I'm going to do my "own" stage 2 upgrade to the RRM stage 1 kit I already have. I'm doing it this way because I want to get a wideband O2, Greddy Emanage, and bigger injectors myself and tune it all myself. I'm going to buy the parts in that order as well (but will likely modify intake side components after emanage).

My question is, what size injectors are the way to go? I see some HKS 680cc for sale, stock EVO injectors (don't know the size) for sale, and others suggesting WRX injectors. And there's always the RC 370cc and I could probably just buy the stage 2 ones from RRM. There are other suggesting over 400cc is the way to go. Is there such a thing as too big an injector?

 

I am doing the same....for the power range we are most likely to achieve it best to get 440's(high impedance)...plus i believe stage 2 also goes to a 255 walbro pump

 

yeah if you're going to upgrade from stage 1 you should have a 255 fuel pump (if you don't already have it) The injectors that RRM supplies with the stage 2 are RC 370cc. I have the stage 2 and I think 370's are fine. Depends how much boost you're going to run and what other mods you have. For as much power as the stock internals can handle, 370's will be plenty I think. If you're gonna upgrade internals then you can go larger with injectors if you want. Maybe 400 or higher. All depends what you want to do.

 

Might as well go bigger while I'm buying new ones. What size pump does the stage 1 come with? I forget and I'm too lazy to search right now.

Also, how does one go about attaching new injectors? Is it:
1) grind down flanges on fuel rail
2) solder in new clips
3) install new injectors
4) plug in stock wiring (guessing wiring needs to be messed with too huh?)

 

Go with has been proven to work well. I'd say the 370 or the 440's mentioned. But really anything higher...not necessary. What is are the stock Evo injectors running anyway?

 

I'd like to know what the EVO stock size is as well, because I know people are upgrading them. Anyone know?

I think I'm going to get something in the 400-500 range, unless I find a killer deal elsewhere.

 

Stage 1 comes with the 255 lph Walbro pump, to answer your question...

 

don't quote me on this but i think the OEM evo injectors are about 540 cc or something like that

 

Thought so, one less thing to buy.

I'll ask some of the EVO guys at the meet tonight (if it happens, stupid weather) and maybe someone will know how big they are. I'm guessing it would be a lot cheaper to ****** a set of used EVO injectors than buy new RC ones.

 

If you jump on NASIOC, you can usually snag some WRX injectors (440cc) fairly cheap.

 

How well do those wrx injectors fit ???

 

Sounds like a good option.

What goes into mounting a new injector? Is there a relationship between the "cc" size increase and the actual dimensions of the injector?

 

PM HobieKopek - he has the experience on this. He said fairly easily.

 

I'm predicting he'll chime in before the end of the day.

 

Stage 1 comes with 190 lph walbro pump, stage 2 consists of 255 lph walbro, 370cc injectors, piggyback, modified maf

370cc injectors are fine but for the HP goal of most is around 230whp+, plus in account for the weight of your car and to keep the injector duty @ 80% or less 440's are more beneficial.(better to get the injector with a more flow rate if planning to upgrade a little more in the long run)

You will be fine as long as you have some type of fuel management for adjusting fuel to stay just a little rich