We’ve had quite a few Speed Triples roll through our doors now for an ECU remap and they’re a bike that responds well to uncorking. The most important thing is to switch off all the emissions equipment before anything else… SAI and lambdas.
Now we get asked a lot what happens on a bike still has standard cans and/or the catalyser onboard. In this case we’ll still switch off the lambda – and remember it’s there only to protect the cat’ and make the bike run a stoichiometric air/fuel ratio of 14.7:1 – and deal with the problems it creates in normal running.
But we’re cautious in our approach here, and run a slightly richer (than standard with lambda) air/fuel ratio of 13.7 but keep it constant without any variation. This mixture isn’t rich enough to destroy the cat’, but does smooth out the power delivery noticeably as the lambda isn’t trying to lean the mixture out. Going for maximum power requires a different approach.
The owner of this Speed Triple had changed his end-cans but still had his cat’ fitted in the branch pipe. The engine was still new with only a 1000 miles up, and he may have to come back for a minor fettle once it’s loosened up.