I got an f1a to run on my 355 LT1, shooting for around 700rwhp through an m6 with meth. What injectors would you guys recommend? Would 60's be big enough?

 

You are going to get some different answers regarding injector sizing here. Additionally, it depends on the formula you use and the different parameters you choose to plug in.

I have a similar set-up to yours except I have a 383 with an F1-A. I'm using 95lb. injectors that are being fired by a Big Stuff-3 system. Some may think they are too big for the application, but I would rather not worry about pushing the limits of smaller ones and there wasn't much of difference in cost. In your case, I believe a set of 83 lb. injectors would be adequate.

 

I'd also make sure your fuel supply is up to par. How is your fuel pump situation?

Ken R.

 

Well right now I just have the racetronix 255 and plug n play kit but i'm going to do two in tank pumps, and get a boost referenced afpr. I don't think 60's will be up to the task. whats the next good size after them? I see Racetronix has some new 79's too.
Boosted z28, what kind of power are you making and at what boost level?

 

83's or 96's and be done w/ it. Like Boosted Z28 said earlier. Do it and do it once.

 

If you plan on running 700+ RWHP by maxing out or running a bit of boost with the F1A, I would say 60# injectors will be either at their max duty cycle, or too small all together. Anything above 70# injectors and less than 100# injectors should be fine with a good tune.

 

Just fork out the cash and be done. I'm running a P1 on a 383 with 50# inj and meth and its still lean at top end. I just ordered 96# and the imped converter

 

Ideally you want the right injector size for your setup. Something running at less than 95% duty cycle, but more than 50%. It is true that its better to have too much injector rather than too little, however 96# injectors are WAY too large for a P1 and a 383. I am running 60# injectors with my maxed out D1SC and a 383 and my setup is perfect, which almost makes me wonder why the 50# injectors you have aren't enough. What duty cycle are they at?

 

I am in the same boat really.. I have the 96# but I am REALLY not keened into the impedance converter. I wish to have a more stock setup than that.

Now, Will the 78s High Impedance be a good buy or are they simply too lazy?

With the 96# I am concerned with the idle being too rich...

 

Running 72# Seimens Low Z with an Acceleronics box. Stock PCM OBD2 with my own flash. I went with LJ's package. Decent price. He also has alot of valued info on High vs. Low Z injectors on his web site... acceleronics.com. I did a twin Walbro intank pump with -8an plumbing. Lack of fuel flow can be a problem with the small tight radius lines (my opinion) Running my fuel system @ 43psi with a remote fuel regulator. My app... 97ss 383 D1 M6. B.