Injectors and Fuel Reg choice??

[prodrive tony]

Hi. What injectors and fuel reg do you suggest is best for my uk98??  Im aiming for around 320/350bhp?  Are they a straight swap? Thanks.

[leon]

hmmm.....i thought a my98 came with 380cc injectors and a my99 came with 440cc, 380cc give a max of 320bhp and and 440cc 380bhp, sx or fse fuel pumps are recommend but ive heard people saying that fse arent that good best person to ask would be JGM

[HOL]

Hi. What injectors and fuel reg do you suggest is best for my uk98??  Im aiming for around 320/350bhp?  Are they a straight swap? Thanks.

 

Im fitting 650's to mine next weekend, so my STI Pinks (somewhere between 530 and 565, depending who you ask) will not go past 380bhp.

Bear in mind the bigger you go, the more erratic you idle may become.

550's would be the obvious choice, with adaptors to fit your car, or you could go for 740's at the same price and leave future modding open.

If you buy from the UK, its quite expensive, if you buy from the states its cheaper, but you have to know what you are doing, when it comes to duty costs.

[HOL]

Just a thought! Do you not have a uprated fuel regulator already?

The walbro will be overpowering your standard one!!!!!!!!!

I had a walbro and FSE on my 98 Type R, had no problems.

[prodrive tony]

Thanks Hol. Ive changed pump but I havnt changed reg!!  Is that bad??

[HOL]

The walboro pumps have been known to overpower the standard regulator which is set to 3bar, based on the original pump pressure.

Its worth fitting a new uprated one. Not too hard a job, but some of the bolts are fiddly. allow 2-3 hours from opening to closing the bonnet.

 

[prodrive tony]

Cheers Hol, my bonnet never shuts anyway!!

[Jolly Green Monster]

the standard reg is only sometimes over powered by the standard reg..  if it was you would know about it already...  it would be very rich and run like a dog and fuel consumption considerably worse than before you fitted the pump.

You can fit bigger injectors and stick with the original fuel pressure regulator..  but the Fuelab or SX reg are good ones to go for.

As to injectors you want to make sure you get multi hole injectors..  Nismo for example..  550s would be fine for your required output.  Paul @ Zen or Andy F sell them, you will need adaptors for them to fit your fuel rails though.

Simon

[Jolly Green Monster]

oh and if you are on a budget you could just go for the fuel pressure reg and run slightly higher fuel pressure (sorted out by the mapper when mapping) and stick with the 380cc injectors.

 

Simon

[alan_newton]

i have an uprated fuel pump but never changed the fuel reg, seems to run normal, would i benefit from an uprated fuel reg? how much r they?

[STiBen]

i have nismo 550s and a uprated pump and reg with a Power FC (mapped by andy F) and im near the 370 mark. runs, idles fine. no probs touch wood. lol

[deani_age]

My understanding is that the STI came with 500cc Injectors, good for upto 400BHP, and that 550cc Injectors are good for upto 440BHP with supporting modifications.

If the mapping goes well on Tuesday after Deano has replaced the plugs and coil packs on my RA, I will be trying it out at Santa Pod on the 8th October.

Maybe a trip to Power Engineering will follow.

 

[prodrive tony]

These Nismo's 550's with multiple holes sounds good!! Cheers.

[HOL]

Dean,

STI Classics came with Yellow 440's.

Im not sure, but I think the V1/2's had something smaller.

[Jolly Green Monster]

Talking classic injectors..

phase 1 (92~96) all 380cc

phase 1.5 (97~98) uk 380, wrx 380, sti 440 (although that doesn't appear to be set in concrete).

phase 2 (99~00) all 440s.

The nismo's (550s and 740s) give wonderful idle..  my 740 nismos in my own car idle like the 380s did.

Simon