I'm hitting close to 20 pounds of boost on my 2.8 stage 2 set up. I have full exhaust and intake. i was getting over boost when i still had factory dp on. Now i have the xtc high flow and i just finished the break in period and still the same thing. What would cause this?

 

I am going to venture out on a limb and say because the supercharger is spinning too fast.

Don't worry about thanking me.

 

Could be becuase its way colder out, you may have a cloged cat, those are just someof the usual.

 

Im hitting 19 with 2.8 and S2. I was hitting 18 before the DP. i thought for sure I had a clogged cat and after the DP i was expecting 17 PSI but to my surprise 19 PSI. Im very curious about this as well. If you find out anything place post here or let me know. I have talked to a few ppl about this and they can't figure it out themselves.

 

clogged cat cant be an option right now. so what would cause it to spin too fast.

 

not sure because a 2.8 does not over spin the SC. A 2.9" pully at 7000Rpm should give you less then 14,500Rpm at the suppercharger. Its red line is 16,000Rpm from what I have been able to find. A 2.7" pully at 7000Rpm should give you BOUT 15,555Rpm at the supercharger.

I think im going to swap out my stock PSI guage, see if that does anything.

 

cold weather ftw methinks.

 

Are you relying on the stock boost gauge to tell you what the boost is?

 

let me know if the guage does anything for you. but the cold whether makes sense. Anyone know of a heated track? this way low temps and sticky tires

 

well for one the stock boost gauge hasn't been know to be that acurate.. alsi we had one over here with that overboosting problem and we tried everything to figure it out... ended up being a few broken cam followers and an f'd up exhaust cam

 

my guess is that one of your rocker arms broke so that valve aint working. as you go through the gear over boost gets worse right? Thats what happened to me no codes no nothing. Finally like 6 months later the whole valve train went 2000 miles before my warrenty ended. happened to a couple of redline guess too. Thats why GM revised the rocker arms for the 07's they new the 05, 06 ones were garbage.

 

Trust me its aworse problem than a clogged cat. Now good luck trying to convice the dealer to look into it.

 

So should i put stage 2 pulley back on? keep an eye on it and if it persists take it to the dealer? Will the 07 parts go in here? I really don't race thing i just get on the car on the free way so it really hasnt been ragged on... The way the boost works right now is i will get to my 17.5 than all of sudden it just starts creeping its way up.

 

well i put the stage 2 pulley back on. seems slower....anyways now im hitting like 17.5 - 18 lbs of boost. it hits 15 holds for a sec than creeps.

 

Actually i have that two. I will go WOT and in the first gears it stays low, but like 3-4 gear it goes unusally high. I just thought it was air being able to go in the motor faster cuz the motor makes the supercharge spin faster???