I've noticed in recent years that the GruppeM intake has had a pretty bad rep around the forums, especially amongst some of our newer members (2007+). I think this is due to it's high price and the common misconception of how the intake actually works. Also note that replica GruppeM intakes aren't true replicas in the fact that the heat shields have different shapes. I had my car apart today while I was replacing my thermostat and water pump, so I decided to take some pictures to illustrate how the GruppeM works.
This is the GruppeM intake installed. I believe many people have based their opinion on this intake purely off what they see in this picture. An intake snorkel that goes nowhere and a heat shield stuck up against the backside of the headlight, yuck!
http://photos.e46fanatics.com/data/500/gruppe6.jpg
This is the intake in it's raw. It is specifically designed to scoop cool air and block heat from the alternator and engine. The heat shield on mine is made of carbon kevlar. Take note of the shape of the heat shield.
http://photos.e46fanatics.com/data/500/gruppe2.jpg
This is the area where the intake will be installed. I've labeled some key components in the picture to help get an idea of where things are in relation to the intake. The alternator and expansion tank can become quite hot when the engine is at full operating temperature.
http://photos.e46fanatics.com/data/500/gruppe1.jpg
This is the intake after it has been properly installed. The alternator and expansion tank have been completely covered by the heat shield. The filter on the intake also has plenty of surface area. Also note how low the intake actually sits.
http://photos.e46fanatics.com/data/500/gruppe3.jpg
Here is another picture of the intake installed. I've highlighted the area in blue of where the air is actually supplied from. This is a rather large opening that feeds down to the bumper, right where the brake duct and fog light sit. Notice how the heat shield sits nicely against this opening. This same opening is used by intakes such as Dinan, Benfer, etc that take their air from the same location.
http://photos.e46fanatics.com/data/500/gruppe7.jpg
Here is a bird's eye view of the opening. I've labeled the fog light and brake duct to give you an idea of where this opening actually leads to. Plenty of cool air is provided by this area. It's common for people with the GruppeM to actually cut a small portion off of the top of their brake duct to supply additional cool air.
http://photos.e46fanatics.com/data/500/gruppe4.jpg
This picture goes back to the intake snorkel that goes nowhere. While it may lead nowhere, it is actually acting as a "cooling fan" for the intake's heat shield. Heat shields can actually absorb a lot of heat. This cooling method helps to keep temperatures down.
http://photos.e46fanatics.com/data/500/gruppe5.jpg
That's all I have. I hope after reading this it has shed some light on how this intake actually works. A common misconception is that the air is take from the back of the headlight. As illustrated in the preceding pictures, the air is taken from the lower part of the bumper, same location that the Dinan, and like intakes, take their air from.
You might be asking yourself, "why does he care so much?", and the answer is, I really don't care. I just think a lot of false information goes around this forum. Years ago the GruppeM was regarded as a great intake and loved by most. In the snap of the finger, nowadays it seems people have nothing but negative things to say.
Feel free to discuss. Comments both positive and negative are welcome.
Additional Info:
GruppeM Dyno:
http://forum.e46fanatics.com/attachm...7&d=1051068218
http://forum.e46fanatics.com/showthread.php?t=24845