For the folks with 'bucking' issues with the Forge, what spring are you using ? The flutter sound is not a bad thing- the valve is reacting to the vacuum to boost to vacuum changes ....I only experienced the bucking once and that was when I was at a really low RPM in 6th gear and then went 50% TPS....

 

I was using the stiff spring with shims so that it would hold boost when running meth.

 

Well that sounds like your problem -- too stiff a setup will not let the DV do its job when you let off the throttle or are at part throttle loads...

 

Ok... so how would you have run it differently... I ran the medium spring with no shims when I wasn't running meth and it still fluttered. The stiff spring and the shims were necessary to hold boost when running meth.

 

I am also looking to switch to this one from a Forge. The fluttering in 5th gear drives me crazy! Doesn't it come with a flange for recirc? You can also use it as VTA correct? Reason I'm asking is I might switch to speed density.

 

Guys, if you are using more spring than you should the car will buck. I am running the blue spring and having no issues running 29psi peak. On super low throttle, ~10% in evsoscan I get get the car to misbehave (this is caused by the vacuum to boost to vacuum transition...I addressed this by adding one shim.

 

^ Update - one spacer/shim was not good for my setup - really bad bucking at ~10 psi and low throttle.

I have now installed a stiffer WGA and removed the shim in the Forge DV (just blue spring) and will see how this works. Obviously this is a problem / issue with the Forge design as one has to 'experiment' to get the proper settings and even then it may still be an issue.

If this does not work I'll try the softer spring (yellow). Either way I'll report back with my findings...

I wish the guys from Forge would come on here and specifically address which setup to use for which boost scenarios.....

 

so synapsis is a good swap for people who are going for turbo upgrades and who are still in stock turbo?