Sta-meng

Can i do the stage 2 tune and put 60lb injectors and run a really small pulley to even things out??

BOOSSTED 06

no you need to get retune for those injectors

Sta-meng

that blows

jimbos'ss

iTrader: (2)

no, you must put in a 60lb injector table. the pcm won't be able to control thse injectors with out it.

Deathcult

what injectors are put in for S2?
and whats stock injectors?

Sta-meng

wat the hell is a injector table?

chris88z24

Stage 2 = 42# injectors.
I forget what stock is.. 36# maybe? Someone else will chime in i'm sure.

BOOSSTED 06

its HP tuners knows what injectors its controlling, single line table in HP Tuners

I think the stage 2 injectors are 42 lbs

Sta-meng

42.5 lb Stage 2
and i belive your correct on the stock.

cobalt_driver

ya stage 2 are 42pounders. 60lbs is an intense jump. hope u got supporting mods.

Deathcult

and what exactly are the functions of the injectors...like the intake is where it gives the car oxygen to run. or well cold air.

Hockeyman

iTrader: (4)

are you serious? you don't know what fuel injectors do?

Onyxd04Redline

What will the car run like with 60's and a 42lb injector tune?

Deathcult

dude, i wouldnt ask if i didnt know.


so injectors are called fuel injectors...does it physically put fuel into the engine???

K-Train04RL

iTrader: (1)

do yourself a favour, if you want to do anything to a car, you might want to know how the basics of engines work.

im too lazy to find out if this site will inform u well but engines are basic, just do some research.

http://auto.howstuffworks.com/

Deathcult

then tell me why is it the ecotec engine is supposedly the "strongest" 4 banger in the market today?

and im still learning btw.

G85 SS

You know what else blows? #4 with too small of a pulley.

I would recommend nothing smaller than a 2.8 on 42.5 pounders.

Badju587

Hey Deathcult, I'll give ya cliff notes on the whole thing. This is my understanding of the subject and might not be 100% correct, keep that in mind as you're reading. If anyone who knows sees anything out of place with anything below, I'm all ears

Injectors physically put fuel into the engine. They're controlled by our Powertrain Control Module (PCM), which has a lookup table that, put simply, tells the computer how much fuel should be pushed through the injectors at a given RPM, also taking airflow into account.

Now, the ratings on the injectors are measured in lbs/hr at an (I believe) 80% duty cycle, or IDC, meaning the injector is receiving power 80% of the time. IIRC, stock is 36-37, S2 is 42.5, and then there are the 60's. IDC is a function of the engine RPM and the Injector Pulse Width (IPW), which I believe is what the PCM has a lookup table for, to determine the IPW for a given RPM. This is why putting 60 lb/hr injectors on a S2 tune is bad, the pulse width will not change and you'll run too rich. Putting a smaller pulley on will only make the problem happen at higher boost, as the lookup table does not change, it just tries to force more fuel in to compensate for the additional air.

You need a tune to change the IPW for the larger injectors, so you're pushing the same amount of fuel, assuming nothing else changes in your engine. The reason people run 60's with smaller pulleys and airflow mods is because the injectors can handle the increased airflow without going static (which is when the injectors are permanently open) and creating a lean condition, which usually results in a blown #4 piston thanks to our returnless fuel system. Now, there are always other mods to consider when pushing that kind of air (cooling mostly, traction with that kind of power is also a concern).

In short, 60's on a S2 tune = bad.

mafiahitman88

ZZperformance have a computer that you can buy that they can set it to 42 lb or 60 lb injectors for a $150.00