exhaust valves only open partially?

[Djhumvee]

I was reading about a, aftermarket valvetronic controller that opens the valves all the way, they claim BMW's only opens the valves partially? Is this true for all BMW including the f85/86?

[Trion_f85]

Is it for exhaust flaps or the exhaust valves in the head?

[Djhumvee]

Originally Posted by Trion_f85

Is it for exhaust flaps or the exhaust valves in the head?

exhaust flaps. sorry should have been more specific.

[Trion_f85]

I think those are more about having total control of when the flaps open/close, than they are about the opening angle. There are some apps that those that for you as well like carly

If your aim is higher flow of exhaust gasses, A sport cat or catless could be better spend tbh.
You get additional free Hp

[Djhumvee]

Originally Posted by Trion_f85

I think those are more about having total control of when the flaps open/close, than they are about the opening angle. There are some apps that those that for you as well like carly

If your aim is higher flow of exhaust gasses, A sport cat or catless could be better spend tbh.
You get additional free Hp

I think they re bout having more control also, but they're also claiming the stock doesn't open up all the way. I actually have an f15 but I am putting f85 bumpers on it, so I have an f85 muffler and I want to be able to close the valves in certain scenarios.

[Trion_f85]

What im trying to say, the F85/F86 has quad pipes directly from inside the muffler, 2 of them are always open (have no valves) while the valve is only on the other 2. So it doesnt really matter if valve opens fully or partially
Becoz there is no pressure build up in both scenarios.
Its probably just a marketing point for them.