Someone forwarded this thread to me and asked i respond.
I have a hydramat in my Evo. Tuned to full-tilt with bolt ons and a stock turbo on 93. At the end of a normal session, i'd fuel starve on most tracks. I'd usually no-throttle through the offending turns last 2 laps of the session.
Had to get creative with some plumbing and modify the fuel return system so that it dumps fuel ONTO the hydramat instead of inside my normal fuel pump hangar. I've got pics somewhere of my install, i'll have to find them. but i cut a large hole in my fuel pump hangar to route hoses from the hydramat to my walbro 255. I'm using a Radium Siphon kit and bypassing the OEM one as its built into the fuel pump hangar. The OEM siphon system uses a venturi on the fuel return to literally pull fuel from the right side of the tank. The siphon kit comes with a handfull of orifice sizes that you'll need to experiment with to make sure that your Fuel pressure is as normal as possible (unless you've got an adjustible FPR). For you turbo folk, this means a tune check as you'll probably be off a few PSI which will affect your trims slightly. Theoretically, a smaller orifice will increase the velocity of the flow, which will pull more fuel from the right side of the tank, but from dicking around it doesn't seem to make an appreciable difference (i still starve on the same turns at the same fuel level). So i recommend using the orifice that will require the least amount of fucking-about with your fuel trims.
For those pushing 600+ hp, be wary. Reports in the evo community show that there are fueling issues brought about by the 1/2 inch fitting on the mats. It is suspected that the 1/2 fitting is limiting fuel flow which can't support large power on these boosted 2 liters. Not sure if they make a 5/8 fitting mat yet in a large enough size. Also, i had to use a 90 degree elbow coming out the mat to clear the pump hangar, which converts the NPT fitting on the map to the barb required for the rest of the fuel system. I also had to use a Radium fuel pump adapter kit to convert the Walbro fuel inlet into a Barb so i can connect to the hydramat, as the mat is now your fuel filter.
Overall, the mat does exactly what it's supposed to. I'm having a weird fuel anomaly but i think its unrelated to the mat (weird lean spot at 4k RPM that i'm tuning around). I still Fuel starve if my fuel gets around 5/8 tank, but it buys me enough time to get through a session now. I'd usually use 4+ gallons per session as long as there's no traffic, which puts me at 3/4 tank at the end.
Next step is to add a 2nd mat on the right side of the tank with a low pressure in-tank pump. This would solve the problem 100% as long as the flow of the 2nd pump can outflow the main fuel pump. Need to figure out the best way to wire said pump. Then i can run the tank down to 1/4 without starving (i hope).
Other notes: turns out my tank (its metal) is magnetic enough for the magnets that come with the mat. They're really strong and will survive any kind of forced slosh without movement. I also purchased the magnets for use with a plastic tank just in case. Those things are so damn strong that if they touch, you're NOT getting them apart. Seriously, i haven't been able to get them apart. So, they're definitely strong enough if you have a plastic tank and you're worried about it.
A handfull of hose clamps to secure hoses on barbs
And a handfull of zipties to secure all the hoses where they need to be :)