ARMA SPEED
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read

Go Back   BMW M3 and BMW M4 Forum > BMW F80 M3 / F82 M4 Technical Topics > Engine / Drivetrain / Exhaust / Bolt-ons / Tuning

Post Reply
 
Thread Tools Search this Thread
      04-21-2017, 10:49 AM   #1
CanAutM3
General
CanAutM3's Avatar
Canada
21105
Rep
20,741
Posts

Drives: 2021 911 turbo
Join Date: Jan 2012
Location: Montreal

iTrader: (1)

Garage List
M4cs Power output analysis - This S55 variant is quite potent

I originally posted this in the M4cs thread, but decided to start a separate thread in the engine section for a more in depth technical discussion. The S55 variant in the M4cs seems to be quite potent. Much more so than the modest 10hp peak increase over the CP suggests.

I had a little fun plotting the base and Comp Pack rated power curves over the CS (preliminary) rated power curve. It is interesting to see that the CS provides substantially more area under the curve over the CP compared to what the CP provides over the base S55; and this despite having half the peak gain (10hp vs 19hp). That is what 37lb-ft of extra torque does for you . It should make the CS quite quicker than the CP and even more so than the base M3/4. It's also interesting to notice the CS has less power than the CP and base S55 below ~2300RPM. I wonder what changes were made to the engine? Is this the result solely from a different tune?

EDIT (Nov-2017)
On a quiet, cold and rainy Sunday afternoon, I had a little time to kill. So I set out to capture test results from European publications (mostly German) for acceleration to compare the different M4 variants. To remove the effect of the added grip at launch provided by PSC2 when the cars are so fitted, I only set out to capture the 100 to 200km/h acceleration. I compiled 21 different tests and then averaged the results for each M4 variant (DCT only). While this is not the most scientific approach, it does provide a decent perspective. Here are the results:

100km/h -> 200km/h acceleration
9.52 M4 Base (6 samples)
.... ∆ 0.20
9.32 M4 CP (9 samples)
.... ∆ 0.67
8.65 M4 cs (4 samples)
.... ∆ 0.20
8.45 M4 GTS (2 samples)

First, I think this dispels the rumours that the CP is not any quicker than the base model, having a ~0.2 second advantage from 100 to 200km/h. Second, it also shows how the CS pulls quite strongly in the top end, being ~0.7 seconds faster than the CP and only ~0.2 seconds short of the mighty water injected GTS. Which is in line with the conclusion reached when looking at the power charts .

CS in black, CP in red, base S55 in blue:
Attached Images
 
__________________
Porsche 911 turbo 2021 992 GT Silver

Previous cars: M4cs 2019 F82 Limerock Grey / M4 2015 F82 Silverstone / M3 2008 E92 Silverstone / M3 2002 E46 Carbon Black

Last edited by CanAutM3; 09-15-2018 at 12:52 PM..
Appreciate 5
M4 CSL229.00
bd307927.00
GrussGott18113.00
dezzracer1173.50
      04-21-2017, 11:02 AM   #2
Sleeper
.
Sleeper's Avatar
No_Country
660
Rep
1,059
Posts

Drives: '23 BSM X5///MC
Join Date: Dec 2011
Location: North

iTrader: (1)

Quote:
Originally Posted by CanAutM3 View Post
I originally posted this in the M4CS thread, but decided to start a separate thread in the engine section for a more in depth technical discussion. The S55 variant in the M4CS seems to be quite potent. Much more so than the modest 10hp peak increase over the CP suggests.

I had a little fun plotting the Comp Pack rated power curve over the CS (preliminary) rated power curve. It is interesting to see that the CS provides substantially more area under the curve over the CP compared to what the CP provides over the base S55; and this despite having half the peak gain (10hp vs 19hp). That is what 37lb-ft of extra torque does for you . It should make the CS quite quicker than the CP and even more so than the base M3/4. It's also interesting to notice the CS has less power than the CP and base S55 below ~2300RPM. I wonder what changes were made to the engine? Is this the result solely from a different tune?

