January is a great time to turn up the space heater and hunker-down in the garage, dreaming of warmer weather and open track ahead of you. We took advantage of the warmer than usual weather in December to complete most of the prep work on the Red MINI for the upcoming autocross season, so it’s time to turn our attention to back the Blue MINI.
Blue MINI is being prepped to be sold. The goals of the refresh are fairly straight forward: reduce harshness of the ride; reduce cabin noise; and install a more traffic friendly clutch. The suspension has been returned to stock; the stock flywheel has been resurfaced and is ready to go back in as soon as the clutch kit arrives; so this past weekend we turned to the issue of cabin noise.
Interior cabin noise in the Blue MINI exceeded 110 db on the highway with the old exhaust. Though not quite painful, it tended to drone and cause ringing in the ears after long drives. Not a problem with the windows down and helmet on at the track, but not conducive to conversation on the highway. The current Ireland Engineering exhaust is much quieter, but still not as quiet as stock. The road noise was a combination of factors: large tread-blocks on the max performance summer tires; the cold air intake transmitting intake noise; the single-mass flywheel rattling at idle; and the exhaust being louder than stock. A change of tires took care of the first issue. Switching back to the stock intake cured the second. When the new clutch is installed we will switch back to the stock flywheel eliminating the rattle. That just leaves the exhaust noise.
We put five sheets of Hushmat under the carpet in the boot to provide a little additional sound deadening from the rear mounted muffler. (It adds weight to the car, but it adds it low and in the back where it’s needed.) When we got out on the highway and up to speed, the overall cabin noise is down significantly. Putting a new exhaust on the car when you don’t have a lift in your garage is a literal pain in the back, one we’re hoping to avoid with the Hushmat.
