Back when I built Thunderbolt, my LS3 Miata, I had a very clear project plan laid out.  I wasn’t the first person to do an LS-based drivetrain conversion on a MX-5 and thanks to a great community of enthusiasts, the tasks for that job were well documented.

There was still plenty of discovery and problem solving to be done as with any project, but all told, it was pretty straightforward.

Project Firebolt, however, is quite the opposite.

As far as I can tell, only a small group of people have done this conversion and while a couple have kindly shared their builds online, there isn’t much to go on. I knew this going in and understood that there would be some trial and error and even some inevitable changes to the plan along the way.

So here’s our first plot twist to the Project Firebolt story. I originally planned to mount a big old turbo on the passenger side of the engine bay just like almost every other LS-based, single-turbo setup you’ll find. What I learned as this build progressed is that as I started filling out the cramped engine bay of the Tacoma, a turbo mounted in that spot would require a bunch of sacrifices. I may be spoiled, but I want to keep my air conditioning and would like to close the hood without anything sticking out of it.

I’d be willing to make those sacrifices if this was a drag truck or more of a fun weekend beast, but I want to drive this thing all the time, so we’re going rear-mounted turbo!

This isn’t a new concept, especially with trucks, as there’s usually a good amount of space to work with back there. This will give us plenty of room in our already cramped engine bay for accessories and such and I’ve always wanted to experiment with a rear turbo setup.

To accomplish this task, I ordered up a truckload of Summit Racing’s finest exhaust pipe, mandrel bends, flex sections, V-band clamps, and hangers.

Combine that and some time under the welding helmet and we have ourselves a rear-mounted turbo! We also tackle a handful of other jobs including choosing a radiator and making some brackets to mount it up.

Need to catch up? See the first seven parts of the Project Firebolt series here:

Building a custom exhaust is easy with the wide range of high quality, affordable exhaust parts that Summit Racing offers. (Image/Tom Tharp)

I use three angle grinders and equip one with a cutting disc, one with a grinding disc and the other with a flap disc. Saves so much time! (Image/Tom Tharp)

Building a complete exhaust setup for a turbo V8 meant the metal was flying. Someday I’m going to find a use for these little chunks. (Image/Tom Tharp)

Here’s the turbocharger that we’ll be using for Project Firebolt. I can’t wait to hear it sing! (Image/Tom Tharp)

To keep the ACDelco starter happy, I wrapped it in one of Thermo-Tec’s starter heat shields. (Image/Tom Tharp)

Summit offers a huge selection of high performance radiators. This one from Be Cool is perfect for our needs. (Image/Tom Tharp)

You haven’t truly lived until you’ve taken a hacksaw to your engine. (Image/Tom Tharp)
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Author: Tom Tharp