Gearing and turbo load

[smokinstroker]

So been talking to a few people about gearing and the load on the motor.

What I'm gathering is that the motor uses the load on it to help spool a charger, so having to little load can actually hinder performance.

Running low gears and smaller tires causes the motor to work less ie. putting less load on the charger?

What I'm getting at is... Is this a valid statement? I know having to tall of gears with small tires will kill your top end but help low end performance as it will get the rig moving easier, but will it cause a turbo to not light as fast?

The way I've been figuring is how it's hard for a truck to spool a larger charger on a non loaded/ braked dyno.
but it performances much better on the street or an inertia dyno.
Sorry of my wording is off, tried to describe it the best I could get on paper.

 

[hawgdoctor]

Your pretty much right on it.

Sent from my DROIDX using Tapatalk

 

[smokinstroker]

so if im understanding correctly, having a low gearset can actually hinder turbo spool etc?

only reason i ask is im running 4:30:1 on 34s and by the time i hit 2k and my charger comes on strong im already doing 20-23 mph

 

[MorganY]

sounds like you got it figured out bud! I can still datalog when you're ready. I have been sick and have been working late hours on this 6.4

 

[hawgdoctor]

so if im understanding correctly, having a low gearset can actually hinder turbo spool etc?

only reason i ask is im running 4:30:1 on 34s and by the time i hit 2k and my charger comes on strong im already doing 20-23 mph

Yeah it will make it harder to light, and keep it up fully spooled. For example all stock on my truck motor wise, 33" tires, and stock axles, by the time I hit two grand it's at 26-27 psi boost, and sideways if I'm not paying attention, but will stay around that until redline without ever dropping off. Have one of my customers with a powermax, 175/75 sticks, 36's on 22.5's, with 4.88 gears. Very quick out off the hole, BUT never sees over 28 psi of boost no matter how hard you push it. Also is very sluggish to get the turbo spooled at the same time.

 

[smokinstroker]

Let me know if you can tomorrow, got a new tune so seems to be running better.

That 6.4 has been giving you some work!

Hawg thanks for the reply, that helps a bit. That pmax psi should be controlled by tubes though if I'm not mistakin.