I've got this sort of high-pitched tinging/beeping/whistling sound when I'm slowly accelerating... around 10 vacuum.

I searched through this whole thread : https://www.evolutionm.net/forums/ev...g-results.html

Someone had a similar problem but the only person that replied to him basically told him to search for the answer... pretty unnecessary and it didnt help at all...

I tried switching out the synapse dv for my stock dv and the sound went away. So I know it's not a boost leak from somewhere else causing the sound. I think maybe my vacuum lines are a little loose on the T fittings near the bov? I have ports A&B hooked up and T'd into a single line which is T'd into the intake manifold and the mbc. It says not to run the synapse dv t'd with an mbc... but the mbc says to run the vacuum line T'd with the dv and the IM... so they're kind've contradicting eachother

No real problems besides that... just getting that weird soft sound before hitting boost. The DV holds 30+ psi just fine... but flutters sometimes under 75% throttle if I let off a little bit. Just trying to get everything figured out and I've tried tons of different combinations... just wanna know whats causing the whistling...

THANKS :]

 

I get the exact same whistle now after I switched to Aby's spring at soft throttle and low boost. As soon as you give her some real throttle it goes away immediately which tells me that there isn't enough vacuum.

If the whistle is what I have to give up for a piece of mind to know that I don't have a boost leak in my DV then so be it. Not to mention that drivability is hard to come by with an aftermarket DV.

The only thing I could think of is to preload the spring slightly but this may give you more flutter at slight throttle lift in boost.

Take this with a grain of salt but it sounds good to me but I'm definately no pro.

 

I have the same "issue" while cruising...I wouldn't sweat it.

 

Thanks for the replies guys... just wanna make sure I'm not doing something terribly wrong. I want to get the best I can out of the setup. After reading that thread the people at synapse made it sound like if you have the "wrong" vacuum line or if your vacuum line is bending then you'll be sacrificing power/drivability...

 

I should have mentioned that I'm running push mode, port B and A port VTA.

 

I posted in this thread about 3 months ago (I think.) I found that the plastic lines were leaking vacuum at the fittings. I had checked for boost leaks to 30 psi with no problems. But, I still found significant vacuum leaks. The "Y' connector and the two fittings on the DV were all leaking. New replacement fittings and lines didn't fix the leaks. I finally went back to rubber vacuum lines with metal hose nipple fittings in the Synapse DV. That solved the problem for me.

I also have the softer spring, and there's no whistling noise at all. Hope this helps.