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Discussion Starter #1
So, I've noticed that when I am on the track and doing high revs and trying to accelerate - the gears don't engage until I let off the throttle and then get back on it.

It is really strange and is affecting my driving.

The basic issue is -

I'm in third gear driving the infield course and hit brakes to slow for a hairpin and downshift to second. I then turn into the hairpin and get on the throttle for the Nascar oval. I upshift at 3700 or so and hit the throttle, but the gears don't engage and RPMs just shoot to 7000 until I let off the throttle and then it engages...same thing happens from 3rd to 4th gear...

Any ideas on what is going on?

SCORPIO
2003 BMW M5
 

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You say gear don't engage.....

I think what you're experiencing is properly engaged gears and the notorious M5 slipping clutch syndrome. Letting off the gas allows the weak clutch to grip. At this point, it is totllay fried and replacement of clutch assy and flywheel is necessary.

You need a UUC 11" clutch upgrade....search on UUC clutch.
 

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Deinelty sounds like the clutch is slipping...

Lscman said:
You say gear don't engag e.....

I think what you're experiencing is properly engaged gears and the notorious M5 slipping clutch syndrome. Letting off the gas allows the weak clutch to grip. At this point, it is totllay fried and replacement of clutch assy and flywheel is necessary.

You need a UUC 11" clutch upgrade....search on UUC clutch.
 

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Yep, sounds like a burnt out clutch to me as well. Please keep us updated on what path you decide to take.
 

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Yes, this is the exact symptoms of the fried clutch. :mad: Mine is at the point where even a "decent shift" from 2nD to 3rd with any real gas applied is useless.

I'm looking at the UUC Stage II setup.

Let us know which path you take.
 

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SCORPIO said:
I then turn into the hairpin and get on the throttle for the Nascar oval. I upshift at 3700 or so and hit the throttle,

Any ideas on what is going on?

SCORPIO
2003 BMW M5
OK, I know this is slightly OT, but why are you upshifting at 3700 rpm on a road course??? It should be closer to 6700rpm!! :cheers:
Regards,
Jerry
 

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rarely when i'm acclerating hard and shift at high rpms esp 3rd to 4th it almost feels like the car brakes for a second before it gets in gear .. is this a slipping clutch?
 
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guys i dont think it really has much to do with a weak clutch. when i first got my M5 it happend all the time when i tried to race people. it's your timing. if you give too much gas before you drop the clutch it wont fully engage, and then you end up smelling burnt clutch when you stop. i've never changed out my clutch for an aftermarket one but i also don't have that problem anymore because i've gotten the timing down. it can happen in any gear, i've done it on the highway from 5th to 6th before. no offense and please dont take it as such, but i dont think it's the clutch i think it's the driver. i've done it before too....i'm sure a lot of us have. just keep practicing
 

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JJC has it right its "clutch frying".
What track was this at? and why are you short shifting?
 

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Brother Methias said:
rarely when i'm acclerating hard and shift at high rpms esp 3rd to 4th it almost feels like the car brakes for a second before it gets in gear .. is this a slipping clutch?
You're not shifting fast enough, allowing time for the engine to slow down to an RPM that is below the speed match in the next higher gear.

Regards, Dick Roberts
 

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Discussion Starter #11
6spd said:
JJC has it right its "clutch frying".
What track was this at? and why are you short shifting?
Phoenix International Raceway.

I think it may be my timing...the reason I am short shifting is because I am a novice. This is my first BMW (good start, I must say) and I am still getting experienced with the car.

SCORPIO
 

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JonnyBoyM5 said:
guys i dont think it really has much to do with a weak clutch. when i first got my M5 it happend all the time when i tried to race people. it's your timing. if you give too much gas before you drop the clutch it wont fully engage, and then you end up smelling burnt clutch when you stop. i've never changed out my clutch for an aftermarket one but i also don't have that problem anymore because i've gotten the timing down. it can happen in any gear, i've done it on the highway from 5th to 6th before. no offense and please dont take it as such, but i dont think it's the clutch i think it's the driver. i've done it before too....i'm sure a lot of us have. just keep practicing
Johnny,

You have adapted your driving style to a car with a very weak clutch. Your gentle method of clutch engagement with light throttle will result in 14 second 1/4 mile times or slower! You've essentially nullified the advantage of a 5L M5 motor by extending shift overlap and interrupting power transfer for a second of more.

