Thanks, I did get a bit further last night and I believe my problem may be with the % RPM in rfactor which is what I'm testing on currently.
I am using RPM percentage for these LED's and am assuming rpm goes from 0-100% but maybe that's not correct as I can go over 100% in the RPM field.
In the screenshot they use actual RPM itself there, but would I with that config not need to set it differently for each vehicle I am intending to drive as they would all have a different RPM scale, hence my intention to use % instead.
Thanks