Author Topic: GT2871 with Synapse BOV- Issue at Idle and Low Speeds (Read 45339 times)

ihawk95 · « **Reply #25 on:** June 13, 2011, 09:24:20 AM »

Air doesn't behave like water in a pressurized pipe. I did a ton of testing on compressed air header systems.

Not sure I can explain it well though.

miller11386 · « **Reply #26 on:** June 13, 2011, 09:39:59 AM »

well there you go lol

And I only thought you knew about cookies?

elff · « **Reply #27 on:** June 13, 2011, 09:43:51 AM »

Miller

Pretty much the air is pressurized and will release just as effectively from anywhere in the pressurized system.

Dejon is the only kit I've seen for Kappa's with the BOV on the driver side IC Pipe.
I am curious to learn more from Shabby on the MAF relocation.

Does that help reduce turbulence and get a more accurate reading all the time?

kennysabarese · « **Reply #28 on:** June 13, 2011, 10:09:27 AM »

If you need to do a boost leak test Steve, I have a tutorial here:

http://www.kappaperformance.com/forum/index.php/topic,5000.0.html

spicy3480 · « **Reply #29 on:** June 13, 2011, 10:13:11 AM »

All I can say is that this is how the kit was designed by DDM. I am pretty sure they know what they're doing. I wish I was more knowledgable on this all but I am not. If elff's kit is working well, then something in mine has to be just a touch off. Dave installed the OCC as well, so I am pretty confident it is run to the right places. I am working on the tuning right now...gonna look at valve timing at idle and also possibly raise the idle speed by 50rpm.

elff · « **Reply #30 on:** June 13, 2011, 10:41:09 AM »

Arabas,
The pics are misleading as they are zoomed in.
If you are standing at our cars and trace the hoses, you would be able to see they go where they are supposed to.
No Worries.

Seems like each one of these installs is slightly different. I'm not experiencing the same thing Steve is, but mine was a little rough before I swapped to port B only.
That smoothed mine out. Also takes the car a little longer to settle after startup than it did with the K04, but once it does, it's about the same.

I'll be able to help out more, once I get my replaced BOV. At the moment I am driving a Hemi powered Pickup truck instead until tomorrow.

miller11386 · « **Reply #31 on:** June 13, 2011, 10:47:08 AM »

I think that the issue is for whatever reason, the Auto trans is taking some of the vac away. Whether it is to engage the trans/torque converter or what, it is creating a vac loss for just a moment, and tells the valve to shut. I wish I could see his log, but I cant.

Can someone get some screen shots up for the log?

I am saving my other cold/hot argument for another thread.

ihawk95 · « **Reply #32 on:** June 13, 2011, 11:03:02 AM »

Ok, without getting into too many questions on my end...because I have a ton of them now!!!

Elff what you said should be correct, once the system is pressurized the release point shouldn't matter because the air pressure will evacuate to equilibrium, or until it can't overcome the BOV spring. This is the case provided there isn't more pressure being supplied to the system and there are no other significant leaks. If there were leaks, then you would see a pressure drop across the system. Or the system could be what I call "starved"...not enough supply to properly pressurize the system. A restriction in the system doesn't matter unless it's where the air is being supplied, because then, the system never fully gets pressurized properly. You can see this with pressure gauges along the system. Once there is adequate supply, you won't see a pressure drop. If you do, then you have a leak or the system is starved. Of course, we can't put gauges all through the cars!

Dang...I have more to add, but have to go to a meeting.

miller11386 · « **Reply #33 on:** June 13, 2011, 11:38:50 AM »

Spiky,

Ask Westers/DDM if there is a vacuum line from your transmission to the manifold to steal your vacuum pressure. I am just curious. If there is, you could put a simple check valve or slow release valve in the line you may clear up the whole issue.

spicy3480 · « **Reply #34 on:** June 13, 2011, 12:36:18 PM »

Quote from: miller11386 on June 13, 2011, 11:38:50 AM

Spiky,

Ask Westers/DDM if there is a vacuum line from your transmission to the manifold to steal your vacuum pressure. I am just curious. If there is, you could put a simple check valve or slow release valve in the line you may clear up the whole issue.

That's a good idea...I will ask. I switched to port B only and it has smoothed out a bit, but I still have the drop in RPM. I am working on it with tuning and checking the logs with Lyndon. I posted the log in the first post:)

ihawk95 · « **Reply #35 on:** June 13, 2011, 12:43:59 PM »

OK, after having reread a few posts, and missing a piece of info the first time around...

I gotta agree with Miller, the best place to evacuate the air is by the throttle body because, like he said then the air doesn't travel back through the IC.

Now, does it make a huge difference? I'm trying to think thru that still. The timing is probably about the same. If there really is a pressure drop across the IC, then Miller has less pressure to vent, but that means the air velocity is lower as it vents. Probably a trade off there. Rate and pressure are linear. Elff and Spiky release at a little higher pressure, but the velocity is quicker.

