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Discussion Starter #1
What are the differences between say a Nismo Adj fuel reg and one of those FSE power boost valves?



aha
 

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Aha,
The electric fuel pump supplies fuel at a high pressure to the fuel rail and injectors, this is then regulated by a fuel pressure regulator. Typically, the regulator is not adjustable and is pre-set to a 3 bar maximum pressure. At idle the fuel pressure valve reduces it by 0.5 bar approximately to 2.5 bar. When accelerating quickly from standstill the fuel pressure increases at a proportional rate retaining a lean fuel mixture strength as required by the E.E.C. for new vehicles. However, the resultant effects of the standard regulator can allegedly produce:

lethargic throttle response
occasional drivability problems at slow traffic speeds
intermediate performance 'flat spots' when accelerating

The power boost valve is valve has an adjustable fuel pressure, effected by the movement of an adjustment screw on the crown of the unit. New Power Boost Valves are pre-set with a maximum fuel pressure of 2.5, 3.0 or 3.5 bar, depending on the vehicle in question, and similarly (to the original valve) the fuel pressure is reduced by 0.5 bar approximately at idle. There the similarities end. On acceleration from standstill the Power Boost Valve fuel pressure will increase at 1.7 times the standard rate. This will produce a healthy, strong fuel mixture strength which will instantly improve the drivability of your vehicle, allegedly providing:

instant throttle response
removal of performance flat spots
faster acceleration
extra engine performance

The Nismo adjusteable fuel regulator does exactly what is says on the tin. It allows you to control different fuel pressures for given volume flow rates. This allows you, amongst other options, to take the option to increase the fuel pressure to increase A / F ratios if there is no option to increase injector duty but obviously running much higher pressures can be detrimental to the life expectancy of the fuel pump but given the relatively low volume flow rate of the GTS pump other factors need to be taken in to consideration

Paul
 

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lol the question now really should be:

"why do you think you need one..?"

answers on a postrcard please
 
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instant throttle response
removal of performance flat spots
faster acceleration
extra engine performance

Im going for the Nismo jobby myself
 

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Discussion Starter #7
Crikey pope, cheers for the reply.
Do you have one fitted?

I think I need either of these due to plans of a bigger pump and injectors
 

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your choice Eddie my old son but you dont "need" either
 
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Im running a bit lean mate according to Richard Bells little gadget & pushing a few more psi of fuel through should help.
 

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Aha
The reason a fuel pressure regulator is not needed is if the tuner is properly adjusting the injector slope parameter in the ecu mapping for the new injectors instead of just cranking up the fuel pressure...

Paul

Saying that I do seem to have a Nismo one :D it is very shiny :D:D
 

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ooo oooo is it to pass your emission tests so you can wind it up on pressure ?
 

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OooooOOOoo smarta$$, I forgot about that one, so I have two then
 

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Eddie,
Was it uniformly lean across the whole rev range?

Paul
 
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Yes mate. The thing in the exhaust (forgot what its aclled) was very nearly white.
 

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At least the little fecker did come out, took me two weeks of knuckle busting verbal abusing grief before mine shifted.
 

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Discussion Starter #18
I think I'll be going for the Nismo fuel reg, but how do you set one up for the pressure you want?
Okay before someone jumps in...............
Obviousely with a gauge, but do you have to do it under load or just free revving?
 

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Given that according to the blah the Nismo one suposed to do 2.5bar at idle, rising to 3 bar under load then that would be a good place to start, you need to fit an inline pressure guage in to the system while you are setting the pressure

It might be an idea to make sure have have a wide band lambda sensor or a gas analyser so you can check its not overly lean etc and a friendly tuner on standby to rib you rotten for getting it wrong but will sort you out at short notice:D
 
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