Blimey’s Meth Lab

One of the MINI’s biggest challenges is the heat produced by the Eaton M45 supercharger. This is a relatively inefficient supercharger design, that has the double whammy of both heating up air as a natural byproduct of compressing it, and creating additional heat of friction by literally beating the air as it spins.

It’s the job of the intercooler to remove as much of this heat as possible before the air enters the intake manifold, is mixed with fuel, and enters the engine. Unfortunately, space and engineering limitations resulted in a fairly small intercooler perched right on top of the supercharger and intake manifold… where it’s subjected to radiant heat every time the car stops moving and air stops flowing in through the grille and hood scoop. This results in “heat soak” – where the intercooler is effectively saturated with heat and unable to cool the supercharged air flowing through it. Much testing of top-mount MINI intercoolers has been done by others and, while aftermarket ICs are available, the stock IC is a pretty good compromise of cooling efficiency and rapid recovery from heat soak once you start moving again.

Once in the engine, cool air has a significant impact on performance. Cooler air is more dense, meaning more oxygen will fit in an engine cylinder when the air is cooler, which means it can be used to burn more fuel, which makes more POWER. You can easily feel the difference in how much torque the car generates on a cold day, compared to a hot summer day. On the first cold day of the fall, I’m always giddy about how much faster the car runs. This isn’t imaginary. The car gains about 1% power for every 10 degrees F of heat removed from the air – so on a 40 degree day, the car has about 6% more power (depending on mods, perhaps 10-15 more hp or ftlb) than on a 100 degree day.

When running wide open, under full boost, air temperatures entering the engine can easily approach 200 degrees F – or even higher. Anything you can do to cool this “charge” has a direct, immediate, positive impact on power.

One way to do this is to add an external sprayer to the intercooler. This can help quickly recover from heat soak, and improve the efficiency of heat transfer to make the intercooler cool the air better. But there are limits to how effective this can be, and at high boost levels, you can still quickly exceed the IC’s ability to cool the air.

Another approach that has been used in racing for many years is spraying water INSIDE the air intake stream – effectively mixing water with the air before fuel is added and burned. At first, this concept is pretty counter intuitive… we are taught early in our studies of internal combustion engines that water in an engine is a BAD thing… see “hydrolock“… but when sprayed in a very fine mist in proper amounts, water’s high heat of vaporization enables it to absorb significant amounts of heat as it becomes water vapor, and this yields denser air in the cylinders. Methanol can be used instead of (or mixed with) water. Methanol adds some combustable fuel to the mix, and methanol has a higher octane than gasoline, further reducing detonation (knock/ping), and enabling the engine to further advance timing, making more power. Methanol also assists with the rapid vaporization of the water.

Quite a few folks have installed various water/methanol injection systems on the MINI over the past couple of years. The typical approach is to use a “universal progressive” kit which includes a reservoir, a pump, a spray nozzle, tubing to connect these components, and an electronic controller which reads supercharger boost levels and controls pump flow to spray more as boost increases. There are some limitations to this approach given the non-linear relationship between boost and fuel/power on the MINI, and the “ideal” setup needs to be a bit more sophisticated to deal with this for highly tuned track cars. But for many street cars, the boost-controlled progressive approach can yield good results compared to no system at all, and can be much less expensive.

There are a number of suppliers of water/methanol injection kits on the market. I was intrigued by a kit offered by Devil’s Own. This kit is relatively inexpensive, in part because it reads boost using the OEM TMAP sensor instead of requiring an additional sensor to be added. It also doesn’t include a reservoir in the standard package, assuming that you may want to use an existing windshield washer reservoir (windshield washer fluid is typically just water and methanol, with some color added).  If you like, you can add a different or larger reservoir.

While a few folks have installed Devil’s Own systems on MINIs, there was no formally documented guide for such an install. When Dustin Etheredge at AutoXCooper decided to resell the Devil’s Own kits, I arranged to work with him to get a kit, work through the MINI-specific installation issues, and writeup my findings. I’m a glutton for punishment. So here goes!

