05blue8

iTrader: (28)

So I've read a ton since installing this thing Saturday night. The install was cake, I even kept my stock recirc hose and it fits perfectly. I have the Buschur upper pipe and intake so it fits perfectly in there. I T'd my wastegate to MBC hose for the C port, then used my old 9 DV vacuum hose for the A/B port split. First test drive right off the bat things didn't go so well. I took it out for a test drive and couldn't get it to release cleanly. I read around about trying just port A, just port B, even adjusting the preload spring. None of it helped. With just port B connected it was identical to A/B connected as far as flutter/surge release at part throttle or even at full throttle 29PSI. With just port A connected my car actually overboosted and I hit fuel cut at 32PSI. Needless to say even when I watched the gauge closely and hit 29PSI with just port A connected I got the same results, no clean release, flutter a few times. My first to second shift always 100% of the time results in over revving. When I get to say 7k in first and shift the car revs to 7500 or so like I never let off the gas. I haven't read much about that happening with the Synapse so I'm not sure if this valve just isn't going to work with my car or what. Any ideas from someone with similar problems that has actually gotten it to work properly? I know some parts just don't work on some cars so perhaps that's the situation here?

Thanks for any feedback you guys can offer!

LV///R

iTrader: (36)

I'm having some similar issues.

I recently installed mine to hold higher boost running E85. I initially just had A and then C hooked up. Supposedly my tuner said this combination wouldn't hold anything over 22 psi. He hooked up all 3 ports, and now I hit 28psi on the stock turbo.

The main issue I have, is if I partial throttle it, and get in to boost (ex. 10 psi) and let off, I get major flutter. This happens in 5th gear especially. It's quite honestly annoying as hell being my car is my daily driver and autox *****.

Also, if I get into boost, lets just say around 10psi and hold the throttle there steadily, my Synapse will just release the boost out of nowhere! My stock diverter valve never did that, not that it's a huge deal, but partial throttle boost needs to be there if I need it.

It's like I have to got WOT or not even get into boost. It's one or the other, otherwise I'll get serious flutter. It's annoying as hell to be honest. Other than that, it seems to do it's job, just not 100%.

05blue8

iTrader: (28)

So do you get a clean release if you go WOT and hit 28 then shift or do you get a bit of flutter after that even? I can't get it clean in any gear period and...it's very frustrating. I'm seriously contemplating sending it back. After the reviews I'm really disappointed in this unit.

LV///R

iTrader: (36)

It seems like I get a clean release, but only if I WOT and hit full boost. I will pay more attention to see if I get the rpm rise at WOT/full boost next time I go out.

It seems if I let off before I hit full boost (ex 22psi then let off), the rpm's rise about 500rpm! I think this is attributing to the fact that I've been grinding a lot lately, however it's possible I could be thinking too much into it!

I don't get flutter unless I'm in 5th gear and barely into boost, then let off the pedal.

Frustrating, to say the least.

will05

iTrader: (2)

I have the same bov and i have notice the way u hook it up from ur mbc, it will really mess it up.... The way i have it know it seems to be working fine it will relase with know probles and hold very well for boost, i hit me boost levels each time.... I have read one time that the boost control may have some thing to do with it... I would be more then glad to help and send pics in any... Email me if u have any question......

05blue8

iTrader: (28)

I am seeing that RPM rise alot too, I hate it, it's very annoying and not expected. It sounds like will05 has it hooked up some other way. I'll send him an email for pics...maybe it will help...I'll post back with what he says!

LV///R

iTrader: (36)

Sounds good man! Keep me posted!

Evo8Emperor

iTrader: (12)

Ive been running the original for almost 2 years now with no issues.

Im not sure about teeing it off your MBC. I have all dedicated vacuum lines for port a and c seeing those are the only two I use. I also run 28 psi with meth and no problems holding boost or part throttle issues. No issues at all nevermind.

LV///R

iTrader: (36)

Where are you routing C from then? I T'd my MBC, as well as the OP. Maybe that is the issue then.

