Feedback on taking the M5 to the track...

[M3Racer]

For those of you who have been on track with your M5, does the car feel different afterward? More specifically, does your driveline feel different, i.e. more abrupt shifting, more difficulty being smooth, perhaps a faint lack of smoothness when running thru the higher rpms at times?

I did 1 track day at Watkins Glen in 85+ degree heat. The car did great and the oil level remained unchanged at 0.8 although the engine temps reached 265 or so. I also almost finished off the front and rear stock brake pads to about 2000-3000 miles remaining according to the iDrive display. I also put the tires much closer to the end of their lives. I started out using MDM and S4 for my first session then progressed to DSC off and S5. I did a session or 2 in S6.

I did the track event almost 2 weeks and 800 miles ago. As I noted above, the car doesn't quite shift the same as before.

I'm at 13000 miles and will soon be having my 15k service. I talked to the service dept. today and they said that the car has "lifetime" tranny fluid and that the diff fluid gets changed at the major Service 2 at something like 60k miles or whatever it is. As for the engine oil, I normally would've changed the oil at 8k or so but have ended up just waiting for my 15k service which, at this rate, isn't scheduled til about 16,300 miles according to my OBC.

Anyway, those are the circumstances. Anyone else have a similar experience?

[chrisn]

I have done six or seven track days with mine, including one particular day of very hard driving with 265+ deg oil temp and brakes that sounded like snap, crackle and pop after each run.

I haven't noticed any problems (other than squealing brakes). I do have a couple of rattles, but not sure if that is related.

On reported brake life, I am pretty sure the computer looks at the rate of pad consumption compared to miles driven and extrapolates. When it goes from 20K life to 3K life, it doesn't mean that you have consummed "almost all" of you pad, it just means that your massive short-term use is tricking the computer (because it assumes that the lat 10 miles of track driving is representative of your future driving).

The proof for my logic here is that you remaining life will actually GO UP after you drive normally for a couple hundred miles.

[Sprocket]

From your sig info you appear to be a track guy. You should change the engine oil, trans and diff fluid after each event if you run the car hard. (sounds like you did). It is no different than your race car.

I had a diff come apart on me once in a club event due to overheating. Ever since I change the fluids!

[chrisn]

Originally Posted by Sprocket

You should change the engine oil, trans and diff fluid after each event if you run the car hard. (sounds like you did). It is no different than your race car.

I had a diff come apart on me once in a club event due to overheating. Ever since I change the fluids!

Now you've got me worried!

[M3Racer]

Originally Posted by chrisn

On reported brake life, I am pretty sure the computer looks at the rate of pad consumption compared to miles driven and extrapolates. When it goes from 20K life to 3K life, it doesn't mean that you have consummed "almost all" of you pad, it just means that your massive short-term use is tricking the computer (because it assumes that the lat 10 miles of track driving is representative of your future driving).

The proof for my logic here is that you remaining life will actually GO UP after you drive normally for a couple hundred miles.

You're right on this. I think I went from 37,000 remaining to 2,600 remaining in one day The caution light just came on for my rear pads (2,000) and I'm sure the computer won't read it as being any worse for quite a while, particularly if I'm doing mostly highway miles. Anyway, the numbers have risen slightly since that time.

[M3Racer]

Originally Posted by Sprocket

From your sig info you appear to be a track guy. You should change the engine oil, trans and diff fluid after each event if you run the car hard. (sounds like you did). It is no different than your race car.

I had a diff come apart on me once in a club event due to overheating. Ever since I change the fluids!

I was thinking I'd change the tranny and diff fluids as well. I don't plan on tracking this car much at all going forward...it was just an exploratory thing for me to see how the car would perform. With that in mind, I don't know whether I should use the BMW fluids or go with Red Line or something like that.

Oh, that reminds me, I need to change or bleed the brake fluid as well. Pedal travel is longer just as I would have expected.

[DrKevM5]

M3 Racer, make sure you have the latest software. I also thought the tranny shifted more abruptly after my first event. However, I had the latest software installed in June and have not had a problem after a track event since. If anything, the car felt stronger. Also, changing to a racing brake fluid will make a huge difference in your braking performance.

