Boosting to about 6 psi
#1
New Member
Thread Starter
Join Date: 06-12-17
Location: Chattanooga, tn
Posts: 19
Likes: 0
Received 0 Likes
on
0 Posts
Boosting to about 6 psi
I have an 06 cobalt ss/sc. I recently bought the car with zzp downpipe, catless exhaust and intake, a lean code, and a hesitation around 2800 rpms. So I bought a new filter for the cai, because it was super dirty, and I also cleaned out the throttle body. After that, the car would not idle and was running even leaner than before, And also the boost would not go above 5 psi. So first thing I did was a compression test and smoke test, mainly because I was curious and to make sure I didn't have a vacuum leak. Both turned out good. Then I put a new maf and map sensor(on the supercharger) on the car. Still didn't idle or run well. Now during all this time I had been watching the live data on a scantool. I finally figured it had to be in the tune. Me and a Good buddy made a custom tune with hptuners, After multiple data logs (no maf, only speed density) and the car is back to running right. Only problem now is boost. Can anybody give me some advice or share an,experience they had? Thanks
#3
New Member
Thread Starter
Join Date: 06-12-17
Location: Chattanooga, tn
Posts: 19
Likes: 0
Received 0 Likes
on
0 Posts
#5
New Member
Thread Starter
Join Date: 06-12-17
Location: Chattanooga, tn
Posts: 19
Likes: 0
Received 0 Likes
on
0 Posts
#7
#8
New Member
Thread Starter
Join Date: 06-12-17
Location: Chattanooga, tn
Posts: 19
Likes: 0
Received 0 Likes
on
0 Posts
well I got on motologic and performed every step on the trouble tree for the boost control system. The actuator, the solenoid, and vacuum pressure seems to all check out fine. Also since I hooked up the boost gauge, I've started to notice that sometimes it will hit 6 or 7, but once it hits the peak boost, the boost level starts to drop off after that. So my guess is that it needs a new sc. Any other suggestions or opinions will be taken though.
#9
New Member
Thread Starter
Join Date: 06-12-17
Location: Chattanooga, tn
Posts: 19
Likes: 0
Received 0 Likes
on
0 Posts
My supercharger does a have a small rattle forming. Not sure if it's the coupler or the timing chain. If it does happen to be the coupler, could that cause my low boosting issue?
#10
You might want to have someone with an HP Tuner log a drive. Timing and fuel also help control the overall boost. Chances are the timing or fuel is being cut back due to ECT or IAT temps.. Boost should only go up and level off once its peak efficiency is achieved.
#11
New Member
Thread Starter
Join Date: 06-12-17
Location: Chattanooga, tn
Posts: 19
Likes: 0
Received 0 Likes
on
0 Posts
I have hp tuner software and just made a custom tune myself, for the idle issue after exhaust and intake. Timing and fuel are right, ect and iat temps are good too. I have the aeroscan iat temp gauge. And also logged the iat temps during multiple drives throughout this past week with the hp tuner while doing the tune. It is a speed density tune, and not a maf tune. I have also done the boost solenoid bypass. Still the same issue. As I said earlier I also did every step to the trouble tree to the boost control system and the actuator and solenoid tested out fine. Which if the boost control system all tests out fine, and the tune is fine, then it leads me to think the sc has an issue.
#12
Senior Member
iTrader: (1)
even if the valve is moving it could be hanging open a little. doesnt take much to loose the boost your missing. id pull the blower off, remove the bypass actuator and have a good look at it.
the blowers themselves do get some wear on the rotors and the case, but they dont generally lose that much boost. its usually an actuator issue or a leak.
you didnt mention what pulley you have, along with other mods.
the blowers themselves do get some wear on the rotors and the case, but they dont generally lose that much boost. its usually an actuator issue or a leak.
you didnt mention what pulley you have, along with other mods.
#13
New Member
Thread Starter
Join Date: 06-12-17
Location: Chattanooga, tn
Posts: 19
Likes: 0
Received 0 Likes
on
0 Posts
even if the valve is moving it could be hanging open a little. doesnt take much to loose the boost your missing. id pull the blower off, remove the bypass actuator and have a good look at it.
the blowers themselves do get some wear on the rotors and the case, but they dont generally lose that much boost. its usually an actuator issue or a leak.
you didnt mention what pulley you have, along with other mods.
the blowers themselves do get some wear on the rotors and the case, but they dont generally lose that much boost. its usually an actuator issue or a leak.
you didnt mention what pulley you have, along with other mods.
