Supercharger setup question/problem

[delcbr]

I've fitted a Mini Cooper S supercharger to my Mazda mx5.
The throttle body is pre charger.
I am using a vacuum operated bypass valve which is opening fully during idle.






When the car is idling the bypass valve is fully open which is correct however the blue hose is fully collapsing being sucked flat. I can fit a metal pipe in its place but I am sure it shouldn't be doing this.
Do I need to adjust the throttle stop on the pre charger throttle body so that some air can can reach the inlet of the supercharger or any other ideas?

Edited by delcbr on Monday 21st October 22:25

Edited by delcbr on Monday 21st October 22:28

[dblack1]

The supercharger is sucking it flat... Isn't the mini supercharger a Eaton M45? Eaton supercharger housings vary from manufacturer to manufacturer, but most have a built in valve into the bottom of it that is operated by a leaver (usually controlled by vacuum). The valve is a recirculation valve.

Your setup would probly work if you used metal.

[mighty kitten]

Anything after the throttle is fighting vac , I had the same issue and made a metal replacement .

[delcbr]

Ah ok I will fit a metal bend in place if the silicone one hopefully that should sort the problem out. What about the throttle body do you think I need to have this open a little as the supercharger is sucking in air?

[mighty kitten]

The only issue you might have is slightly poorer throttke response as you have effectively added the volume of the charger and pipework behind the throttle to your plenum so some adjustment might be needed to get a stable idle , some people use a throttle before and after on mx5 ,s to minimise flow into the charger when the upstream throttle shuts

[delcbr]

Thanks that sounds right I will put the throttle stop back to where it was originally.