Recently installed the OTT stage one which is the 60 pound injectors and 2.8 pulley with minor tuning. So to took off my throttle body to clean out the carbon despoists inside to hopefully help with my idle and what not which it did. But on my way to work i went to get on it and it went up to 15-17 pounds but then bleed off to around 12. Does this threw all gears. So on my break i went out and messed with the vaccum line connected to the throttle body and seemed to semi help...Boost seems sluggish in 1st. holds 14-15 in 2nd and in 3rd goes up at 15-17 but then bleeds off again down to about 12...So with that in mind. Does anyone have any ideas what this could be? I tryed re adjusting my throttle body and what not and unplugged things and plugged them back(the hard line coming off the throttle body). I was thinking maybe the bypass valve is not opening and closed like it should or something along those lines. Idle is normal and does not jump around, so which pretty much rules out vaccum leak. As well as there is no normal driving issues. Only when boosting...Any help?

 

mine did the same thing and it was a vacuum line collapsing. it was the hose that connects to the little black box where the hard line connects. sorry cant remember excatly the name, went turbo lol.

 

Talk to Josh at OTTP,he should be able to help you.

 

Did they send you a new PCM with the tune on it? It sounds like the tune didn't remove the stock boost limit of 12.5 psi.

Could also be that the car is pulling boost becasue of IAT2 temps being too high. The 2.8 can create quite a bit of heat for the stock IC system to handle. You could always try doing some logging to see what is happening, of course that means using HPtuners...

 

The computer got tuned for the new pulley and everything like. I actually took mikes tune since we have pretty much the same exact setup. I am gonna stop by the chevy dealer and pick up a bypass tonight. I redid all the lines and called the guys at smoothflowpulleys and they pretty much said the same to me.

 

Ok well hooked up a by pass and yes its working better but still wantin to drop a tad..I took the TB off and put a new seal on. This **** NEVER happened until i took that TB on so figure thats a start. I am thinkin the computer might have to learn the new flow. **** i dont know. Any thoughts?

Think it could be the acuator on the SC it self?

 

What else is done to the car? You have 60 pound injectors and a 2.8 pulley. Stock IC system? Dual pass? Extra HE?

I would recommend doing some logging on the car to see if you are getting high IAT2s or knock.

 

Its all stock plus....Airbox mod, OTT stage one...

 

Do you have your car in AJ's hptuner so he can do some logs? If you are all stock with a 2.8 and 60s you could just have high IAT2 causing the car to pull boost. You could be getting knock as well which may not be helping. Are you running 93 octane in it?

 

Yes Aj helped me with the HTP tuners and has done everything correctly. Fyi this moring i boosted for S&G's and hit 17 and its holding...So i think i fixed it. Only time will tell