CS in black, CP in red, base S55 in blue:
With all due respect, and I know you're enjoying the analysis of the CS, you can derive almost zero conclusion from overlaying the gimmicky Excel graph outputs that BMW publishes in its marketing materials.
Appreciate 5
Acree377.50
domino_z1196.00
chris7197271.50
      04-21-2017, 01:00 PM   #3
CanAutM3
General
CanAutM3's Avatar
Canada
21105
Rep
20,741
Posts

Drives: 2021 911 turbo
Join Date: Jan 2012
Location: Montreal

iTrader: (1)

Garage List
Quote:
Originally Posted by Sleeper View Post
With all due respect, and I know you're enjoying the analysis of the CS, you can derive almost zero conclusion from overlaying the gimmicky Excel graph outputs that BMW publishes in its marketing materials.
Your statement tells me you don't know much about engine testing and how official manufacturer ratings are obtained
__________________
Porsche 911 turbo 2021 992 GT Silver

Previous cars: M4cs 2019 F82 Limerock Grey / M4 2015 F82 Silverstone / M3 2008 E92 Silverstone / M3 2002 E46 Carbon Black
Appreciate 5
MasterP719.50
SYT_Shadow11421.00
Tornado1M1201.50
      04-21-2017, 01:04 PM   #4
Sleeper
.
Sleeper's Avatar
No_Country
660
Rep
1,059
Posts

Drives: '23 BSM X5///MC
Join Date: Dec 2011
Location: North

iTrader: (1)

Quote:
Originally Posted by CanAutM3 View Post
Quote:
Originally Posted by Sleeper View Post
With all due respect, and I know you're enjoying the analysis of the CS, you can derive almost zero conclusion from overlaying the gimmicky Excel graph outputs that BMW publishes in its marketing materials.
Your statement tells me you don't know much about engine testing and how official manufacturer ratings are obtained
Yes, because the data BMW has published respecting the S55's power output has reflected reality. Enjoy your comparisons .
Appreciate 2
THEROK1264.50
      04-21-2017, 01:05 PM   #5
CaryTheLabelGuy
Colonel
CaryTheLabelGuy's Avatar
United_States
2634
Rep
2,809
Posts

Drives: 2016 M4 ZCP
Join Date: Mar 2015
Location: Jacksonville, FL

iTrader: (0)

Knowing what we now know about the S55 now, they're just running more boost and maybe some overlap changes @ Peak VE to get that extra power under the curve.

I'm not sure why BMW didn't just reuse the water Injection from the GTS, TBH.
Appreciate 0
      04-21-2017, 01:12 PM   #6
Brasko
#LSBM3
Brasko's Avatar
No_Country
1418
Rep
1,973
Posts

Drives: 2016 BMW M3
Join Date: Feb 2015
Location: Oregon / Florida

iTrader: (4)

Garage List
Interesting analysis of the 3 variants. I also think its important to note the flat power curve for the CS model. Doesn't seem to peak like the CP.
__________________


/// M3
Appreciate 0
      04-22-2017, 11:22 AM   #7
shockin330i
Brigadier General
shockin330i's Avatar
798
Rep
4,784
Posts

Drives: 2016 ZCP M3
Join Date: Jan 2007
Location: f y'all, I'm from Texas (RGV)

iTrader: (1)

Quote:
Originally Posted by Sleeper View Post
With all due respect, and I know you're enjoying the analysis of the CS, you can derive almost zero conclusion from overlaying the gimmicky Excel graph outputs that BMW publishes in its marketing materials.
Someone always has to argue with the engineer....
__________________
ERnie
2016 BSM/f80/ZCP
Appreciate 4
CanAutM321104.50
SYT_Shadow11421.00
Racer201029.50
cliverman955.50
      04-23-2017, 06:01 AM   #8
CanAutM3
General
CanAutM3's Avatar
Canada
21105
Rep
20,741
Posts

Drives: 2021 911 turbo
Join Date: Jan 2012
Location: Montreal

iTrader: (1)

Garage List
Quote:
Originally Posted by CaryTheLabelGuy View Post
Knowing what we now know about the S55 now, they're just running more boost and maybe some overlap changes @ Peak VE to get that extra power under the curve.
That was my original thought. But then seeing the power drop below 2300RPM got me thinking something was done to the turbos.

