M4cs Power output analysis - This S55 variant is quite potent

[EricSMG]

I'd like to see more dynos overlaying the ZCP/CS curves. The Evolve dyno shows the CS falling off sooner/quicker near red line than the ZCP which I find surprising. Is this actually the case?

My ZCP car pulls hard to about 6.5k and then sorta goes flat to around 7 and then notably falls off. Therefore I shift around 7.

[EricSMG]

Originally Posted by melvyn

Yep maybe a little more in auto, 6kish in manual

That seems backwards as the DCT has much closer ratios which would/should result in a smaller rpm drop between shifts.

Now, I haven't compared the tranny ratios so I could be wrong.

Edit - wait, I'm reading Can's gearing thread. Let me digest that and I'll rephrase my response here.

Edit 2 - that thread doesn't have the ratios listed. Still hunting for those. I'm "ass-uming" that the DCT has much closer gear spacing since it did in the E9XM but that may be incorrect for this chassis.

[shortseller]

Originally Posted by CanAutM3

More like 5500RPM

1.277 / 1.701 x 7300 = 5480

Originally Posted by melvyn

Yep maybe a little more in auto, 6kish in manual

Now boys!

[melvyn]

Originally Posted by shortseller

Now boys!

We

Will be picking cats hairs next

[CanAutM3]

Originally Posted by melvyn

Yep maybe a little more in auto, 6kish in manual

What are you talking about ? The RPM drop will be the same in auto and manual. The RPM drop is a simple mathematical calculation from the gear ratio ratio.

[melvyn]

Originally Posted by EricSMG

I'd like to see more dynos overlaying the ZCP/CS curves. The Evolve dyno shows the CS falling off sooner/quicker near red line than the ZCP which I find surprising. Is this actually the case?

My ZCP car pulls hard to about 6.5k and then sorta goes flat to around 7 and then notably falls off. Therefore I shift around 7.

I was surprised how quick the CS drops off, even compared to my 2014 F80 which loved the redline.

[melvyn]

Originally Posted by CanAutM3

What are you talking about ? The RPM drop will be the same in auto and manual. The RPM drop is a simple mathematical calculation from the gear ratio ratio.

Oh dear

How do you work that one out .
Auto changes at 7300 .Manual changes at 7600 or 7700 on the limiter.Go do your figures again, only properly this time.

[EricSMG]

Originally Posted by melvyn

I was surprised how quick the CS drops off, even compared to my 2014 F80 which loved the redline.

Interesting. That's why I have little interest in the typical Stage 1/2 tunes as they increase the midrange massively and disproportionately to the top end, thus giving the impression of a bigger power drop up top - so while the car may indeed be faster, it probably is less rewarding to wind out once tuned which means the power-band actually becomes narrower which is always worse.

I have no interest in any more bottom/mid for my ZCP car. It's fast and usable. Where I want more is at the top only. I'd assumed the CS had a more ferocious red line scream.

[melvyn]

Originally Posted by CanAutM3

I would not put too much faith in the CS tune dyno from Evolve. While it clearly shows how much more mid range torque the CS tune makes, it likely under estimates the CS top-end pulling power. According to Evolve's own comments, the car was likely heat soaked when they did the CS tune pulls as they were the last one done:

The CS does not like redlining , I can only say from my own experience I'll be very interested to hear your thought ps on it once you've ran in and got used to it

[CanAutM3]

Originally Posted by melvyn

The CS does not like redlining , I can only say from my own experience

If it really is the case, I find it rather disappointing

Originally Posted by melvyn

I'll be very interested to hear your thought ps on it once you've ran in and got used to it

Same here. Still 1300km to go before break-in

[CanAutM3]

Originally Posted by EricSMG

I'd like to see more dynos overlaying the ZCP/CS curves. The Evolve dyno shows the CS falling off sooner/quicker near red line than the ZCP which I find surprising. Is this actually the case?

My ZCP car pulls hard to about 6.5k and then sorta goes flat to around 7 and then notably falls off. Therefore I shift around 7.

I would not put too much faith in the CS tune dyno from Evolve. While it clearly shows how much more mid range torque the CS tune makes, it likely under estimates the CS top-end pulling power. According to Evolve's own comments, the car was likely heat soaked when they did the CS tune pulls as they were the last one done:

Originally Posted by Imran@Evolve

Its either that or the heatsoak as that was the last test I did back to back on the dyno. I will put some miles on with the CS software and retest in a week or so. The car itself only has 900 odd miles on it.

