[1mm2]

Originally Posted by Robin_NL

Responsive as in: Between 2000 and 4500rpm responsive? Almost nothing happened in E90 M3 6MT when I floored it.

I do understand what you mean. But S65 is not even remotely close as powerful(usable power) in a broad rev-range as N54/N55 and certainly S55.

It's a sort of racy engine but misses torque, that's a pity imo.

The way N54/55/S55 kick in (wheelspin galore etc) make you be aware much more and gives me way more satisfaction, than ALWAYS revving it to beyond 6000rpm in real life to get some effective speed out of it.

Porsche knows how to build smaller 6 pot NA engines(997S 2005 , great engine, lots of torque)

On trackdays it's ok off course.

Cheers
Robin

Given that I owned a 1M for three years (should have never sold it) and have driven a friend's e90 M3 (manual) extensively all I can say is the above post is spot on. The lack of torque down low never failed to surprise me. On the higher range though it was bliss...

[chris719]

S65 needs to be in the right gear. If you mash the throttle at low RPM it won’t go anywhere, but that’s not driving it correctly. It’s throttle response is better and can be more finely adjusted. I didn’t say it had more torque or was more flexible, because it’s not. I agree N54 is a better day-to-day engine.

S65 would have been even better with 8k redline and a longer stroke.

[10"]

Originally Posted by chris719

S65 needs to be in the right gear. If you mash the throttle at low RPM it won’t go anywhere, but that’s not driving it correctly. It’s throttle response is better and can be more finely adjusted. I didn’t say it had more torque or was more flexible, because it’s not. I agree N54 is a better day-to-day engine.

S65 would have been even better with 8k redline and a longer stroke.

The term being used was "responsive" and I think the N54 is a far more responsive engine than the S65.

I think the S55 is also far more responsive than the S65, for that matter.

There is a part of me that loves the S55 in the E9X but it lacks the sheer enjoyment that comes with the lunacy of twin turbo engines. There is definitely satisfaction of ringing a nice engine past 7k RPM but it's not a joy that can be accessed as easily or frequently.

[FreeDarko]

Responsiveness primarily refers to "capability of an internal combustion engine to shift rapidly and smoothly from a stable mode of operation at minimum power to maximum power."

Neither of my two S55 cars or N54 could go through the power band as quickly and smoothly as the S65. The fact that it was designated to a heavy car didn't alter this truth.

But unfortunately the fact remains, in the real world, the S65 in a heavy car muted the abilities of the engine. If it was a 3000lb vehicle like 911 Porsche, we would all be comparing it to GT3s etc.

[TheRealOrosie]

Originally Posted by chris719

S65 needs to be in the right gear. If you mash the throttle at low RPM it won’t go anywhere, but that’s not driving it correctly. It’s throttle response is better and can be more finely adjusted. I didn’t say it had more torque or was more flexible, because it’s not. I agree N54 is a better day-to-day engine.

S65 would have been even better with 8k redline and a longer stroke.

Huh? The S65 has a 8300 redline. Are you saying it would have better with a lower redline?

[chris719]

Originally Posted by TheRealOrosie

Huh? The S65 has a 8300 redline. Are you saying it would have better with a lower redline?

Yes, you would have to trade the redline for a longer stroke or the piston speeds would be higher. I mean, the GTS had 4.4L but I was thinking 5L. I figure 8k is enough to still be special.

[natmad]

An engine’s responsiveness is subjective.

Take 2 sports cars with the same weight, transmission, gearing, etc...

One car has the S55 engine, the other car has the S65.

Ok?

Example 1... both cars are rolling in second gear at 6,000 RPM, then go full throttle, the S65 will feel immediately more responsive. No momentary turbo lag.

Example 2... both cars rolling at 2,500 RPM in second gear, then go full throttle, the S55 will build boost and be gone like a rocket, the S65 will be relatively sluggish until @4,500 RPM or so.

In example 2, the S55 car will feel immensely more responsive.

Mmm hmmm. Subjective... or objective, if your timing the runs.

Or... whatever your ass is telling your brain.

[chris719]

Originally Posted by 10"

The term being used was "responsive" and I think the N54 is a far more responsive engine than the S65.

I think the S55 is also far more responsive than the S65, for that matter.

There is a part of me that loves the S55 in the E9X but it lacks the sheer enjoyment that comes with the lunacy of twin turbo engines. There is definitely satisfaction of ringing a nice engine past 7k RPM but it's not a joy that can be accessed as easily or frequently.

I see, I think we are just confusing terms. I always thought responsiveness was throttle response. I would call what you're talking about flexibility. I think that's what C&D calls it also. No argument from me, S65 is not as good if you aren't really "on it".

[Robin_NL]

Originally Posted by natmad

An engine's responsiveness is subjective.

Take 2 sports cars with the same weight, transmission, gearing, etc...

One car has the S55 engine, the other car has the S65.

Ok?

Example 1... both cars are rolling in second gear at 6,000 RPM, then go full throttle, the S65 will feel immediately more responsive. No momentary turbo lag.

Example 2... both cars rolling at 2,500 RPM in second gear, then go full throttle, the S55 will build boost and be gone like a rocket, the S65 will be relatively sluggish until @4,500 RPM or so.

In example 2, the S55 car will feel immensely more responsive.

Mmm hmmm. Subjective... or objective, if your timing the runs.

Or... whatever your ass is telling your brain.

