The family of Nissan 240SXs have never been known for their prowess as circuit racers, though they’re far more versatile than the cynic gives them credit. In fact, they’ve been making a name recently in time trial categories, and proven they can corner quite incisively if their weak link—traction—is remedied.
In the case of the MCA Hammerhead, a former Australian rally champion and an ex-McLaren engineer helped ensure the power was put to the ground effectively. Murray Coote and Barry Lock, respectively, started tweaking this unsuspecting little Silvia back in 2011 and have since added an 800-horsepower SR20DET, grafted on plenty of tubing to trim weight and add rigidity, and installed an aero package to help the little tire spinner put that colossal power to the pavement.
Boost Control is the Key
An SR20VE head flows the required amount of air, and only uses a little porting, Kelford valve springs and camshafts. The internals are quite simple; a steel crank, decent rods, and basic pistons are all that’s needed. Yet, on E85, the motor makes upwards of 900 horsepower! It’s turbo technology that’s provided that punch, and to make good use of that power, they implemented a clever traction management system.
Though the system doesn’t cut spark, it does limit the amount of boost depending on several factors. Not only does MCA run different boost pressure by gear, they also control boost by throttle position, which emulates the predictable and progressive power delivery of a normally-aspirated motor. Since the turbocharger spools so quickly, the delivery had to be restrained slightly to put the power to the ground. For more on the motor and this ingenious setup, see here.
MCA are principally concerned with weight distribution, traction, and some of the “bigger picture” items, so they mounted the transmission and the driver’s seat much further back—just like a DTM car. All of these tweaks help set the balance further towards the rear and press the driven wheels into the pavement.
The car’s radical aero package is part and parcel of a WTAC timesheet header these days. At the rear, a massive diffuser and an enlarged trunk spoiler have been tweaked subtly over the years, and the shape of the dramatic front wing is what gives the car it’s “Hammerhead” moniker.
Despite all the front-end grip, they’ve been able to shift the balance rearwards over the years for aero stability. Even without a transaxle or a motor to press them into the pavement, the rear wheels handle the power comfortably, and the regular breakaway at the rear is mild and controllable. Over the years, this increase in downforce has helped to help put the increasing power levels down.
This year, the MCA Hammerhead successfully defended its title at World Time Attack Challenge. With V8 Supercar star Tim Slade behind the wheel two years in a row, the chopped another 1.5 seconds off the overall record at Sydney Motorsport Park and netted a scarcely-believable a 1:20.791. To put that time in perspective, that’s a lap seconds faster than anything with a roof has managed at SMP—V8 Supercars included. Only an A1GP car has gone faster. Even more impressive—MCA weren’t even running their finalized aero kit that weekend and anticipate another two seconds dropped off next year’s time.