The other night I put the truck into performance to see what it would run like . One thing o noticed is on mild acceleration it seemed to run a bit quieter. I hooked up torque and noticed icp pressure was always a bit lower( normally I run in economy). I hit the highway and peak icp was 2500 psi. Ijpw reached 4.4ms. It had gobs of go but when I got off the highway I switched back to economy and hit 3300psi with slightly aggressive stop and go traffic quite easily. Also ijpw will only reach a max of 3.2ms in econo or daily. Can anyone explain this for me?

 

Based upon my limited experience and knowledge of these engines and the tunes, here's my guess.

The Injector pulse width is essentially how long the "valve is open" to dump fuel. ICP is how hard the fuel is being sprayed.

The DD / Econo tunes are probably trying to keep the ICP up there as high as possible to keep the atomization as fine as possible to increase the efficiency of the injection and save fuel. It's a matter of making a finer spray of fuel in the cylinder to try and get a more complete, efficient burn.

The performance tune is all about getting as much fuel into the cylinder as possible (efficiency isn't a concern) so they probably backed the ICP off some and just throttled up the INJPW to be sure they're completely emptying the injector into the cylinder. They may also have backed the ICP off in an effort to make sure they have sufficient HPO flow on a truck with a stock HPOP.

That's my guess at least.

Whose tunes are you running?

 

What was the ipr DC% at 2500psi ?
Kinda sounds like your tuner has your icp limited to 2500psi on that tune

 

Dyno proven tunes. I'm not to sure what the ipr dc is mike. Yeah the psi is definatly capped at 2500. That was a wot run in 4th gear from 800 rpm to 3200. When I put it in econo I was under 2k rpm