rev limiter for manual transmission cars - BMW 3-Series Forum (F30 / F32)

nexusonemeover · 05-10-2012, 03:12 AM

While dicking around with my car, 328i with 6MT, I realized that with the car in neutral the engine will rev to red line. However, with car in gear, but clutch depressed, the car revs to about 3000 rpm, drops to about 2000 and will only go back to about 3000 rpm unless significantly more pressure on accelerator pedal is used. Even then, it still wont redline... gets to just over 4000 or so.

I tried to think about why this might be. First thought is that its protective for the clutch... for those clutch dumpers... at only 3000 rpm, the clutch will last longer than dumping at redline. But, then I thought about those exotic supercars that have a launch control feature. Those cars rev the engine at 0 mph and then release of brake causes the poop shoot to give out requiring new underwear.

Do our BMWs have a launch control of some type, or was my first thought, clutch protection, more correct?

I have not tried dumping the clutch at all... but if the car is designed to handle dumping at 3000 rpm, I shall be doing so with great joy.

Feanor · 05-10-2012, 07:27 AM

This seems to be fairly normal. I found that my 118D did the same thing and started a thread on a generalist car forum and the response was that many other new cars do the same thing these days.

I also asked my dealer and his response was basically that there's no sense in revving a diesel when pulling away as the torque is greatest at low revs. With the petrol, I'm not sure.

mocohead · 05-10-2012, 08:34 AM

My impression is the rev limit in gear with clutch depressed is intended to protect the drive line from undue abuse.

05-10-2012, 03:12 AM	#1
nexusonemeover First BMW Drives: 2012 328i Sport 6MT Join Date: Mar 2012 Location: Cleveland, OH Posts: 115 iTrader: (0)	rev limiter for manual transmission cars While dicking around with my car, 328i with 6MT, I realized that with the car in neutral the engine will rev to red line. However, with car in gear, but clutch depressed, the car revs to about 3000 rpm, drops to about 2000 and will only go back to about 3000 rpm unless significantly more pressure on accelerator pedal is used. Even then, it still wont redline... gets to just over 4000 or so. I tried to think about why this might be. First thought is that its protective for the clutch... for those clutch dumpers... at only 3000 rpm, the clutch will last longer than dumping at redline. But, then I thought about those exotic supercars that have a launch control feature. Those cars rev the engine at 0 mph and then release of brake causes the poop shoot to give out requiring new underwear. Do our BMWs have a launch control of some type, or was my first thought, clutch protection, more correct? I have not tried dumping the clutch at all... but if the car is designed to handle dumping at 3000 rpm, I shall be doing so with great joy. __________________ 2013 X1 xDrive 28i - sport 1977 E21 320i (first one sold in the US - featured on the cover of January 1982 Roundel) - Dad's
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05-10-2012, 07:27 AM	#2
Feanor Second Lieutenant Drives: BMW Join Date: Feb 2012 Location: United Kingdom Posts: 294 iTrader: (0)	This seems to be fairly normal. I found that my 118D did the same thing and started a thread on a generalist car forum and the response was that many other new cars do the same thing these days. I also asked my dealer and his response was basically that there's no sense in revving a diesel when pulling away as the torque is greatest at low revs. With the petrol, I'm not sure.

05-10-2012, 08:34 AM	#3
mocohead First Lieutenant Drives: 2012 328i (ED)/ 2011 328i (ED) Join Date: Sep 2010 Location: CA Posts: 301 iTrader: (0)	My impression is the rev limit in gear with clutch depressed is intended to protect the drive line from undue abuse.