Moto East / Deatschwerks Drop-in Surge Tank - tech & discussion
 

Hey folks. We have been working with some track day folks over the years running e85, and one thing that has stuck was that on left handers you run the stock fuel bucket dry really quick when the fuel demands are high. One option is to do a full fuel cell setup, another is to add a complex system using return lines and custom bucket. We're shooting to take care of this with an elegant solution where we utilize a deatschwerks pump (or dual pump for 400+ whp), a custom battery/surge tank bracket, that you can then use with a PC680 or smaller battery. Completely plug and play fuel lines in this solution, and much much cheaper than a fuel cell.

http://www.moto-east.com/main/wp-con...3591287770.jpg

This is a preview of the final placement. We wanted to get this up on the forums so that folks can see what we have brewing and also share any input as we finalize the design and parts list.

A few points:

• Mounts into the factory battery location
• Uses Deatschwerks surge tank and pumps
• Saves about 14 lbs when paired with a PC680 and full (may have to double check this)
• CNC cut plates, then welded as a tray with separate compartments for the battery/tank
• Can be the black stainless reinforced braided hose like our flex fuel kits, or full stainless hose
• Uses -6 AN fittings that plug into the factory lines
• Fully integrates into our flex fuel kit
• Can be provisioned for a fuel pressure sender if wanted

The -6 lines should support 700 hp no problem, and with a good fuel pump in the stock tank this should prevent fuel starvation under all conditions except maybe top speed runs past 200 MPH. :thumbup:

No firm release date yet, but we may do pre-order if folks are interested so that we can allocate our resources appropriately.

Can trays for alternate batteries be made? Particularly, the large form factor Shorai.

Unfortunately not, and it really will work best with the PC680 since it relies on a solid mount to keep the assembly bolted down tightly.

Also, after a shorai almost burned our miata down to the ground, I wouldn't recommend that battery.

EDIT: I should add though, you could in theory cut and weld on a longer plate on the battery side to fit a slightly larger battery. The key here would be that the battery is not loose in the box. If we did that we'd need the battery sent here then make the box around it.

Clever solution, I like it.

Really glad you put this in the bay. I have no need for this (yet?) but it's still badass :)

I'm pretty interested, starvation has been an issue for me. Can't wait for final released product!

Does that battery have enough CCA for those of us who use these cars as DD in cold weather?

In OK, we typically have a month of so temps around or below freezing in the morning.

Love the design. Would the fuel pumps run in series then?

Options are as follows: drop in fuel pumps (250il) or use the pickup tube with a fitting and then mount an external auxiliary pump. These are universal mount and you can tie it to the strut tower or fire wall.

I've used the 680 on i4 engines for years and no issues, but don't expect it to crank nearly as long as a full size battery. You can use it as a daily, the bigger issue is for a car that sits since it will be quicker to discharge. So keep it on a battery tender or actually drive the car and you'll be fine.

Thanks!

I need to pickup the bat phone and ask @GSpeed what they think of this ;)

They have done some fuel pressure measurements and I think they are one of the few who collected data on the issue of fuel starvation.

I am definitely interested as I am suspecting fuel starvation at the track could lead to serious reliability problems in the long run.
@moto-mike, if you can give some more background on the consequences of fuel starvation I bet that will help your product ;)

Only fix (short of fuel cell/recirc) for fuel starvation has been to run with a full tank, which is what all of us have done. Full tanks are heavy, and at 350+ whp you can suck 1/3 down in just one track session.

To hit 350+ whp you will need FI. Fuel starving with FI is a very, very bad thing on a hot engine. My old car was the 335 equipped BRZ and we starved badly on even moderate length left handers after 10-15 minutes from a full tank. Our current shop car (Phil's) runs over 450 whp at the track (570 in road mode....) and you can imagine that runs through fuel stupidly quick if there are straights.

Another reason this issue really stinks is when countersteering in a slide. Having power suddenly drop out will cause a flick back to the other direction and possibly put you in a wall.

Looks very good! :thumbup:

@moto-mike, what is the total weight of the surge tank(full) with the battery?


-Stefan

Does this make the fuel system return style?