I got my Hydramat in. Good news and bad news...

Good news is that a 11x11 mat fits perfectly in the Evo tank, will post photos later this evening.

Bad news is that the tank is only 7 inches deep. The NPT fitting of the Hydramat sticks up at least an inch and a half. That means trying to fit an in tank pump vertically directly on top of the Hydramat is impossible. The fuel pump would be sticking out the top of the fuel sender lid.

Back to the drawing board....

Might entertain mounting the pump horizontally or some where else in the tank. Otherwise, the only viable solution I can come up with is to switch to an external pump.

 

I think chet ditched his stock fuel sender unit or modified it. The pump uses radiums fuel inlet adapters and its just hanging out inside the tank. The hoses seem to keep them relatively stable and they're definately not straight up and down.

Just route some extra hose to allow the pump to mount at an angle.

https://www.radiumauto.com/Fuel-Pump...-Kit-P565.aspx

 

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Front left corner





Rear side and crossover tube





Rear right corner





Rear left corner





Front right corner





Radium inlet<br/>





Rear right again








Front




I got my extra sending unit in yesterday, and started playing with it, rubber submersible line isnt really flexible enough to be able to play the pump orientation, so im going to scoop up some PTFE hose this evening. Right now I have the bottom off the cup sawed off with the pump mounted horizontally in the remains.

 

That might be tough to shove in and out of the gas tank hole from the looks of it.

If you're using the radium siphon system for the fuel return, you probably don't need the fuel hangar at all. You can probably chop it up to just allow the level sensor to hang out in there.

Anxious for your results as i will probably end up doing the same exact thing.

 

If he just had the sender hanging out, how is it keep track of the fuel level???

Also I'd worry about the pump getting wrapped up in the wiring and lines. They produce quite a bit of torque. I bench tested a walboro 255 a while back and it flew off the table.

I'd really like to see what Chet's setup looks like, I couldn't find any pics on the webs.

However...

I got the assembly in the tank after mucking with it for about 30 min.

I had the whole assy. connected as follows:

Hydramat > PTFE tube > sideways fuel pump, cup remains, level sender attached > PTFE tube > pump lid. The whole thing is damn near 3ft long.

I had to:
1. feed the mat and anchor the magnets
2. spiral the 1st PTFE hose in
3. pick up return siphon hose and anchor it with sutures outside the tank
4. insert fuel pump assy and sender
5. spiral the second PTFE hose in
6. stab the two metal rods through the hangar assy.
6. attach stock siphon hose to Radium Jet pump
7.connected fuel pump and sending unit wires to the lid I had about 1.5-2 inches of room at this point)
8. clock the pump lid correctly and bolt down the ring, ect.

It took some messing with but it not impossible. It just so happens that the 1/2 NPT hydramat fitting is in just the right place to hold the plastic cup remains up off the mat, so no worries the cup will rub a hole in it.

My fuel pressure was actually raised several psi, so I had to put the black (medium) restrictor orifice in the Radium Jet pump. This got it close to stock FP and fine tuned it back to 43.5 psi with the AFPR. No tune changes needed, checked the logs with EvoScan.

From the pics I posted you can see it had about 1.5 inches of fuel left (about 10 miles past "flashing empty" warning) I let the car run for about 15-20min, while I cleaned up, drove 5 miles to gas station, let it idle for another 5 min, then filled it up. Since then I have ran it all the way back down to flashing empty, without running out of fuel at a half tank.

This confirms at least the siphon is working.

Once I run the tank low again, I'll post some pics with the lid removed to you can see how it's put together. Its kinda janky and far from my finest work, but it does indeed function.

For the real test, I have a track day scheduled Nov 7 on a high speed, mostly left turn track, so we'll see if it works as advertised.

If it does, this could be a real solution for paying over 1k for a surge tank, and eliminate it's inherent problems/complexity. Total cost was about $480, I believe.

 

So to recap your setup.... Radium fuel pump adapter, radium siphon kit, 15x10 hydramat, and some ghetto rigged fastners to keep everything together?

