Bouncing off the rev limiter

[PawnSacrifice]

Roof down, H&S at full bark, 3rd gear 3-8000rpm down a motorway entry slip... gets me every time :heart:

Probably puts the frightners on the poor unsuspecting slow lane dwellers too oke:
(a little envy there)

Had a quick look, someone posted a dyno for an M and the power didn't seem to drop off much after the peak and probably not a bad spot to change.

 

[ga41]

Hit the rev limiter? Yea a couple of times by mistake but the biggest "OH s**t" moment was a couple of weeks ago when i accidentally shifted to 2nd instead of 4th... :headbang:

I was changing up at around 7.5k and somehow managed to nudge the gear stick to the left and it went into 2nd. I hit the limiter HARD and the car started fishtailing. As soon as i regained control i put it in neutral and pulled over on the side of the road. I could smell the clutch quite a bit. All in all it was in 2nd for about a second and a half. I thought that was the end of the engine.

I turned it off and let it sit there for a bit. Didnt know what i've done. I started it up a few minutes later and drove gingerly back to town. No strange noises or warning lights or anything. Drove it straight to a BMW indy someone had recommended a while ago. Told him what happened and we took it for a drive around the block to see if anything broke. After a few tense minutes of listening to it accelerating, listening to it idle and whatnot he declared it alright.... Havent noticed anything else since then and the engine runs as smoothly and is as powerful as ever.

A couple of bumps on the redline? HA! I wouldnt worry about those. Just be careful not to do what I did....

 

[sixspeed]

bad things

OUCH!

 

[flatout]

Reaching close to the limiter then changing gear - yes, but bouncing on it No No :evil: Although on a few occasions in Germany I have hit the limiter in 4th and 5th doing unfamiliar speeds...

The s54 can easily run to close to 9k as is the case in the race version. The limiter in standard form kicks in at 8.1k but can easily go upto 8.4k without any internal upgrades which is what i plan to do if i ever remap mine.

 

[texasjohn]

Hitting the limiter is an absolute no for me. I'm quite surprised by the amount of people advocating even hitting the orange area of the rev counter let alone 'bouncing' the motor off the hard cut off limit, personally.

It's frustrating perhaps for the first few miles but I never exceed 3000 rpm until the oil hits 80 deg C either!

Just my 2p worth.

 

[Darren M]

Hitting it occassionally shouldn't do any harm, that's why its there for, to protect the engine, just as long as you change gear and not leave it in the same gear hitting the limiter for a lenghty period. Even I hit it a few times in second gear when I first got the car, did't realise how fast it picked up speed. I'd expect an M engine especially to be well within it's limits even when the limiter cuts in. Isn't peak power at 7900rpm? that's very close to the limiter

 

[sammyz]

I think it will do these engines no harm at all to be driven hard, after all that's what BMW designed them for. Some remaps move the limit up a few hundred revs and the engines seem to take it.

I don't make a habit of hitting the limiter but try to change up at about 7500-8000 when I'm getting on with it a bit I guess there will be owners of all performance cars who drive them like a diesel and the engines have hardly ever been near the red line :wink:

I recall a guy who had an S2000 same time as me and on meets never drove the thing over 40. In fact I think poor Roadtrip headed up the group he was in 'the slower drivers' and swore he'd never do it again!

 

[flimper]

I guess there will be owners of all performance cars who drive them like a diesel and the engines have hardly ever been near the red line :wink:

That'll be me then! I never go over 4k in 1st and usually not over 6k in any gear Must try harder :driving:

 

[Mr Whippy]

On a fast revving petrol if you don't hit the limiter once per journey (where appropriate and once warmed up) then I don't see the point in having it :evil:

M54 B30 is quite a slow engine, so you kinda feel it dying by 6000rpm, so I often change nicely before the soft limiter at 6500rpm or so anyway.

I'm sure with the M engine you can just steam straight into the limiter easily.


Should be ok. If an engine fails 'up there' easily then it's weak and it was going to fail soon anyway (imo)
Basically, if it can't take it in normal hard road use, then something isn't right with it.

Dave

 

[AlanJ]

I've hit (or should I say reached) the rev limiter on several occasions. I think if you use it as intended i.e. a safety device to protect the engine rather than a challenge to reach in every gear change then provided you maintain the engine then there should be no problems. If I reach the rev limiter in a low gear more often than not it's because I have misjudged the appropriate point to change gear.

 

[texasjohn]

I hit it a few times on the S2000s I had, but all the power was between 6 and 9 k.

:evil:

 

[ga41]

I hit it a few times on the S2000s I had, but all the power was between 6 and 9 k.

:evil:

Well the S54 isnt far off. Granted it does have some usable torque from 4k but the power, that intoxicating surge is at 6-7.5k. I tell you even if it redlined at 9k i'd still use all the revs! So addictive!

 

[Beedub]

http://s75.photobucket.com/albums/i287/cahzz1/?action=view&current=MOV00329.flv

7900 works well!!!!!!!!!!!!!

 

[sammyz]

For sheer thrills the s2000 up around 9000 rpm is the maddest thing I've ever driven with four wheels. Just waiting for the engine to blow up but it never did!

 

[+49]

Never hit the limiter in the 3.0 SE ...

Strangly it has alot of over Rev to play with you if know what i mean? Max power from what i feel is 5900-6k (without looking at the clocks) but the redline or wher abouts it would boucne is 6500rpm odd?So 500rpm to play with extra ,you could easily hit it as the car still pulls nicly over 6k tho

I'm used to screaming inline fours where max power is about 50rpm from the limiter

 

[+49]

Never hit the limiter in the 3.0 SE ...

Strangly it has alot of over Rev to play with you if know what i mean? Max power from what i feel is 5900-6k (without looking at the clocks) but the redline or wher abouts it would boucne is 6500rpm odd?So 500rpm to play with extra ,you could easily hit it as the car still pulls nicly over 6k tho

I'm used to screaming inline fours where max power is about 50rpm from the limiter

 

[Siener2]

Have never hit the limiter on the MC. Have done it a few times on the E46 when in a bigger hurry than strictly necessary - and felt bad about it as IMO it is mechanical cruelty.

 

[VvrooomM]

these answers all help explain the difference in fuel economy being muted in another thread here!!!

 

[aerobod]

these answers all help explain the difference in fuel economy being muted in another thread here!!!

During a track day last year I measured 215km in total distance in all the sessions I did, used about 75 litres of fuel - 35 l/100km or 8 mpg (imperial). Got over 7500RPM about 10 times every 4km lap, hit the rev limiter accidentally 3 or 4 times. Amazing sound of the engine with the roof down, shifting from 2nd to 3rd at 7900RPM as the sound echoed off the concrete wall at the beginning of the straight. Then on to 216km/h at the redline in 4th gear at the end of the straight, before braking hard into the first turn.

CDN$450 for the track time
~CDN$100 in brake wear
~CDN$300 in tyre wear
~CDN$50 in brake fluid flush
~CDN$90 in fuel
~CDN$15 in dry cleaning bills after 150km/h, 2.5 rotation spin
CDN$Priceless in smiles!!

Car runs very well after a bit of a thrashing, just seems to be in it's element. Have to get out on the track a few times this year too.