BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read
M2 Technical Topics > Track / Autocross / Dragstrip > Let's keep things simple

Post Reply
 
Thread Tools Search this Thread
      09-12-2019, 01:52 PM   #1
Insane_Dawe
New Member
United_States
3
Rep
15
Posts

Drives: 18 Grey M2
Join Date: May 2019
Location: Chicago

iTrader: (0)

Let's keep things simple

I recently joined this great M2 owners club with the intention of having a comfortable street focused sports car. After some spirited driving, I started to feel out some of the characteristics of the car and got excited when it reacted similarly to my sport bike.

Naturally, I drove home and signed up for a track day (09/11). Kept it simple, full street trim apart from removing the random junk rolling around and Sport+/Traction Mode.


Notable observations

Brakes got hot and soft. I tried to counter this by rolling off throttle and shorter more aggressive braking. By my final session out, I was much better at preserving the brakes to the point where I thought they were adequate.

Engine temps seemed fine. Wasn't paying close attention but at 90°F and humid, didn't throw any warnings at me.

I like traction mode. The comfort throttle makes it much easier to modulate the throttle and the lighter steering helps. Transmission didn't seem to keep the RPMs as high as in Sport+ which I cured by switching to sequential(one more thing to think about). Sport+ is also super aggresive on gear changes and I see the traction light come on.

Tires got moderately hot. I noticed that the PSS got up to 43/40 PSI on the TPMS monitoring system and stock mine were 37/37.

During my last session I got pretty good at conserving brakes, keeping a good line and avoiding the traction/stability control.

I have another track day on Sunday (squeezing a 2nd one in before the end of the season). Not enough time for pads and fluid change but to improve things I am thinking about

TLDR;
  1. Sport+ vs Traction Mode - I like traction mode but I saw on the forum that Sport+ forces the cooling into a more aggressive mode. Should I care?
  2. Tire Pressure - What’s a good “hot” temperature for PSS? Is the built in TPMS system “real-time”?
  3. Brake Color Fade - I just read about brake color fade, would pads prevent that? Or is it bound to happen as I spend more time on the track?
Appreciate 0
      09-12-2019, 04:42 PM   #2
5.M0NSTER
Lieutenant
5.M0NSTER's Avatar
United_States
455
Rep
527
Posts

Drives: 2017 BMW M2 6MT Drivers Pack
Join Date: Dec 2018
Location: Little north of Stuttgart, Germany

iTrader: (0)

Congrats on the M2 and awesome that you have it at the track. It really is it's natural habitat

Here would be my recommendations:
1. Don't worry about cooling (particularity since you figured out to back off the throttle to help save the brakes). Throttle map is way more controllable in traction and that is more important.
2. 35psi hot, they start getting greasy over that. This means 28-29 cool and let them get up to temp over a lap or 2. PSS has surprisingly good grip when kept under 36 or so. TPMS updates every 30s or so, so as real time as you can get. In addition to pressures keep an eye out for temp. Over 90C or 190F they will get greasy regardless of pressures.
3. I have 3 days this year on the M2 with PFC08 endurance pads at Spa Francorchaps, Hockenheimring and Nurburgring Norddchleife. Very good warm grip, good fade resistance and calipers are still blue. But braking later and harder but shorter also helps. Plus after 3 days on F1 tracks I still have over 80% of the pad left. I think eventually they will turn but so far so good.

When you have time switch to race fluid and track pads and this car will be gem. Fluid is the first weak link in the chain and pads are pretty much a tie. Also DSC Off in the long run is what you should plan on running when you get used to things and can control oversteer well. Car has a magical balance so it won't be long
__________________
2017 BMW M2 German Spec
6MT, Driver's Package

"Redline a day keeps the mechanics away"

Last edited by 5.M0NSTER; 09-12-2019 at 04:59 PM..
Appreciate 0
      09-12-2019, 10:25 PM   #3
lax01
Major
523
Rep
1,153
Posts

Drives: 2017 M2
Join Date: Jan 2007
Location: Los Angeles, CA

iTrader: (0)

TLDR
  1. Turn off traction control completely - the car is extremely easy to drive without it - I felt way more in control of the car than using SPORT/TRACTION
  2. PSSes start cold at 27-28 - just watch it as the car will go into limp mode (well, it will kick you out of Sport because it thinks you have low tire pressure)
  3. Get track pads and SRF and you are good on brakes
Appreciate 0
      09-13-2019, 09:14 AM   #4
isjoey
First Lieutenant
isjoey's Avatar
216
Rep
323
Posts

Drives: M2, 335is , CBR100RR
Join Date: Feb 2017
Location: Ashburn, VA

iTrader: (0)

TLDR;
1.Sport+ vs Traction Mode - I like traction mode but I saw on the forum that Sport+ forces the cooling into a more aggressive mode. Should I care?
-I recommend trying just Sport mode. I have not heard of Sports+ providing additional cooling. IMO, Sports+ is just too aggressive for the track! Any mode aside from DSC Off will heat your brakes up faster when the TC kicks in. It is good that you are monitoring that. I don't suggest turning DSC Off until you get more time with the car and feel you are ready to do so. DSC Off is the best mode to run in when on the track. It gives Sport shifting and the wheel is in Comfort. Now, I just learned, or was told, officially the pros driving the M2 were the fastest in Sport. I find this hard to believe although will certainly be experimenting. I just feel I will see TC kicking on constantly, in turn over heating the brakes. Would certainly depend on the track and driving conditions too.

