[bryce]

Hi Guys, Newbie forum member asking after some advice please.

Just bought an ex demo 08 STI with 1500 km on the clock. As I collected the car I could feel some vibration through the pedal and mentioned to the dealer the brakes may be warped slightly. I'm lucky enough to live near the Nurburgring and was really looking forward to having a morning on the track with the new toy. So 3 days later, up early and down to the ring.

Sadly the brakes faded from half way through the first lap and I only managed 5 laps before they were pretty much unusable. I know the track fairly well and was pushing pretty hard so assume that the discs had been warped slightly from new (not run in) and a couple of the big stops from high speed had increased the warp to the point were the car was pogoing on the brakes.

No hassle with the dealer - he sent a driver down to collect the car (500 km round trip) and fitted new discs and pads. He assured me he would bed the brakes in properly (at least 5 stops, increasing the speed and pressure and cooling in between) and the car was returned feeling great. (having brakes is nice). One week and 500 km later (brakes had at this point been on 750 km) and its back for a play at the 'Ring. 7 laps later, the discs are fit for the bin only. Honestly, it's almost undriveable;particularly the last few metres of gentle braking to a stop in the wet which has the wheel moving left,right etc. My wife is not impressed with my handiwork on the family car. Particularly as she wanted another bmw.

I've decided to go to Movit discs and pads rather than endlessly be changing the brembos but wanted to hear if anyone else had encountered this problem? I have to admit I'm really disappointed with the car as I had chosen it over a 130i M because I thought it had the brakes, diff etc for the occasional track visit. You can forgive the interior and micron thin paintwork on a car this expensive if the moneys gone on the hardware, but I can't believe the discs are proper performance car Brembos?

Other main point of concern is the understeer. Argh! Best chassis mod cure for this much appreciated. If I can get that and the brakes sorted it will be one quick enjoyable Ring car. But at the moment I'm looking at the EVO X wondering why i didn't wait a little bit longer......

Thanks, Bryce

[Turninconcepts.com]

I have run into a few problems with the brakes on track days here. I started initially with better pads and fluid (Pagid RS5's and RBF600). I cooked the brakes in the first session. They were vibrating horribly.

Then I removed the backing plates from the front rotors and had the front rotors turned. This got the shake under braking fixed....for a while. On the next track day now without the backing plates, the brakes held up for a longer period of time, but still ended up in the same state as before with much vibration and fade.

Now I am on DBA4000 rotors up front with Hawk DTC70 pads for the track. Last track day resulted in quite good braking during 25 minute sessions. Next mod is going to be some brake ducting to keep the heat even further under control.

I would definitely say that true track pads are required for tracking this car hard. I would also recommend changing out rotors as well and having a set specifically for track use.

As far as your understeer goes, get an alignment. The stock one is garbage. Also look into the Whiteline camber bushings for the rear upper arm as they will allow you to dial out some camber in the rear.

Tony

[mikeygar]

same problem in my 08 STI. Stock brakes easily overheat, now my brake pedal feels spongy and is soft on the first press. I think due to the heat my brake lines have air in them. Planning to order a set of braided lines, RBF600 fluid and Project Mu sport pads to improve my braking.

[Dante]

My brakes feel soft, but I've been happy with them so far. I havn't done any tracking yet but I've done back to back sessions at Deals Gap, TN (The Dragon, 11 miles each way) and was impressed that I didn't get any fade. Brakes on my '03 S2000 would fade at that level of abuse. Only thing I noticed with the STI (besides all the squeaking!) was the rear end feeling like it was floating under very hard braking when hot. I attributed this to the rears over heating, does that sound correct?

[Blip]

WOW, becouse the the first mod I did was SS lines all around and a set of Stoptech with HT-14 in the front and HT-10 in the rear.

The STI Brakes are fine for track days.

[bryce]

Thanks for the advice. Have spoken to Movit brakes who equip a lot of race teams here in Germany. An upgrade is definitely the way to go. Having reread my post it comes across a bit harsh on the car. The braking at the 'Ring is pretty fierce in a few areas with high speeds (230 kph) and lots of bumps and I was probably going a lot harder than the last time out. I'm enjoying the cars engine and attitude (in sports sharp anyway) and the fact that there seem to be probably only about 40 total in Germany makes it a bit of a head turner. I'll get back with some feedback on the upgrades. Cheers

[kaz]

I'm getting a Stoptech kit on my 08 soon will post results after the next track day.

[caveguru]

Stock pads and fluid are definitely not acceptable on these cars. I seem to remember some BMWs holding up to track use with stock brakes, and maybe some others (Corvette Z06, EVO?), but the Subaru's rotors are too small and need different pads and fluid to hold up to any kind of track use. That said, once you change those things, it may be adequate for stock hp and tires.

