If noise is likely to be an issue then G56 is the right decision. However, at speed there is no noticeable increase in noise (to the occupants) even with the MMC version and long journeys are no more tiring than with a standard exhaust.
I agree with all the comments above except to say this. When the inevitable crowd gathers and you press that start button, the MMC Stage 1 doesn't disappoint.
Do my neighbours sit bolt upright in bed when I leave early on a Sunday morning. Probably.
I agree with all the comments above except to say this. When the inevitable crowd gathers and you press that start button, the MMC Stage 1 doesn't disappoint.
I am very happy with the G56 system and standard ECU on my M3W. It's a big improvement over the standard system but probably very similar to the Morgan Stage 1 in performance if not noise. It doesn't disappoint on start up either, a nice deep rumble. The insurance (G&W) is unchanged.
And to complete the picture, I cannot fault my G56 with their own ECU, fettled perfectly by the very helpful Dan @Krazy Horse. So much smoother and more responsive than stock and although I've not driven an MMC-S1 car, nothing makes me think I'm missing that 'factory' something.
I'm also with Headley and they were perfectly happy with the update. I suspect there's no such thing as a standard M3W anymore - not even those that leave the factory doors - as they all break in one way or another and are fixed with a range of differing solutions.....
Looking at both, the G56 is better engineered too. The MMC version is a bit of a faff to fit but it can be done without modification and spacers (eventually). After all, the factory manage it.
At one point Williams were advertising a Garge56 (sic) for under £1300 on their website. Maybe a Chinese copy They took two weeks to answer my emails so I gave up. (They have now corrected it) Better to deal direct with G56 I suspect.