Need Info on the Emira Exhaust Valve Motor

[lynchy73]

I’ve recently installed an aftermarket exhaust. I was aware that the valve position is quite critical and that the motor has feedback sensors. I suspect there is a fundamental issue in the implementation of the OEM motor in the new exhaust valve system.

Regards the valve motor, is it a proper servo motor, with an accurate feedback sensor that can position it at a certain angle? Does the motor operate in a continuous way, applying small changes, or is it more open/closed? Do these exhaust valve systems generally have a self calibration whereby it might go to the limits of the range of motion, or it’s calibrated and that calibration is stored (I think the latter). What is the range of motion of these motors, they can turn much more than the range of motion of the physical valve (90 degs), or their rang is also limited?

The OEM valve motor and valve assembly is offset by circa 45degs. There are aftermarket exhausts using the OEM valve, which have the valve perpendicular to the valve. This is the OEM valve open/close position. Surely if you’re gonna use the OEM valve, the valve should be the same, so the OEM valve operates like OEM?

 

[Speedy Emira]

My understanding when I asked the dealer is it opens to the set amount depending on throttle and driving mode and not variable.
I can’t see variable would make a noticeable difference unlike inputs from the throttle sensor. I have never seen an aftermarket tuner like APR taking advantage of that potential feature to gain more power, which you would expect if it created increased performance at low effort.

 

[lynchy73]

My understanding when I asked the dealer is it opens to the set amount depending on throttle and driving mode and not variable.
I can’t see variable would make a noticeable difference unlike inputs from the throttle sensor. I have never seen an aftermarket tuner like APR taking advantage of that potential feature to gain more power, which you would expect if it created increased performance at low effort.

My questions are not about optimising the exhaust or suchlike. I’m trying to understand things like the range of motion of these valves, if the valve has position feedback, so the ECU can tell the valve position.

The OEM valve motor is offset 45deg, but aftermarket exhaust do not typically have the same 45deg offset (as they likely use a bunch of standard parts in their construction and the flapper motor are perpendicular to the exhaust pipes in these standard parts).

Anyway, I’ve purchased some SS pipes and will be preparing a simple adapter to correct the error in my aftermarket exhaust, so the valve is actually closed when the OEM motor is in the closed position and the valve is actually fully open, when the motor is in fully open position.

This should result in no more errors and an aftermarket exhaust valve that operates as it should, without Engine warning lights. All this (hopefully) without having to recalibrate the exhaust valve at Lotus, or fitting the Milltek Valve Controller to trick the ECU into thinking it’s working as it should be.