Euro Spec S50 Rev Limiter??

[Kovs]

First question, does anyone know the RPM cutout on this motor?

I drove my car for the first time post-swap last night - 1990 325i 4 door - and I could NOT the rev limiter. I'm using the stock gauge cluster and the tach was buried in the econo-meter (approximately where the '10' starts) and the engine was still pulling. My friend and I did some calculations, and the tach seems to be dead accurate at 60 MPH - 2900RPM in 5th gear with a 3.46LSD. Is it possible that the tach no longer reads accurately outside of its calibrated range (past 7K RPMs)??

Mike

[ian332isport]

Not sure if you have the 3.0L or 3.2L Euro motor, but my 3.2 hits the limiter around 7800 rpm. Max power is supposed to be around 7250 rpm.

I found my tacho read approx 12% high at all speeds, so fitted a tacho calibration module from Dakota Digital which allowed me to correct this.

Ian.

[Kovs]

It's the 3.0L Euro motor. Thanks for the tach calibration tip - is this the device you are talking about?

http://www.dakotadigital.com/index.cfm/page/ptype=product/product_id=127/category_id=287/home_id=59/mode=prod/prd127.htm

I'm not convinced my tach is off since my car was a 325i and had the 6 cylinder code plug for the tach... any other opinions??

[ian332isport]

It's the 3.0L Euro motor. Thanks for the tach calibration tip - is this the device you are talking about?

http://www.dakotadigital.com/index.cfm/page/ptype=product/product_id=127/category_id=287/home_id=59/mode=prod/prd127.htm

I'm not convinced my tach is off since my car was a 325i and had the 6 cylinder code plug for the tach... any other opinions??

Yes, that's the device I used.

My car was also a 325i with a 6 cylinder coding plug and still read 12% off. Several other people in the UK with similar conversions have also had this issue.

Ian.

[Kovs]

Thanks Ian - that would definitely explain the ridiculous numbers I was seeing and still not finding the rev limiter.

[Kovs]

Anyone know the rev limit of the Euro 3.0L???

I've searched everywhere, and the only data I could find was in my "BMW M Power" book which quoted peak power of 286HP reached @ 7K RPM to be the same as the redline. I find it hard to believe that BMW would design a motor where you are reaching peak power and bouncing off the rev limiter at the same time...

[ian332isport]

Anyone know the rev limit of the Euro 3.0L???

I've searched everywhere, and the only data I could find was in my "BMW M Power" book which quoted peak power of 286HP reached @ 7K RPM to be the same as the redline. I find it hard to believe that BMW would design a motor where you are reaching peak power and bouncing off the rev limiter at the same time...

Just had a look in the TIS, and it doesn't say where the rev limiter is, but it does state the following:

Permissible constant speed 7000 rpm
Max permissible speed 7280 +/-80 rpm

For the 3.2 it's 7400 & 7600 +/-50. Mine shows approx 7800 when the limiter comes in.

Ian.

[Stu]

Mine shows approx 7800 when the limiter comes in.

Ian.

Jealous. :D

[gstuning]

7200rpm is the revlimit,
Do you have the 5speed M3 trans? if so the 5th gear is 1:1

[Kovs]

7200rpm is the revlimit,
Do you have the 5speed M3 trans? if so the 5th gear is 1:1

Yes... 80MPH = 4K RPMs with a 3.46LSD :crazy:

[morerevsm3]

there were also some S50B30 engines rated at 295bhp, these had rev limit of 7600rpm, you can also get aftermarket chips that raise it to 8000rpm (removed one from mine when I changed to Alpha N chip - maffless and still 8000rpm)

[Kovs]

there were also some S50B30 engines rated at 295bhp, these had rev limit of 7600rpm, you can also get aftermarket chips that raise it to 8000rpm (removed one from mine when I changed to Alpha N chip - maffless and still 8000rpm)

Is there a way to tell which motor I have?

[joshh]

In the future this is not a smart way to find your rev limit. It's a good way to screw up your valve train though.

Sorry I don't know the limit either.

[morerevsm3]

Is there a way to tell which motor I have?

a known accurate tacho will tell you, you can bounce these motors off the rev limiter all day without hurting them

[joshh]

a known accurate tacho will tell you, you can bounce these motors off the rev limiter all day without hurting them

Yeah sure, that's what every car owner says till a couple valves get tweeked.
The rev limiter is not nice to motors. The motor has goes from no gas to full gas. It does stress the motor without a doubt.