if you have the stage 2 and the 42lbs injectors, you should be fine all day long. if you try to go to a 2.7 or smaller, you would need to 60lbs'ers.

 

First off, every car is different. The only real answer is to monitor your car with the 2.8 and see what the IDC's are Either using HPT or an Interceptor (IPW + This calc (http://www.stealth316.com/2-calc-idc.htm)).

What Altitude are you at? If your below 2500-3000ft than I would say (based on what others have seen) that Bigger injectors are required (At least 50's). If your between 2500-3500ft I would monitor the car all the time. Temperature can play a big role in this also. If your above 3500ft, the 42's should be fine. Should being the key word. Every car is different so watch what is going on and don't run an unsafe setup for very long.

Yes, the stage 2 belt works fine with the 2.8.

 

How Small Can The Pulley Be With Out Switching The Injectors

 

whodis mentioned this earlier on #2

 

I see how that makes sense with the altitude and less air. If I used an HP tuner on my car with the 42 lb injecters and 2.8" would it make a difference or do the injectores just not have it in them to push it that far? Also what about a bigger fuel pump?

 

we deff. dont need a bigger fuel pump

 

I'll try to sum up all the answers at once here...i have delt ALOT with thsi subject and many like it.

...here we go!

no we totaly dont need a new fuel pump...its good for FAR more HP then our motor is in stock config.

2nd....unless you are at some CRAZY alititude you WILL NEED larger then 42.5lb/he injecters that the stage kit gives...END OF STORY.

i have posted HPT data logs on many ocasion of my old set up wich was a 2.7 with the stage injecters..... the .10in differance between a 2.7 and 2.8 will make a VERY small differance in your IDC's if you were to compare a 2.8 and a 2.7

i saw 118%-122% IDC with a 2.7....thats in excess of 30% higher then you want to run an injecter in a "every day" car(or any car for that matter)

a rule of thumb is that you want to keep your IDC under 90%-92% range.

with it geting colder its only going to raise your IDC's becase the car will command more fuel due to the colder and denser(sp?) air....My logs were done when it was 80deg out with michigan humidity.

when our stage injecters pas the 92%-95% IDC range they go "static"...in other words the just stay open and dump fuel sence they cant keep up with the ECM command

when that happens you loose your AFR control and that can and does lead to blow LSJ's...BAD BAD BAD.

also when an injecter is ran to and past its limits offten the injecter is more prone to breaking it self...and that'll blow a motor in about 3secs....not enough time for you to react.

any time you start steping pully size down and/or you do custom tuneing its always a good idea to get a solid Wideband 02 guage and sensor so you can track your car and avoid a blow motor....they also play a HUGE roll in geting your tune "just rite" for your car.

HTH

 

Well that pretty much sums it up like you said. what size is the stage 2 pulley? I think it is just a hir bigger then 3.0" isnt it? like 3.05 or something? So would I be safe getting maybe a 2.95 If I can find one?

 

if you want that size pully i recomend the BilletFlow 2.9....best looking pully out there and amazeing quality!...they have a pully ring in every color so you can match your car!

run that pully with the 42.5lb/hr injecter(the stage kit units) and a stage tune or a custom HPT tune and you'll be real happy!

rember that as you step down pully size your going to need a clutch
out stock unit has a hard time with stock power levels...you could pull off a 2.9/2.8 with a stock clutch for a while but its going to wear out kinda fast...

anything under a 2.8 i recomend doing a clutch rite then and there becase the stocker cant handle the power.

a clutch may not feel like its slipping while driveing but it is!....

when i had 60's/2.7/I/E with a stock clutch it sliped so bad that i could barly pull on my buddys totaly stock ss/sc and it never felt like it was sliping.

 

HMMMM... now i have to upgrade injectors... i just ordered the 'pulley boys' 2.8 pulley & they said " most people still run the stage 2 injectors, so i dont believe its neccessary" they said not to quote them on it cuz all cars react diff. but i was hoping it would be ok... it looks like the 60# will have to be ordered now....

06black,
what about the plugs?

 

they are rite...most poeple will run stg2 injecters becase they dont know better.

you can get away with it.....i in fact did for a while but its something you always have to worry about...and you cant drive the car 100% when it gets col and such becase you dont have the fuel....its just a pain in the ass to worry about things that a simple injecter swap can fix.

as far as the plugs go you need to have 1-step colder with anything below a 3.0pully

my current fav plug is the ZEX plugs...they are 2 steps colder but with my 2.5pully they are amazeing...great plug!

they might be a bit to cold for the winter but i havent had alot of cold weather to log the car into get a "for sure" answer about that...

the NGK BKR7E seems to be the fav 1-step colder plug...

WHEN GOING COLDER ON YOUR PLUGS MAKE SURE U GET A COPPER CORE PLUG!!!!!!!

 

How much was your spec stage 3 clutch? Im also guessing you did it yourself?
I think Ill go with the 2.9 then. How much is the billet flow pulley? do you have a website?

 

lol the clutch is the 2nd most exspancive thing i've done next to the axels.

they are like 650ish from

www.ultrarev.com

Billetflows website is simple.

www.Billetflow.com

Doug the owner of BF is an amazeing guy....his parts are top notch and he puts more thought into them then any other company.

 

yeah thats a lot of money to spend. I dont have that right now. We'll see what happens.

 

So why does Cobalt Addiction sell there stage 3 with 42's and a 2.7. Also would a spec stage 1 clutch be ok with the stage 3 and an intake.

 

i'm a bit unfamilar(sp?) with the CA kits so an exact answer i cant say...

however that is a question that has been asked many times on many differant cobalt and IRL forums...but no solid answer from CA.

what i can say is that they might be able to do depending on what there rev limiter is set to.....but it has been proven many times in many differant places on many differant cars that at a high limiter(7k plus) a 2.7 over-max's injecters and cause's them to go static thus leaveing your car with no AFR control...let alone COT's and piston protection that is lost when you loose injecter control.

as for the clutch i would only recomend stg2 and higher...rob first went 12.96 with a spec 2+

 

What if instead of getting the reflashed pcm i get the MAF Translator and keep the stock redline. Then do you think I would be ok with 42's or should i stick with something smaller like 2.8. Sorry for beeing a pain i just want to get this stuff strait before i invest money on an unreliable setup. I want to make as much power without having to replace the clutch. thanks for your help.

 

lol...your not gonna like this.

if you pull up the stock clutch specs(its an excedy unit) look at its power handleing abailitys and you'll be suprised by how horibly low they are.

a CAI and exhasut will put you over that limit.....sorry

dam neer any type of stage kit will make the stocker slip...that over time(sooner or later) will blow it out.