Engine power drops off at 6500 rpm, that normal?

[dannytheduck1985]

When warm the engine power drops off at around 6.5k.

is this normal?

 

[breezer]

Nope.

 

[Easty-5]

Nope most definitely not normal. The S54 should keep pulling right up to the limited. Peak power I believe is hit at 7000+ RPM.

 

[dannytheduck1985]

Wondering what it could be? it was fine yesterday

 

[dannytheduck1985]

Just had it scanned, Knock Sensor 3 fault

 

[GedS]

Sounds like the primary 02 sensor. M3s suffer this all the time. Same engine. Worth checking

 

[wspohn]

Nope most definitely not normal. The S54 should keep pulling right up to the limited. Peak power I believe is hit at 7000+ RPM.

7,900 rpm power peak.

 

[mmm-five]

Nope most definitely not normal. The S54 should keep pulling right up to the limited. Peak power I believe is hit at 7000+ RPM.

7,900 rpm power peak.

...and will hit the limiter at about 8100rpm.

 

[Beedub]

Nope most definitely not normal. The S54 should keep pulling right up to the limited. Peak power I believe is hit at 7000+ RPM.

7,900 rpm power peak.

...and will hit the limiter at about 8100rpm.

I'm sure the limiter is at 7950.... but i could be wrong....

 

[mmm-five]

7,900 rpm power peak.

...and will hit the limiter at about 8100rpm.

I'm sure the limiter is at 7950.... but i could be wrong....

You're right, my data logger hasn't logged anything higher than 7988rpm.

 

[Fishy Dave]

Mine shows about 8050rpm at the limiter on data overlay taken from the OBD.

 

[Beedub]

Mine shows about 8050rpm at the limiter on data overlay taken from the OBD.

that sounds like an over rev.....

 

[Fishy Dave]

See 2:47, 4:17, 7.33 and others in my video here: https://www.youtube.com/watch?v=IQXCalSHSXg
It could be that Harrys or the OBD Bluetooth dongle is inaccurate or delayed (guessing upper edge of the revs)?

 

[exdos]

See 2:47, 4:17, 7.33 and others in my video here: https://www.youtube.com/watch?v=IQXCalSHSXg
It could be that Harrys or the OBD Bluetooth dongle is inaccurate or delayed (guessing upper edge of the revs)?

I don't think the ECU datalogger is inaccurate. If you take the engine to the redline with the throttle wide open, the ECU will cut the ignition at say, 7950rpm, whilst you disengage the clutch which will permit the engine to continue to rev more freely, so it's not unusual to see the rpm in excess of 8,000rpm but the engine will not be loaded on the those revs above the rev limit.

 

[hopz121]

Could have been mapped/coded to have a higher RPM?

 

[Fishy Dave]

See 2:47, 4:17, 7.33 and others in my video here: https://www.youtube.com/watch?v=IQXCalSHSXg
It could be that Harrys or the OBD Bluetooth dongle is inaccurate or delayed (guessing upper edge of the revs)?

I don't think the ECU datalogger is inaccurate. If you take the engine to the redline with the throttle wide open, the ECU will cut the ignition at say, 7950rpm, whilst you disengage the clutch which will permit the engine to continue to rev more freely, so it's not unusual to see the rpm in excess of 8,000rpm but the engine will not be loaded on the those revs above the rev limit.

Yes, that makes sense.

I'm certain my car has a standard map and I've never buzzed the engine on a down change.

 

[Beedub]

i try to change at the 7800 mark as th revs rise that fast i end up banging into the limiter, and its no soft cut on this car! lol.

 

[Zettti]

Did you check the camshafts? It is a problem of some S54 engines depending on the year of building...

 

[goldbcfc]

Could have been mapped/coded to have a higher RPM?

yes you can raise the rpm redline on manual but not autos with a ECU remap one of the benefits having manual

 

[hopz121]

Could have been mapped/coded to have a higher RPM?

yes you can raise the rpm redline on manual but not autos with a ECU remap one of the benefits having manual

All Z4M's are manuals

You can raise the redline in SMG cars too don't know about autos but the OP's car is a manual which is why I answered the question