The Targa V8
The ongoing development (and competition) of the V8-powered Targa Miata.
January 13, 2011
Plans for the car are coming together.
There's been a change in the engine specification. There's a proposed Spec V8 series in the making, called V8R Spec. V8Roadsters and V8R Spec has offered to not only provide the hardware for the V8 conversion, but also a built-up L33 engine. In exchange, we'll send off the old LS1 from Elvis that has a few of the parts needed, such as the improved LS6 heads and intake. The support from V8 Roadsters and V8R Spec is fantastic. That's Elvis' old engine in the picture, looking rather forlorn after being booted out for a 480 hp LS3. In case you don't know Elvis, that's Flyin' Miata's first V8 car, the blue car I've been playing with at various autocrosses and at Laguna Seca over the past couple of years. It'll be the sister car on the 2011 Targa team, running in Touring.
So what is this L33? It's a runt in the LS engine family. The big boys run as big as 7.0 litres, but the L33 is only 5.3. It's also known as the Vortec 5300 and is found in trucks. Specifically, the 2005–2007 Chevrolet Silverado 1500 4WD and GMC Sierra 1500 4WD extended cab trucks. What makes it interesting? Well, it's the only one of the truck engines with an aluminum block, making it lighter than most. It's actually a fairly popular one to use for various swaps, as they're generally less sought-after than the bigger variants but still able to make good power.
It will be modified, however. The LS6 intake and heads make a big difference, as does the V8R Spec camshaft. Basically, the engine will be set up for a nice power increase but without sacrificing behavior. Expected power levels are 410 hp and 350 ft-lbs. Steve at V8Roadsters thinks it's the best of the various LS engines. So we'll have approximately double the power and torque of our 2008 car with a weight penalty of around 200 lbs. Seems like a good trade.