E diff Killing rear Brake pads on a trackday. Is it just me

[Rich196]

Doing a few road course track days in the 135. I dont have an LSD. I am driving with the car in DTC mode, just a single press.

However I am eating rear brake pads, which I can only assume is due to the E diff. I am doing a set of rear pads per track day. This may have something to do with the face I am running stage 1.5 tune, and its lots of power to put down out of a bend. If it help I am running semi slicks too.

How does this compare to anyone else's finding? Is there a decent pad to cope with it. Or am I best to buy a cheaper pad and keep changing them?

Whats others experience of this?

[02rsxpilot]

I run stock rear pads, same DTC mode, stock motor/tune though, and I've done 28,000 miles and five events and still have lots of pad life left. Possibly a track layout issue? If you have lots of tight corners on your circuits I suppose that could increase the e-diff effect, but 1 set of rears per event seems excessive to me. Maybe others can weigh in.

[3002 tii]

Or he's putting down that much power that he's constantly losing grip

[fe1rx]

Originally Posted by Rich196

Doing a few road course track days in the 135. I dont have an LSD. I am driving with the car in DTC mode, just a single press.

However I am eating rear brake pads, which I can only assume is due to the E diff. I am doing a set of rear pads per track day. This may have something to do with the face I am running stage 1.5 tune, and its lots of power to put down out of a bend. If it help I am running semi slicks too.

How does this compare to anyone else's finding? Is there a decent pad to cope with it. Or am I best to buy a cheaper pad and keep changing them?

Whats others experience of this?

Since you are using sticky tires, its is your driving. Be smoother on the throttle application and don't slide so much on corner exit. It definitely depends on the track though. I log e-diff activity on my AIM Solo DL. On a very fast track I see virtually none. On slower tracks it shows up at slow corners, even without a lot of sliding. If you see a lot of intervention from the stability control, you are overdriving. Slow down to drive within the limits DTC allows you, or turn it off completely and drive within your own limits. An indication that you are overdriving your rear grip is that your rear rotors turn blue faster than your front rotors. My experience is that rear pads last longer than front, even with frequent track days, providing you respect the total grip available.

[Rich196]

Originally Posted by fe1rx

Since you are using sticky tires, its is your driving. Be smoother on the throttle application and don't slide so much on corner exit. It definitely depends on the track though. I log e-diff activity on my AIM Solo DL. On a very fast track I see virtually none. On slower tracks it shows up at slow corners, even without a lot of sliding. If you see a lot of intervention from the stability control, you are overdriving. Slow down to drive within the limits DTC allows you, or turn it off completely and drive within your own limits. An indication that you are overdriving your rear grip is that your rear rotors turn blue faster than your front rotors. My experience is that rear pads last longer than front, even with frequent track days, providing you respect the total grip available.

I think you are right here. I am driving hard. Probably harder than the car would like.

The track I was doing is this. I probably did arond 150 laps.



The car, has m3 front arm, b12 suspension, rear subframe inserts, semi slicks 225, 255 section. The car was running probaby 380 bhp and 450 ftlb fly fiqures on the day.

I felt I was trying to stop the traction control light flashing and the e diff working, but this meant the amount of throttle i could use just pushed the front of the car wide rather than allowing you to use the power delivery to pivot the car and push it round the bend.

What pads are you all using?

[dcaron9999]

As others have mentioned, turn DSC-OFF (long push of the DTC buttion), but only once your tires and brakes are warmed up, you haven't made recent modifications to your car, and you know the track very well. Ask me how I know.

Been using PFC 08 brake pads lately, and these wear very slowly on the track and on the street. This includes front and rear pads.

Hated the "e-diff" once I started tracking the car on a frequent basis. Got a Quaife LSD and upped the final drive ratio from 3.08 to 3.46. Car now tracks straight and puts the power down safely out of turns. No more one-wheel drive and snap over-steer!

As others have mentioned, you have to be smoother on your accelerations out of corners.

One excellent book to drive these points home and more is "Ultimate Speed Secrets" by Ross Bentley.

[3002 tii]

Originally Posted by dcaron9999

As others have mentioned, turn DSC-OFF (long push of the DTC buttion), but only once your tires and brakes are warmed up, you haven't made recent modifications to your car, and you know the track very well. Ask me how I know.

Been using PFC 08 brake pads lately, and these wear very slowly on the track and on the street. This includes front and rear pads.

Hated the "e-diff" once I started tracking the car on a frequent basis. Got a Quaife LSD and upped the final drive ratio from 3.08 to 3.46. Car now tracks straight and puts the power down safely out of turns. No more one-wheel drive and snap over-steer!

As others have mentioned, you have to be smoother on your accelerations out of corners.

One excellent book to drive these points home and more is "Ultimate Speed Secrets" by Ross Bentley.

Apologies for going off-topic:

Do you find that you're shifting more or less with the 3.46? How's top speed coming down a straight?

Also now that you've had he 08's for a while, any regrets? How do you like them over your previous track pad?

[dcaron9999]

Originally Posted by 3002 tii

Apologies for going off-topic:

Do you find that you're shifting more or less with the 3.46? How's top speed coming down a straight?

I have no scientific data to tell you whether Im faster down a straight away. I will tell you this, you have explosive accelerations out of corners, and must be gentle with the throttle. The Cobb PTF Stg1 custom tune I just got done also helped with the torque delivery. Each gear up to sixth gear (which I never get to use on the three tracks I visit) pulls hard and just sinks you into the seats. I spend my time in 3rd, 4th, and 5th gear on the track. With the 3.46FD, the engine revs at about 500 extra RPM when travelling the same speed as with the 3.08FD.

Originally Posted by 3002 tii

Also now that you've had he 08's for a while, any regrets? How do you like them over your previous track pad?

With the PFC08's, I have run into minor fade issues on tracks that have frequent hard braking zones, with short intervals to allow sufficient speed and cooling of the rotors/pads. I have not set up brake cooling piping yet. Just using Hardbrakes Ti Heat shields and F30 dust shields, and 1-inch wider front wheels which may be blocking airflow coming from front bumper duct openings.

The PFC08's are surprisingly good when used on the streets and cold. Not as much as bite as OE pads, but plenty powerful. No noise to be heard, except for very minor, barely noticeable peep during certain slow stops.

I dont daily drive my 135i, more of a week-end car and for errands, but track it a lot, sometimes as much as twice a week. I can officially put my stamp of approval on the PFC08's as a great dual duty pad on the 135i.

Prior to that, I had the Project MU Club Racer RC09 pads and they were better on the track with zero brake fade regardless of track visited or ambient temperature. They were slightly noisy on the streets as the pad layer scrubbed off the rotors.

Before this, I used the Carbotech XP10's. They ended up fading as well and were very noisy on the streets. Was ready to move up to XP12 pads but got a recommendation for the Club Racer pads instead.