I'm thinking...I have a couple of thoughts, but I need a better understanding of what's going on.

Gentleman Jack · « **Reply #36 on:** June 13, 2011, 12:46:42 PM »

Quote from: ihawk95 on June 13, 2011, 12:43:59 PM

OK, after having reread a few posts, and missing a piece of info the first time around...

I gotta agree with Miller, the best place to evacuate the air is by the throttle body because, like he said then the air doesn't travel back through the IC.

Now, does it make a huge difference? I'm trying to think thru that still. The timing is probably about the same. If there really is a pressure drop across the IC, then Miller has less pressure to vent, but that means the air velocity is lower as it vents. Probably a trade off there. Rate and pressure are linear. Elff and Spiky release at a little higher pressure, but the velocity is quicker.

I'm thinking...I have a couple of thoughts, but I need a better understanding of what's going on.

Could you add a recipe for chocolate chip pumpkin bread cookies while you're at it?

ihawk95 · « **Reply #37 on:** June 13, 2011, 12:52:54 PM »

Quote from: Gentleman Jack on June 13, 2011, 12:46:42 PM

Could you add a recipe for chocolate chip pumpkin bread cookies while you're at it?

Possibly. You know I work for a cookie manufacturer right? And we do make a seasonal pumpkin spice cookie for one of our customers!

miller11386 · « **Reply #38 on:** June 13, 2011, 01:24:01 PM »

Cant see the log

No software yet

Sol Asylum · « **Reply #39 on:** June 13, 2011, 01:31:33 PM »

Some things to consider. When the BOV opens the system is not completely sealed, the engine is still consuming some air, the throttle plate is closed but not sealed. The BOV isn't to keep pressure off the throttle plate but to unload the turbo so it doesn't stall, so the closer it is to the turbo the quicker it can do it's job. If you have an intercooler with restrictions (they all have some) then it will take longer for the pressure to drop if the BOV is after the intercooler.

ihawk95 · « **Reply #40 on:** June 13, 2011, 01:42:20 PM »

True, that was my thinking at first. But since there are losses across the system the pressure near the throttle plate is less. So in my mind, the timing is probably close. And what I'm thinking is the turbo has a little more time to fully unload with those losses with the bov on the other side. Otherwise, It's pretty abrupt when the bov is right there and the airflow is prolly crazy past the maf when that happens. I wonder if it fully unloads like it should.

But based on more info, I'm shooting this down. Pretty unlikely. And doesn't really explain why Elff is getting away with it and Steve isn't.

Sol Asylum · « **Reply #41 on:** June 13, 2011, 01:46:58 PM »

Isn't the MAF before the turbo? If so couldn't the venting of the BOV cause a false reading of airflow to the engine?

ihawk95 · « **Reply #42 on:** June 13, 2011, 02:00:04 PM »

now that I don't know. I was thinking it was after. I need a turbo instead of an NA!

miller11386 · « **Reply #43 on:** June 13, 2011, 02:07:52 PM »

MAF is right behind the filter. So yes it is pre-turbo.

We are venting metered air to atmosphere. Just like the CBV did in the K04.

Luckily the Synapse is so quick and accurate, there are not usually too many issues with running it without relocating the MAF sensor.

Biggest "issue" is the loud crack when shifting mid powerband.

spicy3480 · « **Reply #44 on:** June 13, 2011, 02:19:56 PM »

That's one advantage of the auto....there is no crack between shifts in the powerband because the shifts are so quick.

spicy3480 · « **Reply #45 on:** June 13, 2011, 02:44:27 PM »

I spoke with Synapse this morning....very helpful! They think that my the valve is staying open at idle causing unread air to enter the system...thus making the RPM drop and recover so quickly. I am checking to see if a tuning change can be made to keep the valve closed at idle.

ihawk95 · « **Reply #46 on:** June 13, 2011, 03:36:52 PM »

And here we're all thinking about how the flow works and pressure and all kinds of air stuff!

Glad the customer service was helpful and I hope this is the solution!

Sol Asylum · « **Reply #47 on:** June 13, 2011, 03:40:48 PM »

Quote from: Sol Asylum on June 10, 2011, 03:36:56 PM

I wonder if the BOV isn't sealing all the way at those RPMS and allowing air to flow the wrong direction and thus bypassing the MAF?

spicy3480 · « **Reply #48 on:** June 13, 2011, 03:42:15 PM »

Looks like I might need an anti-stall kit. If you look at the instructions for the Synapse BOV, this is what it says:

The anti-stall valve is designed for use in installations where you
want to vent the Synchronic BOV to atmosphere, but cannot due
to a sensor such as a MAF that meters the air. This kit can also be
used in installations where you do not want charge air to bypass
the turbo under vacuum conditions.

elff · « **Reply #49 on:** June 13, 2011, 03:52:37 PM »

Interesting.

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Author Topic: GT2871 with Synapse BOV- Issue at Idle and Low Speeds (Read 45339 times)