What makes the M3 S54 Engine

[S54B32m]

Power Output (bhp/rpm) M3 / M roadster - M coupe 333 / 315 bhp @ 7900 rpm

Does anyone know why the M3 makes 333 compared to the M coupe w/ 315

[O-cha]

I believe you're looking at the z3 m coupe. Z4ms actually make more then the m3.

[RBull]

^in actual numbers? The ratings are Z4M 330; M3 333.

[VinnieAces]

Yup Z4M is 330 and i believe the Euro Z4Ms have 343?

[blender]

As for why:

definitely different (less restrictive) headers
definitely different fuel (94 octane is common vs our 91)
possibly different cats
possibly different ECU programming
- and perhaps something else I missed

[tekmoe]

Yeah but we have the weight advantage so we actually have a better horsepower to weight ratio.

[epbrown]

Originally Posted by S54B32m

Power Output (bhp/rpm) M3 / M roadster - M coupe 333 / 315 bhp @ 7900 rpm

Does anyone know why the M3 makes 333 compared to the M coupe w/ 315

As said - the Z3MC numbers you quote are due to restrictive exhaust and a lower redline. The US Z4MC is 3hp lower than the US E46 M3 due to the exhaust. The Euro Z4MC has the same hp as the Euro E46M3 thanks to its headers and cats.

[DarrenZ4]

Originally Posted by VinnieAces

Yup Z4M is 330 and i believe the Euro Z4Ms have 343?

True

Euro version Z4MC and Roadster come with 343hp.

[O-cha]

Originally Posted by epbrown

The US Z4MC is 3hp lower than the US E46 M3 due to the exhaust. The Euro Z4MC has the same hp as the Euro E46M3 thanks to its headers and cats.

It's only quoted that way for some reason, the usa z4m makes a good 10hp more then the us m3s do.

[ryanchua]

Mine is a European Spec Z4M running on 98 oct.

[ryanchua]

And this dyno has taken E46 M3s before but running anywhere from 330 to 340+ bhp...

The tuner was surprised that my engine was doing 363 but if you look it up on wikipedia, the engine ratings are a lot better for the Z4Ms.

http://en.wikipedia.org/wiki/BMW_S54B32

[S54B32m]

I am a new owner trying to get all the facts, so thanks

[The HACK]

Originally Posted by ryanchua

And this dyno has taken E46 M3s before but running anywhere from 330 to 340+ bhp...

The tuner was surprised that my engine was doing 363 but if you look it up on wikipedia, the engine ratings are a lot better for the Z4Ms.

http://en.wikipedia.org/wiki/BMW_S54B32

What? Even in that image you posted the quoted number for the US spec MZ4 is wrong. It's 330hp.

You people are mixing different HP ratings and numbers together to get all sort of different "magical" difference between the engines.

I don't know how many times this needs to be brought up, but DIN and SAE measurements result in different numbers. DIN is what the Europeans use and SAE standards are 'Mercan (Society of American Engineers). SAE HP numbers are typically a few percentage points lower.

The magical 343 HP some of you keep insisting that the "European" trim makes is a DIN measurement. Converting that 343 HP to SAE (1 SAE HP = 1.0139 DIN HP) yields 338 HP, which is 5 more HP than U.S. spec E46 M3 and 8 more HP than U.S. spec MZ4, the main difference being where the CATs are placed on European trim cars vs. US trim cars.

[fr8tdog]

Correct^

Euro E46 M3 is 343PS (Deutsches Institute fur Normung..DIN) =338HP or 252KW and 269 lb-ft torque. Makes more power than U.S E46 M3 because location of cats is in the secondary pipes as opposed to U.S being in the headers.


U.S E46 M3 is 338PS(DIN) = 333HP or 248KW and 262 lb-ft torque.

