Quick Fix
Quick Fix
Setting out to “fix” the quick Kawasaki ZX-10R isn’t exactly an easy task. There wasn’t a lot wrong with our Ten Best-winning 2006 testbike, particularly with the engine.
But we like to play. So in an effort to boost engine output using simple bolt-on or plug-in parts, we obtained a programmable Kawasaki race-kit ECU ($1404), a LeoVince Factory Slip-On stainless pipe/titanium silencer combo ($1037) and a Uni Filter foam air filter ($27).
First a word about the ECU. The box itself is only $762, which is comparable to the price of a stock unit, but it requires the purchase of a ridiculously expensive, $600 ECUto-PC interface cable that’s needed to program the box using supplied software. There also is a $42 supplemental wiring harness required to plug the new box into the stock wiring harness. The kit ECU is widely adjustable to accommodate the needs of heavily modified engines, but as delivered, it is programmed with the least-restrictive road-legal emissions/noise map Kawasaki uses.
Stock, the bike produced 162.8 horsepower at 12,150 rpm and 79.4 foot-pounds of torque at 8450 rpm. The main “issues” were a short but sizable dip in the torque curve between 3100 and 3600 rpm, and a mild soft
spot between 5500 and 8000.
With the box, filter and pipes installed, plus dyno tuning (figure 3 hours’ tuner-shop labor), peak results were 163.8 hp and 80.5 ft.-lb.
Something, but not much. More important, though, were the improvements in the torque curve. The dip above 3100 revs was almost gone altogether, and the torque output in the 5500-to-8000-rpm range was boosted quite a bit. At 7000 rpm, for example, the engine produced 5.2 hp and 3.9 ft.-lb. more.
We then ran the bike with the stock ECU, Uni filter and LeoVince pipes, a combination that provided the most peak power at 165.0 hp (with 80.1 ft.-lb.). But the 7000-rpm output was not quite as good, falling in between all-stock and the kit ECU
numbers. Also of note is that use of the Uni filter netted a 1.2 ft.-lb. torque gain at peak.
Overall, we had hoped for more, but engine and exhaust designs are so by the factory that it is difficult to make big gains without porting, higher compression and fancy valve jobs. As for the Kawasaki kit ECU, it helped produce the best midrange numbers, but its high buy-in makes it better applied to engines with serious modifications. The kit ECU does keep the exhaust system’s power valve from impinging on engine output; but because the LeoVince collector eliminates the valve, the box isn’t necessary on an engine that is internally stock.
In other words, save the kit ECU for your AMA Superbike or turbo dragbike debut. In the case of our streetbike, the pipe and the air filter do most of the job.
-Mark Hoyer