Also, did you disable the traction control? There was a post here (TIC?) reporting that the VDC system may cause premature brake overheating when driven on the track. I still don't completely understand what will be the best setting on the VDC for track use, but I assume its going to be whatever setting uses the brakes the least for course correction (unless I do something like install the stoptech's and 355mm rotors).

Frank

[mattjk]

rotors do not warp, they develop hot spots.

i don't why subaru puts on nice brembo calipers and rotors, and then give us crap fluid and pads that dust horribly.

cant wait to change mine out for some porterfields.

[Turninconcepts.com]

POrterfield would be the last brand of pads I would ever choose. Have had WAY to many bad experiences with them to ever purchase their pads again.

[caveguru]

Originally Posted by mattjk

rotors do not warp, they develop hot spots.

From what I understand, rotors don't warp. Under normal operation, some material from the pads transfers to the rotor surface and together the two surfaces function properly for braking. When the pad exceeds its temperature limit, an excess of material transfers to the rotor surface and "cements" (correct word?) into a hard surface that does not work very well for braking. This sets up an uneven surface on the rotor, hence the sensation of warped rotors. It also greatly reduces the braking capacity of the rotors and increases heat build-up at the cemented areas. This causes the pads to overheat even more easily, making the problem worse. I'm basing this description on reading the information that Stoptech has distributed on their website and stated on Nasioc.

I will add that when I first tried EBC greens, which are NOT a high-temperature pad, I could visibly see the changes to my rotor surfaces, and experienced the corresponding deterioration in braking performance. I now use EBC yellow's as street pads because they are extremely friendly to my rotors and still have a very high temperature limit (and they're cheap!). I've used the yellow's as track pads with some success, but with the tiny 11.6" rotors on my '02, they still get too hot. I'll try them on the sti, but may ultimately move to something like the Carbotech XP10's for track days because they have a higher temp limit.

Because of the pad material transfer I mentioned above, and probably differences in how each pad wears down the rotors, its a good idea to always change to track rotors if you run different pads.

Frank

[bryce]

Thanks for the advice, it does seem to be the general agreement that it is pad deposits that cause the 'warped' feeling. Either way it's pretty bad at the moment, normal town driving is a total pain and I don't fancy having to get the discs skimmed all the time to clean the deposits. I think I'll go for the track rotors and swap the pads for track/street. Has anyone fitted the Cobb stabilisers (anti-roll bars) to the 08 yet? Does this improve the understeer?

Re: traction control at the Nurburgring. I had it half on for the first lap then off for the rest so I don't think it was this caused the overheating.

B

[HRCboy]

take out you stock pads and check em... after one trackday my stock pads were melted and cracked. Switched to Hawks DTC 70 and Motul 5.1 and find that plenty for the track.

[caveguru]

Originally Posted by bryce

Thanks for the advice, it does seem to be the general agreement that it is pad deposits that cause the 'warped' feeling. Either way it's pretty bad at the moment, normal town driving is a total pain and I don't fancy having to get the discs skimmed all the time to clean the deposits. I think I'll go for the track rotors and swap the pads for track/street. Has anyone fitted the Cobb stabilisers (anti-roll bars) to the 08 yet? Does this improve the understeer?

Re: traction control at the Nurburgring. I had it half on for the first lap then off for the rest so I don't think it was this caused the overheating.

B

theirs some comments here somewhere that the understeer can be reduced to a point from a stiffer rear bar, but only up to point, after which you're just reducing overall traction I assume. I have 22mm front and rear bars, but I broke a factory endlink so my verdicts not in yet. I'm wondering if adding the stiffer front bar is going to put me in a spot where no amount of rear bar is going to bring the balance back. Remember though that the balance is the sum of a lot of factors, especially spring rates, tire pressures and alignment, besides sways. I could tell you what works on my 02, but the 08 is a new game.

Frank

[mattjk]

Originally Posted by caveguru

theirs some comments here somewhere that the understeer can be reduced to a point from a stiffer rear bar, but only up to point, after which you're just reducing overall traction I assume. I have 22mm front and rear bars, but I broke a factory endlink so my verdicts not in yet. I'm wondering if adding the stiffer front bar is going to put me in a spot where no amount of rear bar is going to bring the balance back. Remember though that the balance is the sum of a lot of factors, especially spring rates, tire pressures and alignment, besides sways. I could tell you what works on my 02, but the 08 is a new game.

Frank

those methods have worked every since cars were made.

basic rule is to stiffen up the end of the car you want less traction.