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
      07-25-2013, 04:21 PM   #23
e1000
that's what SHE said!
75
Rep
1,163
Posts

Drives: 2011 E92 M3 ZCP
Join Date: Jun 2010
Location: OC

iTrader: (1)

Quote:
Originally Posted by ChrisK View Post
Dang-it you beat me toooo it!
Nice car!
__________________
Appreciate 0
      07-25-2013, 04:25 PM   #24
1sckride
Enlisted Member
14
Rep
33
Posts

Drives: 2005 ZHP
Join Date: Oct 2011
Location: Westchest, NY

iTrader: (0)

Quote:
Originally Posted by swamp2 View Post
I'm a recovering physicist and recovering engineer. Now I sell engineering software.

I dunno...sounds like you had a career in the NSA
Appreciate 0
      07-25-2013, 04:33 PM   #25
hellrotm
Banned
4143
Rep
6,924
Posts

Drives: F80
Join Date: Jul 2007
Location: ...Location...Location

iTrader: (0)

Quote:
Originally Posted by positiveions View Post
I want to say ,realistically, it's more like 7500 rpm.
Yup, 7700 tops. 8,000 or above I would be pleasantly surprise, to say the least.
Appreciate 0
      07-25-2013, 04:34 PM   #26
PabloK
Lieutenant Colonel
PabloK's Avatar
United_States
615
Rep
1,805
Posts

Drives: F30
Join Date: May 2013
Location: Orono

iTrader: (1)

Quote:
Originally Posted by neo871 View Post
This is impressive! What do you actually do for a living?
Currently unemployed, but I did stay at Holiday Inn last night.


Edit: haha I just saw somebody else said this..

__________________
2014 F30 335i / 2014 F31 328d / 2014 F22 m235i
2019 G05 5.0 / 2012 E70 X5 50i / 2007 X5 3.0is
2011 e93 M3 / 2009 E60 M5 / 2004 E46 M3
2017 Alpina B6
22 Ram Trx / 22 M5 CS
Appreciate 0
      07-25-2013, 04:41 PM   #27
Ashley Schaeffer BMW
Banned
91
Rep
833
Posts

Drives: E92 M3
Join Date: Dec 2012
Location: Charlotte

iTrader: (1)

Impressive OP!

Some of you fail hard at reading comprehension however. No 8k redline ppl.
Appreciate 0
      07-25-2013, 04:46 PM   #28
Red Bread
Major General
United_States
4458
Rep
9,160
Posts

Drives: Smog machines
Join Date: Oct 2008
Location: Austin, TX

iTrader: (0)

I've always wondered how much integrity there is in redline display? Since BMW fudges (for legal reasons) the speedo, are the tachs honest? I know dynos report the honest number, but are they always directly correlated to the indicated tachometer? Could BMW just say the F8x redlines at 7700 rpm, paint the redline there and have the engine only turn over 7400 rpm at that point, or would the moon just instantly collide with the earth, kill all mankind and doom us all?
Appreciate 0
      07-25-2013, 04:48 PM   #29
swamp2
Lieutenant General
swamp2's Avatar
United_States
643
Rep
10,404
Posts

Drives: E92 M3
Join Date: Sep 2006
Location: San Diego, CA USA

iTrader: (3)

Quote:
Originally Posted by kyleb350 View Post
I'm no expert in this field, but aren't there still a number of unknowns you'd need to know before making these calculations? I see you make an estimate on speed, but wouldn't gearing and exhaust acoustics also come into play? Also, it's probably a safe assumption, but still an assumption that the car is shifting at redline.

Excellent analysis though.
Thanks, gearing and exhaust acoustics absolutely affect the overall spectrum of sound (how much power/peaks occur at which frequencies). There is also a boat load of broadband wind and tire noise in the spectrum. However, you should generally have a prominent peak based on the sound directly from each piston firing and for that gearing and exhaust are not really relevant.
__________________
E92 M3 | Space Gray on Fox Red | M-DCT | CF Roof | RAC RG63 Wheels | Brembo 380mm BBK |
| Vorsteiner Ti Exhaust | Matte Black Grilles/Side Gills/Rear Emblem/Mirrors |
| Alekshop Back up Camera | GP Thunders | BMW Aluminum Pedals | Elite Angels |
| XPEL Full Front Wrap | Hardwired V1 | Interior Xenon Light Kit |
Appreciate 0
      07-25-2013, 04:59 PM   #30
swamp2
Lieutenant General
swamp2's Avatar
United_States
643
Rep
10,404
Posts

Drives: E92 M3
Join Date: Sep 2006
Location: San Diego, CA USA

iTrader: (3)

Quote:
Originally Posted by solstice View Post
Nice!

