BUILT TO THRASH
THIS 500KW FD3S KNOWS HOW TO PARTY HARD AND THE HANGOVER STILL AIN'T KICKED IN!
When the owner of a feature car makes a remark like, “I don’t know how it stays alive, I really don’t”, one is quick to conjure up thoughts of limiter bashing and tyre frying with little mechanical sympathy displayed. Or, more likely for anyone who attends events in the North Island, images of the last time you witnessed Ryan Dorricott delivering said beatdown to his ‘RUFCNT’ Mazda RX-7 come flashing back.
Developed from a street car to a full-blown race car that hides many hidden talents and more data-collecting capability than the GCSB, the RX-7 is a long-suffering victim of abuse, having endured nine years of torture in Ryan’s hands. Like most survivors, it wears the scars to prove it with pride. However, we’d say that Ryan is underselling himself a little when questioning why the FD is still alive, the reason being that he clearly knows what he’s doing when it comes to building a tough race car — which is reassuring given that it’s also his day job!
Having cut his teeth on the drag strip with his self-built 11-second 13B turbo KE25, Ryan purchased the FD as a street car back when, as he puts it, “they were a dime a dozen, and you could pick them up for next to nothing”. Now that he owned the single-turbo streeter rocking a Garrett T71, the drift bug soon took hold of Ryan; slowly but surely, the desire to retain the WOF on the window melted away in favour of making the FD’s full-time job killing tyres. It even contested a few D1NZ rounds in this guise, although it ultimately sealed its fate with a trip into the concrete barrier at D1NZ Baypark. It was time for it to kiss the road goodbye and become a
While it might look a little used on the outside, the engine-bay fabrication is immaculate and extends to a complete suite of custom coolers
Following a crash at Baypark, the FD is now tube framed front and rear using chromoly. These bolt-on structures hold the fibreglass quarters, Rocket Bunny overfenders, fibreglass front and rear bumpers, and rear hatch
dedicated track machine.
From start to finish, the project was bascially all Ryan — the fabrication, the wiring, and even the engine build (with a helping hand from his workmates at Dynopower. The transformation began with the removal of the front and rear panel steel to the limits of the D1NZ rules and its replacement with chromoly tube structures and fibreglass skins on which the Pandem widebody would be attached. With a Lexan rear screen and weight removed from most other panels, the results are a feather-light shell, some 1100kg wet with driver, so we’re talking a sub-1000kg machine with a very rigid chassis helped by the chromoly roll cage tying into the rear subframe. It’s the fourth subframe that’s been in the car — something with which any FD owner will sympathize. Ryan’s torn three others out so far and is hoping that
the latest version, which is half chromoly and half factory to meet D1NZ rules, will put the issue to bed before giving the 13B up front a little more breathing room in the exhaust housing and thus power.
Remember we mentioned that it’s been getting the beatdown for nearly a decade? Well, it might surprise those non–rotary converts reading this to learn that the block, even though it has been through hell and back, is basically still numbers matching. Sure, it’s been apart, but that was only to extract power.
All the work was undertaken at Dynopower and included stage-two porting with only a tiny bridgeport added to the centre plate. The factory rotors were lightened, balanced, and received 2mm I-Rotary apex seals, while the rest are all new Mazda items. The exhaust manifold is an equal-length one, with BorgWarner’s bad-boy EFR 9180 strapped on. The intercooler is a custom job, as are all other coolers on the vehicle.
In 2016, the car had a big birthday, and the engine received a bunch of sensors in the quest for knowledge. The Link Thunder now logs turbo speed, pressure before and aft of the Borg, exhaust-gas temperatures (EGTs), air–fuel ratio (AFR), as well as all of the usuals. The 13B is currently making 500kW on 29psi. All that logging is showing there is much more in it.
“On the dyno, the data shows the turbo is too small and the motor is being corked. I’m waiting for TiAL to release its 1.45 AR V-band exhaust housing, and we will switch to that. It won’t lose the response, but it will uncork the motor and let it breathe,” explains Ryan.