Fuel Pressure

[Boosted420a]

Curious about fuel pressure. Motor is in process of building the complete bottom end.. I understand the break in process and wont be running very much boost until that is complete, but once that is done i will plan on running 15-18 psi as long as everything seems in check.. I am putting in the HRC 500 cc injectors but didnt know if anyone knew at what pressure they should read at idle and at full boost. I do have SAFC and have the HRC stage III.

 

[siueclipse]

i dont know for sure because im doing the same as you are..

but.. when i put in my 310cc injectors, i lowered the idle pressure from 45psi to about 25psi. the boost pressure went from 110 to about 80. i was still running rich.. so i would assume that with 500cc injectors that we should be running around 15 to 20 psi of fuel pressure and around 50 to 60 at boost.. but of course, it all depends on when you actually test it. haha

 

[Kirby]

First, don't boost at all on your break in, not even for a second. Secondly there is no way those things are going to run well with just an afc and sfmu. Your going to have to lean them down so much your timing will advance like a mofo. Call Hahn and see what they say, but I believe your going to need more than the sfmu and AFC. Some guy's at 2gnt have gotten 440's to idle so it's possible, but you better get a data logger and watch that timing like a hawk.

 

[Boosted420a]

Y would having bigger injectors screw with my timing? Seems wierd to think that they will screw up from fuel pressure.. Hmm.. that is something that i would never had thought of.. Anyone else no of this theory with timing issues?

 

[EvuLFleA]

Originally posted by Boosted420a
Y would having bigger injectors screw with my timing?

You wouldn't want to idle below ~20 psi and even if you lower that much you will still be extremely rich. Now you will have to use your AFC and lean things out with that (which THEN will cause problems with timing)

 

[98Turbbo420A]

What's the break in process? Just out of curiosity I want to know what everyone else is doing.

 

[EvuLFleA]

Search google.com for "engine break in process". There are about 1,000,000 ways. Personally I think 95% of a break in is in the first 20 miles. I like the gradually get on it method to set the rings.