[melvyn]

Originally Posted by EricSMG

Interesting. That's why I have little interest in the typical Stage 1/2 tunes as they increase the midrange massively and disproportionately to the top end, thus giving the impression of a bigger power drop up top - so while the car may indeed be faster, it probably is less rewarding to wind out once tuned which means the power-band actually becomes narrower which is always worse.

I have no interest in any more bottom/mid for my ZCP car. It's fast and usable. Where I want more is at the top only. I'd assumed the CS had a more ferocious red line scream.

Fully agree with your interpretation.I don't know why they upped the CS revs to 7600.The CS needs to be changed at 6kish to gain speed.Ive never redlined it in fifth as we don't have roads long enough to do so, but I very much doubt that it would.

[CanAutM3]

Originally Posted by melvyn

Fully agree with your interpretation.I don't know why they upped the CS revs to 7600.The CS needs to be changed at 6kish to gain speed.Ive never redlined it in fifth as we don't have roads long enough to do so, but I very much doubt that it would.

Redline and cutoff have not been changed for the CS, all M3/4 S55 tunes have a 7500RPM redline with 7600RPM cutoff.

[melvyn]

Originally Posted by CanAutM3

If it really is the case, I find it rather disappointing

Same here. Still 1300km to go before break-in

No, don't be dissapointed at all, it will still redline in third and fourth , but I just think once you get used to it , you will be changing gear sooner to make the smile last on your face, which it will

[melvyn]

Originally Posted by CanAutM3

Redline and cutoff have not been changed for the CS, all M3/4 S55 tunes have a 7500RPM redline with 7600RPM cutoff.

No, not the case.CS has been raised to 7600 although the rev counter has not been changed to take it into account

[CanAutM3]

Originally Posted by melvyn

No, not the case.CS has been raised to 7600 although the rev counter has not been changed to take it into account

Not sure where you are getting your infos...

The S55 has always had a 7600RPM max engine speed since launch:

[CanAutM3]

Originally Posted by EricSMG

I'd like to see more dynos overlaying the ZCP/CS curves. The Evolve dyno shows the CS falling off sooner/quicker near red line than the ZCP which I find surprising. Is this actually the case?

My ZCP car pulls hard to about 6.5k and then sorta goes flat to around 7 and then notably falls off. Therefore I shift around 7.

For some reason, I can't seem to be able to get a good resolution pic of the BPM dyno they did on the CS, but the they showed gains over the CP tune across the RPM range up to ~7200RPM, pretty much in line with BMW's official dyno charts.

https://f80.bimmerpost.com/forums/sh....php?t=1449315

[melvyn]

Originally Posted by CanAutM3

Not sure where you are getting your infos...

The S55 has always had a 7600RPM max engine speed since launch:

Your a nit picker sir

S55 engine will rev up to 7600 as states in your image

CP redlines at 7500 revs
CS redlines at 7600 revs

Yes or no?

[melvyn]

Info for you

CS

https://www.gtplanet.net/forum/threa...s-2017.369734/

CP

https://www.gtplanet.net/forum/threa...e-2016.341563/

You can apologize next time I come on.

Enjoy your motor, it really is a special piece of kit out of the box

[JamesGames]

Originally Posted by melvyn

Info for you

CS

https://www.gtplanet.net/forum/threa...s-2017.369734/

CP

https://www.gtplanet.net/forum/threa...e-2016.341563/

You can apologize next time I come on.

Enjoy your motor, it really is a special piece of kit out of the box

Lot of places state the different redline 7600 for CS and 7500 for regular. But the actual limiter kicks in at 7600 for standard car, maybe that's what CanAutM3 is talking about? What RPM is power cut off on the CS do you know?

[EricSMG]

Originally Posted by CanAutM3

For some reason, I can't seem to be able to get a good resolution pic of the BPM dyno they did on the CS, but the they showed gains over the CP tune across the RPM range up to ~7200RPM, pretty much in line with BMW's official dyno charts.

Thanks for this but it's starting to look like the CS falls off more sharply as you approach red line even though it's making more power until the CP regains the advantage at ~7250rpm (however small this might be - the real world this will be moot).

I was hoping that the CS held a flat HP line right up to/near the limiter. Now, I'm not taking anything away from the CS, I just assumed it would have more of a 'racing' dyno curve. No doubt the area under the curve is impressive, though. I'm wondering how much of that area is possible with 91 octane fuel, above an beyond the CP on the same fuel.

[melvyn]

Originally Posted by JamesGames

Lot of places state the different redline 7600 for CS and 7500 for regular. But the actual limiter kicks in at 7600 for standard car, maybe that's what CanAutM3 is talking about? What RPM is power cut off on the CS do you know?

Yep, 7700