Here's a pretty clean audio of the only production I6 turbo M car, it's in cabin but it would be interresting to see what top rpm the SW spits out.

4:24 and 4:28 for example seems like possible redline shifts.
( if you watch the whole thing you will also see two M3s showing who the daddy is )
Thanks. Although it is quick to do I don't want to analyze video after video. Anyone can do this with a plethora of free audio tools on any OS. A quick analysis of this one though around 4:24 indicated a much lower peak rpm than the 7000 rpm redline. The method is absolutely not 100% robust for all recordings but the baseline cases of the dyno runs completely convinced me that it can work. I suspect one reason here is simply the fact of internal vs. external audio. It's no doubt the design of passenger vehicles is to drown out a significant portion of engine and exhaust noise.
__________________
E92 M3 | Space Gray on Fox Red | M-DCT | CF Roof | RAC RG63 Wheels | Brembo 380mm BBK |
| Vorsteiner Ti Exhaust | Matte Black Grilles/Side Gills/Rear Emblem/Mirrors |
| Alekshop Back up Camera | GP Thunders | BMW Aluminum Pedals | Elite Angels |
| XPEL Full Front Wrap | Hardwired V1 | Interior Xenon Light Kit |
Appreciate 0
      07-25-2013, 05:02 PM   #31
Never Convicted
Lieutenant Colonel
United_States
1108
Rep
1,497
Posts

Drives: M4
Join Date: Dec 2012
Location: Charlotte NC

iTrader: (0)

Quote:
Originally Posted by Red Bread View Post
I've always wondered how much integrity there is in redline display? Since BMW fudges (for legal reasons) the speedo, are the tachs honest? I know dynos report the honest number, but are they always directly correlated to the indicated tachometer? Could BMW just say the F8x redlines at 7700 rpm, paint the redline there and have the engine only turn over 7400 rpm at that point, or would the moon just instantly collide with the earth, kill all mankind and doom us all?
My God, I hope not. At least til the end of my lease.
Appreciate 0
      07-25-2013, 05:06 PM   #32
ramuman
Private First Class
14
Rep
164
Posts

Drives: -
Join Date: Mar 2012
Location: USA

iTrader: (0)

Quote:
Originally Posted by positiveions View Post
I want to say ,realistically, it's more like 7500 rpm.
swamp does the analysis, the head of BMW M says it'll be close to 8k, yet your gut feeling is the realistic one?
Appreciate 0
      07-25-2013, 05:09 PM   #33
M3_WC
Brigadier General
1048
Rep
3,622
Posts

Drives: M3
Join Date: Jun 2009
Location: CA

iTrader: (0)

7,700 is worlds apart from 8,300.
Appreciate 0
      07-25-2013, 05:13 PM   #34
bimmerjph
Colonel
bimmerjph's Avatar
United_States
123
Rep
2,024
Posts

Drives: 2005 Z4 3.0
Join Date: Oct 2011
Location: Tennessee

iTrader: (0)

Quote:
Originally Posted by Red Bread View Post
Could BMW just say the F8x redlines at 7700 rpm, paint the redline there and have the engine only turn over 7400 rpm at that point, or would the moon just instantly collide with the earth, kill all mankind and doom us all?
It would certainly seem like it on this forum if they did that.
Appreciate 0
      07-25-2013, 05:33 PM   #35
aajami
Brigadier General
aajami's Avatar
United_States
436
Rep
4,567
Posts

Drives: Space Gray '09 E92 M3
Join Date: Dec 2008
Location: Manhattan Beach, CA

iTrader: (4)

Quote:
Originally Posted by M3_WC View Post
7,700 is worlds apart from 8,300.
Agreed. RPMs become like the Richter scale at some point -- every 100RPMs above 7,500 is an exponential increase over the previous.

