Then why do I hear lift engaging at 6000 "again"?
Go put your car in 1st gear, roll along nice and easy at 4000 RPMs. Note the rather quiet sound the engine is making. Then stomp on the pedal. There should be a difference.
This is little more noticeable with the butterfly valve removed, and a lot more noticeable if you have Intake
and exhaust installed. With the pedal all the way down, there's more air ocming in the engine, corresponding to more gas pumped in, corresponding to more noise. It's as simple as that.
Do you honestly think that TPR, instead of getting the Intakes
and exhausts made and shipped and researching a new header, would play around with this? I'm not sure they have much money for R&D right now, and they strike me as a company that puts the customer first. They wouldn't go play with a new toy while you wait a month for an Intake
I think you oughta search around for more I/E or I/H/E Celica videos to see just how loud that combo is, regardless of lift.