I have a 91 rx7 N/A and I recently had to go back to the stock exhaust system. Anyways I would like to install a cold air intake, however this is where my question comes in (whether its "noob" or not). Hypothetically if I were to remove the standard air box, what exactly do you do with the AFM or mass air flow sensor? Do you have to get a new one to fit the cold air intake? Basically I just want a little more growl out of my car as well as a raspy tone.

 

you have to keep the AFM, and have to buy an adapter which can be purchased via ebay.

 

ah thats what I thought, can you only purchase the adapters via ebay?

 

no you can buy the AFM adapter at other places but ebay seems to be the cheapest route.

 

The AFM on an S5 has a circular end. If you find an air filter to match the size, no adapter is needed, you can just clamp the filter onto the AFM. S4 cars need an adapter as the end of the AFM is not round.

 

Whats wrong with the factory air box? Put your hand in front of the scoop near the front, feel the air being sucked in? Cool right? Now put your hand where you would put the cone filter. Warmer then the factory scoop spot right? IMHO buy a drop in K&N filter and leave it alone. Mazda took time to engineer the intake unlike a company who just engineers their filters. So take a quality engineered filter such as the K&N drop in and use the factory air box. Both of best worlds. As for exhaust why did you go back to stock? Depending on the exhaust you plan on installing you most likely will not be able to hear the intake over it. If you just want it for sound.