so Im waiting for my belt I ordered from a guy off here and my pulley/hub 3". BUT, I have my tuned ecu, colder spark plugs, and 42# injectors that I am contemplating putting on without the pulley/hub for now. My question to you is... will it mess anything up? I was thinking it would run a little rich seeing how it wouldnt be getting the extra boost yet. Should I just wait it out? I have limited time off work and need something to do tomorrow with my day off, because otherwise I will just do yard work

cobaltss > yard work ?

 

is it a gm stage two tune? Mostly all stock tuned cars can benefit from an aftermarket tune, leaning it out, adding timing, etc

 

its the ottp stage 1 kit, which is basically like the gm stage 2. Just want to test out the new 7200 rev limit, and torque management, but not sure if I need the injectors and pulley on, I was thinking the 02 sensors compensate for the air/fuel anyways, I just really wanna test out the tuned ecu.

 

If you put the new injectors in the car it will run fine without the smaller pulley. You may run rich, you may not. Alot depends on how the tune is done as to whether it will run a little rich or alot rich.

 

I believe the Stage 2 tune will probably not like the lack of air that it is expecting from the 77.9mm pulley. I would stay on the stock PCM for now until you get the new pulley/hub. GM's tune is tuned on the rich side, so you may end up running stupid rich.

 

1. He said it is OTTP stage 2.

2. GM stage 2 tune - pulley = GM stage 1

3. Most of the tunes are MAF based, which means that a smaller pulley = less air = lower MAF values = less fuel. As long as you are tuned for the injectors it won't throw the car off by that much. Some tunes can be VE based which will then throw off the AFR if you are tuned for a smaller pulley, however most LSJ tunes are MAF based.

 

ottp stage 1 tune, 3" pulley, #42 injectors. Ill just wait.

 

You will be fine with the 42lb injectors installed. It shouldnt run any richer with the stock pulley. Its all done by the maf. If the maf is scaled right it will adjust the fuel to the amount of air going in. Its just like getting gm stage 1 and then upgrading to stage 2. You should gain hp and youll be able to rev it higher.