Project Lexus SC300 Road Racer: Part 1 – Intro and Fuel Cell

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We’ve outfitted our FCST with two 50-1000 fuel pumps from AEM.

These pumps are designed for unleaded gasoline, and Project SC300 will be running on 93-octane pump gas. While we may purchase barrels of race fuel occasionally, we already have to work hard to keep power down in order to make the power:weight limits as required by our competition class, so we are running very safe ignition and fuel timing. This means no need for fancy (leaded) racing fuels.

Also coming to the party are a brand-new Fuelab FPR with gauge and a Fuelab in-line filter.

The fuel filter is a 6-micron micro-fiberglass unit that will give us great filtration performance if we decide to use street fuel. The gas stations near some race tracks have fuel of rather dubious quality. The 848-series filters also have a built-in check valve that helps to maintain fuel pressure when the car is shut off. This can help prevent excessive vapor buildup in the rail and can help with engine starting. It gets wicked, wicked hot here in the South, so this seemed like an added benefit.

The 51502 regulator is a 1:1 rising-rate unit. This means that for every PSI of manifold pressure above atmospheric, an extra PSI of fuel pressure will be delivered to the rail. So for the ~12PSI of boost we are running, we would see 12 more PSI of fuel pressure above the base setting. Rising-rate regulators can be useful tuning aids, and we’ll discuss that once we get the car running again!

Fuel Safe really wanted us to be sure we remembered where our awesome parts came from! I will definitely be handing these out to friends after I slap a bunch on Damnit.

So, now that we’ve discussed a little bit about the parts makeup of the project, let’s detail the rest of the project.

First, uninstallation of the old fuel tank and lines. Then, proper installation of the fuel cell and what that entails. Then, proper assembly of braided steel fuel lines. And, finally, cleaning it all up and making it nice. As with any fabrication project, there are some gotchas and some important things to take note of, and we’ll do our best to show you those. On to the removal! I’m pretty sure you can figure out how to take a fuel tank out of a car, but here are some gotchas we found specific to the SC300.

The fuel system includes various emissions components and other weird things that a race car just doesn’t call for. On the SC300, the fuel lines actually come out of the bottom of the fuel tank through some banjo fittings. For whatever reason, they also criss-cross underneath the chassis between the two holes in the unibody. I drained the tank as best I could by simply powering up the fuel pump and running a hose from the feed line into a fuel jug. However, the fuel pump only pulls from the factory collector basket, and there is still fuel in the tank. What to do?!

While fuel was pouring out onto the floor of my garage, I wished I had a funnel. In a pinch, I remembered an old trick. Cut off the top of an unused plastic jug, and you have an instant funnel! This one isn’t perfect, but it does the job. Zip ties fix everything, right?