You should be able to upshift under hard throttle or even full throttle. Under these conditions, the RPM will drop like a rock when the clutch is released & the kinetic energy in the flywheel will be efficiently transmitted to the drivetrain and most noticeably, the car will lurch forward & the tires should bark like a dog. Very little heat is generated in the clutch/flywheel when engagement is crisp. It takes an 11" clutch to do this...like the one you find in a Corvette or a UUC car.
 

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I am a new owner of an M5. When driving in normal traffic and getting on and off the highway at what RPM do you recommend shifting at?
 

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SCORPIO said:
Any ideas on what is going on?

SCORPIO
2003 BMW M5
Hey SCORPIO,

It was good to meet you at Sears Point. Sorry you didn't get to run that day. Sounds like you've got it all sorted out now...well, except that you need a new clutch (my opinion as well).

Have fun!

:cheers:
 

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Tom219 said:
I am a new owner of an M5. When driving in normal traffic and getting on and off the highway at what RPM do you recommend shifting at?
Whatever is safe!

Depends on traffic, speed limit, road conditions, etc. There is no magic formula.

Also, in the proper surroundings, shift points should be where it's FUN !

regards,

Al
 

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That is exactly what the dealer said. But, can I do harm by shifting at 2k-3k or 6k-7k. Is there a "best" rpm range for this motor?
 

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As already said, there isnt really any magic number for most engines. With the S62 you can spool it out and exploit the HP, or lug it around and use the ample torque.
That being said, in most day to day driving in just about everything I have driven, I usually upshift at about 3500 ~ 4000rpm, and downshift when the rpms are under 1500. No need to give the valve train a workout, but no need to lug the engine around. Mid rpm range shifts give you the best of both worlds when you are just getting from A to B. I also cruise in the highest practical gear, meaning which ever gear puts the rpms the lowest while still giving me acceptable acceleration. If I need more, I just downshift a gear or two. Hope this helps a bit.
:cheers:
 

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BmwNut said:
As already said, there isnt really any magic number for most engines. With the S62 you can spool it out and exploit the HP, or lug it around and use the ample torque.
That being said, in most day to day driving in just about everything I have driven, I usually upshift at about 3500 ~ 4000rpm, and downshift when the rpms are under 1500. No need to give the valve train a workout, but no need to lug the engine around. Mid rpm range shifts give you the best of both worlds when you are just getting from A to B. I also cruise in the highest practical gear, meaning which ever gear puts the rpms the lowest while still giving me acceptable acceleration. If I need more, I just downshift a gear or two. Hope this helps a bit.
:cheers:
It helps alot! Thanks. I am going to try that shifting range. When would you use the 5th and 6th gear?
 

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5th and 6th (dont use 6th in my Jetta, it only has 5... :biggrin: ) are usually used on the freeways. M5's arent geared as tall as say a lot of GM products, so anything over 50 or so would warrant 5th, 60ish and above 6th. It really comes down to how much you want to hear the engine and how much acceleration you want in gear. When I am putting around I like the rpms very low for better fuel economy, less noise, and less wear and tear on the valve train. Just be ready to downshift if you need more go juice.
If you dont already, learn how to either rev match downshift or double clutch downshift. Being able to move up and down the gearbox quickly helps a lot when you are economy driving (if it can be called that in an M5) but then you need to be down a gear or so for any reason. Board member Greg put out some shifting videos that can be found either through this board or vidload.de .
:cheers:
 

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Tom219 said:
It helps alot! Thanks. I am going to try that shifting range. When would you use the 5th and 6th gear?
In my opinion, when driving around town 4th gear is the highest place to be. I found 5th to be totally useless and never used it. When cruising on the hiway I always used 6th.

al
 
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