I am an owner of a 2001 SLK and was thinking of doing two things:
1. Using another Air filter for better performance. Which would be better is my question.

2.Installing a blow-off valve. Is this possible on a Kompressor (supercharged) type engine? If it is then which company produces it?

Thanks.

People like K&N filters, I think that is what the majority uses.

B.O.V. can be attached to a supercharged engine, but it depends on what type of supercharge, roots type, twin screw, ect...

B.O.V. will not work on our cars, because of our type of supercharger setup.

not true, you have a recirculation or pop off valve or something of that sort. Do some homework.

The BOV will give no gain in HP and K&N is questionable gain.

Umm... so what are you saying? We CAN add a BOV to our car? where in the world would you attach it?

And yes BOV does not give any performance gain, I'm guessing that the_twism wants it just for the sound it makes....

yes you can add a bov if you want to . you would need to remove the bypass valve and then you would be able to put it anywhere after the charger. with the bov you could regulate boost , is what i mean is that instead of the computer now rgulating boost to say 5-6 psi even under full throttle, you may be able to get lets say 7 psi max boost. the current setup on our cars maintains around 5-6 psi no matter what the engine rpm, even the higher rpm. I have a boost gauge on my car and at times can get close to 9 psi, but it will not maintain it. with a bov you could set the release pressure at say 8psi and be able to use it.

That's right xyzpl. I know that a BOV will not give me any hp. I just personally believe that a "sneezing" car sounds cool. It gives it a "racing" touch. Also I forgot to ask if a BOV if applicable, would affect performance either negatively or positively.

A friend of mine has a Smart. He has installed a BOV, and I have heard it. Now what I don't know is if the Smart is a turbo or a kompressor engine. I believe it is a kompressor, and that is what made me think about the BOV.

Speaking about the sound that produce a SLk, I have heard a SLK 230 Kompressor with a sport exhaust (it was a standard engine) from Brabus and it made a real sport sound.