I was considering getting some 720's as my secondaries because I am running the stock turbo with haltech around 13psi.

I will be uprgrading in a year or so so a bnr stage turbo and looking for 350whp max.

Should I get the 720s and later make them my primaries, or should I get bigger injectors for now.

I dont want to get 720's and have them start to max out with the stock turbo spooling around 13-14psi.

 

If you have the Haltech i would just get the 1600's right from the get go and not worry about the 720's, the 550/1600 combo can flow enough gas for plenty of horsepower so you need not worry after that, and they are cheaper.

 

can I get the 1600's to turn down enough as my secondaries to act like 720's around 70-75% duty cycle.

I dont want to have the problem of running too rich up top because I can slow the 1600's down enough.

And I have heard things about transitioning between injectors like this causing hessitation. I dont know if there is any truth in this when haltech is being used

 

If someone has hessitation in their map its because they havent tuned the transition point properly, its possible to get great fuel delivery and no hessitation in the transition with 550/1600 combo.

And yes, you can dial them anyway you want.

 

550/1600 secondaries is enough fuel for over 600 RWHP. Little overkill unless you feel like spending the money to get the fuel rail to accomodate those 1600s.

 

well do you guys recommend me getting a 1000cc injector....

And to make it clear does everyone agree 720's will not support 350whp

 

My car just dynoed 347 RWHP ( thats AT THE WHEELS), on 720 primaries and 890 secondaries.

 

Actually, we're getting only into the 420's with stock fuel pressure levels.


-Ted

 

Those numbers are based on the asumption that the fuel system is up to par, IE pump, aftermarket FPR, etc...

Is this an EMS equipped vehicle?

 

I'm also in the same position. Going to install a TII in my 1st gen with a E6K I just got. Going to get my 550 stock injectors cleaned and trying to decide on my secondaries. Streetported TII with stock turbo.. Are 1600 injectors to big for this? Thanks

 

R/C 1200's fit right into my FCs fuel rails with no problems, and the transition at 3800 RPM on my rich E-Manage maps is fine. You can only feel it if you try to rev it before it's properly warmed. And why not get some 680's in the primaries, in casef you don't think the 1200's will provide enough.

 

I got a set of gsl-se injectors.. I think they are 680's right?

 

i beleve so

 

Yes, 680's are from the GSL-SE.

 

I dont know if im getting off topic here, im under the impression that those "supposed 680cc" injectors are in fact bigger, I have personally flow tested on an injector balancing/cleaning machine with mL messurements a pair of those injectors together with a pair of 750cc and they DO FLOW MORE. So by my calculations those 680's are in fact 800 or there abouts.

Anyway, its all a matter of what you have available to use, if you can get the 1600's for a good price, which they are, in the long run its a lot better, since you wont run out of fuel if your application demands more.

And having the Haltech just gives you the advantage of tuning right. That's my 2 cents.

 

Thanks. I will look for some 1600's then