My question is doe it help with the flutter that occurs when I road race. I absolutely cant stand the flutter in a corner as I adjust the throttle. Does it at partial throttle as well. Fix that, and I'll buy it.

 

I experience the exact same thing as EJEvo and I run the FBCS.

 

This sounds similar to what I see, although it typically takes a load on the drivetrain, like a hill, to induce it. I will definitely post up my experiences once I try this valve and use the configuration suggested. I'm just waiting for the Evo-specific recirc kit to come out. BoxerSix will be the guy installing it for me.

 

PLZ let me know what you find. Seriously.

 

Will do. I just placed my order...

 

Ok, so we've been doing an extensive amount of testing to see if we can further tune out some of these anomalies and I think that I'm getting closer. I had quite a bit of seat time today in an Evo 8 MR. The thing I found is that actually, compressor surge is what makes the car buck. DV flutter, was pretty stable. But compressor surge in scenarios where you slowly let off the throttle and get back on, or part throttle acceleration, and then pull off the throttle with surge really upset the car. And this is most prevalent when driving part throttle at high RPMs. But it almost seems like air surging out the compressor inlet is upsetting the MAF. Possible? I need more seat time, to confirm this.

No matter, we we're able to eliminate almost all of this part throttle surge. I designed the Synchronic BOV to be a pull-type, yet be able to behave like a push-type BOV. So, what I've found is that pulling a boost-only source from the compressor housing, which is before the intercooler is a faster signal to the BOV to open in certain transient conditions.

If there's anybody out there that already has a Synchronic BOV for their EVO, give this configuration a try in a re-circ setup ONLY:

http://synapseengineering.com/pdf/bov-manual.pdf

1) Remove the small pre-load spring and back out the adjustment screw completely
2) Take your boost-only source straight from the compressor to Port C (#7)
3) Only use Port B (#6) for boost/vacuum
4) Leave Port A (#5) vented to atmosphere

It may sound complicated at first, but it is this amount of fine tuning that allows the BOV to perform in all conditions and not just on-boost. Because if that was the only criteria, your seat of the pants alone will tell you that we've got one up on the stock metal DV.

 

Guys if anyone needs any Synapse products we are a stocking dealer

 

I also want to put some add'l details down about the test car:

Evo 8 MR
Stock Turbo
Hallman Boost Controller, hooked up to boost/vac
In and Ex cams

The car only pulls 15" of idle vac and 20" at throttle snap. The Hallman does not leak vac, this was tested with the pressure sensor on the data acquisition system at high res. This can be problematic, since you have less force to quickly open the BOV, which is why you would remove the pre-load spring.

 

FYI, I had this same thing happen on my Evo IX with stock turbo, stock DV, stock intake, etc. and it still does it now with a 50-trim, HKS SSQ and a speed density conversion (AEM). In other words, it's not tied to one turbo, one type of DV/BOV, MAF confusion, etc. It seems like it has to be compressor surge from sky high boost levels at part throttle. As such, to me it seems like a potential solution would be to tap the source for the boost control from the IC tubing pre-throttle body. I use the AEM to control boost and it uses the MAP signal to read boost which doesn't help in this case. My thought was that if the IC tubing pressure was used instead, the WG would open up much sooner under part throttle conditions and keep the IC piping from getting so high pressure... this should keep the turbo out of the surge-prone conditions (high discharge pressure, not a lot of velocity). Basically you would be regulating intercooler piping boost, not manifold boost... Are any of you guys running your boost source from the IC tubing as opposed to the intake manifold?

 

Much cheaper than I thought too!

 

EJ and Bonestock. Are you guys running stock intercoolers? What about you 2JZFan?

And a note on the test car, as 2JZ mentioned is that the test car had his Hallman MBC pulling signal from after-throttle boost/vac

 

The HKS is a great BOV....Well for WOT maybe. Im switching to a tial cause thats what my 3" AMS upper pipe takes but I had a v-band adapter made for the HKS to fit while i wait on my TIAL to come in.

 

Any part listed has been on the car when this issue has been happening. Most of these items were installed in March/April, but the issue didn't start until around late June/July. Only change I can think of that occurred around then was the switch from the HKS RS intake pipe w/ Buschur oiled filter to Buschur intake pipe w/ Buschur dry filter.

I'm running (was ---> is now):

• HKS 272 cams
• Stock IC ---> AMS IC
• 10.5 Hotside
• HKS RS intake pipe ---> Buschur intake pipe (removed breather nipple from HKS pipe and welded onto Buschur pipe)
• Forge DV-15 (red spring) ---> MR IX DV ---> Stock VIII DV
• Forge MBC ---> Turbo XS MBC

 

I can't visualize the BOV functioning as a wastegate. Obviously not an integral WG mounted directly onto a turbine housing, huh. Are you talking about using this BOV mounted remotely on a header flange? How long does it actually hold up to the thermal extremes when you use it as a WG?

Furthermore, how would the valve's Synchronic chamber design be of any benefit when using this BOV in a wastegate application?

 

i heard it dont make any sound at all...but not yet heard one in person