The dictionary defines devious as follows: "showing a skillful use of underhanded tactics to achieve goals." When it comes to ex-pro New Zealand motocross rider Johnny Burkhart's pride and joy RX-3 (with plate DVS3. Get it?), that definition seems to fit about as well as bald Britney would into the cast of American History X-sure she's got the haircut, but realistically, she would only be useful in a fight if you tied a stick to one end and used her as a club.
You see, there's nothing particularly underhanded about Johnny's super-fine rotary-its hoodless front happily displaying its immense manhood to the world doesn't mislead anyone. One look at the whopping turbocharger hanging off the side instantly grabs the interest of anyone who knows anything about cars. It's not so devious, but the definition of deviant is much closer to the money: "departing from usual or accepted standards, esp. in social or sexual behavior." Now, we don't know (or want to know) what Johnny's libidinous proclivities entail, but if you heard his 13B screaming its ring out through the massive four-inch pipe, you'd know that it's not socially acceptable.
During the picturesque photo shoot at Mount Ruapehu in New Zealand's North Island (it's the one that blew its volcanic top a few years back) Johnny demonstrated just how much wick the black RX has got. When he went out to pass the photographer's pickup, a bit too much of the right foot sent the RX-3's back end out, and then back the other way as he shifted up another gear. That's what street-legal rotorvation, Kiwi-style, is all about.
"I've always been into RX-3 coupes and wanted one with big horsepower," says Johnny, who listed his aims for the build-up as "big rims, black, big horsepower, a strong and reliable street car". With 470 horsepower at the wheels running a relatively low 17psi boost setting, it's on the right track. The car laid down a sizzling 11.6-second pass on its first outing while still on low boost. Translate that to the street and it can easily be labeled deviant. But while some folk are happy living boring little lives and driving boring little cars, it just doesn't make sense to the rest of us.
An all-out build like this genuine Savanna is hard work by any standard, but try it while wearing plaster casts and it gets a lot more challenging. After a monster crash at New Zealand's Supercross Nationals, Johnny's dirt racing career was over, so he had some time on his, er, hands. "I built the RX-3 while in a cast," he says. "It was four big operations and seven months all bandaged up after dislocating and breaking both arms and wrists." Now he's got his sights set on some good quarter-mile fun to satisfy the speed bug-courtesy of an angry bridgeported 13B.
Architect of the under-bonnet anarchy is well-known Kiwi engine builder Stu Lawton, who campaigns a Pro Import Mazda SP20 (323) with a 26B four-rotor, twin-turbo engine under the name Lawton Rotorsport. Bridgeported Series 4 (FC3S RX-7) housings were used, with a 3mm SCR Apex seal and a full stud kit. Slotted and balanced rotors came from a Series 6 (FD3S RX-7), which also donated a cross-drilled eccentric shaft with 20B stationary gears.
Feeding the super-tough engine is a Turbonetics Super T-76 hair dryer, with a TiAL 46mm wastegate bleeding off unnecessary boost, and a custom intercooler chilling the intake charge.
But the big turbocharger and four-inch thick-like-a-can-of-Pepsi exhaust system are nothing without the ECU, fuel and spark-and Johnny hasn't skimped in this all-important area. A Microtech LT10 with an X4 16-volt ignition upgrade means no spark fade at high revs, and a hard-pumping Bosch 044 fuel pump and Malpassi regulator feed a pair of 850cc and two more colossal 1650cc injectors. A Gilmer drive system avoids undue risk of a belt slippage-a relatively small investment to protect the other big dollars put into the engine bay.
The drivetrain borrows a W57 gearbox from a Toyota Supra, using an NPC twin-plate clutch and lightened flywheel with a shortened limited-slip diff from a Toyota HiLux pickup, which also donated the car's shortened and re-splined axles. Suspension tweaking in this sort of ride can be a bit of a mission, but aiming the setup toward the strip with a ladder bar arrangement has helped keep the rear end stable. Reset leaves and tramp rods are used at the rear, with coilovers and adjustable camber plates allowing better setup options at the pointy end. Standard sway bars have been used, and the full Nolathane bushing treatment has helped keep DVS stable, even under solid acceleration.
When we asked Johnny why he chose the brake setup he did, the reply was, "they're big and apparently the 3 needed to be able to stop." DBA cross-drilled and slotted rotors, four-pot calipers designed for a FD, and rear disc brakes from a FC seem to do the trick-they are big and they certainly pull up the rampant rotary in a hurry.
But it's the show value that has been noticed this year-the car has already picked up the Best RX Engine Bay trophy at New Zealand's Four and Rotary Nationals at the end of January, thanks to some significant chrome and polishing work. Under show lights, its deep black paint and polished Simmons FR17 rims definitely caught the attention of a very appreciative rotorhead crowd. But with a serious tune-up about to take place and some more boost to be screwed out of the 13B, wheel numbers in the high 500s aren't out of the question. And by then it'll probably be deviant on-strip behavior that this RX will be getting noticed for.
'73 Mazda RX-3 Savanna
Owner Johnny Burkhart
Hometown Down Under,New Zealand
Daily Grind Lobster fisherman
Under The Hood 13B bridgeport with Series 4 housings; balanced and slotted Series 6 rotors and cross-drilled eccentric shaft; 20B stationary gears; Turbonetics Super T-76 turbocharger; TiAL 46mm wastegate; custom polished manifolds; custom front-mounted intercooler; 16-inch Davies Craig fan; Gilmer drive; Series 5 alternator; Bosch 044 fuel pump; fuel cell; Malpassi regulator; custom fuel rails with 850cc (x2) and 1680cc (x2) injectors; four-inch exhaust
Drivetrain W57 Supra gearbox; NPC twin-plate clutch and lightened flywheel;custom 3-inch driveshafts; shortened and re-splined Toyota Tacoma axles; shortened HiLux 4.5 LSD
Brains Microtech LT10 and x4 and 16v ignition booster
Stiff Stuff Front: coilovers with adjustable camber plates; Nolathane bushing upgrade; Rear: ladder bars; tramp rods; reset leaf springs
Rollers 17x8 (front) 17x9.5 (rear) FR17 Simmons; Goodyear Eagle F1s
Stoppers Front: DBA S6 RX-7 gold, cross-drilled and slotted rotors, S6 calipers; Rear: RX-7 S4 rotors and calipers
Outside Jet Black paint; modified front guards
Inside Momo seats, steering wheel and shift knob; Auto Meter Phantom gauges; white custom interior
Props Lawton Rotorsport, NZ Performance, Supreme Autofinishes, Jamie Begga and the boys
Connect autometer.com; dba.com.au; goodyear.com; microtech-efi.com; momousa.com; nzperformance.co.nz; simmonswheel.com.au; turboneticsinc.com