Boost Control Problem - Advice Needed
What WGA are you running on your Green?
What is your WGDC% from 4000 to 7000 RPM?
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Joined: Sep 2006
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From: Newcastle, Australia.
Also look into changing your gate to the Turbosmart IWG range.
I've had awesome results with these, can be ordered in a 25psi model that peaks at 25psi and holds 24.5psi to redline with less than half an eyelet of preload.
I've had awesome results with these, can be ordered in a 25psi model that peaks at 25psi and holds 24.5psi to redline with less than half an eyelet of preload.
Unfortunately a 1.6 mm diameter pill in the waste gate line didn't increase the range of control. 98% WGDC is still 24 psi at 7000 RPM and 99% WGDC is still spiking to 29-30 psi at the same RPM. The spike is not as sudden because the pill slows response of the wastegate actuator to changes in WGDC. This actually ends up making it harder to control transient boost and overshoot during the rapid spool up of my Green. A smaller 1.2 mm diameter pill only made the response even more laggy.
I ran some more tests to double check boost on WG spring alone. It seems my earlier results were incorrect. This time I got 19-20 psi across the RPM range, so it looks like I have a weak spring in my 25 lb WGA
I'm going to increase preload on the WGA arm by hacking a couple of millimeters of the end and cutting the thread longer. If that fails to move the WGDC control range down below the 90% mark I'm going to upgrade to the turbosmart WGA which comes with a set of interchangable springs that should make setting baseline boost on spring only a piece of cake.
I ran some more tests to double check boost on WG spring alone. It seems my earlier results were incorrect. This time I got 19-20 psi across the RPM range, so it looks like I have a weak spring in my 25 lb WGA
I'm going to increase preload on the WGA arm by hacking a couple of millimeters of the end and cutting the thread longer. If that fails to move the WGDC control range down below the 90% mark I'm going to upgrade to the turbosmart WGA which comes with a set of interchangable springs that should make setting baseline boost on spring only a piece of cake.
Like I said, every FP "25psi" WGA I have used, only got 22-23psi when fully preloaded. So its not just yours.
I say try the Grimmspeed 3port.
To keep around 30-31psi I have WGDC at 60% at 4krpm, and tapers up to 75% by 7k.
This is before I swapped my exhaust back to stock though. At the same WGDC I see 1-3psi less boost with the stock catback.
At this point I think I'd rather spend what a GS costs ($105) on a wastegate actuator like the Turbosmart ($229) to allow me to tune the spring rates.
Last edited by CDrinkH2O; Oct 24, 2013 at 05:07 PM.
I'm running the fp 25psi actuator, as Boosted said I only get about 21-22 with it highly preloaded.
To keep around 30-31psi I have WGDC at 60% at 4krpm, and tapers up to 75% by 7k.
This is before I swapped my exhaust back to stock though. At the same WGDC I see 1-3psi less boost with the stock catback.
To keep around 30-31psi I have WGDC at 60% at 4krpm, and tapers up to 75% by 7k.
This is before I swapped my exhaust back to stock though. At the same WGDC I see 1-3psi less boost with the stock catback.
I've got the FP 25 psi actuator. My WGDC is 70% at 4k and 98% by 6.5k giving me 27.5 psi at 4k RPM tapering to around 24 psi at 7.5k RPM. I'm running the GM 3-port.
What BCS are you using?
I picked up a 18psi Turbosmart IWG 75 for $81 on ebay, added the 5lb spring to make a baseline boost of 23psi. I can now easily maintain 29.5psi tapering to 26psi out the top and the problem is solved!
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