Has anyone fitted a cold air intake to a C Class V6? If so does it work? ie any performance gains? Also, what about the MAS, will it adapt or will you get a check engine light?

Thanks!

 

If you're asking about your car, it will adapt. Your car has OBDII. The extra air flowing in will be met with extra gas.

If you're asking if the air will be cold, the answer is no. I don't know why they call these "cold air" intakes. "High flow" intake would be a better name.

The actual advantage to an aftermarket "cold air" intake is an increased airflow with less turbulence. I wouldn't expect more than 10 hp at most, though. You'd have to measure this with a clock (in 1/4 mile) to assess any gain since that's not anywhere near enough hp for you to feel and not enough wind is present on a dyno to simulate driving at 100 mph.

For the 10 hp or less, the engine will howl at full throttle and near full throttle. Depending on which brand you get, the intake may also instill undesirable amounts of water into the engine under certain conditions. A little water, a mist, isn't a problem. Actually, a mist would keep the inside of the engine cleaned. However, there are aftermarket intakes that scoop air from very near the road surface. Theoretically, that's where the relatively colder air is. All's well until you hit an ankle-deep puddle and the scoop enters it. The high airflow characteristic of the intake comes from an unobstructed path for the filtered air to enter the MAS. Factory intakes are designed and tested extensively to prevent water from entering the MAS in any volumes other than a mist. Water from a rainstorm, for example, will not enter the MAS on a factory setup. Some aftermarket setups will swallow it right up.

 

If I get 10HP at the rear wheels, that would be good, but if you measure HP at the flywheel, then by the time you get back to the wheel perhaps 1 or 2HP I had a CAI on a BMW before the Mercedes and it came with a "water jacket" as the cone filter is down around the fog light. How about the the high flows that sit in place of the regular air box, I seem some DTM styles, but big money. I also had tought of fabricating a cone set up myself, with some aluminium tubing and a K&N filter and make a shield on the engine side of the filter? Do you think this setup with add any HP?

Thanks for the very complete answer.

 

You should get around 80% of the hp from the flywheel to the rear wheels, give or take a few %. About 8 hp in this example. So, what's the diff, 8 or 10 hp?

On a stock engine you very quickly run into diminishing returns with an aftermarket intake. Start adding things like water jackets, which is a good safety feature but an obstruction, and the returns are further diminished.

Make sure whatever you get at least looks good because that's pretty much all you're getting is looks--on a stock engine. If you got a bigger cam, bigger throttle body, bigger MAS, high-flow polished heads, then yeah, an aftermarket intake would provide bigger returns. You'd actually need one to take advantage of all those other parts and improvements.

Anything that's completely smooth on the inside, has a minimum of turns, and without obstructions will improve airflow over the factory intake. You can certainly make something that fits that bill. It will add hp, but still not more than 10 hp or so at best. I wouldn't use aluminum under the hood. It will get heat soaked (even with a heat shield) and transfer the heat to the incoming air. Not good, but still probably an improvement over the factory setup if there's less turbulence.

The thing to remember is that no more air can enter the engine than the smallest opening provides. If you remove the bottleneck at the intake, then you have to deal with the next bottleneck, and so on. On a stock engine, your time would probably be better spent trying to rid the intake of turbulence caused by obstructions than merely increasing airflow. Then, you could do something like remove the honeycomb screen on the MAS and port and polish it. That'll get you another 10 or so hp by increasing the ignition timing and incresaing airflow. Another story for another time, I think.

 

Your last paragraph is interesting, especially the honeycomb screen on the MAS, I have taken a good look at the one on my car. If I understand, the screen is to protect the intake. The MAS on my car seem to be completely made of plastic, at least the outside covering. How would you remove the screen? As you know the MAS is an expensive piece and breaking that would cost more then fabricating an intake.

I also made a new grille, a mesh grille. I had an extra frame I picked up on eBay for $10.00. I ordered some mesh grille material, polish aluminium, cut it to shape with a little overlap and carefully fitted it inside the frame and they used some urethane glue to hold it. On the stock grille as you know there is a blanked out area to divert water, I guess, from getting into the airbox nozzle, now there is no interference, air comes straight to the nozzle. The only thing noe is to fabricate a new secondary hood release. I tired to sand down the stock one, with a dremel and probably could have gotten it to fit, but it would be very thin and you would need to be carefull when you pull it. I starte thinking about when it goes in for service, the tech might not be as careful as me. So I took the pull handle off, its only held on with a snap ring and bought a solid aluminium rod 8" I going to try and shape it around the mounting point and hopefully the snap ring will secure it and then cut it in a manner that it doesn't disappear into the grille when closed. But the point I am making is, if I can get the secondary latch handle worked out there would be more direct air flow into the air box, which I use a K&N filter in. I also thought about fabricating inside the stock airbox a flexible tube arrangement, pointed to the filter and spread wider on the fiter end. This might cut down on some turbulence? What do you think?

 

The screen in the MAS distributes the airflow over the heated sensor wires. It's not for protection. The factory calibrates the sensor wires to sense the amount of incoming air by measuring the how much the sensor wires are cooled. When you remove the screen, the sensor wires are no longer calibrated. More air enters the MAS than is sensed. This leans the air/fuel mix and results in increased ignition timing. The O2 sensors catch the lean mix and add more gas to correct. All of this adds hp. However, you run the risk of pre-detonation (pinging) if the gas you use is anything but very, very good premium and the ambient air is not dense (cool). Pre-detonation reduces hp. The ECU reduces ignition timing and richens the air/fuel mix to correct.

I wouldn't remove the screen. It's not worth it. There's no elegant way to remove it. You pretty much have to break them out. You can't replace them.

My car has two intake snouts directly behind the grille pointing towards the front. Each had a diverter flap so air couldn't shoot directly into them but had to go around the flaps. I removed the flaps. I could do more, I guess, but I'm lazy and it's not worth it to me.