Home » DIY (Page 38)

Category Archives: DIY


Screamin’ Demon

I finished the ignition upgrade last night. The latest performance project for the MINI was to improve the ignition system to match the improvements in airflow in and out of the engine. Because the smaller pulley produces more boost, the induction air is a bit hotter than stock. Since the air is hotter, the spark plug is one step cooler. Because the air/fuel mixture has more potential energy, the coil is upgraded to produce a stronger spark. To get that stronger spark to the cooler plug more efficiently, a plug-wire with lower resistance is used. This all doesn’t add up to more horesepower directly, but should reduce horsepower loss due to system inefficiencies, if that makes sense. The net result is a smoother running engine and actually better fuel economy.

The combination I used included MSD 8.5mm wires and a Screamin’ Demon Coilpack (like the MSD coilpack) and NGK Iridium Plugs.

stock MINI plugs

I was actually surprised by the condition of the old plugs. My MINI now has over 60,000 miles in less than 3 years of motoring. These are the original plugs. They’re rated to 100,000 miles and would probably make it. (An even tan color is good.) I’m used to plugs that wouldn’t last 10,000 miles let alone 60. Interesting to note that this is only the second part (after the brake caliper) that I’ve found that says “BMW” on it.

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.

New Seat Covers for BMW 325iC

New Seat Covers

It’s been a busy couple of weeks. The E30 convertible is pretty well sorted out now. I think I have one, maybe two more projects to do on it this summer but as a daily driver it’s all set. Work to date:

Strut Bar

I have the parts to replace the rotors and brake pads. Now I just need the time to do it. The stress bar has really eliminated much of the cowl shake, but I still need to replace the struts and should probably replace the springs while I’m at it. Once that’s all done, I can turn my attention to a new headliner for the hard top and then (hopefully) get the car painted in the Spring.

All of that work and the parts I already have on hand brings me to about $4,800 invested. With a decent paint job and some new suspension work I will have exceeded my $5,000 budget, but we’ll have a pretty decent car.

New Seat Covers

New Project Car, BMW 325iC

87 325iC

My wife would always joke about wanting a convertible when she turned 40. The challenge was to find one that would carry all three of us and enough gear to actually go on a trip with it. As a kid, I used to ride around on the parcel shelf of my parent’s Alfa, which probably wasn’t the brightest thing to do, but back then a “child seat” was the carpeted hump in front of the rear seats in the 20 foot station wagon.

So I got to thinking, why wait, since 40 is still several years away. I found this car listed for sale by a fellow member of the local BMW club. It’s basically a sound daily driver, high mileage (165k), tired paint and interior.

Front Seats

A solid $2k car that with a little TLC could be an excellent $4k car, but not likely to ever be worth much more than $5k. With that in mind, I launched my little scheme and achieved total surprise.

Here’s my cunning plan: Safety; comfort; performance; and appearance. The first step is to pass the safety inspection and get the car titled in Maryland. Level-set the maintenance items (new tires; oil change; change the fluids; timing belt, etc.) and make sure the car is safe to drive. Next is to clean it up and find some decent seat covers.

Back Seats

The leather is not torn, but much of the stitching is coming un-done. It actually cleaned-up better than I thought it would.

After Initial Cleaning

The top is new and the windshield was just replaced. The headlights are new and all of the major bulbs have been replaced. (It came with a hard-top as well, but it needs a new headliner.) Once I get a cover for the steering wheel, the comfort items should be about done for now. (Not sure how to get a cupholder into the car, but I’m sure someone has a slick option for that since this was made pre-big-gulp.)

Once we get some miles on the car, I’ll figure out what can be done performance-wise. I don’t think much beyond some plugs, new coil, and a better air filter. More will come later. Finally it would be nice to get a new coat of paint. Assuming everything else hasn’t busted the budget, maybe try to get a basic respray that will last 3-5 years.

Free Horsepower. MINI Cowl Mod DIY

Remember that an internal combustion engine is really just an air pump. In the Spring 2006 issue of MC2 Magazine Matt Richter explains the Ideal Gas Law in simple terms. Now you’re thinking Zzzzzzzzz, but it’s really very interesting.

The stock Cooper S is able to get a 50 hp boost over the Cooper by virtue of the supercharger. By increasing the pressure of the air entering the combustion chamber, the engine is able to produce more power with the same volume of engine displacement. The increase in pressure is accompanied by an increase in temperature — hence the intercooler. The intercooler drops most of the temperature gain while retaining the benefit of the boost. Make the intake path more free flowing and increase the pressure gain some more.

The first step is to replace the stock filter element with a cold air intake (CAI). Make the pulley smaller, the supercharger spins faster (produces a bit more heat) and the pressure increases some more. The next step is to increase the amount of air available to the filter. That’s where today’s mod comes in. This works if your CAI leaves the stock cowl in place. And it’s free.

The idea is quite simple: Modify the cowl behind the air filter to draw air from the cowl vent below the windshield. The panel behind the intake is not structural, but it still makes sense to remove it first before making the modification so you don’t mess up your brake lines which are directly behind the panel. In my case, I first bought a panel to modify from MINI (part number ) so I’ll still have my original piece should I ever need to swap back. (OK, so not really free, but still cheap.)

I drilled six holes with a hand drill above the center line in the panel. Randy Webb has posted very clear instructions here. The procedure takes about 30 minutes. You remove the cover to the intercooler; your CAI; disconnect the ECU; pull out the lower air box; and pull out the panel. Replace the panel with your “holey” one and reverse the order above. At low RPMs you will not notice a change in the intake noise, but above 5,000 RPMs there is a slight increase in the supercharger scream. I actually enjoy that sound. Here’s what it looks like when it’s all back together.

finished mod

Update: Jan 2015. Randy has long shut down his MINI site so I pulled the instructions from the internet archive. No photos, but simple enough to follow along.