Im know the HP is high pressure, but what is most commonly used for a turbo set-up or when do you use the high pressure pump?

Just the regular 255? I think my stock one is going....

 

for FI use the HP one, this is why...

lets say your using a 1:1 FPR (most all FPR's are), your running 40PSI base fuel pressure, your boosting 25psi, at the top of the run your actual Fuel PSI is 40+25=65psi

 

what if the whole fueling system right now is stock? still get the HP pump?

well, dsm 450's are on it but stock rail and everything else

 

I used the low pressure one, and I'm pretty sure thats what a lot of other people used.. When I was researching I found all I needed to know by using the search function.

 

Get the 255HP. Here's a helpful graph from Lightning Motorsports. This should help you make up your mind:

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by xtrec02 &raquo;</TD></TR><TR><TD CLASS="quote">what if the whole fueling system right now is stock? still get the HP pump?

well, dsm 450's are on it but stock rail and everything else</TD></TR></TABLE>

If you're using DSM's and running a lower boost application the 255lph is perfectly fine. I'm running DSM 450's on 8 psi with a 255lph. I'm sure even more experienced will chime in, but from the graph it looks like if you run 20psi of boost or more you would want to switch. It looks like the blue curve (255lph) starts losing it downhill at 60psi (stock 40psi + 20psi boost). But you could always plan for future and get the HP anyways

 

I run an 255HP and I would recommend it, might as well get the more capable pump right off the bat IMO... the price difference was very minimal when I bought mine.

 

either will work fine. as the graph above shows they flow almost exactly the same until 60+ psi. even then the regular is putting out 40 gph at 65psi, plenty of fuel in most cases. but for $10 the HP may be a good investment.

the HP was mainly designed for low ratio FMUs to avoid the use of an inline pump.

ps. both pumps will probably raise your fuel pressure a bit on a stock fuel system (fpr) nothing that cant be tuned for or fixed with an adj. fpr.

 

i used to use the HP before i went to inline