Quote:
Originally Posted by CaryTheLabelGuy View Post
I'm not sure why BMW didn't just reuse the water Injection from the GTS, TBH.
I agree. I certainly had wished for that

Further, did you notice that in the press releases they talk about a lightweight magnesium oil sump?
__________________
Porsche 911 turbo 2021 992 GT Silver

Previous cars: M4cs 2019 F82 Limerock Grey / M4 2015 F82 Silverstone / M3 2008 E92 Silverstone / M3 2002 E46 Carbon Black

Last edited by CanAutM3; 04-23-2017 at 06:52 AM..
Appreciate 1
M4 CSL229.00
      04-23-2017, 06:49 AM   #9
CaryTheLabelGuy
Colonel
CaryTheLabelGuy's Avatar
United_States
2634
Rep
2,809
Posts

Drives: 2016 M4 ZCP
Join Date: Mar 2015
Location: Jacksonville, FL

iTrader: (0)

Quote:
Originally Posted by CanAutM3 View Post
That was my original thought. But then seeing the power drop below 2300RPM got me thinking something was done to the turbos.



I agree. I certainly had wished fir that

Further, did you notice that in the press releases they talk about a lightweight magnesium oil sump?
I saw that slight dip in power below 2300rpm, but I'm not sure what to make of that. It's possible they did something to the turbos, but I doubt it because the boost appears to taper off at the same point. Larger turbos would have less boost taper up-top unless BMW specifically dropped boost targets more up-top to keep power down?

As for the magnesium oil sump, I must have totally missed that as I didn't see it. I need to go back and read that press release again.
Appreciate 0
      04-23-2017, 07:09 AM   #10
CanAutM3
General
CanAutM3's Avatar
Canada
21105
Rep
20,741
Posts

Drives: 2021 911 turbo
Join Date: Jan 2012
Location: Montreal

iTrader: (1)

Garage List
Quote:
Originally Posted by CaryTheLabelGuy View Post
I saw that slight dip in power below 2300rpm, but I'm not sure what to make of that.
It's a fairly subtantial drop in power at low RPM: ~50 less hp at 1900 RPM. That's 35% less.

Quote:
Originally Posted by CaryTheLabelGuy View Post
As for the magnesium oil sump, I must have totally missed that as I didn't see it. I need to go back and read that press release again.
About midway in the 4th paragraph of the engine section in the "long version" of the press release.
Attached Images
 
__________________
Porsche 911 turbo 2021 992 GT Silver

Previous cars: M4cs 2019 F82 Limerock Grey / M4 2015 F82 Silverstone / M3 2008 E92 Silverstone / M3 2002 E46 Carbon Black

Last edited by CanAutM3; 04-23-2017 at 08:40 AM..
Appreciate 0
      04-23-2017, 08:55 AM   #11
SO17
First Lieutenant
SO17's Avatar
79
Rep
321
Posts

Drives: 2018 MY M4CP
Join Date: Jun 2016
Location: UK

iTrader: (0)

I saw that but assumed that they were referring to the S55 engine in general rather than the CS variant. Didn't the early S55 come with a magnesium oil pan ? (happy to be corrected if it didn't). And what about the extra oil suction pump ? Does the CS variant actually have an extra oil pump or, again, are they talking about the S55 in general ?
Appreciate 0
      04-23-2017, 12:00 PM   #12
CanAutM3
General
CanAutM3's Avatar
Canada
21105
Rep
20,741
Posts

Drives: 2021 911 turbo
Join Date: Jan 2012
Location: Montreal

iTrader: (1)

Garage List
Quote:
Originally Posted by SO17 View Post
I saw that but assumed that they were referring to the S55 engine in general rather than the CS variant. Didn't the early S55 come with a magnesium oil pan ? (happy to be corrected if it didn't). And what about the extra oil suction pump ? Does the CS variant actually have an extra oil pump or, again, are they talking about the S55 in general ?
Yes, the S55 did come with a Mg oil pan at launch, but it was replaced with an Al oil pan after the first year. I was surprised to see the Mg oil pan announced again for the CS.
__________________
Porsche 911 turbo 2021 992 GT Silver

