How much boost?

[91cumminsd250]

I have an intercooled 91 and have a home made air intake, straight piped, and very minor pump tweaks. My guage says i'm only making 15 psi max, so I'm wondering if that seems low or even how to make more. Just wondering what you guys are making.

[Richie O]

15 is pretty close to stock. I run 35 in one truck and 45 in the other.

[soggy]

I could only get 20 out of mine with the stock turbo and pump maxed.

[ahale2772]

i got 32 ish from my baby hc1....

[1STGENFARMBOY]

I can get 30 with a 16cm housing and my mods

[peobryant]

I have an intercooled 91 and have a home made air intake, straight piped, and very minor pump tweaks. My guage says i'm only making 15 psi max, so I'm wondering if that seems low or even how to make more. Just wondering what you guys are making.

Do you have an automatic?

[diesel freak01]

im puling 30 with a midly modded pump and thats all. 30 psi and a max egt of 1200 and thats on a really long hard pull.

[Remps]

24 psi with mine. A torque converter or gov spring would bump it up more I think.

[peobryant]

You may also want to check if you have a leaky intercooler. Not entirely uncommon with an 18 year old truck.

[dpuckett]

I've said this a dozen times or more, and I'll say it again. Check your lift pump output. If it's the stock LP, there's a better than 50/50 chance it isnt keeping up- mine wasnt with stock pump settings. If it isnt keeping a minimum 5psi at all times, you will notice a difference when you upgrade to the piston lift pump.

CHanging to a piston lift pump, and making no other changes gave me 5-6psi more boost, and I made NO other changes. Smoke also disappeared.

BTW- 15psi is about the middle of the road for a stock pump. If you've done much tuning, it shold close in on 20, unless you have a stock auto tranny behind it. Then 35% over stock fuel will still only get you 20psi.

Daniel

[diesel freak01]

i have a ? regarding the piston lp, my truck when trying to free rev it has a stutter spot in it until you get into higher rpms after that its fine just the initial half pedal down it spits and sputters any ideas? is that possibly my lp going out?

[91cumminsd250]

yes its an auto, thanks for the tips ill check out the intercooler/tubing for any leaks cause i ain't got no cash for mods

[doublel89]

before i got a hx35w and intercooled it i 'could' pull about 40 psi, i only had a 35psi gauge that was with tc locked in overdrive, foot to the floor with all the afc stuff pulled out. that's probally why the h1c lost alot of oil into the compressor outlet though.

[Power Ram Man]

with a hx35 and water meth with injectors i make 42 psi

[Bad93Cummins]

I hit 22psi with 4" straight and just dennyt pin