This car started out as a 2006 Ford Mustang with a stock 4.6-liter engine that we found lacking. We debated an LS swap, but the market is saturated with those. We wanted to do something different. After consideration, we landed on a Hemi swap. For transmission control, we knew we would use a Holley Terminator X Max System. We also wanted an automatic transmission with overdrive, and we needed it to be electronic. That limited our options. We settled on a Chevrolet 4L80 transmission. The guys at PTC built us a super nice unit with trans-brake options and a 4000 stall to match our cam setup.
We start the transformation process with the shakedown of the chassis. V1 will be a stock 6.1 Hemi Long Block with a stock 4L80 trans (same 4k stall.) The 6.1 Long Block does have a mild cam in it that wouldn’t benefit from such a high stall, but for dyno curves to be similar it isn’t a deal breaker either. Aside from the cam and the shared parts, such as the intake manifold and headers, the V1 motor is all stock.
We build the engine package ourselves. We use a stock 6.1 block (like in V1), but that’s where the similarities end. V2 has a 426 cubic inch rotating assembly, fully forged and gapped to see a massive boost.
When building an engine, we don’t skimp on fasteners because we don’t want your engine flying to pieces as you reach maximum speed. We use Automotive Racing Products (ARP) to anchor the engine sub-assembly. The heads are fully race-ported with titanium retainers instead of stock valves since the titanium retainers are stronger and more lightweight. To maximize airflow, we use stank collars under the valve covers and stabilizers for the rocker shafts. Double Beehive 660 springs distribute the stress of the 651-lift cam while also reducing the weight of the engine. This block sports a healthy 11:1 compression ratio, making it a dedicated e85 car, taking full advantage of that compression. (This is the setup we will use for the fully built 4L80 trans.)
The complexities of the build really shine in this phase. We added a Billett 96/88 turbo setup to the V2 setup.. With 426 cubic inches and relatively high compression on the 1.32AR hot side, we hope to see usable boost! The full system and the strong block excel under 35-45lbs of boost. While we don’t know where that number will land or how much it will make when we get to this phase, seeing four digits on the dyno should be a breeze with this setup.