I have had exhaust leak problem at the gasket at the exhaust manifold. After the problem was fixed, (which required the manifold and turbo removed) I took my car from the garage and drove home. I accelerate the car and checked the boost guage, 14-15psi max and stable. Acceleration seem slow a bit but everything seem normal.
When I got home and open the hood I found that APC hoses were miss conected.
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The C was connected to wastegate actuator. The W was hanging freely. The R was correctly plug to intake before turbo. (The connector on the turbo where C should connect was left openned).
By what I describe above, there was no pressure from the turbo to feed to APC. I think APC must have turbo pressure (normally from C hose) so it can control the wastegate actuator.
I was confused. Anyway, I reconnected the APC hoses to their correct connection and went out for checking. No different. The car run normal(same as when I drove out of the garage). Max boost still 14-15psi.
I came home, openned the hood again. This time I disconnected the W hose from the wastgate acutuator which mean no presure to the wastegate at all. Went out again and accelerate hard and ... normal
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. Just like before, the boost pressure still rise smoothly to max at 14-15psi without any fluctuation.
I accelerated hard again and checking the boost guage, 15psi max and stable at 4000rpm and the rev. still goes up since I was still WOT.
Can anyone explain if this is normal. I think something is wrong but I don't know what it is.
There are things I should mention here.
- I lost boost spike for sometime. Previously the boost peek and drop slightly ~2psi. Now the boost just rise smoothly to max(14-15psi) and stable until drop again when rev. goes above 5000rpm.
- My car is 9000cs 2.0lpt autobox with maptune stage3. I have top end power, but low end is not good at all. The real power only come at high rev. and high speed, 3500+ rpm/140-150kmh up.
- I hear hissss noise everytime boost goes up but can't find any leak. I doubt if the noise come from the intake air suck in by the turbo.
- I've just changed new APC and new bypass valve. Both are saab standard.
- The wastegate actuator is Forgemotorsport. It is still quite new. I use it for 2months. Basic boost is set at 0.49bar.
- My turbo was leaking oil recently so I had it fixed and upgraded to the larger size compressor prop. (exhaust prop. size remain same.)
Thanks in advance for any comment.
When I got home and open the hood I found that APC hoses were miss conected.
By what I describe above, there was no pressure from the turbo to feed to APC. I think APC must have turbo pressure (normally from C hose) so it can control the wastegate actuator.
I was confused. Anyway, I reconnected the APC hoses to their correct connection and went out for checking. No different. The car run normal(same as when I drove out of the garage). Max boost still 14-15psi.
I came home, openned the hood again. This time I disconnected the W hose from the wastgate acutuator which mean no presure to the wastegate at all. Went out again and accelerate hard and ... normal
I accelerated hard again and checking the boost guage, 15psi max and stable at 4000rpm and the rev. still goes up since I was still WOT.
Can anyone explain if this is normal. I think something is wrong but I don't know what it is.
There are things I should mention here.
- I lost boost spike for sometime. Previously the boost peek and drop slightly ~2psi. Now the boost just rise smoothly to max(14-15psi) and stable until drop again when rev. goes above 5000rpm.
- My car is 9000cs 2.0lpt autobox with maptune stage3. I have top end power, but low end is not good at all. The real power only come at high rev. and high speed, 3500+ rpm/140-150kmh up.
- I hear hissss noise everytime boost goes up but can't find any leak. I doubt if the noise come from the intake air suck in by the turbo.
- I've just changed new APC and new bypass valve. Both are saab standard.
- The wastegate actuator is Forgemotorsport. It is still quite new. I use it for 2months. Basic boost is set at 0.49bar.
- My turbo was leaking oil recently so I had it fixed and upgraded to the larger size compressor prop. (exhaust prop. size remain same.)
Thanks in advance for any comment.
