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Discussion Starter · #1 ·
I've put 2500 miles on my 08 M5 6spd M/T and I took it to Buttonwillow today, it was alot of fun but the car got overheated and it was a bit of disappointment.

it was 95degree today, at about 15mins or 4-5laps in every session, the transmission would overheat and the rev limiter will move back to 5000 RPM or so. :mad:

Overheating a M/T ?? :confused2:confused2 it's very annoying that it cuts engine power and i have no choice but to pit in. see pics




i tracked my E46 M3 way harder even in much hotter days, and it was a SMG, never had a problem.

other thoughts,

the only mods I have the car is RD sport springs, RE pulley and KN drop in filters. The car comes with Conti sport2

Lack of a real LSD ? there's a slight amount of rear wheel spin when cornering

the stock tires suck! well the car is heavy and the tires easily got overheated, and it was sliding all over the place...

Heel & toe is very hard, the pedal doesn't respond very well ? even with P500 Sport mode.


anyone who had tracked their M5, share your thoughts please.
 

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Hey Mike,

I saw you today! You drove the in the Red Group, right? I also saw you coming back on the 5 South in Lane 1.

I did not bring my beast today. I was driving a friend's Race Miata. Anyhow, props to you for bringing the beast to the track. I was gonna come up and talk to you, but you seemed annoyed (probably at the car), so I decided against.

Any hoot, I've tracked the beast (SMG) at Horse Thief Mile at Streets. If you are not familiar with that track, it is much more demanding in terms of low speed, high RPM, no chance for any cool down. It is a 2nd gear run thru 90% of the track. The temp got to the mid point between 210 and High (I forget what that number is now). Basically 3/4 hot and stayed there. I ran it twice. No overheating or warnings. It was a Speed Ventures event about several months ago. Temp was near 100F. The Conti's do suck. Wear 'em down and change to a better tire.

I also attended the M Driving @ Cal Speedway (infield). Much larger track and less demanding on the cooling system. I ran back-to-back-to-back M5's and M6's along with about 12 or 15 other S85 SMG harnessed motors without one single failure for anyone that day (Temp, much lower... about 78-81). But the M Cars got no break in between. They all ran back to back sessions for about 2-3 hours.

Where was you oil temp? Unless you were smoking up the tranny/clutch, I don't think the RE underdrive pulley affects tranny temp. But then again, it would be the first suspect. If someone can confirm, perhaps you may want to yank the pulley for your next summer session. It takes about an hour and about $100 bucks per change. Good luck!

PS. The car has a real LSD that can just about lock when it needs to.
 

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In short, you should have bought the SMG.:hihi:

I'm quite surprised that the transmition overheated so easily. I can't really comment to much as I've never tracked my car in 30+ degrees C

I wouldn't have thought the pulley would affect the gearbox temps at all.

Were you changing gear to slow the car down?

I wonder if the different gearing affects the temps.?

edit...
Did you give the gearbox time to warm up at the start of the session?
 

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Discussion Starter · #4 ·
Hey Mike,

I saw you today! You drove the in the Red Group, right? I also saw you coming back on the 5 South in Lane 1.

I did not bring my beast today. I was driving a friend's Race Miata. Anyhow, props to you for bringing the beast to the track. I was gonna come up and talk to you, but you seemed annoyed (probably at the car), so I decided against.
haha yeah i was in Red group, did you drive the red Miata ?

i was just tired and I lost my sunglasses... i love talking to people on the track and share thoughts! let's chat next time!

Any hoot, I've tracked the beast (SMG) at Horse Thief Mile at Streets. If you are not familiar with that track, it is much more demanding in terms of low speed, high RPM, no chance for any cool down. It is a 2nd gear run thru 90% of the track. The temp got to the mid point between 210 and High (I forget what that number is now). Basically 3/4 hot and stayed there. I ran it twice. No overheating or warnings. It was a Speed Ventures event about several months ago. Temp was near 100F. The Conti's do suck. Wear 'em down and change to a better tire.
on buttonwillow, i had to use 2nd & 3rd most of the time, then 4th&5th in the straights, the 6spd gearing is a bit tall, i had to keep the rev at 5k+ RPM. i'm looking into the R888s, but they don't have the right size for our car yet, supposedly they will come out with the 265s in summer, so i can run 265 front / 295 rear.

I also attended the M Driving @ Cal Speedway (infield). Much larger track and less demanding on the cooling system. I ran back-to-back-to-back M5's and M6's along with about 12 or 15 other S85 SMG harnessed motors without one single failure for anyone that day (Temp, much lower... about 78-81). But the M Cars got no break in between. They all ran back to back sessions for about 2-3 hours.

Where was you oil temp? Unless you were smoking up the tranny/clutch, I don't think the RE underdrive pulley affects tranny temp. But then again, it would be the first suspect. If someone can confirm, perhaps you may want to yank the pulley for your next summer session. It takes about an hour and about $100 bucks per change. Good luck!

PS. The car has a real LSD that can just about lock when it needs to.
my oil temp was at the 3/4 mark, there wasn't any engine temp warning.
i don't think the pulley affects the tranny, we don't have a tranny cooler.

I thought the car has a "electronic LSD" which uses the brake to stop wheel spin ? i was told by a bmw mechanic that the last BMW that had a real mechanical LSD is the E46 M3. all the new bmw have the electronic ones.
 

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take it in and make them fix it......that is completely unacceptable....
 

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Discussion Starter · #8 ·
Z4 M and M5 also have a real LSD. The 135i however, has that fake one.
that's good to know...


