Dyno Result and Other Confusions

[GeeTeePT]

Ok ...it's about this whole whp and bhp and SAE thing. While I understand the principle of each measure the actual dyno readings when compared to a manufacturers claims can leave some confusion. Even addons with their claim of increased horsepower is it whp,bhp, or SAE ? What is the calculated loss between bhp and whp on a FW drive vehicle. ? Finally my dyno results were 193 whp and 252ft.lbs torque at the wheels. The car is sold as having SAE 220HP and 245ft.lb.torque at the flywheel. On the dyno results if using a 25% factor for gain from wheels to the flywheel and adding it to the stock numbers the ratings should be SAE 268HP and 308ft.lbs. torque. Feel like an accountant trying to balance the books.
Have read in another thread where a person got 410whp from a tune on their cruiser through brian@diablo/mindmelt. How would this be possible and could it do damage to the running gear?

[Mike_Levy]

whp is power at the wheels, bhp is brake horserpower and is just about equivalent to flywheel horsepower. SAE is adjusted to specific weather conditions, altitude, etc., so that numbers can kinda be compared (though not really).

Front drivers only lose 12-15% through their drivetrains. Rears generally lose 16-22%, and AWD around 25%.

The numbers Brian made are likely due to increased boost. Its probably on race gas and unusable for the street on pump gas.

[GeeTeePT]

Thanks Mike ...used the 25% ratio 'cause my stock was around 165whp and if I use 15% of 220whp she should have had 187whp. Dyno tech says there was a huge loss in hp.There was some major knocking 3.3 to 6.3 and running rich issues. Timing had to be adjusted. Could get more hp by adjusting boost and removing cat but not sure if I want to go there. First removing the cat is illegal where I'm from and the car is a PT GT Turbo with ATX which means the extra boost will be hard on the autostick tranny. Have read to NEVER boost in 4th gear even as is.

[Mike_Levy]

They're just numbers. They don't really mean anything in the real world. My Jeep only made 392whp and 384wft/lbs, but she still runs 11's. We were expecting 450/450, but it didn't happen. Oh well, they're just numbers.

[cd36]

A dyno is more a tool than anything else. Use it to tune your vehicle, and to do comparisons before/after mods. Comparisons between different cars on different dyno's on different days can be somewhat meaningless. What really matters is how fast you get down the track.

Remember, its not about who has the highest dyno number either, as sometimes the car with less HP can get down the track the quickest. Sometimes it's about the area under the curve, either way, use a dyno to tune, don't worry about comparing it to other peoples dyno's, and just compare your time slips .