Blow off valve surge ?
Posted: Wed, 06/23/2010 - 4:30am
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Blow off valve surge ?
Hi guys, I recently plugged my 4 throttle bodies to my hks ssqv blow off valve (the adjustable one with the nut in the back). The blow off valve is doing its job I hear it open and the pressure is evacuated but for some reason I am also getting a surge problem. It actually sounds like when I was only plugged on 1 throttle body.I did try to loosen the nut a bit on the back of the bov but problem still persists. I am out of ideas. Does anyone have any ideas on what this could be ?
mine does the same. try the OC or modifiers forum?
RNN14
so did you solve your previous problems adn where are your promised pictures?
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Why do I have surge (a woo woo woo woo sound) on my SSQV?
1. This is a result of the valve not pulling the valve open, while the turbo compressor is spinning. The air gets "stuck" in the system and slowly returns causing a repeating woo woo woo sound.
2. The HKS SSQV needs high air flow on the back of the valve and a strong vacuum source to pull the valve open. On some cars where the bov is positioned in an odd location, this may not be possible at part throttle. The turbo is creating lots of air, but little to no boost has reached the manifold due to a pressure loss across the IC.
3. You can re-locate the valve and/or get a stronger vacuum source to help combat this effect. You want a thick single line straight the manifold for a vacuum source, as short as possible.
4. Mild surge at little to no boost levels will not damage your turbo.
5. If you are worried about this noise, you may want to consider re-installing your original bypass valve in addition to the SSQV so that the air flow at part throttle can be released as intended. Otherwise, you may want to change to a push type blow off valve that will operate on less of a vacuum source.
http://www.youtube.com/watch?v=MfsD-6_Dp58
Mine sounds like the first 2 pulls of that video. Under low boost, it flutters/surges, whatever you want to call it.
Under higher boost or heavier throttle (the third and so on in that video) it opens fully.
Surge is more noticeable when I slowly lift my foot off the pedal and I'm at low boost. It will do it on the highway or freeway if I am accelerating at about 50% then very slowly decrease the throttle.
As stated in numerous forums, not to be worried about as long as it is not surging under high boost levels.
RNN14
the gtir will always make that noise if you still have the original top mount. i went threw 3 bov to find out everything was ok. i looked it up and thats what the brits and auzies say