Also in Example 1 @ 6000 RPm S55 will feel way and I mean way more powerful ( because it has more power and torque at those revs). And will start to attack immediately,No worries

No turbo lag ( it's called boost threshold btw ) and no boost threshold at those engine speeds.

Lower gearing would help E9X M3 6MT

Cheers
Robin

[akkando]

Originally Posted by natmad

An engine’s responsiveness is subjective.

Take 2 sports cars with the same weight, transmission, gearing, etc...

One car has the S55 engine, the other car has the S65.

Ok?

Example 1... both cars are rolling in second gear at 6,000 RPM, then go full throttle, the S65 will feel immediately more responsive. No momentary turbo lag.

Example 2... both cars rolling at 2,500 RPM in second gear, then go full throttle, the S55 will build boost and be gone like a rocket, the S65 will be relatively sluggish until @4,500 RPM or so.

In example 2, the S55 car will feel immensely more responsive.

Mmm hmmm. Subjective... or objective, if your timing the runs.

Or... whatever your ass is telling your brain.

If you want to drop the pedal to the floor and move, you got to drop some gears too so you're in the power band. That's true of both engines.

[10"]

Originally Posted by Robin_NL

Also in Example 1 @ 6000 RPm S55 will feel way and I mean way more powerful ( because it has more power and torque at those revs). And will start to attack immediately,No worries

No turbo lag ( it's called boost threshold btw ) and no boost threshold at those engine speeds.

Lower gearing would help E9X M3 6MT

Cheers
Robin

This!! Agreed! There is NO turbo lag past the boost point in ANY turbo engine. Just a bad example presented there...

[Poochie]

Originally Posted by Robin_NL

Also in Example 1 @ 6000 RPm S55 will feel way and I mean way more powerful ( because it has more power and torque at those revs). And will start to attack immediately,No worries

No turbo lag ( it's called boost threshold btw ) and no boost threshold at those engine speeds.

Lower gearing would help E9X M3 6MT

Cheers
Robin

Some vehicles produced more power at high RPMs not because they're not capable or can't be tuned to produced power down low, it's intentionally programmed that way to pass strict emissions regulations.

Here in the US, there is no emission standards at full throttle (85%+). This exception was made so car manufactures could deliver maximum power and the overall effect on emissions would be small, since people rarely drive at full throttle.

Thus, at high RPMs, the O2 sensors go into an "open loop" state and is taken out of the system so the fuel system can be enriched for maximum power, which is where the S65 would be allowed to shine.

This is why a big elephant motor like the S65 gets to roam the streets legally, the same as a small N20 displacement. A turbocharged motor can circumvent this standard of measurement, simply because it can product power down low and still be within compliance, where as the S65 has to neuter its potential, until it's up top in the RPM band.

In theory, a large displacement, naturally aspirated motor like the S65, at part throttle, the timing can be advanced and lower gear ratio can be used to maximize power, if premium fuel is used but it's very difficulty to enrich the mixture at lower RPMs and still remain emission compliant.

A stock NA motor's throttle might feel weaker to its turbocharged counterparts, simple because it's measured for compliance on same arbitrary standards, not because it's necessary lacking in power potential.

TL : DR Don't judge a motor's potential by its throttle response, "low end torque" or its lack thereof..

[natmad]

Originally Posted by 10"

This!! Agreed! There is NO turbo lag past the boost point in ANY turbo engine. Just a bad example presented there...

Ok... That makes sense.

Disregard my example number 1.

[Karmic Man]

To be honest if the 1M had the S65 it would still be in my garage now instead of in someone else's.

Yes the S65 doesn't make much torque under 4k but it is a high revving 4L NA V8 and that is something very special in this day and age. Put that in a compact M chassis like the 1M and you have a masterpiece right there.

If the 1M had the full 414hp 8300 rpm S65 its current price in the market would be even more ludicrous. Perhaps 50%-100% more depending on the condition and rising

[10"]

Originally Posted by Karmic Man

To be honest if the 1M had the S65 it would still be in my garage now instead of in someone else's.

Yes the S65 doesn't make much torque under 4k but it is a high revving 4L NA V8 and that is something very special in this day and age. Put that in a compact M chassis like the 1M and you have a masterpiece right there.

If the 1M had the full 414hp 8300 rpm S65 its current price in the market would be even more ludicrous. Perhaps 50%-100% more depending on the condition and rising

As a counterpoint if the 1M had a V8 I wouldn't have been interested. :P

Fair point though...there is definitely love for the S65 but the N54 is an engine with a massive cult following.

[dmboone25]

Originally Posted by 10"

Totally agreed. The S65 is definitely overrated. I'm very glad the 1M came with an N54 rather than the S65. Hated the gearing on the E9X as well. I like urgency and purpose and to me driving the 1M and E9X back to back felt like a young punk (1M) and a stockbroker (M3). I prefer young punk.

BMW ended up doubling down on the N54 formula big time when they made the S55; which is essentially a further developed idea based on the N54.

I always thought the S65 was a lazy revving engine...especially compared to the S54 in my dad's Z4MC. Sure, it went to 8000+ RPM, but always felt to me like it took a long time to get there. I never understood the hype.

The exhaust note is also completely overplayed IMO - sure, it's a V8 and sounds like a V8...but doesn't sound nearly as distinctive or aggressive (in stock form at least) when compared to the American counterparts at the same time. Many of the S55 sound "haters" were E9X M3 owners that were over-romanticizing the quality of the stock S65 note. Is it better? That's subjective...