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FFWD Question

330Jock

Well Known Member
Question for the brain trust. My engine will be delivered 1st of the year, so things are starting to move.
Is the Transducer Manifold I'm seeing on a lot of FFWD pictures I'm looking at still something that I will need, or have things progressed recently. I will have an IFR dual G3X aircraft with SDS efii. Thanks in advance for the help.
Bill
 
The VA-168 is a convenient way to mount pressure transducers. I used all three locations -- MAP, FP, OP.

Drawing attached.

You can always do something different, just don't mount the transducers directly to the engine.

Cheers.
 

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The VA-168 is used for mounting the OP & FP sensors for the G3X engine monitoring same as any engine installation. The SDS temp(s)/TPS/crank sensors are mounted directly on the engine, MAP is a separate line off the engine to (usually) a sensor mounted behind the panel, similar to the G3X map sensor.
 
I would think with the EFII that the MAP sensors are part of the EFII so you will not need the manifold for that. I would also think but not sure that there is a separate place to get the FP like maybe the fuel manifold.
I do not recall using it for the OP. I think my OP sender was on the engine. I don't think I would want the failure point on an additional oil hose if I don't have to have one.
So in your case I don't see the need.
 
I would think with the EFII that the MAP sensors are part of the EFII so you will not need the manifold for that. I would also think but not sure that there is a separate place to get the FP like maybe the fuel manifold.
I do not recall using it for the OP. I think my OP sender was on the engine. I don't think I would want the failure point on an additional oil hose if I don't have to have one.
So in your case I don't see the need.

Your G3X engine monitor sensors are totally separate from the SDS system sensors. G3X F/Press sender and O/Press senders would be mounted on the VA-168 (on the firewall away from vibration) and lines connected to the engine. O/Temp sensor is screwed into the engine because vibration doesn't affect it, just like the EGT & CHT sensors which are mounted rigidly to the engine & exhaust. That leaves the electronic MAP sensor, fed by a flexable vacuum line either from the intake plenum or #3 intake runner to the electronic MAP sensor which could be on the firewall or better, mounted behind the panel.

Sensors for the SDS system (maybe same for EFII, don't know) are all electronic and not affected by vibration, they don't connect to fluid lines on a Lycoming so don't need mounting on a remote manifold like VA-168, no plumbing. You got a OAT sensor in the snorkel just before the throttle body, the TPS on the throttle body (just like your car), Engine Temp sensor probably screwed into one of the unused injector ports on top of a cylinder, Crank sensor bolted to the case up front by the flywheel. That leaves the MAP sensor, very similar to the one for the G3X and likely fed by the same flexable vacuum line, you would probably mount it beside the G3X one. All the SDS sensors & senders (& coils) are wired back to the control module (EM-5) which should also be mounted behind (but accessible please!) behind the panel. The G3X Fuel pressure sensor (same sensor choice as used in mechanical FI) should still be mounted on the VA-168, but the flexable line would be plumbed to the hi pressure fuel delivery plumbing.

Hope this description helps
 
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FWF Question

Thanks guys I appreciate the quick responses! So I guess all the magic I'm buying doesn't completely replace the old fashioned manifold. Good to know. That's what makes this site so great! Merry Christmas Brian, Larry, Tom, Ralph, & Mark and your families! Here's hoping that 2021 is better, not ready to push the bar to great yet!
 
FWF Question

While I have you guys on the line. Can someone tell me if I have everything that you can get in the way of plans if I have the new RV7A thumbdrive, or are the firewall forward plans that are offered by vans for $20 additional information for working on the FWF?
Thanks
 
Spend the 20 bucks! & any OP plan sheets for any sub kits you chose. The thumb drive really is just for reference & condensed to show most assemblies (in my case, I have full plan sets on hand for nearly every model if I need fine detail on something)

& yes, MAP is still needed but with SDS, it will factor it in automatically... Hands Off:)
 
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OK, ordered the VA-168, and when it arrived I couldn't believe it was aluminum. All the trouble I've gone through to have ss Firewall fittings and ss hoses for all of my fuel and oil lines, and I'm gonna hook them to a block of aluminum? Help me understand this one. Is there a ss manifold available somewhere?
 
I'm fine with aluminum fittings in the engine bay, but all my fitting on the firewall itself will be stainless or plated steel. An engine fire thats bad enough to melt an aluminum AN fitting in the engine bay is already a total loss of the airplane, as it would take the temper out of all the aluminum structure and I would never trust it again, even if I did manage to land it safely. So melting VA-168 when its completely in the engine bay might make a bad situation a tiny bit worse. All the hoses going to that should have restrictors in place to limit flow, so you won't be dumping fuel and oil onto a fire, but you will have a some fluid leaving the hoses. Having a melted fitting in the firewall makes a bad situation catastrophic, because now I don't even have clean air to breathe while I'm attempting to land the plane thats on fire, and likely you'll start melting wiring and losing visibility as well.

The attached risk matrix can highlight what I'm talking about. A melted fitting in the engine bay is improbable or remote chance of happening, but the severity is negligible. You're already on fire and melting that fitting isn't going to do much, so the risk is low. A melted fitting in the firewall is also improbable or remote, but the severity is either critical or catastrophic, so the risk is either medium or serious. The trade-off here is you can buy more risk tolerance but it costs you weight. Up to you to decide what your personal level of risk tolerance is.
 

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