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Increasing fuel rail pressure???

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Old Apr 3, 2003 | 04:32 PM
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Increasing fuel rail pressure???

OK, my car is is the sig below... as most people know.
A
nyways... having spent all my money on ****, drugs, and hookers, I can't afford a set of 680 or 720 injectors.
I have a Walbro pump, and 4x550 injectors.
I know the injectors can be overflowed by increasing the fuel pressure....
I'm only leaning out right at the top of my boost (12 psi) (creeping, unfortunately, even with wategate overported, and a stock DP)
Now, can the return fuel line just be "pinched" to overflow the injectors??? Using an adjustable valve of any kind.....
I have an S-AFC and a wideband, so tuning/compensating isn't a problem.

I only need a little bit more..
This possible???? Makes sense to me..
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Old Apr 3, 2003 | 05:12 PM
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Scott 89t2's Avatar
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you could add in an aftermarket FPR after the stock one. it would be better to replace it fully though.
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Old Apr 3, 2003 | 06:41 PM
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The only problem with this is that raising fuel pressure doesn't equal a linear rise in injector volume output. You have to dramatically raise pressure to make it worthwhile (piecing a fuel system from an N/A car on a now turbocharged platform, I take it?).

B
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Old Apr 3, 2003 | 11:54 PM
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Basically no N/A parts left.... All TII fuel system, (and most of the block) except for the Walbro.
I only need a tiny bit more fuel.... just hping that constricting the return line, combined with the higher flow of the walbro, would be enough to give me the 10% or so that i need.
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Old Apr 4, 2003 | 07:22 PM
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So that's pretty my an "affirmative" on the ability to raise fuel pressure to obtain another 10% or so more fuel??? Just don't want any unforseeable adverse side effects....maybe harder starting?
What should I use on the return line to constrict it??
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Old Apr 4, 2003 | 07:30 PM
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I replaced my lines from the tank up

full -6an fuel
550/1600
fpr
walbro
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Old Apr 4, 2003 | 07:47 PM
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how can you tell you leaning out??
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Old Apr 5, 2003 | 01:14 AM
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he has a wideband.
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Old Apr 5, 2003 | 09:30 AM
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Originally posted by Bambam7
So that's pretty my an "affirmative" on the ability to raise fuel pressure to obtain another 10% or so more fuel??? Just don't want any unforseeable adverse side effects....maybe harder starting?
What should I use on the return line to constrict it??
Your trying to hack something together, nothing good happens when you do this. Either buy a real FPR or stay off throttle till you can afford one.
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