HHR/SS with kit; Boost Versus Vacuum
10-31-2009, 03:13 PM
#21
Senior Member
Join Date: 07-05-2008
Location: Akron Ohio
Posts: 5,464
1st I shall apologize to all about missing the vacuum "In Hg" designation. I looked thru the bottom part of my glasses and "sho-nuff" there it was.
And a sincere thanks to all that have taken time to add input.
Here's where we are today.
Chevy/GM engineering confirmed the HHR/SS with the LNF stage 1 kit installed should see 28 lbs of boost.
1. Chevy dealer has had the vehicle 4 days out of last week.
2. They have torn down and inspected everything in the inlet side - reinstalled and re-inspected, and ran the car under load; result no boost.
3. They removed and inspected the turbo and measured each and every one of the vanes- reinstalled and inspected and ran the car under load; result no boost.
4. Upon recommendation of Chevrolet engineering, removed the catalytic converter and ran the car under load w/o catalytic converter in the system; result no boost.
(Sub-note apparently ONE HHR/SS has had the catalytic converter problem knocking down boost)
5. Re-installed all components, inspected and ran the car under load; result no boost.
Go-forward Plan: All diagnostic paperwork is being sent to GM/Chevy engineering for evaluation. This process is expected to take about 5 working days. The service manager will keep me apprised of the outcome, and the next steps.
In all my years of owning GM products (8 of them) I have never seen a dealership or GM take this much time, interest and effort to resolve a customer issue. In this time of great uncertainty I am very impressed.
I will keep everyone appraised as more information is made available.
In the meantime I have the car back and I must agree with the dealer – no improvement
I really hope this helps some one else out there who may be experiencing the same or similar issues.
Sincerely,
Old Push Rod
And a sincere thanks to all that have taken time to add input.
Here's where we are today.
Chevy/GM engineering confirmed the HHR/SS with the LNF stage 1 kit installed should see 28 lbs of boost.
1. Chevy dealer has had the vehicle 4 days out of last week.
2. They have torn down and inspected everything in the inlet side - reinstalled and re-inspected, and ran the car under load; result no boost.
3. They removed and inspected the turbo and measured each and every one of the vanes- reinstalled and inspected and ran the car under load; result no boost.
4. Upon recommendation of Chevrolet engineering, removed the catalytic converter and ran the car under load w/o catalytic converter in the system; result no boost.
(Sub-note apparently ONE HHR/SS has had the catalytic converter problem knocking down boost)
5. Re-installed all components, inspected and ran the car under load; result no boost.
Go-forward Plan: All diagnostic paperwork is being sent to GM/Chevy engineering for evaluation. This process is expected to take about 5 working days. The service manager will keep me apprised of the outcome, and the next steps.
In all my years of owning GM products (8 of them) I have never seen a dealership or GM take this much time, interest and effort to resolve a customer issue. In this time of great uncertainty I am very impressed.
I will keep everyone appraised as more information is made available.
In the meantime I have the car back and I must agree with the dealer – no improvement
I really hope this helps some one else out there who may be experiencing the same or similar issues.
Sincerely,
Old Push Rod
I just don't want everyone here thinking something is wrong is wrong with their SS if they do not see 28 PSI. We all will just not see it due to where we live and drive.
Just a note you may not know it GM does watch this web siteand other LNF web sites and learn from out post. Kind of nice to know.
10-31-2009, 07:15 PM
#22
Senior Member
Join Date: 04-26-2008
Location: Vancouver
Posts: 292
Is yours a stock SS model? 9 to 12 lbs of boost was the norm. On hard accelleration my gage will go to about 12 for an instant and then drop to 20+ on the vacuum side and stay there. . When moving out from a stop - normal acceleration - it never rises above 0. Flooring it at freeway speeds never moves the needle up over zero. That's all part of the problems. Good Luck.
11-01-2009, 07:47 AM
#23
New Member
Join Date: 10-25-2009
Location: Germantown, TN
Posts: 29
My SS is Auto, so I'm not able to drop a gear. I was just stomping on the accellerator.
And yes this is my first turbo or supercharger. So I am a total newbie.
11-01-2009, 11:59 PM
#24
Senior Member
Join Date: 04-26-2008
Location: Vancouver
Posts: 292
KinseySS, I know you sent this msg in response to OPR, but since I am having similar problems, I thought I would reply as well.
My SS is Auto, so I'm not able to drop a gear. I was just stomping on the accellerator.
And yes this is my first turbo or supercharger. So I am a total newbie.