*This is all figuratively speaking, mind you.
__________________
'09 E92 M3: Space Gray, Black, Carbon Leather | ZTP 2MK ZPP 2MT 6FL | link 1 / link 2
Mods: M Performance exhaust | ZCP retrofit | Euro airbox | GTS DCT flash | JPN 240 ECU flash | Euro LCI taillights | CRT lip | OEM alarm retrofit | Space Gray bumper plugs | BMW Performance: Mk. II spoiler / Mk. II non-electronic steering wheel / mirror caps / front grilles / side gills / intake louvers / emblem
Appreciate 0
      07-25-2013, 05:35 PM   #36
Boss330
Major General
Boss330's Avatar
No_Country
1742
Rep
5,110
Posts

Drives: BMW
Join Date: Mar 2012
Location: Earth

iTrader: (0)

Quote:
Originally Posted by M3_WC View Post
7,700 is worlds apart from 8,300.
No, it's only 600rpm apart... Or 7,8%

Hardly worlds apart...

The E30 M3 S14 engine had a rev limit of 7300rpm

The E36 M3 S50 engine had a rev limit of 7200rpm

The E46 M3 S54 engine had a rev limit of 8000rpm

The E9x M3 S65 engine has a rev limit of 8300rpm

Never heard much complaint about low rev limit on the prevoius straight engine M3's before...
Appreciate 0
      07-25-2013, 05:45 PM   #37
sparkyg
Brigadier General
sparkyg's Avatar
154
Rep
3,522
Posts

Drives: A6 Allroad
Join Date: Sep 2007
Location: Oil Country

iTrader: (5)

Quote:
Originally Posted by swamp2 View Post
Thanks. I wanted to do some more work using actual track clips but did not have the chance. If you can suggest a good, clear redline occurrence for the F10 M5 I would be happy to repeat the analysis. It very quick to do actually, the software does everything.
Swamp2 I dont always agree with everything you write but your technical skills are pretty fckg impressive.

Really nice work.
Appreciate 0
      07-25-2013, 05:46 PM   #38
Boss330
Major General
Boss330's Avatar
No_Country
1742
Rep
5,110
Posts

Drives: BMW
Join Date: Mar 2012
Location: Earth

iTrader: (0)

Quote:
Originally Posted by aajami View Post
Agreed. RPMs become like the Richter scale at some point -- every 100RPMs above 7,500 is an exponential increase over the previous.

*This is all figuratively speaking, mind you.
There's not a MAJOR difference between the sound at 7500rpm and 8000rpm on this S54 on the dyno:



Yes, the pitch (frequency) is higher. But it's not like it's the sound of two different engines... IMHO

You would need to be an "expert" to be able to distinguish between the sound this V8 makes at 7500rpm and 8000rpm... (33Hz difference)


Last edited by Boss330; 07-25-2013 at 06:38 PM..
Appreciate 0
      07-25-2013, 06:09 PM   #39
M3_WC
Brigadier General
1048
Rep
3,622
Posts

Drives: M3
Join Date: Jun 2009
Location: CA

iTrader: (0)

Quote:
Originally Posted by Boss330 View Post
No, it's only 600rpm apart... Or 7,8%
Ok if you say so.
Appreciate 0
      07-25-2013, 06:13 PM   #40
RMB
Captain
RMB's Avatar
232
Rep
676
Posts

Drives: 2025 BMW M2 pending
Join Date: May 2012
Location: Virginia

iTrader: (0)

Garage List
Dude, all of the analysis stuff makes my head hurt!
Appreciate 0
      07-25-2013, 06:25 PM   #41
FogCityM3
Colonel
FogCityM3's Avatar
507
Rep
2,397
Posts

Drives: M3 (E90) & Porsche GT3 RS
Join Date: Feb 2012
Location: San Francisco

iTrader: (0)

Wow..incredible! only on M3 board could you get such innovative thinking and quality content!
Appreciate 0
      07-25-2013, 06:28 PM   #42
Boss330
Major General
Boss330's Avatar
No_Country
1742
Rep
5,110
Posts

