Project Time Attack Part 2 - 1995 Mazda Miata

E-production class Miata race cars have been using zero-offset wheels for a long time with great success, so we decided to look for a wheel with a +15mm offset, since we will ultimately run tires that are 20mm wider. The increased scrub radius of this more positive offset will put more load on the wheel bearings, but we're hoping the trade-off for extra track will improve lateral grip.

There are few 15x8 wheels on the market, even fewer in the offset we wanted. Work Wheels said it could make what we were looking for. Its history of building custom-sized endurance wheels convinced us we'd be getting a light and durable wheel.

After what seemed like a long wait, we received our Meister S1s, beautiful works of art that weigh almost 16 pounds a pop. A little surprising, but not a deal-breaker. Seeing as we've bent our share of unproven super-light wheels in our off-line lawn-mowing excursions, we're happy to stick with Work's products.

Even with all the measuring and hunting for offset-specific wheels, we still ended up with fender clearance issues. To cover up our artistic Sawzall expressionism, fender flares from a small Japanese boutique called Tuckin '99 were added. Tuckin '99, like many other boutique Japanese motorsports suppliers, built its business around a diehard set of Miata fans and club racers, and isn't really interested in scaling its business over the web. Parts are made in small runs and sold by word of mouth. As SCC is all about JDM, we purchased a set from Adrenaline Racing, in the JDM center of the world, Lake Oswego, Oregon.

Sprung weightTaking out sprung weight is far easier and subject to fewer compromises. It's also easier to remove and relocate this type of weight. Big-budget race teams will make everything as light as possible before adding weight back (in the form of lead bars in the floorboards) to satisfy the minimum regulations-all for the sake of better weight distribution. Since the Miata is already relatively well balanced, we opted against such extreme measures and focused on removing as much weight as we could from the edges to reduce the total moment of inertia.

Every removable body panel was pulled off to access the non-essential crap underneath: bumper supports, windows and crash supports, latches, and wiring for stuff we had long since thrown away. Axis Power Racing (APR) created a set of carbon fiber-wrapped Nomex honeycomb-cored replacement body panels-substantially lighter than the stock pieces-to shed further pounds. APR uses a vacuum infusion process to suck out as much excess resin as possible, minimizing weight. Unlike race car chassis components, these pieces are not baked in an autoclave for added rigidity since the panels we replaced are non-structural elements. The honeycomb adds enough rigidity to make the pieces more than just cosmetic and also allowed us to avoid the autoclave, significantly reducing cost.

The pieces were molded directly from the stock panels, but the hood was modified with a vent placed directly behind the radiator to evacuate hot air from the engine bay. This will be a big factor once we turbocharge the car and install various other heat exchangers in the nose. The front fenders were lined and reinforced with Kevlar to save the panels from internal damage due to road debris being thrown up by the tires. The only panels left stock were the rear quarter panels, which are part of the factory unibody. We sourced a Racing Beat Type 2 fiberglass nose to replace the factory piece as it saves a little weight, but also has added cooling ducts.

At 10 pounds per side, the MkI Miata pop-up headlights have a significant impact on polar moment. A time attack car still needs lights, but we didn't want the weight. Advanced Automotive Concepts has a fixed-mount headlight kit that shaves over 12 pounds. Other unnecessary parts (including the soft top, airbags, interior bits, seats, seat belts, stock battery and dash guts) found the dumpster. The stock side mirrors were replaced with carbon pieces sourced from APR Performance and the rear glass in the hardtop was chucked in favor of a Lexan replacement. Our final weight came down to 2018 pounds with a full tank of gas. Not the lightest Miata we've seen, but necessary weight (such as the cage) makes up the difference. Just in exterior body parts replaced, we've shed 154 pounds.

Now that Project Time Attack has spent some quality time with Jenny Craig, it's time for the 'roids. In our next installment, Project Time Attack will receive what is likely the best power-to-weight ratio of any of the monstrosities to come out of our garage.

Other Installments:

Project Time Attack Part 1

Project Time Attack Part 2

Project Time Attack Part 3

By Matt Andrews

Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!