Previous cars: M4cs 2019 F82 Limerock Grey / M4 2015 F82 Silverstone / M3 2008 E92 Silverstone / M3 2002 E46 Carbon Black
Appreciate 1
hakcar62.50
      04-24-2017, 07:47 AM   #13
JoeyBananas
Lieutenant Colonel
692
Rep
1,517
Posts

Drives: NA
Join Date: Jul 2014
Location: NJ

iTrader: (0)

So the "hardware" between all these variants are pretty much the same?, just software tweaks?
Appreciate 0
      04-24-2017, 07:50 AM   #14
CanAutM3
General
CanAutM3's Avatar
Canada
21105
Rep
20,741
Posts

Drives: 2021 911 turbo
Join Date: Jan 2012
Location: Montreal

iTrader: (1)

Garage List
Quote:
Originally Posted by JoeyBananas View Post
So the "hardware" between all these variants are pretty much the same?, just software tweaks?
That is the point of the discussion? We don't know for sure yet. It would be much cheaper for BMW to make through software only.

But I wonder why they would have purposefully reduced the low end-power on the CS by so much if it were through software only ??
__________________
Porsche 911 turbo 2021 992 GT Silver

Previous cars: M4cs 2019 F82 Limerock Grey / M4 2015 F82 Silverstone / M3 2008 E92 Silverstone / M3 2002 E46 Carbon Black
Appreciate 0
      04-24-2017, 12:53 PM   #15
stevehifi
Captain
526
Rep
855
Posts

Drives: 17 F80 M3 ZCP
Join Date: May 2008
Location: Irvine,CA

iTrader: (5)

BMW just plays with the timing and boost control and fine tunes the engine map even more.
Maybe the stepper motor on the boost control is even finer resolution.

I bet you in a year or so some tuner will offer the update for the ECU for all cars...
Appreciate 0
      04-24-2017, 02:36 PM   #16
CanAutM3
General
CanAutM3's Avatar
Canada
21105
Rep
20,741
Posts

Drives: 2021 911 turbo
Join Date: Jan 2012
Location: Montreal

iTrader: (1)

Garage List
Quote:
Originally Posted by stevehifi View Post
BMW just plays with the timing and boost control and fine tunes the engine map even more.
Maybe the stepper motor on the boost control is even finer resolution.

I bet you in a year or so some tuner will offer the update for the ECU for all cars...
Why would BMW REDUCE the power below 2300RPM on the CS engine if it is only from a change of tune ?
__________________
Porsche 911 turbo 2021 992 GT Silver

Previous cars: M4cs 2019 F82 Limerock Grey / M4 2015 F82 Silverstone / M3 2008 E92 Silverstone / M3 2002 E46 Carbon Black
Appreciate 0
      04-24-2017, 04:46 PM   #17
bd307
Chef
bd307's Avatar
927
Rep
1,059
Posts

Drives: Things with wheels or no wheel
Join Date: Dec 2014
Location: Area 51

iTrader: (0)

Quote:
Originally Posted by CanAutM3 View Post
Why would BMW REDUCE the power below 2300RPM on the CS engine if it is only from a change of tune ?
My guess would be to allow better hookup during the lower rpms, but I think that job should be handled by the Cups and the tweaked suspension with ease.

That is the only logical reason I can come up with.
Appreciate 0
      04-24-2017, 04:46 PM   #18
Sleeper
.
Sleeper's Avatar
No_Country
660
Rep
1,059
Posts

Drives: '23 BSM X5///MC
Join Date: Dec 2011
Location: North

iTrader: (1)

Quote:
Originally Posted by stevehifi View Post
BMW just plays with the timing and boost control and fine tunes the engine map even more.
Maybe the stepper motor on the boost control is even finer resolution.

