Just ordered the FM big flex fuel kit (DW300/fpr/bigger lines/fuel rail).

I've been running the numbers, and I'm seeing that the DW300 + ID1000s would be running ~85-90% duty cycle at ~440whp (the most power I'm likely to shoot for).

Would this be enough of headroom, or should I go with the ID1300s?

Worried about how idle will be with the 1300cc injectors on E10 when that's in the tank instead, know the 1000s are a known solid quantity for idle.

Looks like running at ~50 psi should make the pump and injectors have about the same ~85-90% duty cycle.

 

Yes, you should be able to reach the goal with that setup. Bump to 70 base pressure and enjoy better atomization too.

 

I'd definitely like to bump to 70 psi, but at that point the DW300 only appears to be flowing ~270 lph when the calculations I've done for lph required puts me at ~274. So over 100% duty cycle there.

https://www.miataturbo.net/deatschwe...ph-tank-54135/

According to that, at 13.5v it's only putting out 250lph @ 70 psi.

 

I've taken a walbro 255 to 430whp before it was done. evo8 on e85
I'm sure the dw300 can keep up, and with higher pressure your ID's will be happier, and you will end up with a more efficient burn, resulting in better efficiency.

I don't think you're going to run out of fuel, even if you bump up the pressure. I also think this setup should get you to your goal without much problems.

But ask Soviet because he actually did what you're talking about on a miata.

 

Why not the big boy Walbro E85 compatible pump, then?

 

Yeah, Soviet's thread is exactly what I was reading before posting this. He burnt out his DW300 and went to a 465 lph pump, IIRC, though that was on stock fuel lines, but still made me worried about the duty cycle on both ends.

Mainly in that I now own the 300 and that it's a known quantity to me.

 

I would do the 1300s if you can stomach the price. It takes some load off the pump by letting you run a little less base pressure than you would otherwise need to with the 1000s.

 

Less base pressure to be sure, but kind of want that pressure to go up, given the good results. Seeing about switching to the 416, just seems the right way to do things. The only thing that worries me is the fuel pickup, given the flat sock. I like being able to still turn with very little fuel left.

 

Do a fuel surge tank. Have a stock pump in the stock tank feed a small fuel cell in a low mounted location with a return to the main tank via a top mounted vent. The fuel cell will remain full until you are completely out of fuel. Feed the fuel rail from the fuel cell with the high flow pump.

Keith

 

I added a polypro pickup tube in the sock to the pump to get the very last drop of of the tank. Probably added an extra 1.5" pickup depth. Never had an issue with it after either...


Scroll to the bottom
https://www.miataturbo.net/build-thr...13/#post784086

 

I just converted to E85 using 880s. I'm at 80% IDC at roughly 250hp and stock NA fuel pressure (38psi?). Twice the fuel pressure will certainly go a long way towards making up flow, but I'd buy bigger injectors for the headroom if you can afford them.

 

Yeah, that's a really neat idea, but the issue is that the Walbro 400/416 use a flat sock instead of an angled one like stock, meaning it just doesn't get down there. The DW300 should be solid in any case from what I've heard.

 

Is there some reason to not do the surge tank?

Keith

 

Running additional fuel lines, adding another fuel container, would rather opt against that when (Sav?) I've heard that a good in tank pump will run until there's about 8oz of fuel left while on track.

 

I put the normal wally 255 sock on the wally 400e85 in my tank (I just bought the wally255 install kit for like 4 dollars and even used the bracket from it). I assume that means the stock sock would fit as well, I should have put a stock sock in but I wasnt aware there was a difference between the stock one and the wally one.

The stock fuel pump wiring under the dash got scary hot for me so I ended up running my own wiring all the way into the tank with a real fuel tank bulk head fitting.