Ok, some of you guys might have seen my recent threads were I asked for advice on purchasing a new vp44 for my 24valve high output cummins. I was told my the overwhelming majority to install a SO pump as opposed to the HO pump, and I did. Just got it together late last night, drove it all day today. The truck seems to be running perfect, no misses or anything, however it is smoking a lot less and only peeking at about 22psi boost, where it used to peak around 34psi. Anyone have any ideas?

One thing I am concerned about is that I replaced the gasket where the intake meets the grid heater platform with hi temp black silicone gasket maker. Maybe I didn't let it set up enough before tightening the screwes and I squished all the silicone out and it is having a leak there causing it to lose boost?! If there was a small leak there, would it cause me to lose 12psi of boost?!?!?! Any help, suggestions or comments are welcome!!

 

Pop the hood and listen for boost leaks.

 

A leak checker is easy to make. Go to home depot and get a rubber coupler and PVC cap and install an air valve in the cap. Attach it to the turbo inlet and pressurize the system. It's a handy tool to have anyway and it only costs a few bucks.

 

Also what kind of injectors do you have? Were they setup to popoff at the same point as the HO injectors? If so, that could be your problem. The SO pumps run at a lower pressure than the HO pumps.

 

The guy I bought the truck off of put 80hp injectors on it. How do I get them setup to popoff at the same point as the HO?? Thanks for all your comments!

 

They need set to the lower SO popoff pressure. I'm pretty sure they are different pressures. You could call somebody like Scheid's to find out for sure.

 

thanks alot for all the comments. I still have some questions. Seein as how I still have the fass fuel, and the power edge box, it seems like I would still be able to get my peak boost from my turbo?!

Several people on this site told me that when I replaced this pump I should go with the SO VP44 as a replacement, that it would be better for my truck than the HO that came off of it. Is this true? It just seems like I would have been better off to replaced it with the HO that came off of it because now I am having these power problems. And whose to say that even after I get the pressure thing fixed and a gasket put back on my intake instead of that silicone gasket maker that was squished out of the sides when the bolts were torqued down, that I will be getting the same power that I once was?! Does anyone think I will get the same power, or do you think that with this SO pump that my truck will not be able to maintain the same amount of power that it once did? Please help!!!!!

 

I'm thinking about it this way:
The SO pump doesn't fuel as heavy as the HO pump; so, less fuel - less heat in the exhaust for the turbine to extract its work from. The less work the turbine has to drive a compressor, then the less availible work the compressor has to pump air. Thus, it all translates to less overall boost.

I don't know alot about the differences between the SO and HO other than a HO pump generally will deliver more volume of fuel, but I would have probably stuck to what the truck had in it to begin with. It is an HO engine right?

I don't want any trouble I was just looking for some pictures in here.