I know the 2.85 will obviously yeild more gains, but I heard the 3.0 is safer to run on a stock ecu. Is there any truth to this? I would like to go 2.85 but i really dont want any problems that Chevy wont fix. thanks in advance.

yeh im not quite sure....but i wanted to goto the 2.85 also but i herd ecu has to be modded,and could poss. blow the engine!...Hmmm, idk...But i need answers also.

just get the 3.0, not much to gain from the 2.85.

yeh im not quite sure....but i wanted to goto the 2.85 also but i herd ecu has to be modded,and could poss. blow the engine!...Hmmm, idk...But i need answers also.

When you decrease the size of the pully without supporting mods a few things happen.

1) You will throw Check Engine Lights
2) If you leave the stock bypass alone you probably won't throw as many CEL's, but you won't get the full gains from a smaller pulley either
3) If you go small enough, the belt will slip causing a loss of boost.

Just fair warning, but I actually would like someone to try and put just a pulley on the car and tell us what really happens. I know the answer already, but I'm ammused to see what would happen to everyone else. A couple of people on the forum have "magic" pulley's but I don't think they will be the norm.

When you decrease the size of the pully without supporting mods a few things happen.

1) You will throw Check Engine Lights
2) If you leave the stock bypass alone you probably won't throw as many CEL's, but you won't get the full gains from a smaller pulley either
3) If you go small enough, the belt will slip causing a loss of boost.

Just fair warning, but I actually would like someone to try and put just a pulley on the car and tell us what really happens. I know the answer already, but I'm ammused to see what would happen to everyone else. A couple of people on the forum have "magic" pulley's but I don't think they will be the norm.
I just ordered Pulley Technologies 3.0 pulley so I will tell you soon enough what happens with an otherwise stock car! :)

I am supposed to install my 3,0" pulley this very afternoon ! And to dyno it before and after.

I am supposed to install my 3,0" pulley this very afternoon ! And to dyno it before and after.


Awesome!!

I am anxiously awaitting results... don't forget to disconnect the battery to reset the cpu!!

-Rich

Im running a 3" pulley right now on my Redline. Ran 231 whp with it. No track yet though. Car pulls like crazy. I hit 12 psi by 3500 rpm, 14 psi by 4500, and 15 psi by just past 5000. I have the SFPH "DUB" set up and a 3.25" pulley as well. I was running the 3" but resently went back to the 3.25" after noticing possible detonation with the 3" down in the lower RPMs (http://www.cobaltss.com/forums/showthread.php?t=1907). I will be running the 3.25" for dayly driving and changing to the 3" for the track/races. Once I can get a remap of the ECU or a piggypack, I will be running the 2.8" from SFPH. Im to much of a pussy to run the 2.8 without supporting mods.

How the shit do you reset the CPU...?

How the shit do you reset the CPU...?

Disconnect the negative terminal of the battery for a couple minutes.

When you guys go to the 3.0 pulley on the stock car I would be interested to see before and after results as well. Please keep us updated.

Disconnect the negative terminal of the battery for a couple minutes.

When you guys go to the 3.0 pulley on the stock car I would be interested to see before and after results as well. Please keep us updated.
Cool, I dynoed stock at 215 so I will dyno again once installed and post it up.

Why not also look at other ways to help get rid of knock. Such as colder plugs, colder Tstat, and opening up the intake and exhaust. Heat is one of the main causes of KR, so any way you can keep the motor cooler, will help out alot.

A side note on knock. I scanned my car with one set of plugs, then swapped to a set that was one step colder, and lost on average 5* or knock. I'd say its worth a try on your cars.

Plus if I'm not mistaken, the defenition of going "one step colder" on plugs is the ability to drop the temp at combustion by 20*, but if you go to cold, you'll start fouling plugs and end up replacing them pretty often.

Rather then just throwing a 2.8 pully on, why not buy the PSI-FI kit that adds the tuning for a pulley that small and a new tensioner. its only 550 bucks. If I owned a Redline or SS it would be my very first mod. But thats just me.

Rather then just throwing a 2.8 pully on, why not buy the PSI-FI kit that adds the tuning for a pulley that small and a new tensioner. its only 550 bucks. If I owned a Redline or SS it would be my very first mod. But thats just me.
I think the reason someone would just throw on a pulley instead of the psi-fi kit is because $$$. Someone on either this site or redlinforums ran a 14.1@98 with only the 3.0 pulley where as the only posted time I have seen for the psi-fi kit was a 14@100. Pulley only cost around $60 where as the full kit is $550.