I bet you in a year or so some tuner will offer the update for the ECU for all cars...
There would be no point. Stage 1 flash tunes already exceed the performance of all factory available tunes for the S55. For the majority of people, if you're splitting your DME case, you're not going to go with a mild OEM upgrade. VF offers a ZCP-style/performance map, but I can't imagine the uptake on that is very high when the cost for the much more significant performance bump (Stage 1) is marginal.
Appreciate 0
      04-24-2017, 05:47 PM   #19
stevehifi
Captain
526
Rep
855
Posts

Drives: 17 F80 M3 ZCP
Join Date: May 2008
Location: Irvine,CA

iTrader: (5)

Quote:
Originally Posted by bd307 View Post
My guess would be to allow better hookup during the lower rpms, but I think that job should be handled by the Cups and the tweaked suspension with ease.

That is the only logical reason I can come up with.
You're reading too much into the marketing 'power' graph that BMW publishes.. it's a gross representation of the engine power curve and each motor varies over production tolerances. Best thing to do is wait until someone actually dynos a CS and then you can see the differences...
Appreciate 0
      04-24-2017, 06:02 PM   #20
CanAutM3
General
CanAutM3's Avatar
Canada
21105
Rep
20,741
Posts

Drives: 2021 911 turbo
Join Date: Jan 2012
Location: Montreal

iTrader: (1)

Garage List
Quote:
Originally Posted by stevehifi View Post
You're reading too much into the marketing 'power' graph that BMW publishes.. it's a gross representation of the engine power curve and each motor varies over production tolerances. Best thing to do is wait until someone actually dynos a CS and then you can see the differences...
Those power charts are likely coming from the testing BMW did to obtain their certified rating. They are most probably more precise and repeatable than any chassis dyno run done at the corner shop.

The challenge with modern engines, particularly forced induction ones, is that they can produce more power when in transient than in steady state, giving the impression that they are "underrated" from the factory.
__________________
Porsche 911 turbo 2021 992 GT Silver

Previous cars: M4cs 2019 F82 Limerock Grey / M4 2015 F82 Silverstone / M3 2008 E92 Silverstone / M3 2002 E46 Carbon Black

Last edited by CanAutM3; 04-25-2017 at 12:27 PM..
Appreciate 1
Wills28616.00
      11-05-2017, 03:44 PM   #21
CanAutM3
General
CanAutM3's Avatar
Canada
21105
Rep
20,741
Posts

Drives: 2021 911 turbo
Join Date: Jan 2012
Location: Montreal

iTrader: (1)

Garage List
On this quiet, cold and rainy Sunday afternoon, I had a little time to kill. So I set out to capture test results from European publications (mostly German) for acceleration to compare the different M4 variants. To remove the effect of the added grip at launch provided by PSC2 when the cars are so fitted, I only set out to capture the 100 to 200km/h acceleration. I compiled 21 different tests and then averaged the results for each M4 variant (DCT only). While this is not the most scientific approach, it does provide a decent perspective. Here are the results:

100km/h - 200km/h acceleration
9.52 M4 Base (6 samples)
.... ∆ 0.20
9.32 M4 CP (9 samples)
.... ∆ 0.67
8.65 M4 CS (4 samples)
.... ∆ 0.20
8.45 M4 GTS (2 samples)

First, I think this dispels the rumours that the CP is not any quicker than the base model, having a ~0.2 second advantage from 100 to 200km/h. Second, it also shows how the CS pulls quite strongly in the top end, being ~0.7 seconds faster than the CP and only ~0.2 seconds short of the mighty water injected GTS. Which is in line with the conclusion reached in the OP when looking at the power charts .
__________________
Porsche 911 turbo 2021 992 GT Silver

Previous cars: M4cs 2019 F82 Limerock Grey / M4 2015 F82 Silverstone / M3 2008 E92 Silverstone / M3 2002 E46 Carbon Black

Last edited by CanAutM3; 03-25-2018 at 05:22 PM..
Appreciate 0
      11-05-2017, 03:56 PM   #22
Parabolica
Major
Canada
581
Rep
1,120
Posts

Drives: '18 M3 ZCP 6MT
Join Date: Nov 2016
Location: Toronto

iTrader: (0)

Are you trying to justify your soon to be purchased CS?

Would be nice to see the GTS also plotted on that graph.
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 03:37 AM.




f80post
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST