but not all power is lost/transfered in drivetrain, some of it will be lost due to exhaust and pulleys.

Look at it this way. Take beta engine with no tranny, no exhaust( or just something that will get the heat away), no PS, water pump being driven by something else, and nothing else that might take the power away and dyno the engine; it will make exactly 140hp! Because that's where the factories get their numbers from!

 

<div class='quotetop'>QUOTE (tibby01)</div><div class='quotemain'>the exhaust has nothing to do with the energy lost between the flywheel and wheels.</div>

Was trying to get that across. And pulleys make very little difference. Pulleys make power in 1st gear, not 4th in which Tibs are dynoed. The comparison can't be made because different gears make different power... especially when comparing 1st to 4th.

 

<div class='quotetop'>QUOTE (OdessitPashka)</div><div class='quotemain'>but not all power is lost/transfered in drivetrain, some of it will be lost due to exhaust and pulleys.

Look at it this way. Take beta engine with no tranny, no exhaust( or just something that will get the heat away), no PS, water pump being driven by something else, and nothing else that might take the power away and dyno the engine; it will make exactly 140hp! Because that's where the factories get their numbers from!</div>

so when they test an engine on an engine dyno, they have no belts hooked up to it, no exhaust, and no im?

if this were so, the whole ecu used for the engine on the factory dyno would have to be way different than one on a tib at the street.

 

you need a IM and a TB.

 

yeha, i guess you do. laugh.gif:

im pretty sure they dyno the engine with everything on it.

 

Well the numbers that they come out with for the engine HP are not just randomly generated, they are made on a dyno machine and that machine tells the exact power that engine itself makes. So, I'm pretty sure it doesn't have all of the stuff added to it because it wouldn't make the right numbers.

 

but "right numbers" in what sense?

right numbers to me are the numbers the engine makes in the car(not necessarily the ones at the wheels). if they dont measure the flywheel hp with an exhaust(or something that acts in a completely similiar way) the car would run like SH!T(unless timing and a whole crapload of other things were changed).

 

Engeneers must have a way of measuring the engine HP, not whp. Otherwise they would be selling us cars with stickers that say 120whp, but they don't they say that it was 140 HP, so they must of gotten that number from somewhere.

 

right, the amount of hp measured at the flywheel, with all parasitic losses included except for those from the tranny to the wheels.

 

I think I should stop arguin because I'm starting to feel owned by all of my previous throughts and posts. I think you are right man smile.gif

thanks for showing me the obvious!: