fuel consumption - stage 2 hahn

[siueclipse]

hey everyone. i know i was talking about fuel pump issues but this is a new topic, so.. new thread..

anyway.. my hahn stage 2 is installed, im running only 5 pounds of boost right now and my fuel pressor is about 50. My engine is just swallowing gas. So far I have driven about 180 miles on 3/4s tank of gas. Is that normal?

 

[EvuLFleA]

50 at base is fine. We run 52ish stock.

You will definately be going through more fuel because when you boost you are dumped tons more fuel into your engine. Lay off the boost and you will have the nearly the exact same gas mileage.

What is your fuel pressure at WOT @ 5 psi?

 

[siueclipse]

5psi is around 110

 

[green95hrcgs]

Sounds about right. Fuel consumption on my car is the same as when it was stock when I am NOT in the boost. I have driven to Fla from VA about 7 times after I got turboed and was still able to get high 300miles or more to the tank. When I am in the boost I can almost run the tank down to 1/4 after a hard day of driving. Gotta pay to play! I can't imagine what my gas mileage will be like after I am done putting my new engine in with larger injectors and higher boost.

 

[EvuLFleA]

110psi sheeeesh.

That is right but I know a guy selling 30lb injectors for $85. Run some lower pressures for sure 110 is just about maxing out the injectors which is

 

[siueclipse]

yeah ive been looking into some bigger injectors.

damn stocks are like 190cc

 

[optimuspeterson]

6psi should be 80-90 psi. your running way rich, turn it down. and the first week i installed my stage 2 i got 150 miles to one tank

http://home.bendcable.com/optimuspeterson/instruc 11-15.htm

page 15 at the bottom has the correct amount

 

[EvuLFleA]

http://www.2gnt.com/www/corbin/example.html

This is an EXCELLANT page on building fuel systems. I believe your cartech fpr is adjustable and it sounds like you are running it about 12:1 which is why you have the 110psi. 50 base + (5x12)

 

[siueclipse]

Ok so obviously im running very rich... If I just turn up the boost will the pressure balance out or will the pressure go up as well? Since im at like 110psi right now at 5lbs of boost..

 

[optimuspeterson]

no, you need to turn down the rising fuel pressure on the fpr. turning up the boost will only make the fp go up

 

[siueclipse]

a funny things keeps happening too..

i have had to keep adjusting the fpr. i had it set at idle to around 52psi.. but every now and then i check it and its down to 40 and will stay there. looks like i need to do a lot more testing.

 

[EvuLFleA]

, remember why I said a lot of people switch to the vortech super fmu?

The thing does not hold base pressure.

Cartech FMU on ebay goes $150-200 lately for some reason and the sfmu goes $150ish used. I just sold mine for $175 sorry.

 

[siueclipse]

ok so what is the "screw" piece on the side for? its the billet one. I have a feeling we don't have this thing tuned very well at all.

 

[EvuLFleA]

Well it's hard to tune when the cartech keeps changing your base fuel pressures.

 

[siueclipse]

well, it will stay at 40