I did the fuel injector sizing calculator, and it said at 1027 cfm I would need 50#/hr injectors in order to make 700 hp. I have heard that if ur running over 55# injectors...then the low z injectors are the way to go. Is that calculator even right for a FI car? Are 50's gonna cut a S-Trim 383 with AFR 210 heads? If so is it worth the 400 bucks for the Acceleronics module running only 50's?

 

If your going to buy the converter I don't understand why you wouldn't step up to a larger injector like a 83#/hr and never have to worry about injectors again. Just an Idea!

 

NtenseZ28 - I pm'd you.

 

Because once I hit 625 rwhp...I told myself I'd stop modding it out. That's as much HP as I want for a street driven car. I'm not a huge drag racing fan....so the car won't see much track time at all. I just wanna make sure this project comes out PERFECT!...then I'll buy another car/truck to play around with. If 55's get me that magic 7 at the flywheel...I'll be very happy...for at least a month!

 

Get some low-z 72lb injectors so you'll have some room to grow as I doubt you'll want to quit. I'll be going the low-z route when I gi FI since low-z injectors will have a much better idle quality than the large hi-z injectors.

-Tony

 

There is NO DISadvantage to running a 75 lb/hr injector.

 

LJ's FAQ does a good job explaining the why's of running low Z vs. high Z injectors...

http://www.acceleronics.com/faq.htm#1

 

I catch the concept...just wasn't sure if it was necessary....but I guess the cost of upgrading is nominal compared to the overall investment I've made in the car.

I was a technician at a dealership for over 3 years...went to college for cars...yet the hot rodding end of it is so different. I know how all the systems work and how to build a motor, however, the dealership makes you learn how to fix them...not get every possible ounce of performance out of it! Obviously my previous experience helps a lot...but there is a lot more to it. Having you guys a keystroke away really helps a lot...I REALLY appriciate it.

 

wait, if i wanna convert to a low z injector, say 55# or higher, i'm gonna have to get something like this to run it? http://www.acceleronics.com/versafueler.htm Will I burn my injectors or ecu if i don't?

 

Actually, Motron is producing 60# high imp. injectors, and RC Engineering is making 65# high imp. injectors.

http://www.forcedinductions.com/product6.htm

 

It will burn up the ecu if you don't.

 

Those will give you a crappy idle and throttle response right? I've heard those are so large and sluggish...they're essentially useless (kinda like in-laws ) for use in a car that is streetable.

 

No, they're designed for street cars. Several guys on the Corvette and Buick forums have had good luck with them. Also, a friend of mine ordered a set for his Z, as soon as the big F1 is ready to go, he or I will probably post on how well or not so well the injectors work.

 

They wont work near as good as low-z injectors though. I'd bet you get some even bigger low-z injectors with the impedence conveter and they'd have much better driveability than the hi-z ones.

 

Yup, I would recommend doing the impedance box and 72#/hr injectors so that you would do it right and do it once only. I have been running this setup for almost two years without any problems. I have driven this in the traffic jams in 95F temperature. I have driven it without the supercharger and it runs great as well. The car idles great and response really well. This setup also allowed me to get 611rwhp with stock fuel lines, stock fuel rails, one 340M intank fuel pump, and a Voltblaster.

You can go to www.caspeed.com. Allen has a similiar setup as you and tried to run the MSD 50#/hr injectors. He has the dyno and the LT1 files on his site. He was almost maxing out the injectors at ~525rwhp at 49psi fuel pressure. So with 50#/hr injectors you will not be able to get over 600rwhp with any reasonable fuel pressure.

cheers