The Amazing 10,000 RPM Turbo 3-Rotor 20B Mazda MX-5! Kyle Mohan’s American Ethanol/Mazdatrix Formula Drift Monster

In sea of V8 swapped cars in the pro drifting world, the Mazda MX-5 of Kyle Mohan stands out as a bold statement of uniqueness and technical innovation. It is currently the sole rotary engine running in Formula Drift.  A rotary can be a formidable engine in many forms of competition as it has to potential for great power density, making a lot of power for its weight and size. However pure power is not the most important requirement for drifting.

Drifting requires brute power but it also requires a lot of torque and a wide tractable powerband. It also requires good throttle response as drifting it a sport that mixes brute force with delicate levels of control. Sort of like figure skating with hockey players.  In this regard, a big displacement V8 does pretty well.

That’s all good but Kyle’s company, KMR or Kyle Mohan Racing is based around building and supplying parts for the Mazda Rotary engines so Kyle runs a Rotary as a rolling R&D lab for KMR. Over the years Kyle has developed the rotary from being a high strung bomb that made great power to a viable reliable engine that makes competitive power and holds together well.

Kyle’s chassis is a 2014 NC MX-5 which has been updated with 2016 ND bodywork. Never one to do the usual thing, Kyle’s MX-5 is a short wheelbase car which bucks the trend for successful drift cars having longer wheelbases for more stability and for putting down the power out of the turns better.  The widebody kit is a custom built part available through KMR.  The cars looks are done with a wrap by Wrap Legends and AW Graphics.

The engine bay is where most of the tech and innovation reside. The engine is a 2-liter three-rotor Mazda 20B which was found in the Japanese market Cosmo. The KMR built engine makes over 1000 hp at 10,000 rpm on 37 pounds of boost.  With Kyle’s current formula, the engine has been stone reliable and he ran the entire 2018 season on the same engine.

The heart of the engine is relatively stock with standard Mazda rotors and eccentric shaft.  The rotors are modified to take KMR 2mm thick unbreakable apex seals. KMR gets rid of the stock tension bolts that hold the engine together than replaces them with special oversized 0.5″ ARP studs with the housing holes precision reamed to accommodate them.  This way the clamping force to hold the engine together can be increased and the studs act like dowels to keep the housings from moving under the extreme pressure that 37 pounds of boost can create.

The rotor side housings are ported with KMR’s proprietary port pattern to increase the flow of the housings and to add to the port timing.  The rotor housing exhaust port is also enlarged. In a rotary, this is the equivalent of porting the head and getting a cam. Stock Mazda bearings are used but they are polished and WPC treated for longer life.  In fact, the engine makes extensive use of WPC treatment on all metal moving and rubbing parts and it is one of the reasons why this mega boosted engine has such a long service life.

The stock intake manifold and throttle body are used.  In fact, much of the engine is stock.  For power and long life in a rotary, its the details and specs of how you do things rather than a bunch of trick parts that makes for power and longevity.

It is hard to see in this picture but the engine is fed 98 percent American ethanol fuel blended by Thunderbolt racing fuel through a CX Racing fuel rail and 2200cc Deka injectors sourced from Evolved Injection.

11 comments

  1. This car really needs a Power Distribution Module (Motec, Ecumaster, Racepak).
    That organized mess of relays and fuses looks like a pain in the butt to troubleshoot

  2. Going to dig into this more later, but any issues with premix on rotor housing lubrication with ethanol? I’ve seen some anecdotal evidence from people who had housing damage on E85 that worries me.

    1. I am pretty sure that Kyle uses an alcohol specific premix oil, I think its made by redline. I had that discussion with him a couple of years ago and kinda forget the specific oil now.

  3. What kind of benefits are seen from the Wisefab kit, is it worth it for a weekend track car if the funds are there?

    1. You can lower the car a lot without messing up the geometry although its not exactly a bolt in, you need to swap to a BMW steering rack and modify the cross member for it. It is also more for drifting with a lot of steering angle.

  4. I do like the everything and the kitchen sink approach. Lag? Use anti-lag and NOS. Knock? Use ethanol and water injection.

  5. If the throttle is closed, is there any chance of the intake air being blown into the exhaust flowing back upstream into the engine?

Leave a Reply

Your email address will not be published. Required fields are marked *

*
*