This.

Keith had to fab plates to block even the stock gas tank from the passenger compartment for the Targa, so keep that in mind, although on top of fabbing everything required for the fuel cell, it'd add up to a lot of fabrication.

Then again if you're having starvation issues, fuel cells is a good option. Isn't there a accusump type device for fuel though? I can't think of the name.

 

A friend of mine with a 350whp (not E85) track car told me he burns around 9-11 gal of 104 in a 20-30 min track session. This came up in a discussion on E85 in a track car.

 

swirlpot?

 

This reminds me of another point to consider, if you think you may go E85 in the future, plan on carrying about 35% more fuel load.

 

Yes. Not the best info but it has a decent diagram and a picture half way down.
swirl pot questions - NASIOC

 

I believe that Chris already runs E85 (but he'll have to affirm that).

 

I did run e-85 at one point, but my engine guy (who has 100% say so over what enters the engine) has concerns about the upper cylinder lubrication, so I am back to 104 unleaded.

 

Something's wrong with your fuel sock or pump hangar, then. I know to pull into the pits ASAP when I feel the car bog, because I have about ~90 seconds of idling left before the pump runs dry. If there is one thing these tanks do very, very well, it's maintain fuel supply even with virtually nothing left in the tank. Spec Miata guys know this all too well. It's pretty easy to screw up the fuel pump setup - my Walbro had the Walbro-supplied fuel sock facing the wrong direction, and I would get fuel starve with ~7 gallons left in the tank. Put the OEM fuel sock and mounting bracket back on the pump, and immediately fixed the problem.

The 1.8 Miata tank can access about 11.5 gallons with the stock pump and stock fuel pump sock on a stock hangar. The stock tank is located in an extremely safe place - ahead of the trunk, surrounded by subframe and rollbar/rollcage on all side, and with a solid 12" of air gap from the tank to the sides of the car. There should be no question about its safety - those looking to replace it with a cell "for safety" are just looking for places to blow money.

Likewise, if you're looking to replace the tank with an 8 or 12 gallon fuel cell, you're wasting your money as well. Anything less than 15 gallons of capacity would be a total waste.

Fuel cells are something I've considered in my E85 research - I burn ~7 gallons during a 20 minute session (varies at each track) at my current power level, so with E85 at 400whp I figure I would need about 15 gallons of capacity to make a 30 minute session. This may end up being a removable fuel cell that goes in place of the passenger seat - I have the big capacity E85 cell when I need it, and when I'm just doing a lapping day and scaring passengers I can pull it out and run gas from the stock tank.

 

RCI - 15 GALLON LIGHTWEIGHT ALUMINUM FUEL CELL : eBay Motors (item 320484376627 end time Feb-12-10 04:56:26 PST)

thats what im putting in my car to replace stock tank

 

Sav >> We both run NB's, mayhaps this isnt a problem with NA's

 

so does SM though.