Why is the S54 engine in the Z4M detuned?

[glastoveteran]

Am I right in thinking that the S54 engine in the Z4M is actually detuned compared to the S54 that's used in the E46 M3s? If so why detune an engine, out of curiosity?

I'm sure I remember reading that the Z4M is a 0.1 seconds slower to 62 than the M3, which you wouldn't expect given that it's lighter, but maybe the detuned engine is the cause of that?!

 

[Spud]

They both have the same BHP. You should find that in terms of speed it'll go M3 < Z4M < M3 CSL, or so I'm led to believe.

The Z4M shares quite a few bits with the CSL, but I think I'm right in saying the gearbox wouldn't fit?

Though, being a poor 3.0i owner, I'll let someone more qualified comment now

 

[flatout]

They both have the same BHP. You should find that in terms of speed it'll go M3 < Z4M < M3 CSL, or so I'm led to believe.

The Z4M shares quite a few bits with the CSL, but I think I'm right in saying the gearbox wouldn't fit?

Though, being a poor 3.0i owner, I'll let someone more qualified comment now

That's right, i'd add that with a v good gear chance the z4mc is much closer to the CSL which has paddle shifts

 

[aerobod]

Am I right in thinking that the S54 engine in the Z4M is actually detuned compared to the S54 that's used in the E46 M3s? If so why detune an engine, out of curiosity?

I'm sure I remember reading that the Z4M is a 0.1 seconds slower to 62 than the M3, which you wouldn't expect given that it's lighter, but maybe the detuned engine is the cause of that?!

There is a slight loss in power on the Z4M vs the E46 M3 in North America due to a more restrictive exhaust due to space constraints (246kW vs 248kW), in Europe both the Z4M and M3 have 252kW.

The official BMW performance times put the Z4MR 0.1 seconds ahead of the Z4MC which is 0.1 seconds ahead of the E46 M3, but in road tests sometimes the Z4M is faster, sometimes the M3, depends on the car, the driver and test conditions.

 

[original guvnor]

Alex,

Autocar tested the Z4MC in their August 06 issue. The conditions were damp in places and the car had only just had its 1200 mile service (1250 on the odometer).

They figured the car as follows:-

0-30 2.1
0-40 3.1
0-50 4.0
0-60 5.1
0-70 6.6
0-80 8.1
0-90 9.6
0-100 11.9
0-110 14.2
0-120 16.8
0-130 20.0
0-140 25.2

Now I reckon a properly run in Z4MC should be capable of better than that. Especially when you consider that BMW NEVER overestimate on their performance claims and they reckon 0-62 in 5.0 (so 60 in 4.8 seems about right) and standing kilometre in 23.7 (versus autocar 24.4). Autocar tested the E46 M3 at 4.8 secs to 60 and 11.5 to 100 and the CSL 4.8 to 60 and 10.9 to 100. The BHP in the E46 M3 is identical to the M Coupe but in the CSL the engine has 360 (+22 over standard and M Coupe). The M Coupe I suspect would split the two so 4.8 to 60 and around 11.2/11.3 to 100.

Nevertheless even on their figures it still makes the MC very quick. From a standing start to 130mph (all Autocar road test figures) it is 7.4 secs quicker than a 3.0i coupe, 2.3 secs quicker than s-drive 35i, 3 secs quicker than 335i coupe, 1.9 secs quicker than Cayman S, 7.4 secs quicker than Focus RS, 0.1 secs quicker than a TT RS, 1.6 secs quicker than a V8 Vantage Roadster and 0.3 secs quicker than a Bentley Continental GT.

 

[dgm]

Am I right in thinking that the S54 engine in the Z4M is actually detuned compared to the S54 that's used in the E46 M3s? If so why detune an engine, out of curiosity?

I'm sure I remember reading that the Z4M is a 0.1 seconds slower to 62 than the M3, which you wouldn't expect given that it's lighter, but maybe the detuned engine is the cause of that?!

The short answer is that the Z4M engine isn't detuned in the UK. As already noted, 0-60 times vary wildly between tests and I wouldn't put much reliance on them. For what it's worth, I went directly from an E46 M3 to the Z4MC and I feel that the Z4 is the faster and considerably more urgent car to drive.

 

[sammyz]

Wow according to that list the Z4M can take quite a few scalps in the 0-130 dash, might try that next time I've a poser in a TTRS next to me at the lights

 

[rage999]

Alex,

Autocar tested the Z4MC in their August 06 issue. The conditions were damp in places and the car had only just had its 1200 mile service (1250 on the odometer).

They figured the car as follows:-

0-30 2.1
0-40 3.1
0-50 4.0
0-60 5.1
0-70 6.6
0-80 8.1
0-90 9.6
0-100 11.9
0-110 14.2
0-120 16.8
0-130 20.0
0-140 25.2


Now I reckon a properly run in Z4MC should be capable of better than that. Especially when you consider that BMW NEVER overestimate on their performance claims and they reckon 0-62 in 5.0 (so 60 in 4.8 seems about right) and standing kilometre in 23.7 (versus autocar 24.4). Autocar tested the E46 M3 at 4.8 secs to 60 and 11.5 to 100 and the CSL 4.8 to 60 and 10.9 to 100. The BHP in the E46 M3 is identical to the M Coupe but in the CSL the engine has 360 (+22 over standard and M Coupe). The M Coupe I suspect would split the two so 4.8 to 60 and around 11.2/11.3 to 100.