Drives: BMW
Join Date: Mar 2012
Location: Earth

iTrader: (0)

Quote:
Originally Posted by M3_WC View Post
Ok if you say so.
It's a frequency difference of 30HZ (on a 6cyl engine)... Yes, you can tell, but it's not worlds apart
Appreciate 0
      07-25-2013, 06:33 PM   #43
Boss330
Major General
Boss330's Avatar
No_Country
1742
Rep
5,110
Posts

Drives: BMW
Join Date: Mar 2012
Location: Earth

iTrader: (0)

Quote:
Originally Posted by aajami View Post
Agreed. RPMs become like the Richter scale at some point -- every 100RPMs above 7,500 is an exponential increase over the previous.

*This is all figuratively speaking, mind you.
According to Columbia University of New York, it's actually the other way around...

Quote:
The difference to our ears between 101 Hz and 100 Hz is much greater than the difference between 1,001 Hz and 1,000 Hz. We don’t hear a change of 1 Hz for each; instead we hear a change of 1,001/1,000 (= 1.001) as compared to a much bigger change of 101/100 (= 1.01).
Change in lower frequencies are much more noticeable than changes higher up (surprised me, but makes sense when you think about it).

http://music.columbia.edu/cmc/musica...ter1/01_03.php
Appreciate 0
      07-25-2013, 06:46 PM   #44
aajami
Brigadier General
aajami's Avatar
United_States
436
Rep
4,567
Posts

Drives: Space Gray '09 E92 M3
Join Date: Dec 2008
Location: Manhattan Beach, CA

iTrader: (4)

Quote:
Originally Posted by Boss330 View Post
According to Columbia University of New York, it's actually the other way around...



Change in lower frequencies are much more noticeable than changes higher up (surprised me, but makes sense when you think about it).

http://music.columbia.edu/cmc/musica...ter1/01_03.php
Hi Boss330,

I appreciate the thoughtful feedback! It's certainly interesting to see the science behind it.

Per my original disclaimer, though, I was referring simply to the emotion of driving a high-revving engine vs. driving one with a lower redline. Or put another way, when I had my S2000, there was a world of difference between how the car felt and sounded (and how both made me feel) when I would hold the RPMs at 7,000 vs. when I'd hold them 8,000 and at 8,900. The same goes for the M3: 7K RPM feels a certain way -- and 8,000 feels like something else altogether.

Source: My unscientific brain.
__________________
'09 E92 M3: Space Gray, Black, Carbon Leather | ZTP 2MK ZPP 2MT 6FL | link 1 / link 2
Mods: M Performance exhaust | ZCP retrofit | Euro airbox | GTS DCT flash | JPN 240 ECU flash | Euro LCI taillights | CRT lip | OEM alarm retrofit | Space Gray bumper plugs | BMW Performance: Mk. II spoiler / Mk. II non-electronic steering wheel / mirror caps / front grilles / side gills / intake louvers / emblem
Appreciate 0
Post Reply

Bookmarks

Tags
2014 bmw m3, 2014 m3, 2014 m3 forum, 2015 bmw m3, 2015 bmw m4, 2015 m3, 2015 m4, bmw f80, bmw f80 forum, bmw f80 forums, bmw f80 m3, bmw f80 m3 sedan, bmw f82, bmw f82 forum, bmw f82 forums, bmw f82 m3, bmw f82 m3 coupe, bmw f82 m3 forum, bmw f82 m4, bmw f82 m4 coupe, bmw f83, bmw f83 m3, bmw f83 m4, bmw m forum, bmw m forums, bmw m4, bmw m4 coupe, bmw m4 coupe forum, bmw m4 forum, bmw m4 forums, f80, f80 forum, f80 forums, f80 m3, f80 m3 forum, f80 m3 forums, f80 m3 sedan, f82, f82 coupe, f82 forum, f82 forums, f82 m3, f82 m3 coupe, f82 m3 forum, f82 m4, f82 m4 coupe, f82 m4 forum, f82 m4 forums, f83 m3, f83 m4, m forum, m forums, m3 f80, m3 f80 forum, m3 f80 forums, m4 forum, m4 forums

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 07:48 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