So i got my Synapse installed tonight. I decided to try it in push mode first with the vac line hooked up to Port B and Port A VTA. The car seems to build boost faster and pulls really good in 1st and 2nd (only hitting aobut 22 psi in these gears). But in the 3rd-5th I get a flutter sound once I hit around 25 psi. What do you guys think is making the flutter- BOV, wastegate, or compressor surge?

I know I need to retune the car because I'm quite certain now that my old BOV was leaking. I just wanted to get some input on what could be causing the flutter before I tackle the retune.

 

Try the DV in Pull mode hooked up to port B with port A VTA and see if you have the same issues...most in this thread are using Pull mode...

 

Thanks man I'll give it a shot I've read several pages in this thread trying to figure out what the majority of people were using but I couldn't really come to a consensus.

 

Well I tried it both ways and got pretty much the same result. Still getting some flutter in third and a lot in fourth. Could this be a result of running too much WGDC? Now that my BOV isn't leaking I don't need to run as much to reach full boost and perhaps it's causing compressor surge?? IDK What do you guys think.

 

Installed the bov (synapse) a couple days ago, I must say its great. running pull mode with port b. One thing I can say is that when I go wot after around 17 PSI it flutters and jumps to around 22 psi, could it be because I reached my boost limit?. I'm tuned for 27 psi i had to turn it down due to fluttering issues with the old dv (forge). Tonight switch vacuum line to port A and B the throttle respond was amazing, how ever around 6 psi I would here like a leaking sound and it felt like I hit a wall. A couple of days ago I had it in push mode and did not experience the issue but fluttered at higher boost. So I guess I'm going to play with the adjusting screw to see if that helps. Anyone have the issues I'm having? I do love the bov though.

 

Sounds a lot like what I'm experiencing (read the post before yours). I'm going to try playing around with the tune tomorrow unless someone chimes in with a different suggestion. I'll post the results tomorrow. I thought about switching to port A and B but it sounds like you ruled that out for me.

 

I think I actually saw Synapse post in another thread about WGDC...try playing with that some and see if it helps...keep us updated!

 

Thanks for reaffirming my logic. I hate trying to reinvent the wheel if someone already knows the answer to my problem. I'll definitely let you know how it goes tomorrow.

 

It all sounds like you guys are bouncing off the surge line. There are 2 ways to solve this on the same turbo, either unload the compressor by leaking some boost, or take some energy away from the turbine by opening up the wastegate. Either way, the turbo shaft speed just needs to get to the same number on the other side of the surge line. It is better to take a little energy away from the turbine by wastegating rather than leaking it out the compressor side. Compressor side control is pretty efficient, but you will likely make significantly more power taking it out of the turbine than out of the compressor.

One area that needs looking into is the MIVEC timing. We haven't had a chance to dig deep into it, but it may be something worth looking into.

If you're in San Diego, we have some new tools that can get the data we need to answer these questions. You can contact us to schedule a time, if you're interested in answering some of these questions.

 

Please let us know how it goes and take some pics of the area that you worked on if possible.

 

Synapse...What exactly are you referring to when you say mivec timing? Mild mivec map? Aggressive map? I have a pretty aggressive mivec map in my car that john Bradley posted a while ago that I made some slight changes to. I have had no issues with my DV...works great...

 

i just did the mod with the different nipples that synapse said to do and now the dv works great it drives like stock and holds boost so much better. i think this is the best dv on the market

 

Thanks Synapse for your response! I have an 8 so no Mivec for me to worry about but I was running a lot of WGDC with the old BOV to hit my peak boost of 25-26 PSI so I'm pretty confident that that's the problem. I'm sure it's because the old BOV was leaking so I needed more WGDC to hit peak boost. I'll definitely let everyone know how things go tomorrow

 

Finally got to track test the Synapse diverter valve in its multiple orientations over the weekend. In both, autox and road course, I find that the valve works much better in port B only. Running both ports gave me flutter, and alittle bucking. Furthermore, I find that running push mode was the best for my setup. Mind you, I have the TiAL flange setup, and the bov is mounted directly to the uicp, and not the intake pipe like most stock configurations. During the testing, I ran into the same partial throttle issues I did with the TiAL. However, I started playing with the preload adjust, and it started working better and better. I'm right at the halfway point of the adjustment, and works really well. The car feels absolutely amazing on and off throttle.

 

Awesome man! Glad you were able to adjust the preload some and it worked out for you! As far as I have seen I think we may be some of the only people running a Tial flange with our Synapse DV. I have yet to adjust perload at all on mine but I haven't done an autox event or track event yet. All I have been doing is street tuning the car...