Nevertheless even on their figures it still makes the MC very quick. From a standing start to 130mph (all Autocar road test figures) it is 7.4 secs quicker than a 3.0i coupe, 2.3 secs quicker than s-drive 35i, 3 secs quicker than 335i coupe, 1.9 secs quicker than Cayman S, 7.4 secs quicker than Focus RS, 0.1 secs quicker than a TT RS, 1.6 secs quicker than a V8 Vantage Roadster and 0.3 secs quicker than a Bentley Continental GT.

The EVO mag tested the the Z4MR to 60mph at 4.8s and the Z4MC (which is lighter) at 5.0s flat. A E46M3 would do 4.8s too and apparently the CSL which they tested was slower to 60 but quicker to 100. This shows that it will take a very good driver to split the difference between these cars.

However, there is no denying that a TT-RS Coupe and roadster is quicker than the Z4M although power to weight is similar. However, considering that the Z4M is 3 yrs older, i am not surprise that the TTRS has developed a much better traction system.

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[glastoveteran]

Thanks all - some very knowledgeable responses as always

 

[sars]

I believe that the manufacturers power and torque figures are bench mark minimums obtained during the model development, due to manufacturing tolerancing production vehicles should meet this minimum but will probably slightly exceed it. Probability dictates that there will be cases where the tolerance error build up is the right way and those engines will sing, I think I had one is my 2.5si

This invariably means that magazine test data can and will vary between other magazines and the manufacturers figures.

 

[cj10jeeper]

Interesting thread and neat info to learn about.

Do the 2 models referenced have identical gearbox ratios, final drive, LSD set up, rim sizes and tyres brand and tyre profiles?
Thos combined in any different combination would make a huge difference in differing parts of the acceleration/speed scales.

 

[daz05]

That video doesn't seem right to me, especially when you compare the M5 boards take on the Z4m vs the RS4.

http://www.youtube.com/watch?v=nBZN29-nZZE

In fact I would hazard a guess to say that it has one of these packs fitted

http://www.speedlux.com/audi-tt-rs-by-mtm-packs-424-hp-0-100-kmh-in-4-2-seconds/mtm-audi-tt-rs-1/

 

[rage999]

That video doesn't seem right to me, especially when you compare the M5 boards take on the Z4m vs the RS4.

http://www.youtube.com/watch?v=nBZN29-nZZE

In fact I would hazard a guess to say that it has one of these packs fitted

http://www.speedlux.com/audi-tt-rs-by-mtm-packs-424-hp-0-100-kmh-in-4-2-seconds/mtm-audi-tt-rs-1/

i like to think the same and i was curious when looking at the Z4M vs RS4 vid. i almost thought that the Z4M in that vid is tuned but when i saw the car go up against the M3CSL, it says otherwise. i think the RS4 suffers from too much drivetrain loss going 4wd and you can see how slow it is compared to the E92 m3. However, i think Audi has certainly managed to reduced the amount of drivetrain loss in the TT-RS and with that turbo, it certainly has the torque to pull away. EVO mag tested the TTRS coupe at 4.4s to 60mph and 4.7s for the roadster. but just bearing in mind, that vid which i posted is coupe vs roadster which you can argue is not a fair comparison. but damn, the way it walked the Z4M. however, it might be that the driver in the z4m is crap, as we know it is not an easy car to drive.

 

[330indy/z4M]

the Coupe is heavier than the Roadster
by the way, who in the hell said the E85/86 S54B32 is detuned? It has newer engine management than the E46: MSS70 DME, vs. MSS54 from the E46. It has more computing power, and that probably translates to better engine management.
but the hair splitting continues... :?

 

[original guvnor]

The TTRS will be quicker on in gear acceleration tests because it has a substantial torque advantage with the turbo. In a straight line to 60mph the TTRS is a bit quicker as you suggest but by 100mph they are neck and neck and above 100 the Z4MC maintains a very slight advantage up to 130. Autocar got 11.4 to 100 for the TTRS.

 

[AlanJ]

Interesting thread and neat info to learn about.

Do the 2 models referenced have identical gearbox ratios, final drive, LSD set up, rim sizes and tyres brand and tyre profiles?
Thos combined in any different combination would make a huge difference in differing parts of the acceleration/speed scales.

And a 'Stubby' would make a difference......

 

[sammyz]

It's all motor masturbation really

But a stubby would make all the difference.

 

[ga41]

i think Audi has certainly managed to reduced the amount of drivetrain loss in the TT-RS and with that turbo, it certainly has the torque to pull away.

Well drivetrain loss will certainly be much less than the RS4's seeing as the TT-RS uses a Haldex 4WD system which is basically FWD until it detects a slip which then sends power to the rear. If i remember correctly it's 85:15 front/rear in everyday driving whereas the RS4 is 40:60 permanently.

 

[DaveR]

The TTRS will be quicker on in gear acceleration tests because it has a substantial torque advantage with the turbo.

Living proof, then: it's not how fast you go; it's how you go fast.