BOV and vacuum lines

[Tuesday]

I am still having trouble getting my BOV to work properly. The tech at synapse wants to know how much vacuum our sleds make. My boost gauge line reads off the intercooler so I am not really sure how much it makes.

The tech was suggesting we need at least 15" in order for the BOV to work efficiently?

Anyone have readings so I can trouble shoot.

 

[dexter]

3-5 lbs vacuum at idle with mcx and headshim

 

[BigFish BC]

i dont think i have seen any make above 10lbs vac my old vec was close to 10 but my nytro sits about 6-7

 

[Tuesday]

1lb psi = close to 2" of mercury.

Synapse BOV requires a minimum 15" of mercury. Thanks

As quoted:

If you truly are only making 10” of vac with all three cyl tied in, then you’ll need a lighter spring that we can send to you. But it should still work better than having just one cyl referenced even with the spring you have. Ideally, 15” is what you want.

The smaller the displacement, the less useable the vacuum. Which is why the car companies are putting in vacuum pumps into their small 3 cyl 1L engines, because the engines do not generate enough vacuum force to be usable by the brake booster.

What is the engine’s total displacement?

Peter Johann Medina
Synapse Engineering Inc.
+1 (858) 457-1700
+1 (858) 457-1253 fax
www.synapseengineering.com

Prototypical Innovation, by Design

 

[Tuesday]

Well I finally got to do some testing tonight and for some reason things were different tonight. I was using the soft spring that I picked up at the hardware store and I could not get the BOV to seal enough to get full boost??? I tried push and pull, a/b and just a and just b and kept tighten the preload but I could not make full boost. The BOV works 100% of time but it does not seal enough to make full boost, sigh……. I put the original spring back in and sure enough I could make full boost and was getting some compressor surge. I agree I think I need just a slightly softer spring and hopefully the BOV will be functional.

The only thing that was different was I put in a larger T for the new vacuum lines and I pulled off all the lines and blew them out. Maybe there was a partial blockage of the lines before? Not really sure why things are different with the lighter spring now. That was just my best guess.

I agree I plan to run the OEM spring and deal with the surge vs. that laggy bottom end. Any port configuration that would give more vacuum to help release the BOV? I assume push mode with a and b ports hooked up?

Thanks for your help,
Paul

From: Peter Johann Medina [mailtoeter.medina@synapseengineering.com]
Sent: Wednesday, January 25, 2012 6:26 PM
To: 'Paul'
Subject: RE: forwarding and answered questions

Spoke with one of the guys here, and we’ve had several sled guys switch out their old BOV for the smaller DV using the standard spring and they haven’t had any problems.

We can get you one of the lighter springs, but it will take a little while to get to you in shipping. For the sake of safety, I would rather see you seal boost and have the sled ride well and have a little flutter until the spring comes, vs having it not ride safely. We can also send you out some of the lubricant we use and see if that unit you have may be under lubricated.

Peter Johann Medina
Synapse Engineering Inc.
+1 (858) 457-1700
+1 (858) 457-1253 fax
www.synapseengineering.com

Prototypical Innovation, by Design