Really curious if the stock siphon system could keep up at the track. I have no idea what the otherside of the tank looks like or how the siphon picks up the fuel, but perhaps a hydramat could be fitted to the other side of the siphon system worst case scenario??

Also, i don't have an adjustable FPR so i think i'll be stuck retuning my fuel trims no matter what. Do you remember what your fuel pressure was before the setup, and afterwards on the medium venturi fitting before making changes to the fpr?

 

1 x Radium FP adapter
1 x Radium Jet pump
1 x 11x11 Hydramat
1 x Holley Magnet Kit
1 x 1/2 NPT to 3/8 barb adapter
2 x PTFE hoses
1 x package of fuel injection hose clamps
1 x 5/16" submersible fuel line (for jet pump)

If you did stick a mat on the siphon pickup, I think it'd be a waste, who cares if the siphons pickup sucks air, that would mean all the fuel is on the left side, where it belongs. The return line would still operate normally. The discharge would probably be aerated, but if is a couple of inches off the mat, it wouldn't matter.

The main purpose of the radium jet pump was so I could delete the bottom part of the cup, where the stock siphon resides. With the way I have this configured, it is no longer a major source of fuel like the it was when it was on the cup, its just to keep the fuel balanced while cruising on the freeway, which prevents the car form running out of fuel at a half tank.

I also think the siphon is less of an issue with the hydramat. The problem before was on a left turn, you splash a good amount of fuel out of the cup, the only thing refilling the cup is the restrictive return/and siphon pump. Since the fuel pump was able to suck fuel faster than it could return it to the cup, it would start sucking air into the fuel sock.

I like to imagine that the entire left tank saddle has now become what the fuel cup used to be, only bigger.

The way it is setup now, the left tank saddle has a much larger volume of fuel, and with the mat, a much larger surface area to pick up fuel from. if you have more than a half tank, i think it would be impossible to splash ALL the fuel to the right side, some of that fuel will pile against the drive shaft tunnel, so ideally the mat would have some fuel touching, which supposedly all it needs, including the return and siphon splashing on it.

My fuel pressure was 43.5 when I started, shot to 58 psi with the smallest restriction, 46-48 psi with medium restriction. I didn't try the largest, I wanted to keep as much suction as possible from the siphon. YMMV.

I think the AFPR is a good investment, mainly so you can monitor fuel pressure with the gauge, and its cheaper than a dual fuel retune.

 

Good points TerraVista. My thoughts on the hydramat on the right side was mainly to ensure you could run a tank super empty before having to fuel up. We shall see i guess when you hit the track.

If i get an afpr, would i be able to avoid a retune by matching the fuel pressure before and after? Or is there another variable i'm missing here?

With that said, perhaps its a good idea to use the smallest restriction to help suck as much fuel as possible from the right side, then try to dial the fuel pressure back down with the AFPR?? I'm not a tuner so i wanna make sure i'm not missing anything.

 

I like what you did with the fitting of the pump in there. What have you seen in terms of sustained suction? Any issues thus far? My hydramat setup should be online before the end of the year.

 

I went to the track Nov 7, and didn't notice any problems.

However, it was pouring rain the entire weekend, and of course, when it started to dry out, my turbo backed out and burned the gasket.

So I never really had a chance to put any high lateral Gs down. I did run the car past a half tank, and didn't notice any starvation.

No issues daily driving, I have ran the tank past empty for up to 12 miles, so the jet pump transfer seems to be working as intended.

 

Got any updates?

I’m thinking about trying to use the stock siphon system with the hydramat instead of using the Radium Kit. Can anyone think of any reason why you’d use a radium siphon kit over the stock?

 

I just wondering how I need to connect my two 485 walbro's using 100% ethanol, its making 850whp

 

I haven't found any way to convert the plastic fitting on those pumps to something that can go to a NPT fitting. Supposedly there is something out there these days.

 

So i got this system in my car and working.... but now the fuel level sender isn't working. Reading zero fuel. What did i break?

 

Also, where did you get your PTFE flex line? I couldn't find any. I ended up using submersible fuel hose and used a 90 degree barb to NPT fitting on the hydramat. I chopped up the sides of the hangar to let the hose out at an angle. Not sure how i broke the fuel level sender though.