picking fuel injector size

So I'm working towards gathering a lot of new parts to reach my goal and I'm wondering what injector size would you guys recommend. I see the regular 550cc all the way up to 1800cc.

What factors do you base your injector size on?

The car will have a stand alone ecu and see both pump and race gas. My turbo is a old 60-1 garrett.

 

[onesickcrx]

Power level your aiming for would be helpful

 

Ok, just looking to squeeze 450 whp out of that turbo. Stock intake mani with a turbonetics cast exhaust mani I think.

I think the intake mani and TB will be the only thing holding me back from bigger numbers after big injectors and a new ecu. Well, the exhaust could be a bit restrictive since its press bent but...its still 3". That will get a addressed later.

 

[onesickcrx]

I would say 880-1000cc's would be your ball park. It also depends on what pump or pumps your useing fuel line size but I would think 880's would be right around where you wana be.

 

[turbowop]

Didn't Harry make around 550whp with that turbo and setup. What injectors are on it now? If you're running a standalone, just get something bigger that will allow for future growth. FWIW, I run 950cc's, but could probably get away with something quite a bit smaller since I pull fuel when methanol sprays. But since the car has one of Jeff's chips, the 950's work great and idle fine.

 

I don't recall 550. It was closer to 500 but I don't know for sure. Regardless of what it used to make it wasn't anything close when I had it on the dyno here. Since then I have made some changes and hopefully they pay off.

I'm really more interested in a quality injector and what your opinions are on what you have used successfully. Like RC vs FIC or Denso, etc.

The car won't see E85 yet but I may look into it after sorting some other things out.

 

[onesickcrx]

FIC gets my vote

 

[turbowop]

I know Ken doesn't like anything but Densos, but I have RC 550's in 503 and FIC 950's in 1051. Both sets seem to work great. In the past I've also ran Denso 550's and FIC 780's with good results as well.

 

[belize1334]

FIC supposedly sells ONLY flow matched sets (less than 1% deviation) so they seem to be the hot ticket. Considering that the OEM injectors are 450cc and run out of room at about 15psi on the stock turbo(~200whp) I'd say that 900cc or so will get you onto the safe end of things. Granted you can get more out of injectors with a good tune (OEM tune is quite rich).

 

Thanks guys. Figured I should mention that I'm using a stock rail.

 

[turbowop]

Most of us are using the stock rail as well.

 

Mike I'd go with 950's or 1000cc. FIC is what we use in all our customers' cars unless they provide a different brand.

 

Just be careful, because the Delphi injectors that PTE and AFI advertise as "1000cc" are the same identical injector that FIC sells as "950cc". They typically flow ~935cc. The 850/880 injectors typically flow ~840cc. They are basically all the same Delphi injector, 750cc, 850cc, 950cc, etc, just with different orifice sizes to inject more fuel. So, they all have similar deadtimes and driveability. Either the 850's or the 950's will get you 500 crank HP, but the 950's will definitely do it at the stock 36.3 psi base fuel pressure, which will make it easier on the fuelpump and the rest of the fuel system.

 

[VR_IV_MR]

36.3?

 

Quoting keydiver:
Just be careful, because the Delphi injectors that PTE and AFI advertise as "1000cc" are the same identical injector that FIC sells as "950cc". They typically flow ~935cc. The 850/880 injectors typically flow ~840cc. They are basically all the same Delphi injector, 750cc, 850cc, 950cc, etc, just with different orifice sizes to inject more fuel. So, they all have similar deadtimes and driveability. Either the 850's or the 950's will get you 500 crank HP, but the 950's will definitely do it at the stock 36.3 psi base fuel pressure, which will make it easier on the fuelpump and the rest of the fuel system.


Have I ever told you that I love you? Well, I do.

Thankths guyths.

 

Quoting Lexington:
36.3?


The range specified in the manual is generally 36-38psi, BUT...according to the DSM Technical Manual, which I consider to be more accurate:

 

[Dialcaliper]

For something like fuel pressure, the factory probably set the FPR a little to the rich side so that the allowable range varies anywhere from the design (36.3) to the rich side. That way, with a stock computer, you're guaranteed that you'll be rich (safe) and never lean (kaboom!).

Also, because it's a restriction FPR, buildup of crud in the fuel system over time will always cause more restriction (higher rail pressure) and never less. I wouldn't be surprised if a shiny new FPR was pretty accurate around 255 kPa, and that a 100k+ mile unit would run a bit richer.

 

[atc250r]

What engine management are you going to use? If you're going with a standalone then I'd go with something way bigger than you currently need since you can control them properly. If you're going to use the OEM ECU with some sort of piggyback then I'd stick to a little over what you need based on your current HP goal. Also, if you are planning to make the power on pump then you'll need to go to a bigger injector than if you want to do it on race gas. If E85 is available in your area you may want to explore that option and buy the appropriately huge injectors. /ubbthreads/images/graemlins/devil.gif

John