Hi all. My question regards HP and RWHP; I have a '02 5.4 which factory states 260 hp. My truck feels strong enough and I have completed my bolt ons (pulleys, CAI, throttle body, and exhaust), now time to DYNO and tune; pre tune dyno neted 191 rwhp, after tune 205 rwhp. Should there be that much energy loss in the drivetrain? My logic was; stock + bolt ons and tune should equal close to 300 flywheel hp -aprox20%= aprox 240 rwhp. Truck still feels alot stronger, ...but maybe my expectations too high? Any input appreciated.

 

Nope, that is about right. The '04-'08 style trucks only put down about 205-208rwhp in stock form. Those 3V 5.4L's are rated at 300hp at the crank. Welcome to the world of needing a tuner. This will help you tremendously. It has been discussed here before to net you somewhere in the neighborhood of 25-30rwhp with a nice set of custom Troyer tunes.

Want more info on this, PM SinCityFX4. He is one of a couple "tuner gods" here.

 

Thanks. Your feedback makes me feel somewhat better knowing my results are in the norm, and not a loss of pwr somewhere. ...I say "somewhat" only bcs I want more!

 

Sounds about right to me. I don't know the exact RWHP ratings for the truck but I don't think you have anything to worry about.

 

This has always seemed like false advertising to me, when the company lists crank horsepower. The should really list rear wheel hp, or brake horsepower, as I've heard it referred to. It is less misleading, JMO.