What Size To Get?

[CAT_SPEW]

I am wanting to upgrade my injectors on my RB25 but don't know if 740cc's will be too big..

It's currently making around 250rwkw on about 12.5psi and I'm pretty sure they are maxing out about now.

Will 740cc's be a problem if I have the car dyno tuned after installing them??

I'm looking at making more power later on so I don't want to go too small..

[B-Man]

I was running 550cc and getting 330 rwkw

[CAT_SPEW]

I was running 550cc and getting 330 rwkw

<{POST_SNAPBACK}>

What % duty cycle were they running at??

Did the car run fine after you installed them, or was it running too rich??

I need to know if I will be able to drive it to the dyno shop after installing them or if it will cause damage..

[sewid]

550cc is a good bet. Mine's GTR runs 600cc, i believe 740cc would be overkill for most. That being said I have 700cc for my GTR...

[blind_elk]

Do you have an aftermarket ECU?

As a cheaper option, why not try installing a Malpassi, or similar, rising rate FPR, and increase the base (idle) pressure. Installing huge injectors will cause the car to idle too rich.

[CAT_SPEW]

I had a search on google and found some info from Meggala's site on injectors.

Heres the link.

LINK

Going from the 550CC's should be able to support at least 500hp if I worked it out right??

Still don't know if they will screw the engine while I'm driving to the shop to get the tune but..?

[R31Nismoid]

I was using nismo 740's... i'd reccomend to get those. There were great for me. No issues.

direct fit to the stock rail... (unlike sard)

kept stock reg also (no need for a bigger one)

Using a PowerFC it'll be 100% fine. You'd never notice injectors that big were in there

[CAT_SPEW]

I'm using a Haltech E6K, would that be able to tune it to run fine??

[Bullant47]

I think at 250rwkw 550 injectors and more than likely your fuel pump would be struggling. Get 550 Nismo Injectors and a Bosch 044 and a swirl pot and should be good to go.

Edited August 22, 2005 by Bullant47

[CAT_SPEW]

Already have a bigger fuel pump, what is a swirl pot??