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Aftermarket exhausts and air filters

Will the BoosterPlug work with my aftermarket exhaust and air filter ?

The BoosterPlug will keep your bike covered for all combinations of aftermarket air filters and exhausts (with or without a catalytic converter)  - as long as you keep the O2 (Lambda) sensor installed in the exhaust. (Which you should for several other reasons.) 


Here is why this is possible:

Most aftermarket filters and exhausts will flow a lot more air at higher RPM, but at low RPM's the difference between the flow resistance in the original exhaust and the aftermarket system is minimal - so in low RPM conditions, the AFR (Air/Fuel Ratio) is almost the same.

In a modern fuel injected bike, there's no risk of damaging the engine by running it too lean when you install an aftermarket exhaust or K&N filter (With or without the BoosterPlug). The O2 sensor in the exhaust will adjust the mixture back to the original AFR in all closed loop situations (Higher RPM), and keep your engine safe.

(Constant medium and high RPM are closed loop operation, and the O2 sensor is in charge here. The BoosterPlug is active in open loop conditions which is idle, low RPM and during acceleration and engine braking. - See the "How it works" page for a full explanation on open loop and closed loop operation)

But as the aftermarket parts will flow slightly more air in low RPM conditions too, the rideability will be even worse than on the stock bike. Normally we see the open loop AFR go from around 14,4:1 to 14,5:1 with the aftermarket exhausts, and now you really need the small controlled fuel enrichment from the BoosterPlug to restore the smooth throttle action and to prevent the engine to stall easily.

The fact that the AFR difference (between the stock system and the aftermarket parts) is relatively small in open loop conditions,makes it possible for the BoosterPlug to cover all combinations of exhausts and filters on the bike. (The BoosterPlug is only active in open loop)

So the fact that the BoosterPlug works in cooperation with the O2 sensor in the exhaust makes it possible for our device to cover all combinations of air filters and exhausts.