MX5 – Time to get the Supercharger back on

Having got the garage done and the Evo ready for sale I could finally get back to the the MX5 supercharging project I almost finished last year but just ran out of time.

So I got everything out of storage in the roof of the garage and tried to remember how I’d put it all together in the first place.



Didn’t want to miss the snooker so I multitasked. 😉


All the various mountings I made had to go back on.





One small job I had to do was find a place for the intake air temp sensor on the cold side of the intercooler. Just had to drill a hole and weld a nut in place.




All back together and ready to try out.




After a quick boost leak check.


No major leaks so time to start it up.


With the laptop hooked up to the DET3 me and Townie guessed some numbers for fueling on boost and went for a drive.


Our guesses were pretty good so after some minor tweaks we got it back in the garage for a check over before going for another mapping run.

That’s when we spotted this.


Boost goes in, oil comes out.

I had somewhere to be that evening so I panicked and put the car back to NA running so I could try and find out the cause of the leak over the next few days without the added complications of the supercharger.

There was quite a lot of oil spread all over the block and sump making it impossible to locate the source. So to find the source of the leak I cleaned all the oil off then used the car for a few journeys to hopefully show where fresh oil was leaking out.



Fresh oil behind the crank pulley pointed towards the crank seal being the cause with increased crank case pressures exacerbating the problem. It was a bit of a pain but a relief it wasn’t something more serious like the head gasket.


I ordered a replacement seal right away to deal with the problem before getting the charger on again.

Another small issue I noticed has been the increased engine bay temperature from the supercharger, particularly from the outlet near the power steering fluid reservoir. It’s clearly getting a bit hot causing the fluid to expand and over flow.



The only fix for this so far is to make sure the fluid level is nearer the minimum level so there is capacity in the reservoir for expansion. I may still sort out some heat protection for it though.

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