Project FD RX7 Restomod: Part 32 – Deatschwerks DW400 Fuel Pump and Fixing Fuel Starvation

Next, we cut off the OEM electrical connector, fuel feed and return lines.

We scribed the fuel hat and then drilled out the feed and return line holes to fit a -8AN feed line and -6AN return line. There was a gap on the hangar mount where the bulkhead connector would not seal completely against the hat, so we dropped a few beads of weld in the gap to fill it. It was then ground flat and flush with the rest of the bracket.

The OEM fuel hard line (left) is much smaller than the new -6AN return line (center) and the -8AN feed line (right). While -6AN has been proven to make big power on setups with 2-3 fuel pumps and a lot of pressure, with this project we are going to find out how much power can be made on a single fuel pump. We are doing this for a few reasons. We are curious, one pump is less complicated and expensive than 2 or 3, one pump will fit better in our fuel starvation solution which we will cover later on.

In order to make more power with less pressure from a single pump, we are going to need more flow. We are going to accomplish that flow with a less pressure drop and more volume from a large -8AN feed line. An exaggerated analogy of this would be, how quick a gallon of water can drain from a 4” sewage pipe vs a pressure washer. In order for the same gallon of water to flow out of a much smaller nozzle in a pressure washer in the same amount of time, it would need to have a significant amount of pressure behind it to push it through the small hole.

After a quick coat of gold engine enamel, we were ready to assemble our new fuel hat.

We drilled 2 holes for the Radium Bulkhead Stud Kit which will power our fuel pump.