BMW M3 Forum (E90 E92)

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


Go Back   M3Post - BMW M3 Forum > E90/E92 M3 Technical Topics > Engine, Transmission, Exhaust, Drivetrain, ECU Software Modifications
 
GT Haus
Post Reply
 
Thread Tools Search this Thread
      04-02-2012, 02:39 PM   #1
aka_phox
Captain
 
aka_phox's Avatar
 
Drives: 2011 M3 Convertilble
Join Date: Jun 2010
Location: Italy

Posts: 606
iTrader: (0)

ASSISTANCE with reading Dyno my results (european)...

Im in Italy and i took my car to get dyno'd today. I had a very difficult time understanding this guy, he spoke italian, but i figured that the print out could explain itself...
I did understand that there was problem with there machine reading the torque/rpm #, but he said that the power output is accurate.

could someone dumb this down for me?


thanks

Attached Images
 
__________________

'11.5 SG E93/6MT/ALL BOXES CHECKED
BLACK GRILL/BLACK SIDE GILLS/15% TINT/PAINTED REFLECTORS/SPACERS/ANGEL iBRIGHTS/20'' VOSSEN CV3/VINYL WRAPPED SHADOW LINE TRIM/ETS-POWER TUNE/
///M-FLIGHT MEMBER

Last edited by aka_phox; 04-02-2012 at 05:08 PM.
aka_phox is offline  
0
Reply With Quote
      04-02-2012, 05:55 PM   #2
meyergru
No military grade
 
meyergru's Avatar
 
Drives: E92 M3 DCT
Join Date: Aug 2007
Location: Munich, Germany

Posts: 542
iTrader: (0)

OMG. I have never attended a dyno run but even I can tell that there were at least two things that went wrong:

1. The torque figures are obviously wrong since the RPM was miscalculated as you can see from the slip.
2. The power figures are meaningless because shortly before max RPM was reached, power was reduced because of overheating.

You can see this at 1:39 in the video. The coolant sign came on and max RPM was reduced to ~7000 by the safety cutoff. During this run, maximum power was never reached.

Did the guy miss to install the neccessary air duct for cooling? I can only see the open hood.

Get your money back. That dyno run did nothing but put stress on your engine.
__________________
meyergru is offline   Germany
0
Reply With Quote
      04-02-2012, 06:43 PM   #3
M3PO
Colonel
 
M3PO's Avatar
 
Drives: '08 IB E92
Join Date: Sep 2011
Location: OC

Posts: 2,635
iTrader: (6)

Looks like you made 364 WHP. But that plot doesn't make sense. IIRC, the torque and HP curves should cross at 5250 RPM. Yours don't cross at all.
M3PO is offline  
0
Reply With Quote
      04-02-2012, 07:02 PM   #4
italyix
Lieutenant
 
italyix's Avatar
 
Drives: '08 E90 M3
Join Date: Dec 2011
Location: Bay Area

Posts: 464
iTrader: (1)

I translated it for you:
Nominal power - 302kw
Engine power at crank - 271.5kw
Engine power at wheels - 224.5kw
Engine power lost to friction - 47 kw

Hope this helps.
italyix is offline   United_States
0
Reply With Quote
      04-02-2012, 07:33 PM   #5
aka_phox
Captain
 
aka_phox's Avatar
 
Drives: 2011 M3 Convertilble
Join Date: Jun 2010
Location: Italy

Posts: 606
iTrader: (0)

Quote:
Originally Posted by meyergru View Post
OMG. I have never attended a dyno run but even I can tell that there were at least two things that went wrong:

1. The torque figures are obviously wrong since the RPM was miscalculated as you can see from the slip.
2. The power figures are meaningless because shortly before max RPM was reached, power was reduced because of overheating.

You can see this at 1:39 in the video. The coolant sign came on and max RPM was reduced to ~7000 by the safety cutoff. During this run, maximum power was never reached.

Did the guy miss to install the neccessary air duct for cooling? I can only see the open hood.

Get your money back. That dyno run did nothing but put stress on your engine.
I saw this, but i figured it was normal, but then again, i never saw this happen on other youTube vids of other folks run. This was the 2nd of two runs we did and this happend both times with the coolant sign.
He had the hood raised and the floor fan turned on and nothing more. Was there suppose to be something else for cooling?
One thing that raised my attention was these numbers. It looks like the most the car is capable is 364hp. Even tho we did not reach maximum power, 364 is still WAY OFF from 414-420ph which is advertised on a stock M3 correct? My car has been tuned, which is telling me that at stock, my car produced even less than advertised....right?
I highly doubt getting the money back is possible at this point...This was a mere learning experience if anything for me. But now i kinda understand more with talking with you guys here on the post, and doing further research.



