Dyno Mode

[R2D2]

Transmission losses??

When I had my M271 engined C Class I did lots of work on modding the M271 engine and concluded that transmission losses were 18%, however, this applied to the 5 speed auto gearbox only. Now I have a M272 engined car with the 7G autobox and my research suggests that the losses are still 18%. ie my 272bhp engine should produce 223bhp at the wheels.

Can anyone add any figures or experience to my findings? Cheers

 

[R2D2]

Hmm maybe found the answer here. Brabus say the M272 has 272 bhp or 200 RWHP and their 4 litre conversion offers 332bhp and 244rwhp ie 26.47% losses.

Edit this post is rubbish the 200 is not RWHP but KW Derrr!

 

[merc85]

transmission loses are only a gestimate, size of tyres, tyres pressures and other things will all have a effect on the end result of whp.

 

[John Jones Jr]

When I had my M271 engined C Class I did lots of work on modding the M271 engine and concluded that transmission losses were 18%, however, this applied to the 5 speed auto gearbox only. Now I have a M272 engined car with the 7G autobox and my research suggests that the losses are still 18%. ie my 272bhp engine should produce 223bhp at the wheels.

Can anyone add any figures or experience to my findings? Cheers

Can't really see why the transmission losses should be much different between a 5sp & a 7sp box - prop, diff, d/shafts & wheels still have to be powered.

Edit: 18% seems optimistic, I'd have guessed 25%.

 

[R2D2]

Can't really see why the transmission losses should be much different between a 5sp & a 7sp box - prop, diff, d/shafts & wheels still have to be powered.

Edit: 18% seems optimistic, I'd have guessed 25%.

Reading some of the US Forums; that 26% figure and 200bhp at the wheels maybe not too bad a guesstimate.

 

[Mike Walker]

I'm lost! Do I need to worry at all?

 

[R2D2]

I'm lost! Do I need to worry at all?

Don't worry bout a thing, coz everylittle thing , it gonna be alright

 

[R2D2]

Dyno Mode gives you access to hidden menus and of course the ability to temporarily turn of ESP, ABS, Brake Assist etc. Obviously this is to enable you to run Dyno Tests without the car's safety systems cutting in.

As this forum is able to be read by any one and we don't want every drifter and loon in the UK turning off his ESP and crashing into innocent people I wont publically post how to get into Dyno mode but for interest sake I though some folk might to see what it looks like.


The First Menu gives you a choice of Vehicle Data and Dyno mode

In Vehicle Data

Chassis number

Then these numbers which I don't know what they are!

Then Engine Data

Then back to the Dyno menu

Turn ESP etc off
Note all the warning lights come on!

and there you are in Dyno mode, no safety systems present. Hope this is of interest/use.

 

[R2D2]

A C350 Dyno run from the net.

So stock was 268bhp at the crank and 198.2 rwbp at the wheels ie 26% losses

They claimed after tuning 214.8bhp ie 290bhp after tuning.

The figure of 26% for the 7g gearbox seems about right then.

 

[whitenemesis]

Does the "Dyno mode" cancel automatically when one cycles the IGN?

 

[Rashman]

Does the "Dyno mode" cancel automatically when one cycles the IGN?

Yes, when you turn the car off and start it again, the systems will be back to normal.

 

[Ginger55k]

Yes, when you turn the car off and start it again, the systems will be back to normal.

I am not sure that's true, may be on the modern cars, i am sure on my 55 you have to re-set it to normal, although i may be wrong, all i will say is if you do put it in dyno mode double check its disabled again.

I like to see the ESP flashing as it shows what a great driver i am.......not, its keeping me out of a hedge/ditch/telegraph pole and so on.

 

[R2D2]

My w204 needs to be turned back on again. I'm not sure if it times out after 15 minutes or so though...

 

[mymini007]

Mine too, after my dyno run the other day, you have to go back into the menu and select off, to get it back to normal.

If you are able to use the google function on your laptop its easy enough to find out how to turn it on and off

 

[Mike Walker]

Transmission losses??

Don't worry bout a thing, coz everylittle thing , it gonna be alright

Phew! Cool man!

 

[Alps]

w211 you have to turn dyno mode off too, same on the r230 and the new SL

 

[Rashman]

I am not sure that's true, may be on the modern cars, i am sure on my 55 you have to re-set it to normal, although i may be wrong, all i will say is if you do put it in dyno mode double check its disabled again.

I like to see the ESP flashing as it shows what a great driver i am.......not, its keeping me out of a hedge/ditch/telegraph pole and so on.

Mine resets itself once I turn the car off.

I gave dyno mode a go a couple of years back.

Good fun.
Got home and though "crikey....how do I turn the madness off!?!"
But found that the car was back to normal when I restarted it.

 

[whitenemesis]

A Google search reveals cancelling the Dyno mode is different for different years/models..

The CLS55 resets after cycling the IGN..

 

[Neil Mackay]

Thank goodness my good old w203 resets it's self and has 18% trans loss

 

[M271]

informative thread