Talk to me about boost plugs!

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Tomcat
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Re: Talk to me about boost plugs!

Post by Tomcat »

Ditchfinder wrote: Mon Oct 28, 2024 1:09 pm From what I understand all they do is alter the air intake temp to try and make the ECU pump more fuel to richen mixture at closed throttle. Shouldn't affect oil in anyway.
Pretty much that. Most modern bikes run very lean at low to mid revs under closed loop control, for emissions purposes. This robs them of midrange torque and throttle linearity. By spoofing a lower OAT the ECY richens up. Unfortunately this can lead to the bike running very rich higher up, burning more fuel and running inefficiently.

The Power Commander used to be considered the answer but it really only works on open loop early FI systems. If you try and override closed loop fuelling with it the ECU just carries on leaning down and you get the PC and ECU fighting each other which can cause some odd fuelling quirks (as I found). Taking off the cat as some like to do makes the situation worse, since with the lambda sensors can't cater for such a large air mass flow increase and it runs even leaner.

On the latest engines there are really only two ways to tackle this. Either get it reflashed or use a lambda spoof device. Woolich software allows most ECUs to be flashed though it needs to be set up on a dyno to suit your setup. A cheaper way, like I have on my KTM, is a plug n play box by Austrian firm Coober, which sits between the lambda sensors and the ECU, reading the actual AFR and feeding an artificially lean signal to the ECU so it richens up to the ratio the box wants.