gmdealerguy

I still think I have a slight bog issue kicking down from 2rd to 2nd at around 40mph. Off the line,nailing it,it will hit 20-22 lbds. If I am doing around 50-60 and nail it I get 22-23 lbs. Kicking down from 3rd to 2nd though I get 14-17 lbs.
It does not seem like its ok to me. Mine is an 09 automatic.
Post up what you guiys are getting so I know I am not "imagining" my little issue? I thought I saw some are getting 24-26 lbs?

JeramieJJ

I took mine in for a surging at times, not fully boosted at others. They determined mine was the Bypass Valve. (status: they ordered the part this past Tuesday 6/16)

In past, I have seen well over 22 PSI and many times over 25 (25-27).....but then I think the bypass valve started malfuntioning....as I am lucky to get the 20's now. It's steady one in the high teens though, when needed.


As to your exact RPM/Speed dropping issue....I think I have observed that at times...and thought I read something about it. Maybe others will chime in. Could be a fail-safe, for in case it dropped gears on full boost.

gmdealerguy

Thanks for the reply. I'll keep my eye on my car and see how it goes.

pitbull76

I usually see 22-23psi max boost, and in some situations it will only boost to 16 or so. But most times it will hit 22-23.

bad03xtreme

I average around 15 -17 when light on the throttle but when I punch it it will shoot up to about 25-30. I have 5 speed.

87silver

I have a manual trans with LSD.

In real numbers, around 6psi tops in 1st gear, but once in 2nd through 5th all hell breaks loose and it's pushing about 21 to 22psi.

I used to see higher numbers a few weeks ago, but the ambient air has gotten warmer lately, so I imagine there's less air density (thus less molecular volume at a given pressure).

Cokeybill

23 - 24 since my install in Jan/09.

Snoopy

Could the lower boost you see in first or second gear by GM's "parts saving -warranty reducing" aid by reducing HP in the lower gear range???? (automatics ONLY)

hyperv6

I am at 1050 feet and see 20-22 with an auto. I have seen this level in first and second gears.

At higher speed and depending what RPM I see on kick down it may hit 16-17.

The higher the revs the more boost.

Alt and temps will also effect this.

camaro98z28

20-22 on the go.