Wheres' My horsepower

[E7mack96]

Allright everyone, You all seem to think that 190 dyno'd hp at the wheels is sluggish for a 2001. 5 ram 5. 9 HO. 6 speed???



Well, what could be the cause of this. . I want to get that missing 55 Horsepower back.



Any ideas????

 

[Lsfarm]

Rearwheel Horsepower

Your factory advertised horsepower is at the flywheel, not at the rear wheels.



There is at least a 20% loss of power through the drivetrain.



So 190 rearwheel horsepower is about right.



Also power readings vary from dyno to dyno, and from dyno operator to operator.



Add an EZ box, clamp down the wastegate, and you will have the power you want. [for awhile anyway]



Be carefull, power is addictive!!



Greg L

 

[CumminsAholic]

That is weak. Lsfarm, Actually I think that dodge rates their motor output at the rear wheels. Chevy and ford rate it at the crankshaft. That's why the trucks are always so close on a dyno, but not on the "manufacturer ratings". Just look at BD's ad in the snowmobile magazines for example. The dodge actually has more rear wheel horsepower than the ford. But yet ford claims (in their ads) to have more horse... right, I know the dyno doesn't lie. Any dyno results I have seen from a dodge have been at what dodge rates them at and those from ford and chevy have always been lower than what they rate them at. I know why that is, but the sad thing is most of the general publis doesn't.

E7, Your losses of that power could be a boost leak, a computer that has to be reflashed or a weak lift/transfer pump. Just the things that came to the top of my head.

Corey

 

[COBRAJET]

All ratings are at the crankshaft... how else would the 5 speed and the auto have the same ratings. A stick should put down 5-8 percent more power than an auto. The majority of the dyno's I have seen including many of the links here provided by Diesel Dynamics and Bully Dog show a stock H. O. well below the 245 rating. Usually the torque is close and sometimes over the rating , but the HP is always lower. The dyno and the operator have a lot to do with it. The PSD's are usually close to the ratings like the Cummins, with the HP being down and the torque being equal to and sometimes more than the rating. I have not seen a Duramax dyno yet that showed more than 245HP or 450ftlbs. That Allison must eat up that rating.



My PSD stock except for the exhaust made 227/486 at the rear wheels. The Cummins below was 206/508 with an open K/N. With the mods they made the power listed below.

 

[CumminsAholic]

Cobrajet, you're right about the hp ratings. But, I think dodge did rate the 5 speed and auto different for a while there. Then they came out with the 6 speed H. O. and things changed. If they're rated at the crank then why does yours have more than what dodge rates them at at the rear wheels?? I'm sure that the k&n didn't help a stock engine breathe that much better. It should be a bit less because the transmission, auto or in your case stick should take up some of that power. Either dodge rates them conservitively or at the rear wheels. Those are good #'s for both of the trucks, I'm glad that somebody has both trucks and will post the results of both. I personally like the bombed #'s better. Of course the allison eats up a lot of hp, without a lock up TC it has to. Try to dyno a ford or dodge out of lock up, I bet they'd loose a lot of power. That's why DTT is so great, they get more of that non-lock up power to the ground.

Corey

 

[BIG BOB]

You guys are right, Dodge/Cummins rates HP at the flywheel. However, I have seen quite a few stock H. O. dyno at 235-255 hp at the rear wheels. To name a few, Cummnntstrkn and Vaughn MacKinzie. Maybe a reflash is in order, just a thought.

 

[Beast2B]

I dynoed my stock truck at 212hp, 441lbs, so I think you are in the ballpark. I believe that any discrepancies are heavily affected by dyno and operator. JMHO (worth something less than $. 02)

 

[E7mack96]

does tire size affect dyno readings?

My truck has the bigger tires, which , i think, would effectively reduce the available Hp/Tq??



What your opinion here?



Also , What reflash is available for a 2001. 5 that addresses power?