#15
New Member
Thread Starter
Join Date: 06-12-17
Location: Chattanooga, tn
Posts: 19
Likes: 0
Received 0 Likes
on
0 Posts
the actuator arm moves freely. We took the actuator off and the valve rotates freely in both directions. (from stop to stop) my buddy ziptied the actuator arm closed thinking the spring was to weak to hold it down under boost. But still nothing get 5 or 6 psi.
#17
New Member
Thread Starter
Join Date: 06-12-17
Location: Chattanooga, tn
Posts: 19
Likes: 0
Received 0 Likes
on
0 Posts
#18
Is this the highest boost you have seen the car do?
Do you have an evap smoke machine or a high pressure unit. The evap units only produced 1/2 pound of pressure.
Maybe post a pic of your Torque management / Supercharger settings. I think these are the stock Stage II settings.
Do you have an evap smoke machine or a high pressure unit. The evap units only produced 1/2 pound of pressure.
Maybe post a pic of your Torque management / Supercharger settings. I think these are the stock Stage II settings.
#19
New Member
Thread Starter
Join Date: 06-12-17
Location: Chattanooga, tn
Posts: 19
Likes: 0
Received 0 Likes
on
0 Posts
Is this the highest boost you have seen the car do?
Do you have an evap smoke machine or a high pressure unit. The evap units only produced 1/2 pound of pressure.
Maybe post a pic of your Torque management / Supercharger settings. I think these are the stock Stage II settings.
Do you have an evap smoke machine or a high pressure unit. The evap units only produced 1/2 pound of pressure.
Maybe post a pic of your Torque management / Supercharger settings. I think these are the stock Stage II settings.
#20
New Member
Thread Starter
Join Date: 06-12-17
Location: Chattanooga, tn
Posts: 19
Likes: 0
Received 0 Likes
on
0 Posts
Is this the highest boost you have seen the car do?
Do you have an evap smoke machine or a high pressure unit. The evap units only produced 1/2 pound of pressure.
Maybe post a pic of your Torque management / Supercharger settings. I think these are the stock Stage II settings.
Do you have an evap smoke machine or a high pressure unit. The evap units only produced 1/2 pound of pressure.
Maybe post a pic of your Torque management / Supercharger settings. I think these are the stock Stage II settings.
#22
New Member
Thread Starter
Join Date: 06-12-17
Location: Chattanooga, tn
Posts: 19
Likes: 0
Received 0 Likes
on
0 Posts
I don't think you're understanding. the computer would realize timing and boost Are off and then would decrease boost through the computer telling the boost solenoid to. With the boost solenoid not even connected to the actuator and the actuator arm ziptied closed, it has no choice but to boost. There is literally no way for the computer to Tell the supercharger to stop boosting. Its all mechanical at that point.
#24
I understand that you have zip-tied the valve, but that is not the only thing controlling power.
Did you not know that the valve is not the only item controlling boost? Fuel, Timing and the Electronic throttle all are used in controlling overall boost.
If there is an input telling the PCM to cut back boost, it can be done with the valve, timing, fuel and the throttle motor. As ECaulk mentioned, you can have your foot to the floor but the throttle body can still shut the throttle plate.
The reason I am pointing this out is you are blaming the SC and the SC is likely not the issue.
Did you not know that the valve is not the only item controlling boost? Fuel, Timing and the Electronic throttle all are used in controlling overall boost.
If there is an input telling the PCM to cut back boost, it can be done with the valve, timing, fuel and the throttle motor. As ECaulk mentioned, you can have your foot to the floor but the throttle body can still shut the throttle plate.
The reason I am pointing this out is you are blaming the SC and the SC is likely not the issue.
#25
Senior Member
iTrader: (6)
I understand that you have zip-tied the valve, but that is not the only thing controlling power.
Did you not know that the valve is not the only item controlling boost? Fuel, Timing and the Electronic throttle all are used in controlling overall boost.
If there is an input telling the PCM to cut back boost, it can be done with the valve, timing, fuel and the throttle motor. As ECaulk mentioned, you can have your foot to the floor but the throttle body can still shut the throttle plate.
The reason I am pointing this out is you are blaming the SC and the SC is likely not the issue.
Did you not know that the valve is not the only item controlling boost? Fuel, Timing and the Electronic throttle all are used in controlling overall boost.
If there is an input telling the PCM to cut back boost, it can be done with the valve, timing, fuel and the throttle motor. As ECaulk mentioned, you can have your foot to the floor but the throttle body can still shut the throttle plate.
The reason I am pointing this out is you are blaming the SC and the SC is likely not the issue.
Could also be the MAP and bar sensor connections are backwards.