Got the m3 dyno'd on her 7th birthday

Cyrus

Cyrus

Cyrus

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my 02 reg m3 was manufactured in dec 01 so i thought now would be a good time to see how many of the claimed 343 horsies were still being produced.

i arrived hopeful as the car has been well cared for, however the first couple of runs dismayed me, the car was making about 312bhp :eek: talked to the guys at couture and they asked me had i changed fuel recently, which i had, last two fill ups were higher octane maxol e5, they decided that a quick reset of the ecu should set me right.

so they cleared the ecu, gave a couple of power runs to get the car used to the fuel and then dyno'd again, here are the results :)

pretty happy with them, torque looks high, but the e46 on after me made the same and they reckon the e46s make more than claimed on torque normally. car has just hit 54k

5os208.jpg
 
You cant relate dyno results to manufacturer results. Done under different conditions, the engine isnt dyno'd in the car by BMW etc. The only thing a dyno is good for is fault finding and checking your torque curves etc..
 
Looks like some good results - I wouldn't of been too dismayed with your original results either - remembering that RR figures are a good indication and nothing more.
I thought the standard E46 made around 270ft/lbs?
 
So is that E5 stuff super unleaded? I noticed over in Ireland they don't seem to sell super at most service stations.
 
strange that a car makes a lot more than stock torque, given that the E46 M3's are renowned for producing lower than stock figures.

I would think that someone adjusted something to massage the figures. most make 320-330bhp iirc.
 
uoc said:
You cant relate dyno results to manufacturer results. Done under different conditions, the engine isnt dyno'd in the car by BMW etc. The only thing a dyno is good for is fault finding and checking your torque curves etc..
Click to expand...

Exactly, although it is also useful to use a dyno if you race in a spec series and the other teams use the same dyno as a comparism.

Otherwise you might as well save the money and pull out a random figure rather than put a single car on a dyno really.
 
I would say there playing with you to make you happy.

Generally....once the ecu is reset it takes time to relearn its self.
This is lifted off another forum i frequent.

Originally Posted by tmarshal
Was talking to a mate of mine, ex Lotus engineer and currently working for Ford as an engineer mainly on new development diesels...

He reckons the ecu would learn only on part load, not on full load... and that the full load map would be adjusted from that.
correct

Quote:
Originally Posted by tmarshal
I was interested because I was under the impression the advice is to reset the ECU and then boot it as hard as possible.....

or is it better to take it for an hour's 70~80 mph tootle?

and how long does it take the ecu to "learn"? I believe some systems can learn incredibly quickly.
I would imagine it works the same way most EMS "optimise" themselves and thats by trial and error.

The stock ecu will advance ignition as much as posible within pre programmed parameters whilst trying to maintain other parameters such as knock within theirs (closed loop monitoring). The same with injector duty at low revs whilst monitoring return signals from the lamda probe etc to etsablish a reasonable fuelling map.

lamda readings etc are ignored under hard load but if the hardware sertup is correctly then it should be roughly right but due to saftey constraints tends to run rich at the top end

So to answer your questions both your suggestions are not really ideal, the best way is to run the car round town in mixed driving speeds so it gets a reasonable set of parameters established across the rev and load range before giving it a big long prod

Oh yes and they are always learning / refining the map its just better sometimes to wipe its prelearned info and start again when you change things like fuel ratings air filters, plugs etc

This wee graph shows it trying to track down a good map over a few runs.
The black is the base run before reset, red first run after reset, green the second run after a reset. Notice how it is slowly narrowing down to something more sensible as it slowly learns
attachment.php


full thread here http://www.skylineowners.com/forum/showthread.php?t=34795
 
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lads if you think its crap fine but there were 5 or 6 e46 m3s done that day, one made 300bhp, one made 320 and the rest all made 335-345,

the reason he offered to reset the ecu was because my power curve went 'funny' at the top end, indicating to him it was running rich as i had changed to higher octane fuel.

in the end he was proved right, there was no massaging my ego, it was a RR day the irish bmw owners had organised, and overall the results made sense (12-15 cars dyno'd) 330d made 177bhp, e36 m3 non evo made 270bhp, supercharged e46m3 'only' made 395bhp (issue with the supercharger somewhere going back to simpsons)

the rolling road used was a dyno dynamics one aswell btw
 
Just commenting...Nothing serious fella :)

Lifting off at certain points on rolling road or planting it more here and there does allow for different than true figures. Another way is to alter the setting for the temperature

HOW MUCH CAN AIR TEMP EFFECT PERFORMANCE YOU ASK???


From the table below, you will note that air at 0C contains almost 30% more oxygen per given volume, than air at 77C.

Air Temperature
Air Density
% increase of oxygen

77C
0.9950 kg/m^3

40C
1.113 kg/m^3
+ 12% oxygen

27C
1.1614 kg/m^3
+ 17% oxygen

0C
1.2763 kg/m^3
+ 28% oxygen


So if your car is tuned for say 12.0:1 fuel mixture (rich) for maximum power and the air going into your engine is at 77C, you might make say 241bhp @ wheels. Now if you could get that intake air down to 0C and still have your engine tuned at 12.0:1 fuel mixture, you will make 30% more power based simply on oxygen levels in the air = 241bhp @ wheels x 1.3 = 314bhp @ wheels. That’s a massive 73bhp increase!!! Now obviously, unless your using dry ice somewhere along your intake path, you won’t get the air to 0C, but that is just to give you an indication of the true effects of air temps and their relation to power output.

:)
 
UltimateBadger said:
Looks like some good results - I wouldn't of been too dismayed with your original results either - remembering that RR figures are a good indication and nothing more.
I thought the standard E46 made around 270ft/lbs?
Click to expand...

yep thats right, i asked him about it after as a few of the e46 m3s that made over 340bhp all were around 290 on the torque, in his experience he found most tended to go over quoted as the engines loosened up ?

OllyM said:
So is that E5 stuff super unleaded? I noticed over in Ireland they don't seem to sell super at most service stations.
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yep its unleaded with 5% ethanol, typically 97-98 ron, as good as it gets over here

Matt82 said:
dynos are a joke

wasnt the car 343ps anyway?
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no 348 ps, it was obviously a nice coincidence the final run made 343, it was the only one to do so

obviously had i got the car dyno'd on my one id be a little more paranoid but as i had 4-5 others to compare to made me happier,

maybe the results were a little up? But im happy with the nice flat torque curve in any event and its a good indication the she runs well

and the car felt a lot quicker on the way home :)
 
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