fuel pressure mods

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ka240de
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Location: humboldt, saskatchewan, canada

fuel pressure mods

Post by ka240de »

hello i have a vg30e in my pathfinderand it has a few mods to increase airflow and therefore have a leaner mix with the stock ecu?
i understand this would only be slight but i want it to be 1)reliable , 2) make the most of the money i've dumped into the truck.

relative mods include:

60mm ka24de throttle body upgrade with port matched upper intake
deburred lower intake
pacesetter headers straight tube 2.5" exhaust comes out in front of drivers rear tire.
jim wolf technologies pop air filter
rebuilt heads, performance oriented 3 angle and back cut
17degrees btdc, 91 octane.

my question is, with slightly leaner mix, could i gain reliability and a few ponies by increasing base fuel pressure by 2 psi or so, while being able to monitor fuel pressure?

you may not think this is significant but this dyno shows how restricted the vg is.

"Another dyno graph, this time from a non-turbocharged VG30 engine and retarding cam timing instead of advancing. The only other modifications to this engine were intake piping (not plenum), exhaust from the engine back, and fuel delivery. The lowest (blue) line is a stock baseline, the second (red) line is from the other modifications, and the top (green) line is the other modifications plus a cam timing retard of 5 degrees."

Image
Last edited by ka240de on Sun Nov 09, 2014 5:36 pm, edited 2 times in total.
1991 sil-eighty se sold
1995 bmw 540i written off
1995 pathfinder se, sold
1995 Altima gxe, sold
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nissanfanatic
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Re: fuel pressure mods

Post by nissanfanatic »

You'd definitely be safer to be on the rich side, but you need to measure AFR to know for sure. More than likely, the stock computer will detect the extra airflow and account for it.
-Cory

2020 Subaru WRX
A long time ago...
https://www.ka-t.org/cory_b.php
Use Linux...
ka240de
Knows Some Stuff About 240's!
Posts: 357
Joined: Wed Jul 31, 2013 8:34 pm
Location: humboldt, saskatchewan, canada

Re: fuel pressure mods

Post by ka240de »

as the dyno graph above shows, i have all of those mods except fuel, and he had significant power increases- 33whp & 19ft-lbs
p.s. i also have an aeromotive fpr and fuelab 8an filter laying around. the same guy said that he saw a 1psi increase in pressure by simply upgrading to a z32 filter for 15$.
1991 sil-eighty se sold
1995 bmw 540i written off
1995 pathfinder se, sold
1995 Altima gxe, sold
User avatar
nissanfanatic
SuperMod
Posts: 5078
Joined: Sat Nov 20, 2004 1:16 pm

Re: fuel pressure mods

Post by nissanfanatic »

Yea, you could definitely do small stuff like that.

I'd think a walbro (if they make them for your app) and/or a fuel pump rewire could also make a good bit of difference.

Changing out to a Walbro when my car was NA made a noticeable difference. I definitely am not one to say "I can feel a difference" after changing oil or plug wires, but changing from a factory fuel pump to a Walbro did make a noticeable difference.
-Cory

2020 Subaru WRX
A long time ago...
https://www.ka-t.org/cory_b.php
Use Linux...
ka240de
Knows Some Stuff About 240's!
Posts: 357
Joined: Wed Jul 31, 2013 8:34 pm
Location: humboldt, saskatchewan, canada

Re: fuel pressure mods

Post by ka240de »

well thanks man ! i will definitely look into getting a fuel monitor set up, and play with a few things to increase pressure before increasing airflow any more. i will also read the max efficiency page, i havent yet.
1991 sil-eighty se sold
1995 bmw 540i written off
1995 pathfinder se, sold
1995 Altima gxe, sold
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