Dyno doesn't match with RATED horsepower

[Jeevin]

Hey just looking at this article and a 2005 RSX type S, completely stock, only put out about 180 Horsepower - when the rated horsepower is 210.

http://www.vtec.net/articles/view-article?article_id=274182&page_number=3


Are most cars like this, or did they just get a lemon, or what?
cause I want a 2002ish type-S and I want it to make 200 HP when I get it....what's this all about?

[Weapon_R]

Dyno's measure horsepower to the wheels, whereas manufacturers measure horsepower to the flywheel. There is a pretty big loss from the transfer of power to the wheels, which is why you'll see the difference.

[GT2NV]

that 200hp figure is at the crank, cars lose horsepower through there so thats why it only ends up being 180, cause thats at the wheels....

[statick]

:werd: , thas pretty much it, i heard rwd cars lose less hp in the rtansition as compared to fwd, is thsi tru ?

[BigDL]

As well as different Dynos are calabrated differently.

[BigMass]

Originally posted by statick
:werd: , thas pretty much it, i heard rwd cars lose less hp in the rtansition as compared to fwd, is thsi tru ?

its the other way around. FWD cars have the least amount of drive train loss. For example, a Mini Cooper will dyno very close to its rated HP numbers.

[Chester]

when the cars engines are tested for power from the factory aren't they tested without power steering and without a/c too?

[///M3]

^^ yes i would think so.

[Jeevin]

awesome, i get it now.

[iceburns288]

No, I think they are required to dyno the engines with all accessories that will be installed in the car. They do not, however, require an automatic.

[bcrdukes]

Flywheel HP to Wheel HP:

General Drivetrain loss

FF: 15%
FR: 20%
MR: 15% / 20% (longitudal/latitudal)
AWD: 30%

Example:

RSX Type-S
210hp x 15% Drivetrain loss = 31.5hp loss

210hp - 31.5hp loss = 178.5whp.

[Factory rated power - (Factory rated Power x Drivetrain loss percentage)] = approxiamate wheel hp.

180whp sounds about right. Newer drivetrains are a lot more efficient these days, thus, lower percentage of drivetrain loss.

[///M3]

100whp = horsepower to the wheels
100hp or 100bhp = horsepower to the crankshaft.

[DSM Power]

Originally posted by bcrdukes
Flywheel HP to Wheel HP:

General Drivetrain loss


The key word here would be general. :zzz:

[bcrdukes]

^
Would you like to be more precise to the very little bit of a ten-thousandth?

[donz]

Actually Bhp is brake horse power, it is a differnt measurement, and is less when converted to hp.

And I read some where that there is actually a lot of varience in the way manufactures dyno. For example, the R34 GTR as been dynoed at higher than the japanese horsepower limit of 280bhp. In fact it is rumored that nissan had to put extra restrictions in the exhaust systems inorder to get a lower number. I am boosting numbers is true too, remember the original hp rating for the Rx8 before people complained!! So I would not be surprised if some companies didn't include accessories in their ratings!

[5.9 R/T]

Optional accesories do not have to be included, but it doesn't really matter, whats the difference going to be, ~.5hp from losing some belts?

[benyl]

Actually, belts and A/C can cause up to a 10% loss in power.