I’ve modified nearly every car I’ve ever owned, and my G80 will be no exception. For starters, I’ll install a BMC air filter in the stock G80 air boxes. Is it hard? No. Is it worth it? Well…
Before you begin
You’ll need some things:
- BMC high-flow air filters (I got mine from AutoCouture), because those guys are awesome and they won’t steer you wrong on this platform).
- A flat-head screw driver
- 13mm & 16mm Wrench (socket)
- T25 Torx driver
How hard is this to do?
If you feel uncomfortable installing this on your own, you probably shouldn’t be working on a car, because it’s as easy as it gets.
DIY Step 1: Strut Tower Brace removal
Remove the front strut tower brace. The rear bolts are 13mm, and the front one is 16mm. Then, lift the bar up and set it in a soft place so it does not get scratched.
Step 2: Air Box removal
Take your Torx driver and unscrew one air box at a time. The screws are designed to stay in place on the air box, so you don’t need to take them all the way out. You’ll feel the screw release the bottom half of the air box, and that’s when it’s time to stop turning.
Next, take a flat-head screw driver and unscrew the intake tube. Pull the top half of the air box out. Repeat for the other side of the car.
Step 3: Charcoal Filters removal
Ahh, the charcoal filters.You can grab them at the bottom and tug. They fold like an accordion and come out easily enough.
Step 4: New filters
Take out the old air filters, and pop in your BMC air filters. Then reverse the steps. You’re done.
Q&A: Will removing just the charcoal filters make a difference?
If you’re interested in the science, this video explains if taking the charcoal filter out improves engine power and response. In short, it does, but by a small amount.
Are oiled filters a rip-off?
I’ve used them on every single car I’ve owned, from my 3000GT, 350Zs, E92 M3, etc. I used to go to K&N, but this BMC air filter comes highly rated, and the principals are the same. I’ve never had any issues with warranty, clogged throttle bodies, or rough idles.
Do BMC filters make a difference?
BMC claims that they add 10 horsepower to the G80, and have provided a dyno result with an F82 M4 as proof. They have yet to test a G80, but let’s say it is in fact 10 hp.
On a car that makes 473 horsepower, adding 10 amounts to a 2 percent difference in power. You won’t feel it.
Should I get a full intake system on my M3 instead?
Debatable, but for me, that’s a no dog. Take a look at the stock air box – BMW knows what it’s doing. Each side features a cold-air tube that leads to the front of the grill. The boxes themselves are well insulated and sealed nicely. Adding a cone filter and new tube will give you a louder turbo woosh sound, but performance improvements are minimal. We don’t want to be sucking in hot air from the engine bay.
Did you feel a difference?
Yes! I did not notice more power (2 percent…), but the car does have a smoother rev to redline, and feels like it revs faster.
Also remember that mods work together. Adding an intake and exhaust together will yield a greater result, and so on.
Do you recommend the BMC air filter kit for the G80?
For $180 at ACM, it’s a cheap and easy mod that makes the M3 a bit more enjoyable to drive. Now, onto picking an exhaust…
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