Thanks,
Brent

05blue8

iTrader: (28)

Ditto to ill_take_one...where are you running the dedicated lines for A and C from? It says wastegate and most of us have MBC's so can you please tell us where you are tapping them at? Maybe this is the key, will05 also said read about similar issues. Man you guys are dangling the meat right in front of us, please just TELL US. Still no response from will05...Evo8Emperor can you chime in on this?

Evo8Emperor

iTrader: (12)

port c is supposed to be connected to a boost only source such as the nipple on the j pipe. I def think you should get it off the same lines as your MBC.

A+B is obviously your choice as which one works better for you car. Theres a thread somewhere from synapsis on all the different way to hook it up. I have only port a connected and port b vented.

I use a vacuum block for all my vacuum connections too so not sure if that would make that big of a difference. Im actually thinking about trying a direct vacuum source from the intake manifold. You can also test your vacuum lines pre throttle plate and post.

05blue8

iTrader: (28)

I swapped back to the original 9 DV this morning before work because I'm just that annoyed with it...the problem is that it's sad just how unresponsive the 9 DV is compared to the Synapse. I hope someone can chime in here to offer some more assistance on this. I don't have a nipple on my J pipe though. Damn this thing. Would a tune help with this thing at all? I think I've read every single post from Synapse and none of them really offered any assistance with trying to figure this problem out. None of their recommendations have helped

CharlieGsanD

iTrader: (1)

first, switch your boost only source (C-Port), from the MBC output to the MBC input. it sounds like you currently have it Tee'd in between WG & MBC, it needs to be Tee'd in between Compressor housing/MBC so it sees constant pressure. this is the same as using the J-Pipe though being Pre-FMIC it may be a few PSI higher than you'd see in the J-pipe

only run one vac line to the either of the Syanpses A+B ports(no Tee), and make it a direct shot into the intake manifold (no Distribution blocks etc) for my setup i use the weaker of the two ports for minimal closing effect from manifold boost

if your still having probs.......

try lowering the valve preload as much as possible

unlike OEM the valve (push Type) the Synapse (pull type) Will not leak under high pressure without preload, the preload is only there to get the valve to close earlier/faster during low boost part throttle conditions (1-10 psi or so). synapse actually has a lower rate preload spring that they can get for you if you call them & ask for it. it will allow the valve to remain open at low boost pressure/part throttle & while this can change the way your car reacts to pedal input when putting around, in real world driving leaving the BOV/BPV open during these conditions only increases snoothness and drivablilty. it just takes some getting used to, if you do want to go fast it just takes a bit more pedal travel to close the valve fully & get the car into "kill mode"

05blue8

iTrader: (28)

Thanks for the info Charlie. I have my MBC set up running from the intake manifold - t'd into the bov, then running to the mbc, and for the other mbc line it's wastegate to mbc straight. I know everyone talks about the compressor nipple but I can't see/find that spot on the damn turbo, maybe I'm blind? Hell I don't know. I've rebuilt a dsm motor but can't find the compressor nipple...sounds like a personal problem right? What spot on the intake manifold are you using as a "clean" source for vacuum? There are the emissions ones, the bov one, and the fuel pressure one. The fuel pressure one runs my gauge and meth, the bov goes to bov and mbc so which ones are you using for what? Where the hell is the compressor nipple while we're at it?

Thanks!

CharlieGsanD

iTrader: (1)

the first step is getting that MBC off of the BOV's signal line & give it a boost source off of the turbo

the nipple for the compressor is actually not on the turbo itself, but on the black 45 degree turbo outlet pipe that bolts onto the turbo as the 1st part of the lower IC piping. its on the drivers side of the pipe & the nipple actually comes out facing upwards

for my setup i have a distribution block inline with the vacum vent for the Evap emissions line. my MBC is run off of a compressor based boost source, my FPR is connected directly to my intake manifold, my BOV vacum signal is connected directly to the manifold & my side port on the synapse runs to a nipple in my UICP all other signal or metering vacum lines go to the distribution block


to be honest though, i think you may really need to get a nipple on the "J" pipe (or any part of the UICP) for a pre T/B boost source for the synapse valves third (side) port