The Z4M makes 330HP and that is 3 less than the U.S E46 M3 because of an extra set of cats in the secondary pipe

But!! the Z4 M is lighter by almost 200lbs and so therefore quicker


Sooo.. the moral of the story is: Go buy some Supersprint V2 Step headers cheers


EDIT: I edited this post because I was corrected by O-cha about location and number of cats. Thanks O-cha

[O-cha]

Originally Posted by fr8tdog

The Z4M makes 330HP and that is 3 less than the U.S E46 M3 because of slightly more restrictive headers.

The headers are the exact same design, the difference is the presence of secondary cats.

Regardless, once again, of the ratings, the z4m Makes 10hp more then the m3 consistently.

[fr8tdog]

Originally Posted by O-cha

The headers are the exact same design, the difference is the presence of secondary cats.

Regardless, once again, of the ratings, the z4m Makes 10hp more then the m3 consistently.

If the U.S E46 M3 has less power from the Euro because of a second cat... then why does it have 3 more than the Z4 M which I know has secondary cats. They both have an extra set of cats, so why the 3 hp difference if its not related to headers? This is a legit question... not trying to be a smart ass. if the header design is the same, then is it because of the "placement" of the cats?

EDIT: or is it maybe in the exhaust somewhere... as in the Z4 M is less raspy, so maybe some restriction there

[Shipkiller]

[O-cha]

Originally Posted by fr8tdog

If the U.S E46 M3 has less power from the Euro because of a second cat... then why does it have 3 more than the Z4 M which I know has secondary cats. They both have an extra set of cats, so why the 3 hp difference if its not related to headers? This is a legit question... not trying to be a smart ass. if the header design is the same, then is it because of the "placement" of the cats?

You don't know what you're talking about. The euro and US m3 both have 1 sets of cats, the euro is in the secondary pipes (minimal effect) the US is in the headers (large effect). That accounts for the difference between the two.

The z4m have a second set of cats in addition, but they are in the secondary pipes where they make minimal difference, especially when the breathing is already effected by the primaries a sort of there's a sort of backwards diminished return.

[trsbmw]

Originally Posted by The HACK

What? Even in that image you posted the quoted number for the US spec MZ4 is wrong. It's 330hp.

You people are mixing different HP ratings and numbers together to get all sort of different "magical" difference between the engines.

I don't know how many times this needs to be brought up, but DIN and SAE measurements result in different numbers. DIN is what the Europeans use and SAE standards are 'Mercan (Society of American Engineers). SAE HP numbers are typically a few percentage points lower.

The magical 343 HP some of you keep insisting that the "European" trim makes is a DIN measurement. Converting that 343 HP to SAE (1 SAE HP = 1.0139 DIN HP) yields 338 HP, which is 5 more HP than U.S. spec E46 M3 and 8 more HP than U.S. spec MZ4, the main difference being where the CATs are placed on European trim cars vs. US trim cars.

Actually, it is Society of Automotive Engineers...

[fr8tdog]

Originally Posted by O-cha

You don't know what you're talking about. The euro and US m3 both have 1 sets of cats, the euro is in the secondary pipes (minimal effect) the US is in the headers (large effect). That accounts for the difference between the two.

The z4m have a second set of cats in addition, but they are in the secondary pipes where they make minimal difference, especially when the breathing is already effected by the primaries a sort of there's a sort of backwards diminished return.

Thanks for clearing that up I new the Euro had one set of cats and Z4 M had two. I actually read about the U.S E46 M3 having a second set of cats from Wikipe... of course their not always correct either. Thanks for clearing up the confusion, especially location of cats. Cheers

By the way... will I have any issues installing SS V2 step headers onto my OEM sect1 pipe as far as codes or emissions testing? Will the OEM section 1 cats be sufficient? Thanks

[O-cha]

Originally Posted by fr8tdog

By the way... will I have any issues installing SS V2 step headers onto my OEM sect1 pipe as far as codes or emissions testing? Will the OEM section 1 cats be sufficient? Thanks

Yes codes, unknown on emissions, depends on testing stringency.

[pokeybritches]

Codes if you don't relocate your O2 sensors to post-secondary cats. I don't know for certain that you won't get codes with the O2 sensors relocated, but I haven't read of a Z4M that has relocated its O2 sensors and still gets a code.