injector size??, maybe someone is running this setup? Options

[SPOOLED91]

i'm gonna do the 3" Gm mas w/ translator setup. I know you can tune fuel with this and i just wanted to know if i should go with some bigger injectors when i do this to aid my tuning. i have a walbro 255 and plan on getting that new FPR natedogg showed us.
the turbo will be an EVO 16G and i wanted to know if bigger injectors will help or harm. i know sometimes too much fuel can be just as bad as not enough. if so what size? 550cc? 650cc??

[natedogg]

The only thing I disagree with in your original post is where you say he HAS to go with at least 550's. You know how well my car ran on the stock fuel system with the 16g. You logged it with me plenty of times. But like I indicated in my previous post I think 550's are a good idea, necessary or not, better to go with the insurance than to later find out you should have. So I did agree with you that its a good idea, just not that it may be absolutely necessary. Basically, giving my spin on it based on my experience with a 16g turbo.

I attributed much of your knock to running 19 to 20 psi on a 14b turbo. Way out of its efficiency range, esp. on a stock sidemount IC. Not necessarily overrunning your injectors. You may remember still knocking like a whore even when you switched up to 550's. Buuut 19-20 psi felt better to the famed butt-o-meter, so that's what we stuck with. (Disclaimer: it felt faster to me too, yet at the expense of another engine, but that's cool because the ragged edge is your thing and I respect that.) Remember I was only running 17-18 psi on my 16g, which is even still a more efficient turbo than a 14b. This helped keep my knock down even on the stock fuel system.

Also, the fact that WI helped knock down your knock counts by cooling the air charge, lends itself to an inefficiently hot air discharge from your turbo causing the nasty detonation, rather than insufficient fuel supply.