KAWASAKI ZRX1100 TURBO
Longer in the making than the Bible, this series finally sees light at the end of the tunnel! Dowds, it’s over to you…
Alan Dowds has something to report (at last!)
It’s the beginning of the end for the ZRX project build now. With the engine in the frame, the Rotobox carbon wheels fitted (see box) and some usable stock (for the moment) front forks sourced, it’s starting to look like a proper bike. And the next big hurdle is being jumped as you read this. I’ve finally got hold of a turbo, and my pal James Mccarthy is limbering up with his TIG welder to fabricate the necessary pipework to get it working on the ZRX. He’s gathered up the stainless steel parts required, and once his fabrication diary clears for a few days, he’ll whistle up the turbo manifold, plenum chamber and intake pipework in no time at all. James is a proper artist, and I’m really looking forward to seeing what he comes up with for the install. We’ve gone for a Borgwarner S200SX turbo in the end. Sean Mills from Big CC had one sitting spare on a Hayabusa manifold and he’s donated it to the cause. It’s good for about 350bhp on a Busa, so
we should easily be able to get our target 250-280bhp from the ZRX1100 lump. Serendipitously, it’s also the same brand of turbo as on my old Audi RS6 – that uses a pair of Borgwarner K04 chargers. So we’ll have a trio of Borgwarners, powering the Dowds household! Next step is surely a Borgwarner on my Burgman 650 city hack… Last time, we’d received the Rotobox carbon-fibre wheels for the ZRX, weighed them and then just drooled gently over their super-light mass, gorgeous construction and sweet finish. Now, though, we had to fit the buggers! Had the Slovenian wheelwrights done a good job with the Zrx-specific wheels? Well, yes, mostly. The front wheel fitted a treat, even taking the stock old school mechanical speedo drive. Half an hour had the old wheel out and the new Rotobox rim in place, wearing a smart new Pirelli Diablo Rosso Corsa: lovely. The back was a bit trickier though. I did that thing where you spend an hour faffing about with wheel spacers, adjusters and brake brackets, getting more and more frustrated and tired as it nearly-but-notquite all lines up. What’s wrong here? Well, the Rotobox wheels are for the ZRX1200 really, although there seemed to be a consensus that they’d fit the 1100 no bother. But as Sean came to help out, it became clear that there was a couple of mm clearance missing. The 1100 rear brake mount and spacer is pushing the eccentric adjusters out of the swingarm. What to do? The good thing about having a professional like Sean about is that he’s seen this sort of thing a thousand times before, and has no qualms about getting stuck in. So he whips the brake mount off, and heads for the lathe. A quick whizz round, and we’ve trimmed a couple of mills off the brake mount. Five minutes later, we’ve got the Rotobox wheel in the ZRX arm, everything lined up, and the job is a good ’un. Chain on and riveted and we’ve ticked another box on the list. Bike ignition is one area modern riders don’t need to think much about. It’s incorporated into the ECU, and with plug-top coils, and ECU control, they’re reliable, powerful set-ups. And even a medium turbo tune can use the stock ignition setup, with some fettling. But our ZRX has an old-school setup, and adjustment or upgrading is trickier. So Sean asked if we could sort out a Dyna 2000 ignition system. These set-ups are produced by the same folk who make Dynojet Power Commanders, and the top folks at Dynojet UK let us borrow one for the ZRX.
It’s a total replacement for the stock ignition system, with uprated coils for more spark output, plus adjustment functions on the control unit to alter the ignition timing to suit different tunes. We’ll need a lot of control over the spark once the turbocharger is running, and the Dyna 2000 will give us that. Fitting is simple enough. The kits are made to suit specific installs, so you get a bespoke bracket for the ignition pickup coils, plus a new crank rotor: a small wiring harness taps into the bike’s stock wiring harness where needed (for the tacho pick-up) and connects the Dyna 2000 control box to the ignition pick-up coils. The control box itself can just sit under the seat, or somewhere else convenient, like a Power Commander would, Velcroed in place. The kit also included a new set of coils. These mini units bolt on under the tank where the stock parts are, as a straight swap. Dyna ignition leads complete the install, and these need to be cut and have the plug caps and coil ends crimped on to suit. Big CC had a special little crimping tool that made this a breeze, but you’ll be able to do a decent job with some big crimping pliers, or water-pump grips or similar. A couple of hours’ steady work, with the odd coffee break, and we had the Dyna 2000 set-up in place. Another step forward for the ZRX…
The original crime scene: yuck!
Rotobox carbon wheel – yum.
Dyna 2000 ignition module – proper kit.
There was much faffing at this point.
Stock pickups are junked for Dyna’s own set-up.
Ta-da! New silver chain, Öhlins, carbon rim.
The good stuff: Threebond silicone to seal the pick-up wiring into the cases.
New Dyna mini-coils bolted onto the ZRX frame.
Dyna wiring carefully clipped alongside the stock harness.
Crappy old stock coils head skip-wards.
Making the connector to the pickups.
Special tool for crimping Dyna leads.
A bit of silicone grease in the connector.
Ensure pins locate correctly.