99 GSX Bad Brake Fade

norths03 · 06-26-2012, 11:02 PM

The car is relatively new to me but I have plans to make it a track/HPDE vehicle. My last car was a 2005 Legacy GT and I was able to enjoy HPDE sessions with multiple sessions of braking from over 100mph down to about 25mph without too much fade. My setup was nothing more than stock calipers with Centric Premium Rotors, ATE Super Blue fluid, and StopTech Street Performance pads.

Back to the GSX. I noticed an annoying squealing when stopping (but not all the time, ie wear indicators) which led me to believe there was buildup on the rotors. I checked the pads and they had between 1/2 and 3/4 pad remaining. I went out to a rural road to re-bed the brakes and was shocked at how fast the fade came on. My standard re-bed is 6 hard braking applications back to back from 60mph down to about 5mph (being careful not to come to a complete stop). The first braking application went okay but it was almost not strong enough to engage the ABS. The second braking application resulted in a vague pedal and significant brake fade. The fade got worse through the next 4 stops to the point where it was scary how bad the brakes were performing. There is no way that this would work at a track or even an autocross for that matter.

What I'm wondering is, what affordable brake upgrade should I look into considering that I would like to enjoy some autocross and track time but still be able to daily drive the car (the HP+ pads I had on the Legacy early on made stopping in cold or wet less than ideal)? Can I simply upgrade the rotors, pads, and fluid like with the LGT or do I really have to upgrade to one of the pricier big brake upgrades?

Just so there's no confusion, I do really like the car, just not this scary brake fade.

Thanks in advance.

Aproductions · 06-26-2012, 11:08 PM

Maybe try some Motul RBF 600 fluid with a decent set of slotted rotors. As for pads the EBC ones or Hawk are good. I went with the whole package:

Brembo's, hawk HP pads, Slotted rotors, SS lines and Better fluid.

WES_393 · 06-26-2012, 11:11 PM

In my experience, cheap semi-metallic pads will do this. Cheap rotors don't help either. Not saying your cheap, but who knows what the previous owner put on the car. As a suggestion, why not look into upgrading to Outlander front brakes with quality rotors/pads and Early 95 rear vented rotors/calipers with quality rotors/pads? I would imagine this would give you a great increase in braking force over the stock 9" front rotor and solid rear rotor, and at a fraction of the price of big brake kits. SS lines and a good flush/refill with better brake fluid might help as well.

luv2rallye · 06-27-2012, 12:50 AM

Carbon-kevlar pads will totally eliminate brake fade. The hotter they get the more grip they produce. Porterfield or Hawk are good brands. Slotted vented rotors, SS lines and synthetic brake fluid will also help with hotter brake system temps.

norths03 · 06-27-2012, 10:23 AM

I've been doing some searching but I want to make sure I've got this right before I spend any money. If I was going to upgrade the fronts to the larger Outlander setup I could reuse my calipers as they are the 2 pot 99 GSX calipers but would need to upgrade the caliper brackets (part # MR 307282) and rotors. Is this correct or will I have to upgrade the caliper as well? I will surely be upgrading the pads as well as I'm thinking they are certainly a contributing factor to the fade.

I would love to go to a brembo setup but those funds are already earmarked so I can't

I'll have to do some more research into the rear vented setup as that would help as well I bet. I did look up the sizes of the Legacy GT brakes and they are 316.5mm vented rotors up front and 289.6mm vented rotors in the rear which probably also helped avoid fading.

Thanks for your help guys.

Would it be possible to simply add vented rotors in the rear or do I have to get the early 95 calipers to go with them?

One other question: Would the Brembo rears (bolt-ons) be too strong in terms of braking balance with the Outlander setup on the front?

WES_393 · 06-27-2012, 05:32 PM

I'm not sure if you need new calipers, I was under the impression you could use the 2g dual-pot calipers. Here's a good starting point on upgrading to Outlander brakes.

05/06 Outlander "BIGGer brake upgrade"

For the rears, I'm also not certain if you need the early 95 calipers or not. They are single piston, but the hat of the rotor is taller with solid rear disks.

Part numbers for vented rear disks and calipers.
C9198 ( RR Caliper)
C9199 ( LR Caliper)
76569RGS (Rotor)