So I've been doing a ton of reading about this. I "think" I understand that due to the under hood layout CAIS may be able to move more air but because you are pulling from the engine compartment, and there is no hood scoop on the CM (don't get why MINI would do that...) you are not pulling cold air. Stock system has the snorkel whic gets cold outside air, but closed airbox limits volume. (Correct me ANYWHERE along the way. I'm a noob). I've read that despite most manufacturers claims most produce more noise (turbo/BOV racer sounds) but little to no actual horsepower increases? If that's true so far, I have questions

1. Why do so many people buy them? With no performance advantages is it really all for the sounds?

2. If I put a K&N or similar in the stock box, would I be doing better performance wise than going with an aftermarket CAI? I like sounds but I like performance more.

3. Has anyone ever perforated the lid of the stock box? My thinking is if you put in a high flow air filter like a K&N into the stock box, but drilled a pattern of ,say, 1/2 inch holes across the top, would you get the benefits of having the cold air coming through the snorkel, plus extra airflow as now you are not using a closed box but are now more open due to the holes?

I don't know if that's a stupid idea or what. If I can get my hands on an extra OEM box lid I might try it. Anyone with more mechanical knowledge?

 

Anyone?

 

I'll give it stab. Here's what I've read about this stuff.

Most "cold air" intakes are getting air from the engine compartment. That air is not cold so they are really not cold air intakes. Most people get them for looks and or sound.

For good performance of an intake you will need;
1. low restriction of air flow, and
2. a cold(er) air source.
and of course it has to filter air to the engine.

With those in mind, look at any air intake or mod that you would do and ask yourself if it would give you a performance benefit.

As far as other filters being more or less restrictive, I am not sure of how much of a difference that makes, but there is a lot to read about different filter types if you Google it.

 

People are just using the term CAI out of convenience even though it is not a real cold air intake. With some exceptions like the AEM or DOS.

Some companies like NM use the more appropriate term "high flow intake" instead.

 

I had similar questions, and not being an expert in any capacity eventually came to the following conclusions.

The stock intake directs air from outside the car, into the bottom of the airbox, through the filter into the top of the airbox before getting to the engine.

So stock is a CAI, and drilling holes in the top of the airbox would be a bad idea.

Also, from what I have read here, performance gains from an aftermarket intake are negligable to nonexistent.

If you are looking to increase driving performance by increasing turbo noise you should also consider just putting a K&N filter in the stock airbox.

I live in CA, so some of my options are limited, based on CARB requirements and mods that are actually effective here are some initial ideas instead of a new intake:

1. JB+ if you have the N18 engine
2. K&N filter to release the turbo noise and make driving more engaging
3. Lighter wheels and tires, You should be able to reduce rotational weight by almost 10 lbs per wheel.
4. NM torque arm insert. Cheap, and I believe it did decrease torque steer.

 

Unless you have the JCW Cone filter airbox, do NOT put holes in the lid!!! The lid of the air box is where the filtered air is! If you are going to put holes in the air box you must put these holes in pre filter, or the bottom of the air box. Note where the cold air intake tube connects to. That way you can get more volume, but the air still gets filtered. You do not want to suck up the wrong thing and have it go through your turbo!

 

Thanks all! I just got the car and hadn't had the box open yet so yes, I was wondering which direction air went through the box. Question answered there! So I think I've decided to throw a K&N in the stock airbox and see how that seems and go from there.

 

Except DoS is no longer a choice..... don good is 100% right

 

And the AEM won't work on a Countryman (but looks like what I would want if I ever get a different model)

 

Having an air box is not a restriction and putting holes in it may actually cost you power.

MINI probably did a better job than any small aftermarket company could.

Here's why:
Air is a fluid with mass. It has inertia. It doesn't like to go around corners and it doesn't like to change directions.

A good intake will have a smooth inlet that reduces air drag and friction at the inlet. The best way to do this is a flared horn. It reduces the intake velocity at the edge of the horn so there is little friction.

the intake will also have a smooth flow path from the horn to the filter. As you approach the filter, you'll notice the size of the intake increases (becomes a plenum or "box") so that the flow area is spread out over more filter media. The more surface area of filter you have, the lower the restriction to flow it offers. The transition doesn't have to be very smooth because the turbulence and obstruction from the filter will dramatically alter the flow characteristics anyway.

Ideally the plenum exit would be another horn in the box.

Anyway, since the stock airbox was designed to work with the car, maximized for power and efficiency on a dyno over many hours by skilled engineers... I doubt they are leaving anything on the table besides noise (since NVH is a significant consideration), but noise doesn't necessarily mean power.

 

I don't know that I agree... If everything was truly maximized for power and efficiency there wouldn't be much need for an aftermarket! Really though I do think this is a balancing act, with additional considerations like cost and regulations in the mix as well. There are sacrifices made (giving away power to maximize efficiency...) so we aren't second guessing the engineers as much as changing the balance toward our own preferences.

Anywho...I just got a K&N FILTER in the mail and plan to drop it in this weekend. No holes!! I'll report back on whether it makes a difference

 

Well I put the K&N IN AND WOW what a difference! Throttle response in much crisper, much less turbo lag and seat of the pants dyno says its accelerating harder than ever. Between the JB+ and the new K&N it's like having a totally different car than what I drove off the lot!

 

Next mod is VIP strut tower brace. Should arrive in the next couple days. Then??? Planning magna flow catback and VIP adjustable sway bar. Lighter wheels in the spring. Plan to put snow tires on the stock rims

 

One of the first things I noticed when opening the hood on my '13 S was how long the whole air intake system is. I know you have to plumb an intercooler, but altogether its gotta be like 20 feet from opening to throttle body.

 

Anyone know what the K&N filter part number is for my 2015 Countryman S?

 

I think it's K&N 33-2936 High Performance Replacement Air Filter

 

That was it. Thanks!

 

It looks like we have a new option offered by ECS Tuning
http://www.ecstuning.com/ES2719002/
this is the "JCW-style" intake I have always been wishing to have, and now it became true!

 

Thanks