Hi guys and gals. Happy to be posting here with an actual subaru this time and not that princess of a 325xi i had. Here's what my car sounds like - I REALLY want to get rid of this flutter. http://videos.streetfire.net/video/What-is-Flutterdump_151792.htm I bought the car with these mods and the AP (for 8700.00!) and she has about 89k on her. -Megan Racing catless turboback exhaust 3" -Megan Racing catless uppipe -WBR front mount intercooler (powdercoated black) -Blitz DD BOV -Cobb Tuning Accessport -Blistien front shocks The flutterdump is extremely annoying. It happens whenever I let off the throttle between 2k and 4.5k rpm, some higher as well. I've loosened the blitz DD bov spring adjustment all the way, and then increased it completely, and tried a few in between with no change. It's a recirc type, so I'll have to disconnect that, plug the tube and adjust it while it's moving to set it right so i can see it's movement. Could it be related to the fact that the BOV is on the opposite side of the engine bay from the turbo, making the vacuum line too weak over a distance to create proper pull on the valve? Is it possible this could be wastegate flutter instead? Much appreciated - if there's anyone you think I should take it to, or someone who would be willing to stop by to take a look I'd greatly appreciate it!
If it sounds like that video, it is compressor stall (to some people aka surge), and terrible for your car. Based on your mods, I'd reccomend putting the stock TMIC and BPV on. You may also want to thoroughly check for vaccum leaks and make sure none of your lines to the BOV are kinked or blocked. WG flutter sounds more like a constant fluttering or ticking when you are at 5-10 PSI of boost. WG flutter happens when you are in throttle, not when you let off. As a side note, WG flutter is 100% normal and will not hurt anything.
****UPDATE**** I narrowed the problem down to the Blitz Blowoff Valve. Turns out the thing had a HARD spring (the red in color) installed, and there was no way the vacuum could pull it back. Figuring I'll have to buy a stock bov or a lighter spring anyways, I grabbed the side cutters and cut it about 2/5's of it's length so I had either a 3/5 or a 2/5 to work with. I put in the 2/5ths and got a little better result, then pulled it and cut another coil off of it. Seems to be working better, about 85% of the chatter on deceleration is gone. I've got a stock BOV coming in the mail, and hopefully only running 8psi won't be a problem for it with the WBR FMIC. Sounds much better! In the mean time, I think some serious wear has been put on the turbo with the hard spring that has been on the car for a while, so I'll be listening for more wear and possibly finding a remanufactured or swappable turbo to go on it. VF46 or VF52.
