It’s not just about power figures: getting your bike on a good dyno could transform the way it rides
It’s not all about peak power figures, dynoing a bike can transform how it rides
‘We’re fixing the fuelling and how the bike rides’
Getting your bike on a dyno has far more benefits than just being able to bore your mates down the pub with a chart proving how much power it makes. While a manufacturer spends countless hours developing a brand new high-performance engine, rules and regulations on emissions then require them to undo all their hard work to meet stringent targets. And the result is a bike that is often compromised, with a jerky throttle response and snatchy fuelling a common complaint – which is where a skilled dyno operator can help. “I’ve had my Yamaha MT-10 for about a year now and while I love it, its throttle is way too aggressive and jerky at low speed, especially on roundabouts and in town,” says MCN reader Charlie Ward. “Also, when you roll-on the throttle at 70mph there seems to be a pause before the power comes in and when it does, it’s brutal.” This is a scenario with which BSD Performance’s hugely experienced dyno man Andy
Cartledge is more than familiar.“We hear this all the time,” says Andy, “but luckily it is easy to rectify through an ECU remap. We alter the fuelling to make the engine run how it wants to, not how emission regulations dictate, and then we also look at the throttle map, ignition map and manifold air pressure map. The maps on a ride-by-wire bike determine how you interact with the engine, so we can tweak them to make it less aggressive and give the bike far better road manners. In effect we correct the compromises that the manufacturer has been forced to introduce.”
And even though Charlie’s MT-10 still has its original exhaust system and catalytic converters, Andy reckons the benefits of running it on the dyno should be very noticeable. “You may gain a bit of top-end power with a can and the cats removed,” he says, “but what we are correcting is the fuelling and how the bike feels to ride, which we can do with the bike totally standard.”
To some the idea of strapping a bike on a dyno and then revving it its red line is a cause for concern, but as Andy explains, this shouldn’t be a worry.
“As long as you go to a professional, the risks to your bike are minimal. A dyno puts no extra stress on a bike’s engine than you
‘It’s 100 times better than before’
would on the road or a trackday and it doesn’t excessively wear a rear tyre,” he says. “And while we will re-write its ECU, we always ensure we retain the original data, meaning we can return it back to standard if required. You can add an aftermarket fuelling module if an ECU remap worries you, but you can’t alter as many parameters, so a remap is a far better solution.” Inside the dyno room and with the MT-10 strapped to the rollers, Andy quickly removes not only its ECU, but also a few of its sensors. “We remove the Lambda sensors and disable the closed-loop oxygen sensors, both of which are only there for emission regulations, and also switch off the secondary air system while doing the runs, but will turn it on later,” Andy explains. “We have a base map for the MT-10 which took us several weeks to develop, so we load that into the ECU and then tweak it to suit the individual bike.” Confronted with a baffling chart of numbers and 3D representations that look like something out of The Matrix, Andy spends the next few hours altering the MT-10’s fuelling and ignition maps before declaring the bike ready to go. Although not before he also lowers the point at which the Yamaha’s cooling fan kicks in to stop it running too hot, another common MT-10 trait that can be cured via the ECU. Handing the bike back to Charlie, Andy is confident he will be pleased with the result. And he’s not wrong. “I can’t believe the transformation, it’s 100 times better than before,” reports an elated Charlie having spent a few days getting used to the changes. “As soon as I pulled out of BSD’s drive I noticed the bike no longer hesitated when you initially open the throttle, which used to annoy me, and now it is so smooth. Once up to speed the delivery is more progressive and lacking that annoying kick, and it is smoother when you shut the throttle. The bike still has all the MT-10 character I love, but it is so much easier to ride. All of its irritations have been ironed out. I was looking at selling it before the dyno work as I didn’t like how it responded, but now I’m going to keep it. I loved watching Andy do his stuff and although I have no idea what he was doing, it has certainly worked. And as an added bonus, I now know that it makes precisely 146bhp!”