Quote:
Originally Posted by M3PO View Post
Looks like you made 364 WHP. But that plot doesn't make sense. IIRC, the torque and HP curves should cross at 5250 RPM. Yours don't cross at all.
I remember him trying to explain to me that because of my newer model M3 (2011), his machine wouldnt calculate the RPM correctly and the torque. I dont know why. This was my first dyno experience so i would know right from wrong.
I did take note on how it was hooked up tho...the only cables that was hooked up where a positive and negative terminal under the hood. I questioned that and he explained that the machine somehow reads the thru the battery of the car??? I was like..."ok"
I imagined something would be hooked to the OBDII link or something...

Quote:
Originally Posted by italyix View Post
I translated it for you:
Nominal power - 302kw = 405hp
Engine power at crank - 271.5kw = 364hp
Engine power at wheels - 224.5kw = 301hp
Engine power lost to friction - 47 kw = 63hp
Hope this helps.
thanks man. that helps
__________________

'11.5 SG E93/6MT/ALL BOXES CHECKED
BLACK GRILL/BLACK SIDE GILLS/15% TINT/PAINTED REFLECTORS/SPACERS/ANGEL iBRIGHTS/20'' VOSSEN CV3/VINYL WRAPPED SHADOW LINE TRIM/ETS-POWER TUNE/
///M-FLIGHT MEMBER
aka_phox is offline  
0
Reply With Quote
      04-02-2012, 11:56 PM   #6
M3PO
Colonel
 
M3PO's Avatar
 
Drives: '08 IB E92
Join Date: Sep 2011
Location: OC

Posts: 2,635
iTrader: (6)

I would take these numbers with a grain of salt. There's just too many issues with this dyno session. Why is the dash lit up like a Christmas tree? Why'd it over heat? What gear was he in? The RPM issue. Etc.

I was wrong. Your car only made 300 WHP which is 364 BHP (roughly). He didn't quite make it to peak power but it shouldn't be ~60 WHP low.
M3PO is offline  
0
Reply With Quote
      04-03-2012, 01:05 AM   #7
meyergru
No military grade
 
meyergru's Avatar
 
Drives: E92 M3 DCT
Join Date: Aug 2007
Location: Munich, Germany

Posts: 542
iTrader: (0)

Quote:
Originally Posted by aka_phox View Post
I saw this, but i figured it was normal, but then again, i never saw this happen on other youTube vids of other folks run. This was the 2nd of two runs we did and this happend both times with the coolant sign.
He had the hood raised and the floor fan turned on and nothing more. Was there suppose to be something else for cooling?
Yes, see here - and I've even seen larger cooling systems. Preferably, they provide air from the outside. Many tuners' dynos are rubbish.

Cooling is the critical factor for measuring a car's power. You would have to reach an airflow of about 120mph in order to simulate the car operating on the street. With our M3, the air intake is through the vent on driver side of the hood which normally separates the hot engine bay from the cold outside air. With the hood open an inadequate cooling, the engine sucks in hot air from the engine bay, much like with so-called "cold" air intakes. It would be better to use an air duct for the intake with a stationary car (like this).

Quote:
Originally Posted by aka_phox View Post
One thing that raised my attention was these numbers. It looks like the most the car is capable is 364hp. Even tho we did not reach maximum power, 364 is still WAY OFF from 414-420ph which is advertised on a stock M3 correct? My car has been tuned, which is telling me that at stock, my car produced even less than advertised....right?
I highly doubt getting the money back is possible at this point...This was a mere learning experience if anything for me. But now i kinda understand more with talking with you guys here on the post, and doing further research.
I meant "get your money back for the measurement", not neccessarily for the tune. As I said, the numbers were meaningless considering all that went wrong. All you can say is that probably your engine did <insert power number here> at 7500 RPM at which point it shut off.
__________________

Last edited by meyergru; 04-03-2012 at 03:14 AM.
meyergru is offline   Germany
0
Reply With Quote
      04-03-2012, 01:58 AM   #8
LenitaUllrich
New Member
 
Drives: aodi
Join Date: Apr 2012
Location: hot

Posts: 8
iTrader: (0)

There's just too many issues with this dyno session.
__________________
LenitaUllrich is offline  
0
Reply With Quote
      04-03-2012, 04:13 PM   #9
aka_phox
Captain
 
aka_phox's Avatar
 
Drives: 2011 M3 Convertilble
Join Date: Jun 2010
Location: Italy

Posts: 606
iTrader: (0)

Quote:
Originally Posted by M3PO View Post
I would take these numbers with a grain of salt. There's just too many issues with this dyno session. Why is the dash lit up like a Christmas tree? Why'd it over heat? What gear was he in? The RPM issue. Etc.

I was wrong. Your car only made 300 WHP which is 364 BHP (roughly). He didn't quite make it to peak power but it shouldn't be ~60 WHP low.
Quote:
Originally Posted by meyergru View Post
Yes, see here - and I've even seen larger cooling systems. Preferably, they provide air from the outside. Many tuners' dynos are rubbish.

Cooling is the critical factor for measuring a car's power. You would have to reach an airflow of about 120mph in order to simulate the car operating on the street. With our M3, the air intake is through the vent on driver side of the hood which normally separates the hot engine bay from the cold outside air. With the hood open an inadequate cooling, the engine sucks in hot air from the engine bay, much like with so-called "cold" air intakes. It would be better to use an air duct for the intake with a stationary car (like this).



