Got the m3 dyno'd on her 7th birthday

Matt82 said:
sounds like youll believe anything

you left a happy customer, thats what really matters
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sounds like you are trying to start an argument, your behaviour is definately as such, read what i am saying

i was one of 15 or so people that had their car done as part of a meet, the results overall made sense, ive no reason to believe anything was untoward with mine

but you werent there and you do:confused:
 
David _b said:
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



:)
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yeah i know some dynos can be manipulated by varying the throttle inputs, by all accounts the dyno dynamics one cannot be manipulated in this way

same system as used by simpsons

http://www.simpsonmotorsport.co.uk/default.asp?id=154&pid=69&name=Rolling Road&page=Services
 
makes perfect sense to reset the ecu. The long term ignition trims will be slighty retarded if you have ran on crap fuel in the past. Although e5 fuel should allow more ignition advance, it may have affected the full throttle fuelling correction based on the closed loop fuel trim.

Fwiw a lot of s2000 owners reset the ecu from time to time. Gets rid of the effects of a crap tank of fuel etc.

Of course this could all be irrelevant if it was actually heatsoak, the first run is often low as the car sits there cooking before the run and the inlet temp sensor will tell the ecu to back out the timing, the second run often gives a better figure as the first run will actually cool the temp sensor down.
This happened on my s2000, went from 212 to 249 on back to back runs.
 
Cyrus said:
sounds like you are trying to start an argument, your behaviour is definately as such, read what i am saying

i was one of 15 or so people that had their car done as part of a meet, the results overall made sense, ive no reason to believe anything was untoward with mine

but you werent there and you do:confused:
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no, not starting an arguement, i was gauging whether you understood the huge number of variables involved in a rolling road. the main one being, it measures the torque at the wheels, estimates the engine rpm, then estaimtes the tranny losses and then comes up with a calculation for the estimated flywheel power.

i highly doubt a bmw ecu defaults back to the peak timing settings due to safety and the number of people who will be running it solely on low octant stuff.

i think your figure was low and they altered the dyno calculations to give you a happier figure

things like ambient temperatures, tyre pressures, the number of runs done on the dyno that day will will all effect the figures

rolling roads are not a tool to measure engine output, i will put money on yours not being close to the figure they said
 
Tim said:
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I wouldn't expect any 7 year old car to lose power.
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Unless you treat it like some of the guys from work. I'm amazed at the number of people I see ragging the cars out of the carpark from cold... and some of them are pretty nice cars too.
 
Matt82 said:
no, not starting an arguement, i was gauging whether you understood the huge number of variables involved in a rolling road. the main one being, it measures the torque at the wheels, estimates the engine rpm, then estaimtes the tranny losses and then comes up with a calculation for the estimated flywheel power.

i highly doubt a bmw ecu defaults back to the peak timing settings due to safety and the number of people who will be running it solely on low octant stuff.

i think your figure was low and they altered the dyno calculations to give you a happier figure

things like ambient temperatures, tyre pressures, the number of runs done on the dyno that day will will all effect the figures

rolling roads are not a tool to measure engine output, i will put money on yours not being close to the figure they said
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jesus you arent reading anything ive said, there were m3s that made circa 300bhp on the day, he didnt alter anything to give me a happier figure, i didnt ask him to,

looking at the printout he felt it was an issue with the ecu running the car too rich due to the change in fuel and he reckoned a reset would fix that, which it seemed to, the next m3 on the rollers made 340 and the one after made 305.

how can you put money on mine not being close to the figure they said? how can you prove otherwise, you dont believe in rolling roads, fine, got a better way of measuring bhp without removing the engine?
 
agw_01 said:
Unless you treat it like some of the guys from work. I'm amazed at the number of people I see ragging the cars out of the carpark from cold... and some of them are pretty nice cars too.
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heh yeah. I mean obviously i'm aware that cars lose power over time, but not 7 years?

We dyno'd mine (W reg) recently at 187hp, it's bang on what it should be. None of my cars have lost a significant amount of power.

Jonnycoupe said:
Does the number of miles/hours run not matter then?
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yea I suppose I was just assuming it'd done average miles.
 
agw_01 said:
Unless you treat it like some of the guys from work. I'm amazed at the number of people I see ragging the cars out of the carpark from cold... and some of them are pretty nice cars too.
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Chocolate factories must be like that, junctions in front of every Cadburry's spot is black with rubber.

Conclusion Umpalumpas drive like loons.
 
agw_01 said:
Unless you treat it like some of the guys from work. I'm amazed at the number of people I see ragging the cars out of the carpark from cold... and some of them are pretty nice cars too.
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But if they're short term leases or company cars you do tend to drive them like you stole them.
 
[TW]Fox;13186189 said:
Why would it lose power over time? Does this mean that after X years it will have 0bhp and simply stop moving?
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Pardon?

Well wear effecting engine tolerances, particularly piston sealing and hence compression in the cylinder and cam wear reducing the valve lift, gumming up of inlet tracts can appear quite soon on engines with cheaper materials, poor tolerance control at the factory when assembling them. M3's and Civic Type R wont have these issues as early or even in the life of the chassis but then thats part and parcel of anything making 100bhp/litre NA.

I was simply refering to years is not an indicator 7 years with 30k or 3 years of 100k? come on Fox :p but then nor really is miles. Exactly why aircraft service and maintainance are based on hours operated rather than the rather random car mileage.

I dont see the point of what you posted when you dont much about engines.
 
My point is that if my car had not lost power when I had it dyno'd at 5 years and 150,000 miles I cannot see why another car with lower mileage would have :confused:
 
[TW]Fox;13186437 said:
My point is that if my car had not lost power when I had it dyno'd at 5 years and 150,000 miles I cannot see why another car with lower mileage would have :confused:
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It could have had a worse service history, nailed from cold, redlined through every gear.
 
[TW]Fox;13186437 said:
My point is that if my car had not lost power when I had it dyno'd at 5 years and 150,000 miles I cannot see why another car with lower mileage would have :confused:
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Are you assuming that

a) engine dynos are accurate to the point you are using in your comparison
b) your engine is built the same way as the 3.2 M3 unit?

Maybe a car with more cold starts than your MPG experiment jaunts would actually have more wear. Like i said, miles isnt the total storey of engine use, particularly on 30k a year, sat on a motorway doing next to nothing with a very low ratio of cold ran miles to operating miles.
 
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