I beg to differ concerning the trans and diff fluids needing to be changed after every track event. These vehicles were made to run aggressively at autobahn speeds all day without issues. Trust the OBC. Make sure you are cognizant of the oil levels, though.

[Sprocket]

Originally Posted by M3Racer

I was thinking I'd change the tranny and diff fluids as well. I don't plan on tracking this car much at all going forward...it was just an exploratory thing for me to see how the car would perform. With that in mind, I don't know whether I should use the BMW fluids or go with Red Line or something like that.

Oh, that reminds me, I need to change or bleed the brake fluid as well. Pedal travel is longer just as I would have expected.

I have tracked my car four times now (used it to take students around). I always do a few laps at speed for fun. Ever since the first time on track I have had a long pedal. I have changed pads and fluid. It not horrible just not right.

[SGM5]

I agree with DrKevM5. I'e done three BMW Club drivers school weekends with my car (Mid-Ohio, Watkins Glen, and Mosport), and after each the car felt a little different at first, but was back to normal at some point during the trip back home. I think a large part of the different feel was the tire wear at the track. I do think changing the brake fluid to something with a higher boiling point than the stock fluid (like Ate or Motul) is important for track use. As to engine oil and other fluids, I just let the computer tell me, although I don't think I'll go more than 7500 miles between engine oil changes. Coming back from Mosport, the car called in to the dealer that I had 700 miles left on the rear brakes, and the dealer called me on Monday to schedule an appointment to replace them (under maintenance). The front brakes still had more than 50% on them. So far the only thing I've had to pay for is the dealer's work to change out the brake fluid. I have about 6500 miles on the car. I also have the long brake pedal travel. The dealer's tried several times to fix it (under warranty), and it's better, but still there. The brakes work great, including at the track, but it's taken getting used to. If anyone has a solution, please let us know.

[chrisn]

Originally Posted by SGM5

Coming back from Mosport, the car called in to the dealer that I had 700 miles left on the rear brakes, and the dealer called me...

A bit OT, but my car does not call the dealer (although I see that area in I-drive, it seems unconfigured)-- did you configure yourself or did dealer?

Originally Posted by SGM5

I had 700 miles left on the rear brakes...front brakes still had more than 50% on them.

My rears alway wear MUCH faster than fronts on the M5, which is opposite of my (limited) prior experience with cars (fronts go first, or at least more balanced). I have assumed that this is due to me being a novice girly-man who leaves MDM all the time, causing the nanny to drag the rears when I "overdrive" the car in the turns.

Do you guys think that this is the case, or is the "natural" (i.e., no DSC) pad wear skewed toward the rear for some reason?

[M3Racer]

Originally Posted by chrisn

A bit OT, but my car does not call the dealer (although I see that area in I-drive, it seems unconfigured)-- did you configure yourself or did dealer?



My rears alway wear MUCH faster than fronts on the M5, which is opposite of my (limited) prior experience with cars (fronts go first, or at least more balanced). I have assumed that this is due to me being a novice girly-man who leaves MDM all the time, causing the nanny to drag the rears when I "overdrive" the car in the turns.

Do you guys think that this is the case, or is the "natural" (i.e., no DSC) pad wear skewed toward the rear for some reason?

I'm nearly sure it would be the MDM use.

[SGM5]

I hadn't thought that MDM might be the reason the rears wore faster, but I'll bet that's the case. I had MDM mostly on at Mid-Ohio (first track time with the car, and I thought it might save me while I was learning the car), off (except for two runs on a damp track) at Watkins Glen, and mostly on at Mosport (my first time at that track). I felt MDM working each time I had it on. So that might be it. As to configuring the car to call in, I picked up my car at the Performance Center in Spartanburg, and they did all the configuring there. I think it's part of BMW Assist or something, and I thought all new M5s were configured to do that. I don't remember talking specifically with them about configuring the car to call in. Technically, what happened was I saw the warning message on the dash while driving home from Mosport on Sunday, and the dealer got an email Monday morning with the info and called me.