The owner of this KTM RC8 rode up from Bristol for his ECU remap (he was on holiday and was desperate!). We’ve done a few of these now and have some useful experience; we’re seeing a lot of the earlier models coming through on later plates, we’re guessing because they took a while to move off dealers’ floors.
We started by switching off the SAI (Secondary Air Injection) valve, then the lambda sensor. We then went into the secondary butterfly map and adjusted both – and this is critical to get these engines running smoother. They must not be removed, they just need remapping to open when really required, not as per standard. Ignition next – there’s a huge amount in the bottom end, which multiplies the snatchy throttle response no end. We then mapped the fuelling (it was on stock exhausts).
A question we get asked a lot is what about the catalyser? The answer is simple – from our perspective keeping the cat is no problem, as we’re not trying to make the engine richer, we’re essentially trying to make it run more efficiently. The cat does need a hot engine to work, and efficient engines run a little hotter. These earlier bikes used lambda to blindly lean out the mixture (and get the temperature up) to get the cat working. A full road-spec remap like this will give an air/fuel ratio of 13.2/13.4, which is not an issue for the cat – it would be if it was down at 12.8 (for absolute performance).