I've been wondering what differences in HP gains if any there are between an auto trans 6.0 and a 5spd 6.0? My buddy has a Joe Gibbs 5spd and he's been wondering what the difference in gains are also so thought I'd ask for him.

 

Any HP gain from the 5 speed is trumped by difficulty shifting the getrag trans at high RPM.

 

Will the nv 3500 hold decent power? My buddy is doing a H/C 4.8 swap in a 67' c10. He's not looking for huge power. Just will be a cruiser.

 

So are there any benefits to tuning a 5spd?

 

If you're talking about a regular tune EfiLive or HPtuners well of course! The only thing in the tune that is played with for automatic is line pressure, shift times, upshift/downshift etc etc. The increase in power comes from adjusting parameters on the engine, not the transmission.

 

GM vehicles are pretty rich from the factory and at about 4500 RPMs have almost 5 degrees of spark retard.

Thin it out some and reduce the knock, the engine will perform better by being able to span the RPM zone quicker. Apples to Apples.

Now throw in the transmission tuning for quicker and firmer shifts, and the autmomatic would feel much faster.

If both engines put down say 400 HP to the wheels, Id put my money on the tuned automatic to win

 

Didn't figure there would be much difference between the 2 but I'm not a tuner and don't know what all is done with tuning. Guess it's just how fast you can mash the 3rd pedal and shift.

 

A street tune with a manual is a little easier. There is no converter so tuning the lower rpms works better.