Should I Think About Upgrading Fuel Injectors?

[BosnianLanos]

Here's the list of mods:

Full-length CAI.
Nitrous 50 Wet Shot.
Fully upgraded and tunable fuel system. (4 AN Stainless Braid Hose, AN Fittings, Aeromotive FPR)
*Coming Soon* Polished and Slightly oversize Leganza TB (Will be done at local machine shop)
*Coming Soon* TB Matched Intake manifold (Bored to the same diameter as the TB)
*Coming Soon* Header-Back Exhaust System (If Kinkyllama sells it!)
*Coming Soon* Custom Made Exhaust Manifold from local speed shop.

I know that currently the mods are light, but after everything is said and done, I'll be pushing what the 1.6 can make without internal modifications. Currently the A/F gauge reads optimal under most conditions, except those moments when I go fully off throttle after a WOT run. But those aren't worrisome. Should I think about getting some better fuel injectors or even a fuel pump to compensate for the fact that the motor will be breathing better? Or should the OEM injectors be able to take the extra fuel? The pressure in the system is now set to 45 PSI, but I've accidentally run it up to 75 PSI and it held. Should everything hold so that I don't have to spend any more money?!

[PrecisionBoost]

I would not say your close to the limits of the stock injectors because your using a wet nitrous kit.

Basicly your fuel jets in the wet nitrous kit should be doing all the fueling when your hitting the nitrous.

As such your really only using the factory injectors for non-nitrous use.

Remember, the 1.6L was tuned to nearly 150BHP by Lotus during development of the engine.... and many of those gains came from more agressive cams, better fuel maps and most likely higher octane fuel.

So even with a 50 shot your probably not far off the numbers that Lotus got during development.

If you had increased compression and put more aggressive cams in there.... and ran it to 8000 RPM... then yes... you could bump the injector size just a bit.

[BosnianLanos]

I know there are companies in the US that can add metal to the cam lobes to make it a more aggressive cam, but do you recommend this on a street car? Is it as reliable as a new cam altogether? I could deal with a little rougher idle, but excessive fuel consumption and reliability issues would be a deal-killer. But then again, would a mild or medium cam create noticeable gains?

And what would be a type of software where I can change fuel maps? Like I said, my A/F gauge reads optimal under most conditions.

[PrecisionBoost]

A decent cam should make a very significant difference in power levels.... and companies like Kent Cams have both Street and Race cams available.

Reprofiling a cam is common and reliable if you find a good shop (which may not be the easiest thing)

You would increase fuel consumption based upon the simple fact that you have more power.

Increase power by 30% and your fuel economy will drop by 30% ( assuming of course that your using that extra power.... otherwise normal driving will give nearly identical fuel consumption)

I'd have to think that you'd gain 20hp or more with the mods you've allready done.

There is no software to change your fuel map at the moment.... the easiest way is to increase fuel pressure slightly.

Running at 75psi will make your car run stinking rich but it shouldn't hurt anything in the short term.

Project GSIturbo runs pressure from 30psi all the way up to 80psi (needs bigger injectors ) as boost rises.

Don't get me wrong.... running 80psi is not good for the injectors.... but for now it's a short term fix to keep the A/F a perfect 12:1


You mentioned your A/F is good.... but remember that with nitrous your probably going to want to keep it well below 13:1..... 11:1 is really nice and safe.

[BosnianLanos]

I've run 75 PSI only once...That was when my eBay POS FPR was stuck shut (not returning any fuel to the tank). The car ran...not well, but it did run. It was definitely misfiring, the CEL was on and flashing, but I didn't feel safe running it any more than that. Then I dropped $165 on the AEROMOTIVE FPR and haven't looked back, definitely the nicest part I've put on my engine! I think I'm currently running 45 PSI (ON VACUUM) I haven't noticed any bogging, any ratio issues, or any excessive fuel use. Car seems to respond a bit quicker. If it was your car (with the current mods), what PSI would you run it on vacuum?

I've heard of Kent Cams and I've gone to their website before. Of course all of their dealers are in Europe and the UK, but that's not really the issue, shipping can be arranged. I'm guessing the 1.6 16V is the same as in the Opel Corsa? Or does it come from another car? I'd like the street cams. Something that could bring out the grunt in the engine and complement the modifications I've done and will do. I'd also like to punish some of the Honda boys that like to roam the streets around Tampa. The Nitrous makes them sad...I want to make them cry. Also, would I need the intake or exhaust cam...or both? Could you take a look and throw a part number at me?

Thanks a lot for your help man, I trust your input over a hell of a lot of other people!