Mark ---

What is this -------> FSCMs <------

You reference this in your original post -- and I can't come up with a suitable "name" -- something something Control Module??

I'm running a SPAL PWM fan controller - is this something "similar" where it really doesn't drop the voltage to the pump but rather Pulse Width Modulates the motor?

Sorry I'm so dense....

You got it Greg !

It's a compartment with a lowered floor that has the sump pickup for the pump and it's surrounded by walls. In the walls, down by the lower flange are the transfer holes (just like the tank dividers you made - just lower the round holes all the way down to the flange) - but there's no other access for the fuel to move. The flapper connects on the compartment side that has the sump by 2 bolts so the fuel flows in by gravity and/or lateral forces - but not back out.

It was patented in 1941. Pretty simple device so I’m sure someone is using it. Here's a pic.

Beautiful work on your tank Greg - I'd be proud to have something like that ! And yes, it is shiny !!!

Jim

Fuel System .......... I think

FSCM (Fuel System Control Module) used to step down the voltage to the fuel pump.

Sorry for the confusion

Mark

you friggin' engineers.................... :lol:

Thank you Jody!! My thinkin' egg zackedetly

LOL

Okay - found the controller at Aeromotive website -- nice little billet jobbie. Seems they only make ONE - so that's REAL EASY... I'll add this to my system - and then check the fuel temps as soon as we "thaw out" here in the Pacific NorthWet.

I'll be certain to have this all redone before Power Tour. Damned if I'm going to have you guys flipping me off as I sit on the shoulder.... steam rolling out the front - one tire shot - A/C blowed up... Tailgate draggin'.... tools spread out for half a mile...


:>)

wow, some awesome info in this thread for sure!!

Does anybody have any sort of link, or any way they can lead me to more information about or a source automotive jet pumps? I've tried to hunt down info on the 'vette and the cts-v setup and am getting nowhere...Seems like a jet pump might be a wiser way to do a surge tank (albeit still not as wise as an internal setup).

So it seems at Mark has done all the R&D for perfect tank .. and Ricks- Hector can build one. So why they dont offer us one at the first place ?

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Take this for what it is worth -

It's been awhile since my Fluid Dynamics classes back in school, but I just thought I'd chime in (and probably confuse things and myself in the process).

Cavitation occurs when the pressure of the liquid drops below the vapor pressure of that liquid at a given temperature, essentially boiling. The creation of these "bubble" and their collapse causes little shockwaves inside the pump, causing vibrations and can cause the impeller to pit/break etc.

This Wikipedia entry was helpful in refreshing my memory and/or relearning.

http://en.wikipedia.org/wiki/Cavitation

I'm guessing that what is being seen in these applications is discharge cavitation - caused by too high pressure at the exit of the pump, caused by restrictions. The rule of thumb that I saw in the Wiki entry was this is likely to occur when the pump is running below 10% of it's most efficient point - not sure how accurate that is, but it may be a good rule of thumb.

I'm not sure that this helps or how practical any of this is, but it may help explain some of what is going on.

On another note, it was mentioned that running the regulator at the tank required running a higher pressure to get the needed pressure at the fuel rail. That would be expected as you will see a pressure drop proportional to the length of the pipe run. I think Bernoullis Principle is used to figure this out, but more practically, just measure it and adjust accordingly.

OK - I'm done rambling about stuff I used to know about...............


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The Fuel System Control Module sounds like the way to go. I've yet to build anything that makes enough power for this to be an issue!!!! Maybe one day!

Mark, what controls the FSCM? What does it use as a reference to adjust the voltage? Is it controlled by several factors from the ECM - like load, throttle position etc.?

Brandon --

The Aeromotive version takes a TACH input...

It's pretty simple wiring - Ignition - power - tach.