First, the disclaimer: These instructions are designed to augment – NOT replace – the Devil’s Own Universal Stage 2 Kit Installation Instructions. Please read those instructions thoroughly and ensure you understand them before undertaking this project. While I believe this installation can be accomplished by anyone with moderate mechanical skills, it DOES require removing and replacing several vital parts of the car, and if you get over your head, you could end up in a state where your car is undriveable until reassembled by a capable person. This installation was completed on 1st generation MINI Cooper S Convertible  with Xenon headlights – installation may vary slightly for other models. These instructions are NOT for 2nd gen turbocharged MINIs – while the kit may work on those models, I have not tested it!

Here’s the kit:


From the top, it includes a pump, plastic split cable looms, hose, the controller, zip ties, electrical and fluid fittings, nozzles and a checkvalve.

Standard installation instructtions are included with the kit, and can also be found here.

Before you begin, read ALL instructions, and think through how the installation will go – where you’re going to put the pump and controller, how you’re going to route the wires and hoses, where the reservoir will be, what tools and supplies you’ll need to get it done. Plan it all out, and mentally work through the entire process in your head. If something doesn’t make sense, don’t start taking your car apart until it does… believe me, I’ve learned this the HARD way.

Here are the things I ended up using, and what you’ll need to for a similar install:

  • Devil’s Own Stage 2 Progressive Kit, with 2 gph nozzle and 2.5bar controller
  • Devil’s Own Self-Sealing Tank Tap (“Bulk Head”)
  • Circuit Tap for adding a circuit to your fusebox (like this, available from any auto parts store)
  • 7″ long, 1″wide 12 gauge galvanized steel strap
  • Two 1-1/4″ long, #10 stainless pan head screws, with washers and nylock nuts
  • Optional but recommended: Hose clamps for air intake hose (approx 3″)  and bypass valve hose (approx 2″)


  • 1/8NPT tap (works best with a tap handle)
  • 11/32″ drill bit
  • 1/4″ dill bit
  • 3/16″ drill bit
  • Electric Drill
  • Work light
  • T30 Torx Driver
  • 8, 10, 11mm sockets
  • Ratchet and extensions
  • 11mm wrench
  • Various pliers and screwdrivers
  • Wire stripper / crimper tool
  • Magnetic pick-up tool
  • Recommended: magnetic parts tray

Let’s get started!

The Reservoir

My car has xenon headlights, with built in washers. While the washers are cool, I HATE the idea of these things spraying fluid on the front of my car every third time I use the windshield washers when the lights are on… if that ever actually happens… I don’t know if I’ve EVER used my windshield washers with the headlights on… I keep my car and headlights clean… and I don’t need the washers… so I decided to use the Xenon washer tank as my reservoir for this system. It’s located behind the left (driver’s side) A-panel, just to the rear of the front wheel. It holds about 2/3 of a gallon – sufficient for my needs – should last for a couple of tanks of gas for normal driving, and for at least one track session.

To access the tank, first remove the front left wheel:


There are several (I think 8 or so) plastic expanding clips and two screws attaching the plastic wheelwell liner to the chassis. One of the clips is under the sill to the right. The clips remove by unscrewing the center screw about 1/2 inch, then pulling the whole clip out. Remove all of these, and the liner should pull out easily – if it doesn’t, stop and look for more screws or clips. When done, you’ll see the tank:


With my kit, I also got a “Self Sealing” tank fitting – I hear this will come standard with kits in the near future, but be sure to ask, because it’s a key part to make the install easier. With this fitting, you WILL NOT need to remove the tank! If you don’t have the Xenon headlights, I THINK you can buy this tank and install it if you like – though I haven’t tried that. If you need to remove the tank, you can do so easily by removing one bolt and nut shown in the photo above, plus one bolt hidden behind the side vent (below). Remove the vent by prying out the front end with a plastic tool until it snaps out, then slide forward.


In my case, since I’m disabling the Xenon washers, I removed the washer pump. Just unplug it:


And pull up to remove pump and clip. Slide the clip that locks the hose onto the pump and remove the pump from the hose. This will leave a rubber grommet in the plastic tank. Remove the grommet. The resulting hole is just large enough to snap in the self-sealing tap – you’ll have to tilt the tap and snap the edge of the base of the tap through the hole – you can’t push it straight through. Once in place, tighten the fitting until snug (but don’t overtighten).


