Can a 2.9" pulley be used with the Stage 2 injectors and tune safetly?

 

yes it can

 

Would I feel much of a difference?

And what if I decided to get a downpipe and header as well? I am just afriad that the GM stage 2 tune will not be supportive enough.

 

the difference would be in torque not much in hp so your low and mid range would pick up a good amount of power ... and the header and dp and you should gain a good amount of hp. ct has the same setup and is putting something around 240-260 tq/hp

 

I'm not sure but I do know you will THINK you feel a difference at least, lol

 

Okay, well I am thinking very seriously about doing this. I have stage 2 right now, and well I want more haha. I would get an HP tune, but nobody is remotely close to help me out with this so that is the reason I was wondering if the GM stage 2 tune would support it. Does anybody have a clue as to if this would run lean?

 

according to cobalt addiction the 2.8 is actually the best for the gm stage 2 tune

sorry 2.79
" The top of the groove has a diameter of 2.79” . These have been proven to run great on the GM stage 2 reflash as it is very rich fuel wise to start with and this will bring you right into the correct AFR"

 

There is no way I'd go down to a 2.79 with stage 2 tune, heck I"m worried about going to the 2.9. Reason I was asking if the tune was rich.

 

yeah the stage 2 tune is so rich that a 2.9 is definately safe

 

that is wrong unfortunately

 

Can the stock tensioner and GM stage 2 belt be used?

 

well like I said, thats CA not me lol

 

the stage 2 belt is super tight as is and people were using that stock setup with even 2.8" pulleys back before it was discovered a 2.8 was bad so yeah you can use it

 

I just ordered a true 2.90" pulley,


cant wait to see how that feels compared to the 3.06" which is on the stage 2.



dont see how you cannot gain HP from a pulley.... since it is making the blower spin faster..... but nonetheless i cannot wait to get it on.

IIRC the boost should be around 17?

 

you do gain hp just not much at all. boost depends on a lot of other factors but if all you had was a stage 2 and 2.9" it should be right about 17.

 

I have had the stage 1 with 2.9" pulley for about 3 weeks now. Love it. And yes, its about 17 PSI.