Just thought id throw this up here to see what people thought about it, I took my old 95 f150 to Meyhem Motorsports Friday afternoon to have some baseline dyno numbers made before I swap in the new motor, there's nothing wrong with this motor it actually runs quite well but its got 132k on it and its completely stock so im throwing in a 306 gt40 headed motor because I tow a lot with it. Well I made 3 pulls and all 3 were almost dead consistant I picked up 2hp and 6ft lbs tq on the runs. The pulls were made in drive and it held drive correctly on each pull, it never downshifted or skipped a beat. I was surprised because I know autos tend to be hard to dyno and hold gears with.

1st was 150.54hp/203.34 tq
2nd was 152.66hp/209.58 tq
3rd was 152.73hp/207.44 tq

I was actually quite surprised it made this much because its a 4x4 truck with the 4r70w automatic and 32x11.50x15 swampers on it. Do these numbers sound about right? The motors completely stock cept for hooker long tubes with true duals and a k&n intake kit. How much power drain am I loosing through the driveline?

 

Are we talking about a 5.0?

 

Yes I forgot to mention that. It does have the 5.0 in it

 

thats better then i tought it would be.

 

what gears

 

I think the loss is like 20-25%

 

Its got Yukon 4:10 gears, but the gears don't matter because you dyno a vehicle in its 1:1 gear so it measures true engine power at the wheels, which in the 4r70w and aod-e is drive (3rd gear).

 

BULL CHIT. Gears have alot to do w the dyno. It would be like running 31" tires over running 38" in tires. The 4:10 helped you tremendously. Try it again w the stock 3:55s

 

That's incorrect information, it doesn't matter if I have 3:55's or 5:38's you dyno a vehicle in the transmission gear that is 1:1, tire size will effect how much power the vehicle puts down based on how big or how much they weigh, heavier tire is gonna draw more power. All the gears do is help the engine get into its power band quicker and easier while driving (street driving) Putting gears in DOES NOT help you gain horsepower or torque, I wish they did but they don't. They will make a vehicle feel completely differtent in street driving situations though.

 

If a larger tire takes away hp like you just stated, a higher gear will do the same thing

 

That's really good numbers especially with big tires. Too bad you didn't mention at what RPM your motor made it's power.

 

Not necessarily, the reason the larger tires hurts RWHP/TQ is because it has more rotational mass... they takes more power to turn.

The OP should make the same numbers regardless of the rear gear.

 

If this were true, then the 300 and 302 have the same amount of power, with the 302 having only ten more horse. I've seen a 300 dynoed on YouTube at 140 horse / 200 ft lbs, with an automatic. I believe the YouTube numbers as much as I believe this OP.

Lower gears multiply torque. Simple as that. Lower gears create more power.

You guys are smoking some weird stuff if you think lower gears don't create more power.

 

Show me where cars/trucks dyno higher numbers after a gear swap.

And don't get caught up in comparing different dyno numbers from different sources. There are different dynos out there(Mustang, Dynojet, etc), the weather plays its part (DA factor.) Dynos are more of a tuning tool than anything. In the performance world, RWHP means little-- what does it run at the track?

 

Does a dyno basically calculate horsepower by how fast the wheels spin or what? I've googled this question but it seems like there are a lot of different dynos out there and different calculations. I've seen some that say that gears play a factor and some that don't, some say gears play a factor on torque numbers only. Kinda a gray area.