I meant "get your money back for the measurement", not neccessarily for the tune. As I said, the numbers were meaningless considering all that went wrong. All you can say is that probably your engine did <insert power number here> at 7500 RPM at which point it shut off.

What should be the power output at 7500 RPM? This way i can kinda see how much it was off if any. Or could it be safe to say that it was accurate up until 7500 RPM?
__________________

'11.5 SG E93/6MT/ALL BOXES CHECKED
BLACK GRILL/BLACK SIDE GILLS/15% TINT/PAINTED REFLECTORS/SPACERS/ANGEL iBRIGHTS/20'' VOSSEN CV3/VINYL WRAPPED SHADOW LINE TRIM/ETS-POWER TUNE/
///M-FLIGHT MEMBER
aka_phox is offline  
0
Reply With Quote
      04-03-2012, 06:31 PM   #10
M3PO
Colonel
 
M3PO's Avatar
 
Drives: '08 IB E92
Join Date: Sep 2011
Location: OC

Posts: 2,635
iTrader: (6)

Quote:
Originally Posted by aka_phox View Post
What should be the power output at 7500 RPM? This way i can kinda see how much it was off if any. Or could it be safe to say that it was accurate up until 7500 RPM?
Do you have a speed limiter? It looks like he hit the speed limiter because the maximum speed was 250 km/hr which is 155 mph which is what the car is limited to. That may have been why it cut him off when he hit 7500 RPM.

Regardless, from looking at some other stock dyno plots, it looks like they make about 350 WHP at 7500 RPM. Power seems to pretty much level off in that area of the curve. So like I said before, he didn't quite make it to peak power but it should be much closer and not 50-60 WHP low. I don't know what the gearing of the DCT is but he may have used the wrong gear which could produce this discrepancy.

There's just too many unknowns here. NOTHING about this dyno session is correct from what I can tell. I'd have it done again and consider these results garbage.
M3PO is offline  
0
Reply With Quote
      04-03-2012, 07:05 PM   #11
aka_phox
Captain
 
aka_phox's Avatar
 
Drives: 2011 M3 Convertilble
Join Date: Jun 2010
Location: Italy

Posts: 606
iTrader: (0)

Quote:
Originally Posted by M3PO View Post
Do you have a speed limiter? It looks like he hit the speed limiter because the maximum speed was 250 km/hr which is 155 mph which is what the car is limited to. That may have been why it cut him off when he hit 7500 RPM.
Regardless, from looking at some other stock dyno plots, it looks like they make about 350 WHP at 7500 RPM. Power seems to pretty much level off in that area of the curve. So like I said before, he didn't quite make it to peak power but it should be much closer and not 50-60 WHP low. I don't know what the gearing of the DCT is but he may have used the wrong gear which could produce this discrepancy.

There's just too many unknowns here. NOTHING about this dyno session is correct from what I can tell. I'd have it done again and consider these results garbage.
It should not be limited...I had the speed limiter removed. But havent REALLY checked to see if it is or not. Is this how the car reacts when it hits the limiter 150mph/250kph?
__________________

'11.5 SG E93/6MT/ALL BOXES CHECKED
BLACK GRILL/BLACK SIDE GILLS/15% TINT/PAINTED REFLECTORS/SPACERS/ANGEL iBRIGHTS/20'' VOSSEN CV3/VINYL WRAPPED SHADOW LINE TRIM/ETS-POWER TUNE/
///M-FLIGHT MEMBER
aka_phox is offline  
0
Reply With Quote
      04-04-2012, 01:36 AM   #12
meyergru
No military grade
 
meyergru's Avatar
 
Drives: E92 M3 DCT
Join Date: Aug 2007
Location: Munich, Germany

Posts: 542
iTrader: (0)

Quote:
Originally Posted by aka_phox View Post
It should not be limited...I had the speed limiter removed. But havent REALLY checked to see if it is or not. Is this how the car reacts when it hits the limiter 150mph/250kph?
No. At 1:39 in the video, it can clearly be seen that the revs were limited exactly when the coolant warning lit up - just look at the outer ring of the rev counter. That was "limp mode", not Vmax limiting when gas is cut at a given wheel speed regardless of RPM.

Nearly all results from a dyno run (power, torque, gear losses) are calculated from the exerted force at the wheel and via known parameters like wheel diameter, gearing and so on. From the fact that torque was wrong, we can assume that gearing was miscalculated. Thus, losses are incorrect. The exact RPMs at which maximum power is reached can be anywhere between 7500 and 8600, especially with a tune, so you can tell almost nothing from this run apart from: "power at the wheels was no less than ..." and even that I believe only because it's an M3.
__________________
meyergru is offline   Germany
0
Reply With Quote
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
Forum Jump


All times are GMT -5. The time now is 02:34 PM.




m3post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
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