I probably read a dozen posts on ballast upgrades in the forums, but I haven't read much on the 3-pump upgrade process specifically (using the 3 reversible vein pumps).
I've spoken with Jason @ WakeMakers about this and I'm about to move forward once I double-check with the members on the forum ... There are a few technicalities I cannot work out and I was hoping for some input from fellow Supra owners with more knowledge or experience.
My goal is to keep as much of the stock configuration as possible, as follows:
I'd like to use the stock Thru-Hull pickup (no new holes) >>to>> Shutoff Ball-Valve >>to>> Water Filter >>to>> the original 3-way "T" manifold strapped to the transmission, and here's where the stock setup would end.
From the original 3-way manifold, I'd run hoses to the 3 reversible vein pumps.
Now I realize that some people have said you need to drill 3 separate thru-hull fittings (one for each pump) to accomodate the volume, but I've researched the capacities of a 1-to-1.25" pipe, and it should be enough to supply the 30 GPM volume with mild pressure. Keep in mind that internally those pumps are plumbed as 1/2" which has an effective opening of roughly 0.20". The 1" hose is 4 times larger at roughly 0.80" area. I'm assuming the stock thru-hull in the Supra is a 1 or 1.25", does anyone know for sure? (BTW - I have a 2005 Launch 21V).
So that's my first question -- do you believe that a single thru-hull will be enough to supply all three pumps @ roughly 30gpm (which academically appears to be true), and whether that stock thru-hull is a 1 or 1.25" fitting?
2. Where would you choose to mount the pumps? I've only owned ski-boats (direct drive) in the past, so I'm not sure whether it's a good idea to place the pumps alongside the ballast bags themselves, or whether this creates undo wear/overheating/etc.
3. It seems like we'd need to upgrade the wiring, to power these vein pump (12 Amp each @12vdc, I belive). If my assumption is correct, the new pumps should require 10-12 gauge wire, which is much larger than what I believe is running to the Sprinkler Valve solenoid's.
Is this a valid assumption, and if so, would that mean that I have to run new wiring all the way from the battery, to the ballast switches, to the pumps? And would I keep the same ballast switches for the reversible pumps, or would I have to get new switches as well?
4. There are 3 different options for the rear locker bags. There are the FlyHigh's at 50x20x20 (750 lbs) or 50x24x24 (1,100 lbs) and the SUMO at 50x22x22 (900 lbs). Most people have used the 750 it seems, is this the best option to stick with?
I'm sure no one will have the answers to all of these points, but any feedback you might have would be greatly appreciated!
Thank you in advance,
RKM