My friend with a manual m5 also had the same problem. It only happens with the manuals. It ruined his day too. His car is stock and I don't know if there is anything you can do to fix it. I suggest buying an m6 or a 911 turbo. :cheers:
this sux, not only the tranny temp problem, it was very difficult to shift from 3rd -> 2nd, if i shift too quick i would hit into the reverse lock.

m5 will probably stay as a daily driver, it's stupid to go all raced out on a 4dr family sedan... when i have more time for track, i'll probably consider a porsche.
 

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My friend with a manual m5 also had the same problem. It only happens with the manuals. It ruined his day too. His car is stock and I don't know if there is anything you can do to fix it. I suggest buying an m6 or a 911 turbo. :cheers:
Errr...how would an M6 be better on track? :confused2
 

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Proof that smg>6mt


/thread


just kidding...that doesn't sound right. might be time to swing by the dealership to see what they have to say. i'm sure that there must be more people on the board that track 6mt. after all, they're for the true enthusiasts, right :hihi:
 

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Hi All, just wondering if anyone has approached BMW (Dealer and/or Corporate) with this 6MT transmission overheating subject?

I had this same thing happen to me at Roebling Road a few weeks ago. . . cut my afternoon sessions short both days. . . extremely annoying and disappointing.

Am considering bringing it to my dealer's attention and asking for correction but would like to know if anyone else has gotten an opinion from BMW as yet. There is certainly enough data out there (Edmunds test) to document this as a real problem.
 

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Errr...how would an M6 be better on track? :confused2
Well....funny you mentioned that.:3:

Ghost had a lets just say "hot issue" on the track. I was cool as can be and those vented seats in the M5 work really well.:hihi:
 

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I remember reading about a Road and Track review where they ran the 6-speed at the track and it overheated. I can't seem to find that post and article, but I found a similar one where other members have had the same issues with the 6-speed and there is mention of Edmund's review (so maybe it was an Edmund's article). It seems this is a known problem with the 6-speed.

http://www.m5board.com/vbulletin/showthread.php?t=105789&highlight=track+overheat

Funny thing is that it is the same tranny as the E39 M5 which I owned and the clutch was always spinning when I wanted to get on it. One time I sat there with the clutch spinning while I got smoked by a honda when I hit second gear. So it seems the warning light that was probably meant for the SMG is interfering with the 6-speed. Not sure it was meant to work this way or needs to.

This is why I have been most happy with the SMG as I have ALWAYS been able to get the power to the wheels. This is the first car with more than 300HP that I have not experienced issues with the OEM clutch.

IMO, in order to make the 6-speed tolerable to drive they did not use a strong enough clutch (this was a problem with my previous mustang cobra, as well). This would not be a problem with the SMG since the driver does not have to use his/her muscle for the clutch and since hydraulics do the job instead. Based on this it is my guess that the SMG was able to be made with a stronger clutch since it would not interfere with the drivability.

I am not trying to debate the two tranny's as I know there are a ton of you waiting to let me know how crappy the SMG is and how it leaves you so disconnected from the road, etc.. I just think it is sad that they just tossed an old 6-speed tranny into this car (that did not work well in the previous model) to please the American's that were complaining and people are so happy to plunk the same money for this antiquated technology. At least there should be a credit when selecting this option.

My only thought is maybe they can (or should have) tone down the sensitivity of this warning with the 6-speed through software (there was no temp warning that I know of or experienced on the E39) and/or have a stronger aftermarket clutch kit or something installed (if one exists).

Of course, this is all just speculation on my part...

Good luck...<O:p</O:p
 

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This issue continues. . .

Hi all. . . just to let you all know that this 6sp overheating is definitely an issue and has become very significant, at least for me. Have had 3 more driver ed days since the first time this happened and it has happened every session. . . even my first session this weekend at Sebring which was a new track for me and very much a learning session that was not really even that aggressive. And. . . I'm only a blue group driver so not nearly maximizing the potential of the car.

Temp warning comes on about half way through each session and red line was reduced to about 6k at first then to as low as 4.5k if I continued to drive the session.

In addition, I attended the Advanced M School at VIR (wow. . . what a fun track) a couple weeks ago and discussed this issue with some of the instructors. . . and yes, they were aware of the issue as well as evidently, BMW NA had had the same thing happen in a couple of 6sp M6's when they were conducting a demo day of the cars at a track.

Anyway, I have escalated the issue to BMW NA Customer Care (800-831-1117) so I would encourage others to as well that are having this issue as BMW has definitely shortchanged us on the 6sp version of this car by not including a transmission cooler. And, they were aware of the issue enough to build a "band aid" into the software to monitor the issue and reduce the revs. . .

And. . . to fuel the SMG/6sp debate, I love the 6sp and totally wanted the 6sp over the SMG but now very much regret the choice unless BMW does something to fix this issue. The car is a lot of fun and very capable on the track but this transmission issue ruins the whole experience.

Anyway, for those interested, here is the Edumunds review that I referenced in my earlier post where they experienced the issue after only 12 minutes of hard driving. Interesting though that they found the 6sp to be .4 sec faster 0-60 then the SMG. . . that should start some debate. :blabla:

2008 BMW M5 Review - Edmunds.com

I have brought this article to BMW's attention as well. I would hope that some others will contact BMW about this issue as well and hopefully we can get some action from them to correct it. Warranty should not be an issue as in the book only "competitive events" are excluded from warranty of which Drivers Ed days are not.

Have not had a response from BMW NA as yet but will let you know when I do.

Cheers. . .
 
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