Help me select the right size injector

[oldman]

All ready searched. Hey guys, please help me choose the right size injectors for my new turbo t04b h3. Engine is stock 123,000 original miles except for lifters with 2g mas. I will eventually rebuild the head and bottom end but would like my stocker to last for a while. My question is which injector size will allow me to take as much advantage of the turbo without endangering my engine? I was thinking Denso 660's or 720's. A link to tech articles concerning relations between turbo, ic, mas, injectors...etc. I plan to go to the book store tomorrow so any reading recomendations are welcome as well. Thanks.

I guess tunning 101 or something.

 

[yo2001]

I would go with 720cc if you can tune it. It's pretty big for a stock ECU's

 

[PieTSI]

What device are you going to be tuning with? If its an S-AFC, use 660's.

 

[oldman]

I wil have eprom ecu with keydiver style setup and safc. I will rely heavily on the eprom setting to handle the mas and injector then use safc to fine tuning. I do know either the 2g mas or the engine flow will be the restriction so I guess if some one can tel me what the cfm of the 2g mas and an unported head (safe level) would help me decide which injector size. This is where things gets complicated, sorry I'm trying to be as clear as I can.

 

[herostar]

720's if you're getting the ecu work done. 660's with just the safc.

 

[oldman]

720's if you're getting the ecu work done. 660's with just the safc.

herostar, I see that you do not have any afpr with the 255lph. Are you having problems with overunning of the stock fpr? Thanks.

 

[Mirage2LTurbo]

I've run 880's and 750's on just an SAFC. No problems, just retard the base timing a few degrees. Ran reall strong.

 

[oldman]

Please keep in mind my main concern is keeping my stock bottom end intact. I'll be removing the rev limiter and fuel cut so I don't want too big of an injector where I might hurt the stocker. I do understand I will not take full advantage of the turbo until engine rebuilt. Thanks.

 

[logic]

If you're having keydiver burn a custom EPROM for you, you might as well get the biggest injectors you can afford. 950s, properly compensated for in the ECU, will idle like stock, and 99% of the folks out there will never outgrow them.

You will not hurt your engine with bigger injectors. Where on earth did you get that idea from? You WILL hurt your bottom end by doing silly things like removing the ECU's built-in safety features, and then revving the crap out of your engine. Frankly, you'd blow up faster will smaller injectors, since you'll go lean earlier.

Stupid behavior begets broken parts.

 

[oldman]

Thanks for all the input guys, 720cc is what I've decided on. Last question before I wrap it up, Are Denso's really with the extra money and why? I heard that FIC's does not flow consistantly, true?

 

[logic]

I heard that FIC's does not flow consistantly, true?

There's a lot of DSMLink owners who'd disagree with that; FICs are a favorite on the 'link forums.

 

[oldman]

I'm about to buy a set of Denso's, the guy tells me they're better because of the pulse width. Can some one educate me on that?

logic, Thanks for that info. If this deal falls throught I'll probably just go with the FIC's.