I did the wastegate rod mod because after my GMPP stage one tune +HPT I never really saw over 20psi boost. So I did the mod and seemed to lose boost, is that possible? I moved the locknuts halfway back towards the diaphram housing shortening the rod length. I have only a drop in filter otherwise all stock.
Could I have a boost leak and where would I look for it? Any suggestions would be appreciated!
2008 Cobalt SSTC S1
67 RS Camaro 406 ci 12 sec 1/4mi
87 Pachanga22 502ci 500hp
Is the sensor a tight fit in the lower charge pipe? Intake mani? PAW supplied larger o-rings to seal it. Perhaps it's leaking there or an intercooler end tank cracked.
If it's leaking around either sensor it may be lying to you & the ECM, pressure is high, but the ecm sees it as lower than actual due to the leak.
Edit: I never did the rod mod but wouldn't you lengthen it to make the wg open less? Less movement of the wg as the diaphram pulls on the rod?
Last edited by Iam Broke; 06-19-2010 at 11:26 AM.
'12 Camaro T3 2SS/RS LS3 M6, SLP TVS 2300, Flex Fuel
how much did you adjust it? you should only adjust it a few threads at a time iirc. did you mark where you had started?
I read over at the kapa sites and they all said to shorten it. But I was scratching my head on that thought. Does anyone know for sure? I think the wastgate rod pushes on the lever arm to open it. Because if I loosen both nuts the lever moves away from the vacuuum solenoid and wont move toward it. So I'm thinking shorten?? There was about .750 inch of thread left to move the nuts toward shortening the rod from stock position and I went half way. With the stock GMPP tune I was only getting 15-16psi.
Last edited by quickboat; 06-19-2010 at 06:01 PM.
2008 Cobalt SSTC S1
67 RS Camaro 406 ci 12 sec 1/4mi
87 Pachanga22 502ci 500hp
On our kappas, turning it inwards definitely increases it.Originally Posted by quickboat
I had shortened mine as well on the HHR, and I was having way to much turbo surge, so I backed it out to where I thought the stock location was, and it cleared up the surge.
If you are only seeing that much boost, I would look elsewhere, you don't need to shorten the rod at all with the stage tune and HPT!
2008 HHR SS 5-speed
HP-Tuned
Note: The wastegate adjustment is sometimes a very fine process. When adjusting the wastegate, only small adjustments should be made. Loosen one nut at a time and only adjust the nut one turn at a time; then tighten the other nut against the shaft and test drive to verify. This may have to be performed several times to achieve the desired boost level. To ensure proper adjustment, the vehicle should be at full operating temperature when testing. The vehicle will be very hot and may need to cool between adjustments. Too large of an adjustment can cause repeat DTCs.
Adjust the turbocharger wastegate. Refer to Turbocharger Wastegate Actuator Adjustment in SI.
Troubleshooting Tips for DTC P0299 - Turbocharger Engine Underboost
To increase boost, adjust the nuts (in) towards the actuator; in essence making the shaft shorter.
Troubleshooting Tips for DTC P0234 - Turbocharger Engine Overboost
To reduce boost, adjust the nuts (out) towards the end of the shaft; in essence making the shaft longer.
Last edited by gmtech16450yz; 06-20-2010 at 03:11 PM.
This is the adjustment procedure I used.
Remove the turbo charger heat shield. Lock wastegate actuator rod from rotation when doing this procedure.
Loosen locknut (2). Hand Tighten Locknut (1) till the wastegate arm is seated and slight spring tension felt.
Mark Locknut (1) to begin the starting adjustment position—and tighten 3 complete turns.
While holding the wastegate actuator rod, tighten locknut (2) to 90inlb. Your wastegate rod is now properly adjusted.
To increase boost, adjust nuts ‘in’ towards actuator. To reduce boost, adjust nuts outward to end of shaft if you end up with a P0299 or P0234 DTC.
Thanks guys
2008 Cobalt SSTC S1
67 RS Camaro 406 ci 12 sec 1/4mi
87 Pachanga22 502ci 500hp
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