Is this a new DD Dyno feature?

[VYClubby]

I was browsing some dyno sheets on another forum and came across the one below. Is the rear wheel HP to flywheel HP shown on the sheet a new feature on a DD dyno?

http://i201.photobucket.com/albums/aa135/vyclubby/Conversion.jpg

[Phizzle]

It must be! Cool feature, however I believe it would be insignificant compared to the before and after 'bum dynos'!!! That is where the proof of the pudding lies :)

[Delft Maloo]

Fairly new.

[Oztrack Tuning]

Its just another calculated value.

[MickmeMate]

Yeah it should always be shown on a printout i think.

[VXSS346]

Its just another set of numbers to confuse everyone. :rolleyes:

Cheers :)

[Delft Maloo]

Its just another calculated value.

Steve every number is just a calculated value:).

Its actually a handy feature, most people talk about how much power there car has based off the badge so when it comes to having mods done a lot of people find it easier saying 'this car came from the factory with 225kw and now it has 310kw' and most non car people will have no idear about fwkw vs rwkw.

[Krizto]

I was told to work out rwkw from fwkw just maultiply by 0.25 and thats approx on the money, basically the drive train looses 25% of power or there about.

Handy to see in on Dyno read outs!

:goodjob:

[VYClubby]

Steve every number is just a calculated value:).

Its actually a handy feature, most people talk about how much power there car has based off the badge so when it comes to having mods done a lot of people find it easier saying 'this car came from the factory with 225kw and now it has 310kw' and most non car people will have no idear about fwkw vs rwkw.

I wonder how accurate the figure is though?

[Krizto]

I wonder how accurate the figure is though?

Can only be an estimate without going on a engine dyno

[vz6.0]

i call bullplop.

Can a smarterer person please explain how this is actually derived?

Smacks of marketing brilliance rather than anything that remotely resembles accuracy, about all its going to good for is measuring rotational inertia under zero load which is irrelevant in all but the most high end of motorsports.

I can think of at least 5 reasons it cant possibly work to accurately predict flywheel hp, but will reserve my thoughts until the clever people arrive.

The marketing brilliance comes from deciding that a piece of paper with a nostrodamus like prediction on it carries more "weight" with the forumites than a lairy "yeah mate. 25 or 30% loss equals xxx at the fly"

Im happy to recant if this is the most remarkable piece of technology ever devised, but i doubt it lol.

[bourny]

Must be one hell of a guess.

Most cars will not have the same "loss" through the drive train. It depends if you run a manual or auto, stall, etc. There is no calculation that can exactly tell you how much power your loosing between the engine and the wheels.

[VYClubby]

Must be one hell of a guess.

Most cars will not have the same "loss" through the drive train. It depends if you run a manual or auto, stall, etc. There is no calculation that can exactly tell you how much power your loosing between the engine and the wheels.

I agree, but I wondered if DD had come up with a magic formula

[feistl]

Please dont flame, this is a serious remark....

Cant you calculate the flywheel power by letting the car run down (in gear) and measuring the rolling resistance? I remember James May talking about it on top gear :P

Cheers

[bourny]

I seriously doubt it.