Fuel Pressure

[want-a-fast-svx]

I was just wondering if anyone knew the stock fuel pressure is on the svx???I'm asking because i was wondering if there would be any ill effects in putting in a fuel pressure regulator and increasing the pressure slightly...Would i need a new fuel pump to do this???Also would this pose any possible harm to the engine???Someone said to be careful because you can blow your injectors with too much pressure and fuel...If any of you can help me out its greatly appreciated...I'm not going to tell you all yet, but just wait till you see what the inside of my engine bay is going to look like in about 2 weeks or so...OH so nice..hehe

THanks
Derek (almost done with the engine swap, finally i might have my car again)

[Subafreak]

Dude, your kinda scaring me.



Some SVX injectors have leaking problems already. I assume you have some other reason for uping the fuel pressure? I'm not sure if it 's a good idea or not, but let us know.

[lee]

First, I know little or nothing (closer to the nothing side) about modding computer controlled engines.

That said, it seems to me that if the pressure was higher than stock, then the system would run rich, and you risk cat damage?

Or have you figure out how to push more air without the MAF sensor knowing?

[want-a-fast-svx]

Hmm i forgot about the leaking injector problem that some people have had. Isnt there someone who found injectors from australia?? that might work?? Also didnt someone cross-drill 300zx injectors and they fit in the fuel rail???
Lets say i did replace the stock injectors would the fuel pressure regulator provide any increase in hp???I am thinking maybe not but just wanted to check...

[want-a-fast-svx]

bttt

[want-a-fast-svx]

bttt

[svxfiles]

the stock pressure is 36.3 lbs. subaru makes a fuel pressure regulator that bolts right in with 45.4 ( or so,) its from the 2000 and up 2.5s the stick is slightly higher than the automatic. i put one in my 92 with good and noticeable results. no hesitation, and seemed to be stronger all around. it then went into my now ex wifes 2.2 impreza with the same results. i now have a universal adjustable fpr and run 45psi to 50psi. my injectors are fine and ive had this set up for 30,000 miles or so. on my girl friends svx we will probably go the 45.4 factory route, its simple, it works, and for under $100.00 its cheap

[mbtoloczko]

Originally posted by svxfiles
the stock pressure is 36.3 lbs. subaru makes a fuel pressure regulator that bolts right in with 45.4 ( or so,) its from the 2000 and up 2.5s the stick is slightly higher than the automatic. i put one in my 92 with good and noticeable results. no hesitation, and seemed to be stronger all around. it then went into my now ex wifes 2.2 impreza with the same results. i now have a universal adjustable fpr and run 45psi to 50psi. my injectors are fine and ive had this set up for 30,000 miles or so. on my girl friends svx we will probably go the 45.4 factory route, its simple, it works, and for under $100.00 its cheap

Interesting. How do you figure it improves performance? Do you think the fuel map is a little lean in some places?

[svxfiles]

yes, with higer pressure, it squirts more fuel ,farther into the airstream for better atomization, the o2 sensor still controls the air/fuel ratio at all but wide open throttle and during warm up.

[mbtoloczko]

Originally posted by svxfiles
yes, with higer pressure, it squirts more fuel ,farther into the airstream for better atomization, the o2 sensor still controls the air/fuel ratio at all but wide open throttle and during warm up.

So the ECU can learn to dump in less fuel to compensate for the higher pressure?

[Subafreak]

I thought the SVX ran rich already?

[svxfiles]

yes, the o2 sends instant info about the a/f ratio, and the ecu leans the mixture to suit/match the pre-programed maps, or ramps keeping the mixture aproximatly 14 .1 parts air to 1 part gasoline, if the pressure is too high the ecu shortans the pulse cycle to correct within limits. a normal fuel injector runs at 42psi,the normal injector can handle about 55psi before it starts to stick or leak.( hi preformance injectors can handle up to about 100psi,) by the way, our fuel pumps have more than enough
capasity for non supercharged or non turbocharged applications.
444hp as i recall. you cant make power without fuel, but it must be in the right mix.

[mbtoloczko]

Originally posted by svxfiles
yes, the o2 sends instant info about the a/f ratio, and the ecu leans the mixture to suit/match the pre-programed maps, or ramps keeping the mixture aproximatly 14 .1 parts air to 1 part gasoline, if the pressure is too high the ecu shortans the pulse cycle to correct within limits. a normal fuel injector runs at 42psi,the normal injector can handle about 55psi before it starts to stick or leak.( hi preformance injectors can handle up to about 100psi,) by the way, our fuel pumps have more than enough
capasity for non supercharged or non turbocharged applications.
444hp as i recall. you cant make power without fuel, but it must be in the right mix.

What's the part number for the fpr you used in place of the stock one?

[want-a-fast-svx]

I was planning on getting this one from HKS...Do you think it would work alright with the svx???ALso do you know the injectors that i can fit in the rail???I swear i remeber hearing someone cross-drilling the rails and fitting 300zx injectors, as well as some from australia i believe....Thanks for any help in advance..

http://www.hksusa.com/products/?id=811&rsku=

[Phast SVX]

you cant make power from nothing. Just adding an FPR will not do anything, i can garuntee it. You may think youfeel something from it but you cant dump more fuel in and expect to have more power. You have to be able to add air, then add fuel. Remeber fuel is added according to the amount of AIR that is being put into the the engine, not vice versa.
phil