i got my 07 ss/sc from a dealership a couple months ago. just finally go in intake in tonight.
but how can you tell if your vehicle is stage 2? my pulley says 77.9mm on it and has 4 blue screws. i boost about 12.5 pounds though, isnt that normal? and how can i check if i have the 42's injectors?
thanks



p.s. the injen intake is a BEAST! i fell in love as soon as barely revved it.

 

being in colorado. i'm going to have to say yes, it is stage two even though you're only hitting 12.5<-tats where colorado comes in to play.

 

alright. yeah i can beat stock sti's from a roll. could a regular cobalt do that?

 

no idea

 

damn 12.5psi lol

 

You are def stage 2! And welcome to High Altitude! My 2.8 inch pulley only boosts 14.5-15psi in colorado...

 

what would a stock ss boost?

 

12psi where i am atleast lol thats y i found it funny stg2 where u are from is only 12.5

 

thats why i thought it wasnt a stage 2. but the pulley is stage 2.

 

The higher the altitude... the less boost you'll make. Your car will also run a lot slower at the higher altitudes than someone at Sea Level.

Does your car rev to 7k or 6.5k?

7k = Stg2
6.5k = Stock

 

then im stage 2. i can run to 7k rpm. well thank you guys. whats the smallest pulley i can run with the stage 2 injectors?
i know ill need a tune and that.

 

I ran a 2.8" pulley on my Stg2 for 3 years. I definitely wouldn't go any lower than that though.

 

2.9, and make sure whoever does the tuning KNOWS you're on the stage2(42#) injectors

 

okay cool. whats the lowest i could run with 60's? i know ill need a heat exchanger and such

 

With 60's you can go down to a 2.5"... but that is VERY VERY Dangerous unless you and/or your tuner know EXACTLY what they are doing.

You can throw a 2.9 or 2.8 on there now and not necessarily NEED a tune. But once you stick those 60's in, you will need a tune.

 

i wanna probably have a 2.6 . would it be safer to go up to the next injectors?

 

Yes... anything smaller than 2.8 would require larger injectors. Some would argue that you need larger injectors for a 2.8... but I ran that setup for 3 years with no problems at all.

A 2.6" Pulley requires a good bit of knowledge about what you are doing, along with a really good tuner that knows what they are doing. Not something that should be done overnight.

 

You need larger injectors for a 2.8, especially in Colorado. Your idc's are going to be through the roof without injectors and you will be starving your motor of fuel. Risking an injector going static and flooding your motor over a 200 dollar part seems pretty stupid if you ask me.

Also if you are going below a 2.8 pulley I highly suggest methanol injection. It's the best cooling mod we have and the best shot you have of not blowing up your motor!

 

yeah after a 2.9 i plan on getting meth and a heat exchanger. what other cooling mods are worth the money?

 

bigger coolant resivor for the intercooler system or a dual pass or single pass

 

Nah, he's fine with the 42's to run a 2.8 w/ a proper tune. 2.9 untuned is the safest, but 2.8 untuned has never caused issues from my many experiences. Methanol may work, but there is maintenance involved. BEST mods to do are second h/e and dual pass or find a shop to do a single pass. Larger reservoir for the intercooler works WONDERS from my research

Why does everyone freak about the 2.6? I learned to tune on a 2.6/60's combo w/ ONLY a second h/e. No issues. Still stock motor and tranny/clutch.

The only worry would be winter for him, run the stage 2 pulley for winter and the 2.8 for summer and you will be okay. You can pick up power from a good tune tho.

 

2.8? ur maxxing out ur injectors alot with that. with stg2 pulley i was at 110%

 

This makes no sense at all.
I'm in colorado and I run a 2.8 on my 42's and never see over 90% duty cycle, ever! I only see 14.5-15 psi because in Colorado we are at 5000-6000 feet.
Your comment about "especially in colorado" doesn't make any sense. There is Less air at altitude and thus less boost and thus less fuel to maintain the AFR the tune is calling for. Pretty simple, I think you got it backwards.
At altitude we can do things people at sea level can't because of the limited amount of air but in the end we still make less power because of it.

If you think about it, a stage 2 pulley in colorado "should" work fine on the STOCK tune and injectors because he is only seeing 12psi. The only difference is the boost will come on quicker due to the smaller pulley.
Also, a 2.8 on a stage 2 tune in colorado is fine as it's only making 14.5 psi which is what the stage 2 makes anyway. I have dyno proof of this if you would like...

Fact is, people always forget altitude when they tune for and change pullies on the LSJ!!!

But, the winter thing is very true! It gets damn cold in the winter in colorado and you should swap back to a bigger pulley during this time to make sure everything is safe... Thats what I have been doing for 3 years now without any issues and dynos to prove that it works and is resonably safe. But, there are also better ways and 60's and a 2.8 with cooling mods is the best way to go!