Hey Guys,
I have 1989 Camaro with a fully built 383 stroker motor with all forged internals. I have the stock injectors that I think are 21# and a stock fuel pump. What size injectors should I put in there for optimal performance? Also do you think that I will need a new fuel pump?
Thanks

 

What heads cam and compression? What intake manifold?

 

Stock intake, 10.5:1 compression, edelbrock performer heads, comp cam extreme energy cam

 

Stock intake, 10.5:1 compression, edelbrock performer heads, comp cam extreme energy cam

 

It needs tuned. What cam part number?

24 lb injectors typically should be used in a stock tpi setup. May stretch them 21's depending how much power its making. Those heads arent anything super special and stock tpi is gonna limit hp, so likely wont need alot if injector.

I would def consider new fuel pump, drop in walbro 255 kit

How do you know for sure its starving for fuel?

 

Had a tune made for it and plugged new chip in computer. I think it needs put on a dyno and redone though. Cam Part number: 08-412-8 The heads got a new set of springs done on them.

 

get a data log. To check your Current Duty Cycle. Internal material is meaningless. So TPI, Pistons must be dished OR you have larger CC heads. With only 10.5
24lbs injectors will cover a 350 LT1 with 360HP. If you are above this HP range you should be looking to upgrade. between 28-30lbs depending on HP and actual DC.
most importantly.. your running a STOCK prom??

 

Had a prom chip made for it with all the new specs. Motor builder said it will be making around 450 HP

 

you need the PROM's info. Did this tuner give you a print-out??? 450- with the face value right now. is NO.. it's a mild cam.

 

I sent out for the chip. I gave hawks 3rd gen all the specs. It's balanced and has roller everything.

 

you still have no clue. What they set the injectors for. and so- ON. The forged, Roller. Is a great Luxury. This will not add HP.. Balanced is mandatory.. You need to know your injectors Duty Cycle along with other readings from data logs. SO if you told them a guesstimate of 450HP. Why are you using 21lbs injectors?

 

.

 

All I gave them were the specs of the engine/heads/cam/etc. I just want to know what size injectors I should run with this set up until I rip this fuel injection set up off and put on something better. The purpose of the motor was to be "bulletproof" and make a decent bit of horsepower.

 

again. I really think 450 at this point is NO. 360 - 380 is more realistic. if this is the case?? 24 - 28lbs current guesstimate. You need to get a data log of your current injector duty cycle. Also what is your current fuel pressure @ idle & WOT?? You have accomplished the short blocks build durability!!! you may need to increase this a few points. A intake upgrade such as the HSR. Will change this HP dramatically. But now you will need more tunes.

 

What should the fuel pressure be at idle and WOT?

 

43 - 45PSI also depends on the Injector Manufacture.

 

Where in pa are you? If you are near east of pittsburgh take it to FJ Performance for a dyno pull and log. We'll tell you what needs upgraded.

Cam is mild. That wont make anywhere near 450 hp. 375 maybe with stock intake. Mayyy stretch 21's that far with right tune. 24's def will cover it