th400/208 to a nv4500/205....more power?

[84CUCV]

not my truck. helped a friend with this. been on the road for a bit now. i think its a great set up. i just cant lay out 2500 or something close to that to do it. to think of it anyone know a cheaper way? most of his stuff came from a place called geartech. lots of money.

anyway, its a m1028 with a 6.5 turbo motor. with the nv4500 in there, i thought it felt like there was more power. he said the same thing.

why tho??

thanks

 

[Wrench]

That's not surprising. The TH400 has a first gear ratio of 2.48:1, whereas the NV4500 has a first of 5.61:1 or 6.34:1, and a second gear of 3.04.1

So in addition to having two gears below 1st on the TH400, you're also not spinning a TC full of tranny fluid to get a power transfer. Direct power transfer, less drag, and both 1st and 2nd gears are lower ratios than 1st on the auto.

I'm currently in the middle of the same swap, just in an '82 crew cab
http://coloradok5.com/forums/showthread.php?t=224312

 

[84CUCV]

ok never thought of it like that. got it. thanks

 

[tRustyK5]

Don't forget the power it takes to run the pump on an automatic...you can lose up to 20% of the power at the crank through an auto. Significantly less through a manual tranny.

The more power felt would be in any gear. Another thing to keep in mind is the th400 doesn't have a lock-up convertor so there is always some slip going on.

Rene

 

[84CUCV]

thanks rene i got ya