I'm kind of assuming its because It was SO cold last night, If I got to half boost(12lbs) and held it steady, my blow off valve was surging very hard and fast to keep it at 12lbs and not go higher. It spools good strong and gets to full boost without a problem. But if I only put my foot down to get half boost, that's what I'd experience. Is it simply because the air was that cold and dense or is it something else?

 

Partial throttle flutter. It can be a pain to adjust out. If you have any adjustment left give it a 1/8 th turn. Drive to test repeat if needed.Watch video I'm betting it like what happens at 1:00-1:05. Car is an 06 RS.


http://www.youtube.com/watch?v=Qa_Yg...e_gdata_player

 

How is your boost controlled? Are you tuned on TephraMod? If so, do you have "WGDC = 100% under X load" enabled?

 

What adjustment are you talking about? Give what an 8th turn? I use a Hallman mbc and just had the car tuned

Sweet video btw

 

Your bov is cracking open and bleeding boost at partial throttle. It's the adjustment on the valve. The vid is not me. It's J.erk on here.

 

Was it tuned on TephraMod and if so, is "WGDC = 100% below X load" enabled?

 

I don't know. And as for bov adjustment, I don't think there are any adjustments on the HKS SSQV 5

 

Ask your tuner, if it's enabled just have him set it to 0 and see if the problem goes away.

 

Compressor surge? The car jerks around a bit too when this happens. I just read that the newer hks bov's aren't adjustable and what I hear and feel is compressor surge, and that if I vent to atmosphere most of this might go away. Is this true?

 

Its not necessarily BOV related. Some turbo's surge at part throttle, usually smaller ones that spool quick.

 

Well it is a stock 9 turbo, which isn't really small unless compared to a bigger aftermarket turbo. And I've never noticed this before on the stock 9 bov. Or on stock tune at 12lbs max. It seems to only do it when boost is up high and the colder it is out, the worse it seems to get. I'm kind of assuming it does have something to do with this HKS bov. I read that the hks is designed more to vta than recirculate and they will all surge like this. I also read that they are double piston systems where there should be a smaller piston that opens at low boost and a larger one at high boost, and when recirculated at high boost, It messes up the way it was designed to vent=hard surging

 

I didnt watch the vid yet but mine does the same thing when the throttle is like half or cracked, once I go WOT its all good, I say its just the bov spring tension

 

I'll ask the same question to you as I did the OP. Are you tuned on Tephra and is "WGDC = 100% under X load" enabled?

I had a similar problem at partial throttle when I had it enabled. Skip ahead to 2:25 and listen at 2:30-31

http://www.youtube.com/watch?v=1xOQC...AAAIAA&t=2m30s

Now that I have it disabled (set to 0) I don't get that anymore.

 

I have the same issue with my synapse bov and my preload spring is already cranked down to the max. Anyone know how to fix this without changing the tune? I'm thinking about switching over to their diverter valve. I would hate for the car to buck due to partial throttle discharge and re-engagment while going around a corner at a high speed..

 

The Synapse BOV is outstanding, that's what I'm using and have no flutter now since I've disabled that Tephra feature.

Here's how my car behaves now. As you can see, I can very gradually get on the throttle and there's no bucking, surging, etc.

http://www.youtube.com/watch?v=Ujp7T...e4AUAAAAAAABAA