[earlyapex]

Originally Posted by krisa9977

I think that your problem was with your rotors. Pagid Yellows are one of the best endurance race pads, but if you use them with old rotors, you'll get terrible performance. Other brake pads such as PFC01 have softer compound and work fine with any rotor.

But if you take brand new rotors and Pagid Yellows (RS19 or RS29) they'll last forever! You'll get the same or even better performance then PFC01, but it'll last at least two times longer with very little rotor wear.

They weren't old rotors. Just a couple of easy track days. There wasn't any problem here with the pagid yellows (they performed very well, just wore out). The pads/rotors are too small for the power/weight of this car.

[earlyapex]

Originally Posted by The Nebulizer

Maybe I don't understand, but why would more pistons help in this case?

It wouldn't really. I was being a smartass. It's more of a general reference to the internet concept that the M3 engineers know what they are doing and the brakes are "just fine," when they really aren't. They are too small and too get much bigger, you'll need multi-piston calipers.

In my experience, stock porsche brakes are objectively substantially better suited for track work with better feel, more durable, more torque, easier to modulate, etc.

To be clear, the M3 brakes are VERY capable, they are just the weakest link in an EXTREMELY capable car. It's not like the brakes are some huge problem. They are really outstanding, just relatively less outstanding than the handling/power.

[krisa9977]

Originally Posted by earlyapex

They weren't old rotors. Just a couple of easy track days. There wasn't any problem here with the pagid yellows (they performed very well, just wore out). The pads/rotors are too small for the power/weight of this car.

If one of your "easy track day" was in Sebring and you did low 30s, I don't think that this day was that easy on your rotors.

My brand new PFCs were completely worn out after 3 twenty minutes sessions at Sebring last year with E46 M3. That's why I don't really like this track.

But you are right anyway. The car is great, but brakes could be better.

[earlyapex]

Originally Posted by krisa9977

If one of your "easy track day" was in Sebring and you did low 30s, I don't think that this day was that easy on your rotors.

My brand new PFCs were completely worn out after 3 twenty minutes sessions at Sebring last year with E46 M3. That's why I don't really like this track.

But you are right anyway. The car is great, but brakes could be better.

Fair enough, but the rotors didn't show much in the way of wear. Very minor surface spider cracks (that disappeared after a session at VIR). There weren't any grooves or anything that would accelerate pad wear. Maybe I'm missing something, but how does a used rotor that's still round without grooves accelerate pad wear?

[krisa9977]

Originally Posted by earlyapex

\ Maybe I'm missing something, but how does a used rotor that's still round without grooves accelerate pad wear?

That was exactly the same question that I asked my experienced mechanics before one of the endurance races. I didn't listen to them and didn't replace my old rotors that had no visible signs of wear. I had to pit after two hours and replace brake pads to finish the race. Last race the same brake pads (Pagids Yellow) lasted for six hours when I had new rotors.

I can not explain that, but I only can tell about my own experience with those brake pads.

[Mvez]

Originally Posted by krisa9977

That was exactly the same question that I asked my experienced mechanics before one of the endurance races. I didn't listen to them and didn't replace my old rotors that had no visible signs of wear. I had to pit after two hours and replace brake pads to finish the race. Last race the same brake pads (Pagids Yellow) lasted for six hours when I had new rotors.

I can not explain that, but I only can tell about my own experience with those brake pads.

Good to know. I have some yellows for the rear, but I guess I should replace my rear ZCP's before using them. They are due for replacement for next year anyway.

[sly1types]

That just shows how more weight changes a lot of things....I do agree with the others the PFC 01s are great never any problems, but that's on E46.

Like you said it would benefit from having bigger rotors and most of all brake cooling kit!

The sad thing is I think bmw could have done a BBK for not much more...but then you have a lot people (general public) upset about brakes squeal. There were 2 complaints in Motor Trend this month about brake squeal.

Think how bad it would have been with R Comps....lol

[MCE92]

Originally Posted by earlyapex

I've had the E90 at a couple of track days now (Sebring and VIR). I've got 12 years of DE, instructing and racing experience.

Overall impressions are incredibly favorable. The car is far more balanced than the E46. It simply does everything you'd want it to do (like throttle steer) in a very balanced manner, and is infinitely catchable when it steps out (even when it steps WAY OUT). It's a very fun, capable machine with a lot of power and control. It's also very fast in stock form (very low 2:30s at sebring and mid 2:teens at VIR full course on street tires).

I was also surprised at how well the car could use the entire contact patch of the tire with a highly inadaquate (-1 degree camber) street alignment. The suspension manages dynamic camber changes via roll very well. You still use more of the outside edge of the tire, but it's less than most cars.

However, the brakes aren't up to the same level of capacity and ability as the rest of the car. I went through a set of pagid yellow endurance pads in a day and a half at VIR. These were brand new pads:



The rotors clearly aren't big enough either. Look at how the metal has melted into the cross drilling (also, they were glowing RED! at the end of the back straight on a 50 degree day!):



And on street tires too (albeit Potenza RE11s). Which are INCREDIBLE street tires by the way. Feel like 15% better track tire than PS2s while giving up very little on the street (just a tiny bit harsher ride).

So all of the "theoretical bench racing" on internet forums about single pistons and BMW engineers knowing more than internet junkies is pretty much total pig manure. The car is an outstanding machine, but the brakes are overwhelmed by the power and weight on far less than max-g-braking street tires.

In short, the pads would fade prior to engaging ABS, which is an easy analysis of inadaquate brake size.

If you are a serious track junkie with R-comps, you are going to HAVE to get a BBK for this car.

Couldn't agree more with your assesment of the E9X on track. I have been tracking a GT3 for the last 4 years at MSR Houston where I am a member. The track is 2.39 miles with 19 turns and a longest straightaway of 1100 ft - very technical and a low time relies heavily on in/out in corners.

Purchased my E92 a few weeks ago and took it to the track just to see how she would do. Alot of people have complained about this car insulating the driver too much from what is going on whether it be steering or braking. While it does not give the same feedback or response as GT3 (see GO-KART); it is amazing in the way it communicates to you what it is going to do i.e.; "stepping out", stays in control and never throws any surprises at you. The throttle steer can definitely help you get to a line that the understeer will not allow. As a good friend of mine states " any amount of understeer can be solved with the proper amount of oversteer". UNTIL the brakes go away! I too am going to stay with the stock calipers for now; but the stock pads lasted less than 2 - 30 minute sessions and completely disintegrated. I have put RS19's on for now because a friend had some at his shop but will probably go to PF's as on the GT3. FYI - GT3 fast lap = 1.41, E92 fast lap 1.50 (first day out). I believe this car will get within 6-7 seconds of GT3 time which will be fine with me!

[Mr.G3]

Originally Posted by MCE92

FYI - GT3 fast lap = 1.41, E92 fast lap 1.50 (first day out). I believe this car will get within 6-7 seconds of GT3 time which will be fine with me!

very good numbers indeed

[Greg S]

Originally Posted by krisa9977

If one of your "easy track day" was in Sebring and you did low 30s, I don't think that this day was that easy on your rotors.

My brand new PFCs were completely worn out after 3 twenty minutes sessions at Sebring last year with E46 M3. That's why I don't really like this track.

But you are right anyway. The car is great, but brakes could be better.

What compound?