advise on fuel pressure regulator setting

pac_jb

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pac_jb

Known Member
Feb 28, 2013
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Kuala Lumpur
Hi bros,

I need advise in fpr setting for evo 3, im using walbro fuel pump with stock ecu n injectors, my foreman set the fpr to 3.5 bar with the vacumm line on, but car feels really heavy, and with aircond on its even worse, today I reduced the fpr to 2.9bar on idle with the vacumm line on. Any recommendation for ideal setting for the fpr. Tq
 

vr2turbo

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Helmet Clan
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vr2turbo

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Helmet Clan
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Have to check what is wrong? Too much fuel or too little fuel going in. You reduce the pressure so was it better? Reducing the pressure means less fuel forced in
 

pac_jb

Known Member

pac_jb

Known Member
Feb 28, 2013
131
14
518
Kuala Lumpur
After reducing the fuel pressure the car feel much lighter and more response , I set the pressure around 43.5psi @ 3bar without vacuum hose, so with the hose its around 2.6bar..
 

vr2turbo

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Helmet Clan
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vr2turbo

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Helmet Clan
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May 11, 2010
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Since it is adjustable now, just try other settings and see how it works. Find the best that suits you.....
 

Izso

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Helmet Clan
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Izso

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Helmet Clan
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Mar 28, 2004
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I've found that butt dyno like what you're doing now doesn't really work. In the past I adjusted mine to 4bar and that felt good. But on a dyno it showed the AFR too rich on the higher end and that caused my plugs to foul a lot faster. After dyno tuning the thing, it worked better overall at 3bar instead.

So best to get it dyno tuned la (at least a dyno with AFR readings)
 

vr2turbo

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Helmet Clan
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vr2turbo

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Helmet Clan
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May 11, 2010
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I've found that butt dyno like what you're doing now doesn't really work. In the past I adjusted mine to 4bar and that felt good. But on a dyno it showed the AFR too rich on the higher end and that caused my plugs to foul a lot faster. After dyno tuning the thing, it worked better overall at 3bar instead.

So best to get it dyno tuned la (at least a dyno with AFR readings)
Work better at 3bar, but butt feel good or not?......hahhahahhahah:rofl:
 

Izso

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Helmet Clan
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Izso

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Helmet Clan
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Mar 28, 2004
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I don't recall to be honest. There was some slight knocking in the higher rev range I think. Resolved with 97 petrol
 

vr2turbo

Beyond 20,000 RPM!
Helmet Clan
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vr2turbo

Beyond 20,000 RPM!
Helmet Clan
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May 11, 2010
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8,209
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I don't recall to be honest. There was some slight knocking in the higher rev range I think. Resolved with 97 petrol
Means running richer fuel ratio no knocking, both ways also use more RM....hahaha:rofl: