Alta Exhaust MINI DIY

This past long weekend I picked up a new Alta Performance Exhaust. The cat-back exhaust is a relatively simple DIY project if you don’t mind getting under the car. If you have a lift or a pit, I’d say it could easily be done in a couple of hours.

The exhaust ships in two boxes. The larger square box has the rear exhaust section and a longer box with the mid-pipe and first muffler. It might fit in your MINI with seats folded, but I took the Volvo to get it. The first thing you’ll notice about it is that it’s beautiful. Not something you usually associate with mufflers and exhaust systems, especially if you take a look at the one that just came off the car. The stock Cooper S exhaust is actually one very long pipe with a resonator on one side and a muffler on the other in a single path. Although it flows fairly well, its heavy and not particularly sporty.


It wasn’t until I got the old exhaust off of the car that I realized that the coke-can tips were hiding some rather small pipes. The stock exhaust also goes from small to larger sized pipes a couple of times in it’s rather long length which I’m sure can’t be good for exhaust flow. Without the brackets which I hopelessly mangled during the removal, it has a weight of 46 lbs, with the majority of the weight at the rear. The new system had two parts each weighing 16 lbs. That’s a loss of 14 lbs. plus a shift forward in the center of mass of the car. Plus it looks really cool. That’s got to be good for 5 VHP (visual horse-power).


Instructions came in the box and you can download them from the Alta website. You can also find several good guides online if you search in the usual places. Here are a couple of tips I didn’t find listed in any of the instructions I found:

  • Working without a lift is a real pain in the neck. No really. My neck was killing me. I had the car on ramps in the front and jack stands in the rear. Working with about 15 inches of clearance I was contorted and twisted but was able to maneuver where I needed to be.
  • The Alta Exhaust now ships with two sets of gaskets and bolts as well as adjusdtable brackets for 02-04 and 05-06 cars. Make sure the orientation of the clamps match the brackets you are using on your car.
  • The brackets I had used a retaining clamp that requires a 7/64th allen wrench. Check to see if you have it before you start. The ones on the rear muffler are actually 1/8th inch.
  • Extra jack stands, jacks or just plain boxes are handy to balance and hold the exhaust when you are removing the old one and installing the new one. Make sure you have enough adjustment that you can actually position and center the new exhaust before you tighten everything down. This helps center the system.
  • If you plan to reuse the stock exhaust bushings, have a plan B. You will rip one of them.
  • And finally, before you start, check the condition of the bolts to the OEM exhaust right where it comes off of the cat. After three Mid-Atlantic winters, mine were severely corroded. The lower nut had lost so much mass it was almost 1mm smaller than the other one. It looked rounded and stripped before I event put a wrench to it. Be sure you have plenty of PB Blaster, WD-40 and a stripped nut extractor before you start.


Impressions: It is louder than stock, but doesn’t drone or sound like a certain unnamed cars. I had to bend some of the heat insulation away to avoid rattles at certain RPMs and the battery tray skid shield won’t fit back on without lots of modification. The car seems to rev even more freely and has a very pleasant burble upon deceleration. I’m very pleased with the outcome and look forward to seeing (and hearing) how it does on the track.