EFII Boost Pump Module Customer Comments

Hi Guys, I have held the EFII fuel boost pump (as well as the others in this test and comparison) in my hands and seen it in operation.

  1. This EFII unit is Engineering Excellence at its finest: An elegant and highly effective, SIMPLE solution. No more spaghetti.
  2. The Walbro pump is: MADE IN THE USA. Top quality, Top rated, do a search.
  3. The EFII fuel regulator and check valve are far superior in quality and operation to the others in the test.
  4. The Billet CNC machined unit is beautiful. I have asked Robert for a "factory second" billet manifold to put on my mantel.
  5. Do not discount the importance of this EFII boost pump lowest suction loss, and the simple "straight through" design of the EFII pump. The effect of altitude on a low pressure point in the fuel system can be magnified, and if you are considering Auto Fuel in the future, this EFII system may have a very large advantage.
  6. I have seen all 3 units in question and on this thread, I read earlier in the thread: "The size comparison photo isn't very fair". I strongly disagree. The EFII unit is much more compact than the AFP unit in person and on the comparison photo on the website.


PA 20/22 Pacer; Extra 300; MD80

     I'll second Steve's evaluation above!

     I got a chance to see the pump yesterday when I popped down the hill from Big Bear to meet Robert and see his shop. I an used to being handed high-tech valves and various other jewels of the aerospace industry, and this assembly would fit right in with anything I have looked at in my "day job" space operations. We sat and talked design philosophy and failure modes - I could find nothing that left and doubts in my mind that this is a high quality product as well as a sound design. I am looking forward to getting one from the first production batch to install I the new -3! My only regret is that it will be some time before I can give Robert a flying report.

     Thanks to Robert and Bill for the tour of Cable, and the chance to see the product. I am not particularly easy to please with a new product, but in this case, I placed the order while I was still there.



Paul F. Dye

RV-8 - N188PD - "Valkyrie" - 1250+ Hours! TMX-0360 (180 HP), Hartzell Blended Airfoil, GRT EFIS panel

RV-6 (By Marriage) - "Mikey" - Dynon/TruTrak Panel

RV-3B - Fuselage out of the jig! G3X Avionics Suite and other systems install in progress

VAF #35

EAA Tech Counselor/Fligh Advisor

Polly Ranch Airpark (7XS0)

I witnessed the testing that Robert accomplished on all three boost pump systems: Andair, AFP, and EFII (Robert's). All three systems were tested via the same test setup.

Before taking data at the system level, Robert measured the pressure drops (suction loss) across the respective pre-filters as well as some other similar-size filters (Flow Ezy, for example) with stainless steel mesh elements between 25 and 125 microns. The "bottom line" regarding the pre-filter testing was that the suction loss across the pre-filters was remarkably similar near 0.5 inch H2O as long as the filter element was 75 microns or greater. If the element was rediced to 50 microns or lower, the suction loss would increase. For example, the Flow-Ezy filter (4ILA model) with a 25-micron element registered a suction loss of 1.6 inches H2O.

After the pre-filter testing, Robert tested all three boost pump systems. When activated, they all performed remarkably well in terms of delivering the 30psi input that the servo needs(. . . a Bendix servo was included in Robert's test setup). The only noticeable difference was that the Andair and AFP systems has a higher mechanical (boost pump off) suction loss. . . about three times greater. What this really means in terms of overall system performance is that the lower suction loss of the EFII boost pump system might be an advantage for very high, very hotm or high continuous power operations. In other words, higher margin with respect to potential vaporization at the mechanical pump inlet. For normal operations, the mechanical suction loss difference is probably not a big deal; the Andair and AFP systems will work fine.

What I tool away from the testing was:

  1. The Andair pump is remarkably loud! Evidently, the brushless motor turns at an extremely high RPM. If you install one of these, you won't need a boost pump light; you'll hear it!
  2. The AFP boost pump system works fine, but it's the largest system in terms of packaging.
  3. The EFII system is custom-egineered, from the bottom up, as a boost pump system and works as well as, or better than, the Andair and AFP systems. The EFII system has nicely-machined manifolds at each end and an integrated, nicely machined flow management module. A personal observation: The EFII system exudes "high-quality" when compared side-by-side with the Andair and AFP systems.

My personal "Bottom Line:" Does anyone wast to purchase my "new" AFP pump and filter? $350 or best offer. Never installed; only tested once, recently; worked fine. Please reply via PM. I'll post in the classified section also.

I think the next step for Robert is getting more actual flight hours on his new boost pump system. Although the boost pump system is similar to the dual-electric pump system in his already-flying EFII electronic injection and ignition systems, more flight hours would be a good thing, in my opinion. On the other hand, for those needing to make a boost pump decision now, I don't see anything wrong, based on the bench testing, with purchasing Robert's new boost pumps system. That's what I'm doing.

Happy New Years to All!

Bill Palmer

USAF (ret)

RV-8A in progress