The silver tape is from an experiment that didn’t work out. I also purchased a float-based fluid level sensor, to detect when the reservoir is low on fluid. Unfortunately, there’s no good place to put it in this reservoir that is (a) low enough, (b) wide enough to accommodate the length of the sensor, and (c) with enough outside clearance for the external part of the sensor and wiring. So I’ll just check the fluid every time I fill up with gas.

Attach one end of the tubing, and feed the tubing up through the top of the opening, in front of the bonnet hinge. Ensure that the hinge doesn’t snag or crush the tubing when the bonnet closes and opens. Feed the tubing through the rubber wiring grommet under the weatherstrip, into the cowl area (you may need to enlarge the hole in the grommet).


Replace the wheelwell liner and wheel, and you’re done with the reservoir!

The Pump

I chose to install the pump in the right side cowl, beside the ABS/DSC unit. I experimented with various ways to mount it in there, and eventually settled on a simple bracket to enable it to mount to an existing stud.


This is just a simple 7″ long piece of 1″ 12 gauge galvanized steel strap, with three holes – the 1/4″ hole you see above, plus two 3/16″ holes to which the upper pump mounts are attached with stainless screws and nylock nuts. The heads of the screws are on the back of the strap, to allow it to lie flush against the black plastic panel behind the ABS unit. It’s held in place by an existing nut and stud which holds one corner of the black plastic cowl panel.


Attach the ground wire to this same stud, or extend it and attach it to the existing ground stud in the outside end of this cowl space, near the bonnet hinge (as shown).


The Nozzle

This is the most technical part of the installation. If you’re not comfortable with this part, you might opt to have a tuner/mechanic install this part, and you can do the rest!

The nozzle is installed in the intercooler outlet horn. To do this properly, this horn must be removed from the car, to prevent getting any metal shavings inside the engine!

This was easier for me because I recently replaced my Bypass Valve with the Detroit Tuned BPV, and the procedure to remove the intercooler outlet horn is the same. Helix has an excellent writeup on the BPV install that you may wish to reference!

FIRST – use a Sharpie to mark the location for the nozzle – find a spot where the nozzle and checkvalve will not interfere with the intercooler or any hoses. See below:


Remove the four torx bolts holding the plastic intercooler cover in place, then remove this cover. Remove the two black brackets holding the front of the intercooler by removing two bolts from each – CAREFUL – don’t drop these bolts!  Loosen (but do not remove) the eight Torx bolts on the intercooler boot clamps. Slide the intercooler to one side to remove it from one of the boots. Then tilt it up and pull it out of the other boot. Remove the boots with clamps intact. Set all these pieces aside.


Remove the clamps that attach the air intake hose to the airbox and the throttle body. Also remove the small breather hose that plugs into the intake hose. If you are still using the OEM clamps, you may wish to purchase some “normal” hose clamps for reassembly later – it will make things MUCH easier. Remove the intake hose.

Remove the clamp that attaches the main part of the plastic snorkel to the rubber segment, then just snapping the scoop portion of the snorkel out of the radiator surround.

Now it should look kind of like this:


Snap the snorkel out of the airbox by pulling it forward, and set it aside.


Unplug the throttle body. Remove four bolts holding the throttle body in place. Lift the throttle body up and set it out of the way on top of the engine.

Note the hose connected to the bypass valve, under the intercooler horn.


It’s where you see a hose clamp in the lower left of the photo above. This will probably be an OEM-style clamp – this is another place where you’ll want to substitute a normal hose clamp as shown for ease of reassembly – it’s about a 2″ clamp. You need to release this clamp.

Now remove the three nuts holding the intercooler horn onto the studs on the intake manifold. Be VERY careful as you remove these… if you drop one into the engine bay, it may be quite an expedition to find it… I find it’s best to use a magnetic wand to hold the nuts as you unscrew them, to prevent dropping them.

Once the nuts/washers are removed, you need to GENTLY work the intercooler horn out. The trick to this is that you have to unplug the bypass valve (on the bottom of the horn) from the hose, while simultaneously pulling the horn off the studs. The problem is, the bottom end of the bypass valve hose is connected to a plastic manifold that connects the throttle body and the supercharger. It’s pretty easy to break this plastic manifold if you force it or move it too much in any direction. You can wiggle it back and forth gently with your right hand while wiggling and pulling up on the intercooler horn to work the bypass valve out of the hose – but do NOT let the plastic manifold move too much… take your time.

Whew! Once this horn has been removed, you’re ready to drill and tap it.


Use a 1/8NPT tap, and the drill size specified for your tap (probably 11/32″). Use some cutting oil to make drilling easier and to save your drill bit. It’s important to drill perpendicular to the spot on the horn where you’re drilling to enable the best seal for the nozzle. Once the hole is drilled, tap it, again using cutting oil. Clean out ALL metal filings that may have gone inside the horn or bypass valve area. Inspect this carefully. Thread the nozzle into the hole to test fit. Then attach the 90 degree fitting and checkvalve to the nozzle to protect the filter.


Reverse the procedure to reassemble everything. Be sure to affix all hose clamps, and be sure to plug the throttle body back in! Ask me how I know!

Route the tubing through the cowl area, to the inlet side of the pump, and from the outlet of the pump, back through the cowl, through the driver’s side cowl wall into the engine bay, and past the airbox and hoses to the nozzle. Attach the hose to the checkvalve.


The Controller

The controller unit is small and can be placed anywhere convenient to the driver for monitoring and adjustments. I chose to install mine in left end of my euro parcel shelf.


I removed the shelf and drilled a hole for the controller cable, then threaded the cable through and slid the controller into place. I’ve seen others install the controller below the center stack, velcroed to the bottom of the toggle switch panel. You could also install it on the steering column.

The green and blue wires must be run into the engine bay. You can thread them through a large grommet in the firewall, up behind the dash. These come out above and behind the brake booster in the driver’s side cowl.


Route the green wire along with the tubing into the engine bay toward the nozzle. Here it helps to remove the rubber seal along the top of the radiator surround. It just slips off and back on. This provides easier access to the TMAP sensor. Use the red Posilock tap to tap the Yellow/Purple wire (passenger side) of the TMAP sensor on the front of the intake manifold. Cover the wire with a protective split loom.


Route the blue wire through the cowl to the pump, and attach to the red pump wire. Again, cover the wire with a protective split loom. While under the hood, check ALL the wiring and tubing one more time – make sure all wiring is protected with split loom covers, and make sure neither the wiring nor the tubing passes too close to a hot heat shield nor near any mechanical parts where they may get pinched! Use zip ties as necessary to tie your routed wiring and tubing in place. Leave sufficient slack to allow for movement of the engine – it moves around quite a bit in the engine bay when under load!

Back inside the car, attach the black wire to a good ground point – I found a suitable screw into the metal dash frame. Attach the pink wire to a switched power source using a 10amp fuse. I chose to use a circuit tap from the auto parts store, and plugged it into a switched fuse slot in the footwell fusebox as shown. This is easy to disconnect for testing or maintenance.



Fill the reservoir with water/methanol solution. I use -20F windshield washer fluid, which is about 35%methanol/65%water. Set the knobs on the controller so that the “turn on” knob on the left is at about 25% of your maximum boost (I set mine to 5) and the “max” knob on the right is at about 75% of your maximum boos (I set mine to 12). Turn on the ignition – the red light should come on, and the yellow light should give two long blinks then flash quickly a few times. If you get no lights or different lights, something is wired incorrectly.

Take the car for a drive! The green light should come on, dim at first, when you reach the “turn on” boost level, and should be brighter as boost increases. When you hit the “max” level you’ve set, the yellow light will come on steady and the green light will be at full brightness. I bet you’ll feel a difference at wide open throttle and full boost!

Keep your reservoir topped off, and every few months remove your nozzle for inspection and cleaning of the filter.

Enjoy! I’m liking mine so far. Hopefully I’ll get some dyno time in the next several weeks and can test with and without. But the ultimate test will be this summer when it heats up outside – if I’ll be able to get something closer to “cold weather” performance… based on the results others have had, I think I will!


  1. WOW! Does it actually do what’s it’s supposed to do? Other than a seat of the pants check how will you know?

  2. Lots of folks running similar systems – some who have dyno tested with good results. I’ll be doing dyno testing and street acceleration tests soon, and will be posting results. The best real world test for me will be street acceleration tests comparing cool weather runs with the system off, vs. hot weather runs this summer with the system on… so I’ll need a few months to test if this is really meeting me expectations!

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