My SS is Auto, so I'm not able to drop a gear. I was just stomping on the accellerator.
And yes this is my first turbo or supercharger. So I am a total newbie.
If your just doing a "normal" acceleration on a freeway, say for passing people or what not, your boost wont go any further past 0 psi. The only time you'll get any kind of positive boost (especially while already moving) is getting the revs up high by dropping a gear. The turbo needs time to spool up so if your in low revs it's gonna take awhile to spool up before it will get any kind of positive boost.
I hope that doesn't sound to confusing.
11-02-2009, 08:11 AM
#25
New Member
Join Date: 10-25-2009
Location: Germantown, TN
Posts: 29
Oh you definitely can drop a gear alright
If your just doing a "normal" acceleration on a freeway, say for passing people or what not, your boost wont go any further past 0 psi. The only time you'll get any kind of positive boost (especially while already moving) is getting the revs up high by dropping a gear. The turbo needs time to spool up so if your in low revs it's gonna take awhile to spool up before it will get any kind of positive boost.
I hope that doesn't sound to confusing.
If your just doing a "normal" acceleration on a freeway, say for passing people or what not, your boost wont go any further past 0 psi. The only time you'll get any kind of positive boost (especially while already moving) is getting the revs up high by dropping a gear. The turbo needs time to spool up so if your in low revs it's gonna take awhile to spool up before it will get any kind of positive boost.
I hope that doesn't sound to confusing.
I have been testing the car some more on the highway, and I can get the boost up to 15 for about 5 seconds, when I accelerate heavily, but then it drops back down to 10 psi. I can't seem to keep the boost at 15. It's almost like the turbo stops working for a second and it has to spool back up.
Hope this makes sense.
11-02-2009, 11:47 AM
#26
Senior Member
Join Date: 12-09-2008
Location: Detroit Area
Posts: 224
I think maybe should state that the SS Can see up to 28 PSI under the right conditions. GM stated a long time ago on a Soltice site that the way the LNF is set up that it adjust to alt and temp conditions. If you are at sea level you will never see 28 PSI unless you are in a hurricane and then only maybe.
I just don't want everyone here thinking something is wrong is wrong with their SS if they do not see 28 PSI. We all will just not see it due to where we live and drive.
Just a note you may not know it GM does watch this web siteand other LNF web sites and learn from out post. Kind of nice to know.
I just don't want everyone here thinking something is wrong is wrong with their SS if they do not see 28 PSI. We all will just not see it due to where we live and drive.
Just a note you may not know it GM does watch this web siteand other LNF web sites and learn from out post. Kind of nice to know.
You are correct, the kit should not see 28 PSI boost. Most I have seen is 24 PSI and just briefly under certain conditions. The boost pressure is just the result of the temperature of the inlet, barometer and humidity. We DO NOT control the boost level.
11-02-2009, 07:08 PM
#27
Senior Member
Join Date: 04-26-2008
Location: Vancouver
Posts: 292
How do I drop a gear with an Automatic transmission?
I have been testing the car some more on the highway, and I can get the boost up to 15 for about 5 seconds, when I accelerate heavily, but then it drops back down to 10 psi. I can't seem to keep the boost at 15. It's almost like the turbo stops working for a second and it has to spool back up.
Hope this makes sense.
I have been testing the car some more on the highway, and I can get the boost up to 15 for about 5 seconds, when I accelerate heavily, but then it drops back down to 10 psi. I can't seem to keep the boost at 15. It's almost like the turbo stops working for a second and it has to spool back up.
Hope this makes sense.
You really shouldn't be worrying about your boost numbers on the freeway anyway. They only really matter on a closed track like the drag strip where you start from a stopped position.
11-15-2009, 10:31 AM
#28
Senior Member
Join Date: 07-05-2008
Location: Akron Ohio
Posts: 5,464
I too only have seen 24 PSI on a rare limited occation. The ususal is 20-22 PSI at best.
11-16-2009, 01:33 PM
#29
Member
Join Date: 09-29-2009
Location: Pasco, WA.
Posts: 45
I just got the stage 1 kit installed last week, and I don't notice any additional lag. The A/T version is an outstanding improvement, especially if you like torque steer. I floor it at about 40 MPH now, and it kicks down a gear or two, and immediately jumps to the right about a foot, and you fight the steering wheel until you let up, or the tires stop spinning. Great fun! I wish I bought the manual trans now, despite the fact my wife hasn't ever driven a clutch. Sure wish GM would update their transmissions to 5-6 speed autos.
