what will the stock injectors handle..
what kind of pressure and how much hp at that pressure? i've moved to an aeromotive a1000 fuel system but don't have cash for injectors. looking for 400rwhp now and i was thinking of adding a dry shot to it, so i need to know what they'll take, because i have headroom on the rest of the system...

mike

 

They have been run on 400rwhp applications, but its risky. They go over 100% work load I believe. You don't want injectors to go over 90%. The more they work, the more likely they are to break. If an injector stops working at 6,000 rpms going down the strip............................................. ....................................KABOOM!!

 

You don't have cash for injectors, but you want to add a dry shot to it huh? That makes a lot of sense.

You can get bigger injectors for less than $300. Save some money. If you half *** a dry shot you'll be buying another motor, so do it right and do it once.

BTW I was at 92% duty cycle with mid 300 rwhp.

 

30# injectors will bring you to around 90% duty cycle at around 400rwhp.

 

He can up the fuel pressure by adjusting the regulator to get that duty cycle down some.

If I read it correctly, he wants 400 rwhp, then add a dry shot on top of that. You've got to be f***ing insane to try that on stock injectors.

 

lol, ok, well i'm shooting for 400 anyhow, it's a 230/236 car with heavily ported stock castings and all the other basic bs, like i said i have the system to raise the fuel pressure, i've heard of people running 90psi but i don't think you can do that on stockers. as far as the dry shot i have a bottle and my buddy has a carb kit, all i need is a nozzle and i could rig a shot up easy enough. wouldn't cost me $300, but if i've got injector issues running NA i'll just have to wait on spraying it.

so basically your saying i'm maxing them out running NA....

what the highest pressure's the stockers will take?

 

In my opinion you'll need to upgrade them for 400 rwhp. Some people will tell you it's borderline, and some will tell you that you won't have enough fuel. I'd rather spend $300 more dollars and be sure. Although I don't think you'll see 400 rwhp with that cam unless you have the best flowing stock LT1 castings ever.

Heads/cam/dry shot on stock injectors=a motor that's all s***ted up. I bought a set of 38 lb/hr injectors from racetronix for about $280 plus shipping, and those should be fine for your goals. You might have to end up raising the fuel pressure to compensate, but it's no biggie.

 

You may be just fine with stock injectors and a WET shot, but i would want to know the duty cycle before i pushed it. and you may not have 400 rwhp so who knows. I wouldnt want to run a dry shot just for the risk of relying on the comp and any injectors to supply the added fuel that will be needed.

 

Here's a calculator for injector sizing. It's for flywheel HP.

http://www.smokemup.com/auto_math/fuel_injector.php

 

nice, according to that if i bump the pressure up to 75psi i should be good.
so anybody ever run stockers at that pressure?

 

i used to think the same way, but your always relying on your o2's to set your fuel flow, so what's different? anyway, i'm only talking 100 shot or so, i've got stock pistons and rod's in her yet so i've gotta keep it light.

 

I'm running a gm847 cam and the works with stock injectors. Should I up the fuel pressure on my setup to compensate for the stockers?

 

You don't want to push any injector above 80% duty cycle. If you are adding a dry system you may want to run 42# injectors.With increase in pressure over stock (43.5psi)to 58 psi these injectors will flow 48.8 #s.
Remember , you will have to have them tuned for the larger injector AND the increase in operating pressure.
Cheap insurance to drop the $280 for injectors rather than grenade a motor.

 

GET BIGGER INJECTORS OR YOU ARE GOING TO BLOW YOUR CAR UP, IDIOT.

How hard is this to understand? Do you want to chance your whole motor to some 11 year old fuel injectors that you are slamming with almost twice the fuel pressure they were designed to work with? Sorry to be rude, but people on here are telling you what to do, but you are not listening because we're not telling you what you want to hear.

 

I agree. It seem slike running stock injectors would be like running stock bearings with 11 years already on them.