Okay, under WOT acceleration I can hear random pinging from 4K to 6K rpms, from 6k to 7k everything sounds smooth. The engine light has lit up two times but goes away with a few minutes of easy driving.

I decided to switch the 2.8 Pulley with the Stage 2 Pulley to see if that would make a difference.

(Side story: The lug that you use to relieve tension on the belt has rounded off and a wrench won't fit it anymore. I had to order the "Idler Pulley Tension Relief Tool" from Pulleyboys. It works great, I love it. Thanks for the UPS Two Day shipping.)

Well, after putting the Stage 2 Pulley on, the pinging went completely away. So my question is how do I use the 2.8 without pinging? Bigger fuel injectors? (60 LB)

If so, will I need tuning or can I use the stock stage 2 tune since I'm obviously running lean with the 2.8?

Thanks

 

tune man... all in the tuning

 

With anything other than the S2 42# injectors you will definately need tuning. I would recommend getting a wideband AFR gauge to keep an eye on your A/F Ratio.

From what I've researched, you're cutting it real close using a 2.8" pulley and the S2 injectors. I don't necessarily want to get 60# injectors because they hurt driveability and are just too big for a 2.8" pulley. I'm trying to find something in the middle, but it seems to be uncharted territory. If I were you, I would hold off on using the 2.8" pulley, at least, until you can get it tuned with the pulley on the S2 injectors.

EDIT: I've heard a 2.9" pulley is safe on the S2 injectors and tune. There are quite a few people on these boards running 2.8" pulleys on the S2 injectors and tune. I haven't seen any dyno charts or data logs showing that they are not maxing out the 42# injectors though. Just be careful, the gauge would be your best investment.

 

Also, try dropping your spark plug gap a little...I gapped mine at .38 and had no troubles at all. It may not fix it, but it's a cheap and easy guess.

 

You actually hear pinging? What do you have like superman hearing?

Pinging is the first step on the path to detonation and that has been ending up with nasty result like cracked/chipped pistons. With a 2.8 the boost and added heat comes on faster, that said I run a 2.8 with 42# and nitrous and I never hardly EVER get spark knock even when spraying a 50 shot. Only difference that I see between me and you is copper plugs with a 40 gap and I run stock timing which is less aggressive, I do lose power cruising without the juice on.

Maybe check on some new plugs and gap them correctly, there are tons of plug threads with all sorts of opinions.

 

I have looked into getting some 55# injectors because I believe the PCM could map them correctly. I have also heard the 60# Siemens injectors aren't the best injectors on the market and aren't accurate (flow matched) and can leak when they get some mile on them.

 

No, pinging = detonation

Maybe I should put my stock plugs back in and see how it reacts.

 

Having helped on 4 vehicles now, I can say with some authority that the Stage 2 + 2.8 works JUST FINE as long as you follow a couple simple steps.

Get them both done at once and do NOT drive the vehicle until you get the new flash
Make sure you get the 1 range colder plugs and gap them between .035 and .038
You MUST run only high octane fuel for at least a couple of tanks, do not use lower octane with booster


So long as you follow these steps, I have not yet seen a problem.

- SK

 

What was the CEL that was set? Do you know?

 

2006 Cobalt SS Supercharged w/G85 LSJ
GM Stage 2 - Installed (6-26-06)
Pulleyboy's 2.8 - Installed (6-28-06)
Injen Intake w/Hydrashield
Autolite 3923 CopperCore's (Gapped at .040)


Theres your problem man. Its your intake. I had the same problem.... The intake is making your car run lean... The intake is throwing off your MAF tables....

Get the car on a dyno & tuned or put your stock intake back on.

Good luck and don't blow it up.

 

i run 91 BP gas with Octane Booster i gots the GM Stage II and a 2.79" pulley with NGK Iriduim IX Gapped to .30 n it seems to be runnnin fine! boosts as 18-19psi at bout 5800 thru 7000rpm. i do need to get sum electronic equipment n freer flowing exhaust, but it runs totally fine so far! i will have the Cold Air Intake on on Friday, to see how much of a difference it makes, see if it gives me that same problem or not!?!?!?