2.Tire Pressure - What’s a good “hot” temperature for PSS? Is the built in TPMS system “real-time”?
-Yes, real-time. Hot rage is 36 to 40, from Michelin. The more pressure the more the tire will "stand-up". It depends on the track, outside temps, etc. It is better to have a tire stand-up than rollover. I would say you would want 38 hot without camber plates. The M2 tends to read 2 lbs lower than most temp gauges fyi. If it is a cool day (50-60s), try 35 hot.

3.Brake Color Fade - I just read about brake color fade, would pads prevent that? Or is it bound to happen as I spend more time on the track?
-This will occur when the brake fluid gets too hot or brake pads get to hot, basically. It is very common. I know an instructor that ran a number of HPDE - completely stock - and did not have any issues, color change, etc. Just heavy tire and pad wear. Driving and braking technique play a very big part in all of this.

If you are going to do a number of track days a year I recommend getting the basics done - brake fluid, track pads and camber plates. Leave it at that, have fun and learn! The M2 is such a great car the way it is!
__________________
BMW CCA and PCA HPDE Instructor

Last edited by isjoey; 09-13-2019 at 09:21 AM..
Appreciate 1
bentom252.50

      09-15-2019, 11:36 PM   #5
Insane_Dawe
New Member
United_States
3
Rep
15
Posts

Drives: 18 Grey M2
Join Date: May 2019
Location: Chicago

iTrader: (0)

Post event update.

I have never been to this track so I didn't think I could push hard this first session. I did have an instructor ride along to show me the line even in the first session even though I wanted to wait until the 2nd. I'm glad I did. The novice group was a complete mess and I was unable to get up to pace. The slow pace let the instructor was able to give me a complete walk through of the track but the instructor took me for a crazy ride-along to show me what it feels like at pace.

Before my first session, I dropped pressure to 30 psi cold. Leaving the track after the first session, the TPMS monitor showed that pressures reached 35-36ish. Perfect. Second session should be much better. Waiting in line for the second session, pressures dropped to 30s and I got a TPMS error. I didn't think anything of it, but little did I know, it kicked the car into limp mode. Car just felt wrong, traction was cooking my brakes, I just took it slow and steady the remaining half.

I tried to fix the error after coming off track, tires still hot at ~36 psi, I reset the TPMS. I believe that cleared the error and got me out of limp mode. To counter the error, I pumped up a little, waited to just before my 3rd session and dropped them to ~34 in hope that by the time I hit the track they won't drop to low.

Thankfully that worked and I immediately gained appreciation for not being in limp mode and Sport+ mode as it lets the car step out just a little and I got my power back. Sadly it was wet all day and going into the 3rd session there was a light on/off drizzle. But even with the drizzle by the end of the session, I got quite a bit confident and finally felt at pace.

Being at pace in the 3rd session made me want to turn traction off. I would have no TC kick in through the whole corner until I am 70-80% throttle at the corner exit, on the rumbles, trying to drive the car out. I'd have to wait a sec, then power would rush in. Sadly this was the last session of the day so I wasn't able to explore DSC off.



1) What's the proper way to clear the TPMS error?

2) How do I bypass the TPMS limp mode?

3) If I bypass it can I still get reading?

4) If I bypass will I still get a warning if my tire goes out on the highway?
Appreciate 0
      09-16-2019, 12:59 AM   #6
lax01
Major
523
Rep
1,153
Posts

Drives: 2017 M2
Join Date: Jan 2007
Location: Los Angeles, CA

iTrader: (0)

Quote:
Originally Posted by Insane_Dawe View Post
1) What's the proper way to clear the TPMS error?

2) How do I bypass the TPMS limp mode?

3) If I bypass it can I still get reading?

4) If I bypass will I still get a warning if my tire goes out on the highway?
You cleared it from the TPMS in iDrive? If so, yes...

You can't...without coding or a tune (I believe)

Don't know

Don't know
Appreciate 0
      09-16-2019, 08:39 AM   #7
Insane_Dawe
New Member
United_States
3
Rep
15
Posts

Drives: 18 Grey M2
Join Date: May 2019
Location: Chicago

iTrader: (0)

Quote:
Originally Posted by lax01 View Post
You cleared it from the TPMS in iDrive? If so, yes...
I triggered the TPMS to reset, does that mess with the calibration of the sensors or does it just clear the code?
Appreciate 0
      09-16-2019, 10:52 AM   #8
5.M0NSTER
Lieutenant
5.M0NSTER's Avatar
United_States
455
Rep
527
Posts

Drives: 2017 BMW M2 6MT Drivers Pack
Join Date: Dec 2018
Location: Little north of Stuttgart, Germany

iTrader: (0)

It only changes the trigger point for too low pressure warning. I typically drive to the track at 35psi, and when I gas up before entering the track I drop pressured to 28, then do the reset. This way I'm good for the rest of the day and I have a few extra PSI I could drop without triggering the warning. I think the set point is 15% below the pressure you reset the monitor at.
__________________
2017 BMW M2 German Spec
6MT, Driver's Package

"Redline a day keeps the mechanics away"
Appreciate 1
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 07:30 PM.




m2
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST