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Difference between Mini Cooper S 06 Supercharged and Non Supercharged?

Ok, first of all, can you put a superchaged head on a non supercharged motor? Are there any difference between those heads? Is there a compression difference? I managed to put a supercharger on a non supercharger motor and it did turn on but shut down and wont turn on any more. Could I have damaged some valves?

That’s a very specific question, you’ll have better luck posting it on a Mini forum. I’d bet (but don’t know) that there are lots of differences between the two motors.

The supercharger/turbocharger engines have larger volume combustion chambers than the normally aspirated engines.

This is because when the supercharger/turbocharger forces more air into the engine, more fuel is also added.

This extra volume is achieved by making the cylinder head combustion chambers larger and in some cases changing the stroke of the pistons.

If this isn’t done, the cylinders pressures can get so high that the engine can be destroyed.


You need to redefine the question.
A supercharger increases the amount of fuel and air that gets injected into the cylinder, and thus the pressures generated by the explosion. The question should be “if I boost the pressures in the cylinder beyond what the parts can withstand, what might get damaged?” The answer would be that you could bend a connecting rod, break a connecting rod, and even… if you do it well enough… blow the engine up. Could you damage a valve? Sure. But that’s only the beginning.

Please don’t decide to experiment with nitrous oxide. Your next post will be from the afterlife.


ssshhhh…! don’t tell him.

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Yes, a very sizable one. The N/A 2006 Mini had a compression ratio of 10.5:1 The supercharged mini had a compression ratio of 8.3:1

Did you start it without any ECU tuning at all? Because that could be disastrous. Without being told to introduce extra fuel to go along with the extra air, you’re going to have a very lean condition, assuming it starts and runs.

Or worse.

Good point. Supercharging requires higher capacity injectors and remapping of the ECU.

The only stock engine I’m aware of that can safely accept a supercharger without internal modification is the Scion tC engine. Toyota developed and offered a supercharging kit through their TRD division that could be installed on the stock engine, and if the dealer installed it, it wouldn’t effect the warranty. The kit came with everything needed, including new injectors, the oil lines, and whatever is necessary to remap the ECU. It allegedly adds 20HP (or was it 40? I’ve forgotten now). As tempted as I was, I abstained. I wanted reliability for the long haul. And it would, I’m sure, elevate the cost of any other work… all them extra parts being in the way. The good news is that this being the case, it gave me confidence that the engine was built with a bit of extra robustness. I found that thought comforting.

The point is, successfully supercharging an engine requires more than the average DIY knowledge as well as some additional components and extra skills. I tip my hat to your willingness to try stuff like this, but you now need to deal with the “flip side”… the true cost.

A highly knowledgeable team from a DIYer car magazine tried a few months back to install a turbocharging kit bought off the internet on a stock V8. They did the project in a highly equipped test lab under the supervision of an expert in building race engines. They first tested the engine thoroughly to be certain it was solid, then proceeded, trying to follow the enclosed directions. They ended up installing the turbo upside down, after doing some welding, some heating and ball-peening, and bracket manufacturing themselves. Once it was installed, they fired it up and had to abort the test when the pressure ran away, for fear of blowing up the engine. Turns out, the supplied burp valve was completely inadequate, allowing the pressure to build freely. They were able to correct the problem and get it running. But they strongly advised against trying this yourself. They had the monitoring equipment, the expertise, lab safety, and the ability to get it done done without blowing themselves up. Most DIYers don’t.

Ok, I did not do an ECU tuning and it is an automatic car. So the non super charger head and super charger head are not the same? What would be my compression rate with a supercharged head on a non supercharged motor? Would it be low compression? I would assume if its low compression, I am safe, but if its too high I could have damaged it?

The heads are different, the pistons are probably different, the fuel injection is different, the computer is different, what else? Who knows. There is no way to know what the combination of parts would yield unless somebody has done LOTS of careful measurements. I guarantee nobody here has done that. Maybe (just maybe) somebody on a Mini forum has.

You could have answered the compression question yourself when you had the heads off by just cc-ng a chamber on each head. I am not familiar with these engines but the manufacturer may have taken the opportunity to increase valve lift on the larger combustion chambers of the turbo head. That is something you could have also measured with the heads off.

Your first post said you put a supercharger on a non-SC motor. Nothing was said about the head. The next post said you had also changed the head? I believe the pistons are different on both motors. The SC pistons are “domed” while the non-sc pistons are flat?