Simply put, there are some moments in your life when you are just blown away. Something, someone, or an idea, might hit you in the face with utter disbelief to keep you feeling human. It’s a common phenomenon that doesn’t seem to happen too often these days in the automotive scene. Mainstream motorsport gets duller by the year, show cars that were once big in the wow factor are slowly dying off and tried and true combinations take place over trial and error.
During a pit walk at Phillip Island during the Topstage Composites Vic Time Attack Challenge, that moment of disbelief hit me so hard in the face, I nearly dropped my camera, coffee, and doughnut. I think not for the fact of what I was seeing, but for the fact that it was almost so sacrilege, I thought never in my life would I see it completed.
The disbelief in question was the sight of this particular Mazda RX-7 FD sitting among a stable of BYP Racing Hondas. That in itself should have been the giveaway that I was looking at no ordinary Mazda RX-7, but rather one that BYP Racing had cooked up in their deep dark lair, west of Sydney.
Yes, that’s right. This Mazda RX-7 was built by BYP Racing. Why is this so significant you’re wondering? Well, BYP Racing are a Honda tuning workshop and haven’t been known to dabble in the Wankel tuning world… So instead, a plan was hatched to install a K20A engine into this particular example, that is owned by Adrian Pazman.
A client of BYP Racing, Adrian is not new to the Honda tuning world, having owned a very potent B16A turbo Honda Civic, that makes its way around Wakefield Park in 1:05.4. With the proof evident that Hondas can cop a beating, but having owned Mazda RX-7s in the past, the team at BYP Racing pitched the idea of a K20A-swapped RX-7 when Adrian was ready to move into another rear-wheel drive platform. It had the reliability box ticked, wouldn’t upset the weight balance a great deal, however, an N/A K20A engine wouldn’t be enough, so from the get-go, a turbo setup was also planned.
An RX-7 was purchased that had a damaged engine, and the BYP Racing team set to work immediately fixing the issue so that the engine could be sold as an engine conversion package. In the meantime, a factory K20A engine had its valvetrain upgraded to handle boost and in it went bolted to an S2000 gearbox for the initial dummy fit. Things at this stage were extremely promising as everything lined up surprisingly well. Oh, and the RX-7 received a nickname, too — Rhonda.
Daniel from Impossible Fabrication was enlisted to tackle everything that required a welder. Engine mounts, gearbox, manifolds, and more were made by him and the workmanship is excellent. To get the K20A working in a rear-wheel drive configuration the factory manifold had to be mated to an S2000 unit as to have it forward facing. After that, Daniel fabricated a K20A turbo manifold for the application, mounted the Garrett GTX3076R turbo and downpipe. Considerable modification had to be carried out to the factory Mazda subframe too, which required new mounts for the K20A engine. Mated to the custom and now high-temp coated turbo manifold is a Precision 46mm external wastegate that would soon be plumbed into the exhaust system, complete with V-band clamp for easy removal.
Fabrication didn’t stop there as you can imagine and when it came to mounting the front-mounted intercooler the team decided that for this application a V-mounted unit would work best. Rob from Speedfab produced a beautiful and well thought out setup that has minimal charge piping. Custom ducting was made for the aluminium radiator, along with custom aluminum radiator piping to aid in the hunt for reliability. Another touch you can’t see under the vehicle is the custom made three-inch titanium exhaust system. There’s one muffler and plenty of lobster-back welds — it sounds as good as it looks and the entire system only weighs 4kg in total!
Once everything was in place, plumbed in and coated in matching black heat paint and wrinkle coating for a more factory-like appearance, the team had it strapped to a dyno for its initial run and check. On the stock bottom end, and with wastegate pressure of only 16–17psi, it produced a stonking 310kW at the rear wheels tuned with a Hondata Kpro ECU. Now in its current guise, power is up at around 330kW.
Handling wise, the BYP team installed a set of GAB SS coilovers and Cusco front and rear sway bars. Braking has been taken care of with a Brembo Evo X upgrade kit, which includes a set of two-piece 355mm discs. For the street and initial testing, Adrian decided on a set of 19-inch Advan RZ wheels wrapped in Federal RSRR tyres to complete the combo.
Inside the cabin, things have been kept fairly minimal with the addition of a Buddy Club fixed back racing seat, Nardi steering wheel, Type R gear knob, and an AIM MXl2 gauge cluster. We can’t get over how awesome Rhonda has become over a very short period of time, and we’re excited to see how it develops with further testing. Once again the BYP Racing team have done a fantastic job with a wild, unique, yet fairly simple time attack combination. Sorry rotary owners, in this application the K20A has our vote!