aFe Air Intake System

[The HACK]

Installed these two weekends ago after swapping out the brake pads for this past weekend at Chuckwalla:

http://afepower.com/shop/details_new...BH1&brandID=52
Installation was straight forward, except you've got to watch out for dropping the small nut that secures the air box to the bracket since you'll have to reach underneath the bracket blind to put it on. Also, the instruction wasn't 100% clear on how to remove the rivets that the OE air box sits on in order to install the nut and bolt onto. You have to pry up the top "cover" of the rivet, then the rivet itself will twist and come right out. I've taken pictures with my iPhone and will post as a follow up.

What I notice immediately was an improvement in the low end range of the torque curve. Car's significantly more responsive on throttle tip in while cruising. The high end range of the rev, the difference isn't as dramatic. In fact, while on track I don't see my terminal velocity being significantly better down the straight, which means the top end gains are not as significant, given that there's more grip in the corners. Since conditions varied from last year's trip to Chuckwalla, take that with a grain of salt. The one thing that the butt dyno picked up on was the low-end stuff.

Now, if my primary reason for the mod was for sound, then it's a worthy mod. The intake now GROWLS like the engine is angry. The sound is almost intoxicating enough to keep my foot buried all the time. Alas, for testing reasons, I decided to "cruise" only for the trip home from Chuckwalla, and compared to last year's cruise home, I picked up at least 1-2 mpg. I made it home without having to fill up after the track day, while last year I wasn't sure if I could make the 180 mile trip that I decided to stop at Cabazon about half way home to do a quick splash and go.

While fuel efficiency wasn't my primary concern, it is definitely a welcome bonus. Unfortunately, the MZ4 Coupe doesn't get driven on a daily basis so the benefit is hardly felt. I think I need to go through a few more drive cycles to give a full assessment on this one.

[Nate4641]

Your link doesn't seem to work. Did you go with the wet or dry filter?

[speddmn]

Originally Posted by Nate4641

Your link doesn't seem to work. Did you go with the wet or dry filter?

Works for me, he went with the oiled one

FWIW I never had a problem with a K&N, even beating the jesus out of the car but the second I went FI my Oiled K&N started pissing off the MAF.

[Arsonism]

I went this route as well. Unfortunately mine didn't come with the lower nut/washer for the bottom of the box/manifold. I ended up going to Lowes and picking up some hardware and solving the issue. without that secured it did jump and hit the hood a time or two, wasn't super happy about that but nothing I can do now.

I rock it cover off these days, too awesome to see the 5.5" conical filter absurdity.

[The HACK]

Yes, that filter is absurdly HUGE.

[gpdriver]

Mine did not come with any hardware for the bottom flange, only for the two factory air box attachments where the rubber and twistable rivets were. Did you remove the rubber bumper that supported the factory air box at the very bottom and attach the protruding bolt to where the "star" opening is on the Afe lower flange.

[The HACK]

There's no protruding bolts on mine...I attached the fasteners (2x nuts and bolts) with washers to the holes vacated by the rubber rivets to secure the bottom of the airbox.

[3002 tii]

Surprised that you had such positive results. I never thought much of these open cone intakes. The stock sealed system seemed pretty efficient, didn't think there was enough margin for improvement.

[ried]

My understanding is that the aFe intake actually reduces engine performance significantly, confirmed by dyno. See the existing threads on the issue:

http://www.zpost.com/forums/showthread.php?t=175180

http://forums.5series.net/e60-parts-...ock-rpi-63222/

[DasGerman]

Nope. Our car isn't a 5 series, so the comparison is pointless. Not to mention that small amount of variance can be attributed to many factors. If you've actually run one, you'll notice the quicker throttle response and no 'determinable' loss of power. I could show you a dyno report that shows an increase of 8hp. Meaningless.

[ried]

Meaningless perhaps. But the controversial issue is that the stock system pulls cold air from outside the engine bay, while the cone intake also pulls air from the engine bay itself, which is of course hot and results in poor engine performance. That affects the M Coupe, M5, and any other car that has a stock airbox which can be switched out for a cone filter.

The issue is mitigated (and possibly eliminated) at high speed. But for normal, everyday driving I'm not convinced it's as beneficial as simply using the stock airbox with a K&N filter.

Unless you just want it to sound cool, of course. To each his own.

[The HACK]

If you read through those posts, you'll probably find that most of the argument against comes from aFe's competitors. If you then do some more research into it, you'll probably find that a few of the dyne numbers come from shops that sells aFe competitor's products. I've stated multiple times that I used to work in the automotive aftermarket industry, and while it's comprised mostly of great people, the opposite is true...There are some very VERY shady people in that business as well. There are folks that choose to do business the honest, right way, and there are people who can't compete on the quality of their products alone and must bring others down to make a profit.

I'm not going to get into the p*ssing match between RPi/aFe/Burger and whatever entity they're called right now. I'm out of the industry, and while I was part of it, I've always worked for companies and manufacturers that choose to conduct their business the right way by respecting their own products, but also respect their peers. I'm not about to change that.

One thing I will add, is chassis dynamometers and how to operate it is a voodoo science, and it's easily manipulated (and often times imprecise). It wouldn't be hard for someone to conjure up some numbers one way or another. The only thing dyno numbers are good for, is if you do back to back test on the same dyno under the same condition, done with a baseline run and an after run for comparison purposes. For those without a baseline run, done outside of controlled environments, the numbers are meaningless.

And the myth about how the intake is pulling in hot air? These air intakes operate on differences in air pressure, and the open air outside of the front kidneys has higher pressure than the hot air in the nearly sealed engine bay. It's unlikely, that even stationary, that hot air would be sucked in rather than the cold air from outside the engine bay. In some prior, older intakes that I had on my E46 323Ci, it's not a fully sealed design, yet the air inside the air box remains cool. The "box" was more to prevent the heat from radiating into the intake.

[The HACK]

Originally Posted by 3002 tii

Surprised that you had such positive results. I never thought much of these open cone intakes. The stock sealed system seemed pretty efficient, didn't think there was enough margin for improvement.

The stock system is pretty efficient, and if it weren't for a great deal on the intake I probably would still run the OEM system, since the MZ4 Coupe doesn't lack for power.

And the majority of the gains I felt were in the low-end of the torque curve, so for what I do with the MZ4 Coupe, it doesn't shine on the track. But for every day use, the low end of the torque is what we all live on, so in that regard, the benefits are "tangible."