Grassroots Motorsports
Issue link: http://grassrootsmotorsports.epubxp.com/i/501675
Grassroots Motorsports 104 tricky feat of switching steeds. And we'd like to share those secrets to success. This new project would have some of the same goals that guided the build of the little Honda, but with a few key new requirements added into the mix. Although the CRX was built as a track car for One Lap, we always knew it could also cross over to autocross and run up front there as well. With that in mind, every modifcation was done in a way that would keep the car within the rules for Street Mod FWD–or that could be easily converted. So the goals were simple: super-fast on track, streetable enough to do the transits on One Lap without kidney failure, and SMF-legal. The new project would again center around One Lap competition, but with an eye toward NASA Time Trial. So "streetable" is still in the mix, but ultimate track performance is key. We also wanted this project to offer remedies to three fun- damental design limiters that hampered the CRX: front-wheel drive, 65 percent of the car's weight on the nose, and a limited tire height of only 23 inches. Fixing any of these is most easily done with a change in platform, so it soon became clear that this project would involve building a totally new car. Here's how our podium-fnishing team keeps a build like this on the rails: Step 1: Don't Start With a Blank Sheet of Paper The surest way to get nowhere quickly in motorsports is to build from scratch. The more variables you eliminate, the easier the job. Fewer knobs to turn also means there are fewer possible combinations to try before you fnd the one that unlocks success. And working with familiar knobs makes that process much quicker. We originally drew upon our many years of Honda autocross experience to build our frst track car, and the result was essentially a Street Touring Civic with lots more power via an engine swap. Once the drivetrain was working, we quickly had a running car that we could enjoy. And we also had relevant experience on which to base handling adjustments with the higher speeds. The other car we had a great deal of success campaigning during our halcyon autocross days is the Miata. Over a seven- year period of ownership, our 1992 model competed in Stock, Street Prepared and fnally hit its stride in Street Touring, where it won a pair of national championships. (The story of the latter stage's develop- ment was told in these pages and remains an often-referenced series in digital form at grassrootsmotorsports.com.) We'll employ that same development process for this build. The spark that fred this best-of-both- worlds project was a forum thread at grassrootsmotorsports.com describing the swap of a Honda K-series engine into a Miata. The benefts were tan- talizingly familiar: rear-wheel drive, 50/50 weight distribution and bigger wheel wells. We were intrigued, and followed the build closely as it went from prototype to running track toy this past summer. Our decision to follow this path was made even easier when the swap was commercialized into a kit; we jumped in on the initial group buy. Step 2. Get It Running and Then Make It Faster We are big on planning, so our team keeps "to-do" lists for all of our devel- FEATURE: BUILDING A WINNER This could be the hot s One Lap of America: an NB Miata power. It's a bolt-in swap, too. Follow its progress at onelapmiata.com. tom suddard photo andy hollis photos