.

Anything that blocks airflow to them, can't be good.

However, look at it this way then.

it's weight savings.

 

Guys I've been running stock setup with upgraded pads and brake cooling guides and heat is a problem especially on the inner side of the rotor. Upon visual inspection the insides of my rotors looked thinner than the outside after 2 years and multiple trackdays. This time I'm helping the guides work more efficiently by cutting off a portion of the understray as shown in the guides installation notes to allow it to scoop more air and guide it towards the rotors. I'm also installing Girodisc Ti brake shims to fight brake fade.

I did contemplate installing brake cooling kits from other vendors but decided against it because of the need to hack and cut the fender liner, take off the dust sheilds and put scoops on the front of the car that could possibly impede airflow/cooling to the oil cooler and tranny ... my thoughts were let it get the cool air it needs from the underbelly of the car ...

 

I used to run the mitsu scoops. I didn't even think about them. I ordered AMS's kit, just haven't installed it yet.

 

Dang, so you never cut the undertray for your mitsu air scoops? haha.. I followed the instructions when I installed mine.

I had the Forge BCDK before and routing the tubes through my car just made everything a PITA to work on. I also didn't like partially blocking air to the oil cooler either. In the end, I decided simplicity was best.

 

I'm not advocating giving the rear more pad, just the same friction/MOT. Do you have personal experience with rear instability from high-speed using same pad compound?

 

do you have a source for this?

 

Yeah ... they still worked tho ... just not as well.

 

Long as you have the fancy mitsu abs, you can go with a more aggressive pad in the rear, the abs wont let it lock up. I went with a more aggressive rear and it stabilized my car more under hard braking. Once I lost my abs at my last race, id lock the rear brakes up all the time. No abs put on a pad with less bite, abs you can go more aggressive. Oh and get an ams cooling kit like Eric said
Marty

 

Yes. With the 97s all around, i'll occasionally scoot the rears on initial brake, which makes things interesting quickly.

Marty, thats interesting, because it's the opposite of what i'm feeling. With 0 rear toe, i still get the issue from time to time.

 

WarmPepsi, I've been trying to combat the high speed braking rear stability issue myself. It seems to come and go depending on brake pad combination. When I ran Hawk DTC pads front and rear, I never had a problem. Once I switched out my fronts to the PF97s, the problem came back.

So I got my car corner balanced and realigned and the problem seemed to have gone away. I did go from -1.4 rear camber to -1.5 deg. Perhaps more negative rear in combination with being corner balanced may have been enough to give me more high speed braking stability.

 

Guys... the whole brake compound bias thing is an interesting sceince/vodoo. Traditionally the thought is to put more agressive pads on the front (say PF01s) and slightly less agressive on the rear (say PF97s) with the idea that with all the traction on the front of the car (with weight transfer) the more agressive pads can get the job done, while not having much weight and therefore traction on the rear the lower friction pads wouldn't lock the rears up. Yeah I know I likely just preached to the choir...

Marty and I have found that with the EBD on the Evo 9s that it will work with more agreesive pads on the rear and take some of the load off the front and balance out the car as well. Just think about it, EBD using the wheel speed sensors can tell if the rear tires are either about to lock up or if they are traveling faster than the front (which will give you the loose rear feeling under braking.)

I personally run PF01s front and rear and can hammer it into braking zones without any control issues. Marty prefers Hawk DTC70s as he likes the way they wear better, (they give me pedal vibration). This is the sort of thing that you get in to a driver preference and feel...just like tires. If you want my advice, go as agressive as you need and can afford (race vs. track day) but go with the same compound front and rear, then let the computer figure the rest out, this only goes for the Evo...other lesser cars need not apply


Most recent word is that Marty has qualified on the pole for the SARRC race and outside pole for the National Race at Road Atlanta. Since we don't run Regionals any longer he withdrew from the SARRC race, but tommorrow should be a good show. Go get a win for your sight impaired (I had laser eye surgery this week) team mate and temporary remote crew chief!!!