No, I don't really believe that. I would say most of them are brilliant. But I do wonder why, in the eyes of others, they haven't made a single intake air box in the last 20yrs that can flow enough to meet the demands of the engine? Or did they?
Does anyone really know? Or do we just toss out what they designed, and instantly become smarter than them.
The airbox on my 05 MCS looks to be a well designed piece. It is already a CAI. It has a nice radius at the throat to simulate an airhorn. Seems like the throttle body is a bigger cork.

Is it inadequate from the get go? or does it become that way as other mods are made? Has anyone done dyno pulls, or have any timeslips to back up their design? How about a simple vacuum gauge plumbed to the top of the air box to see if there is any measurable resistance.

Don't get me wrong, I am not trying to bag on any of you. To each his own. Just playing Devils advocate for the sake of discussion.

An engine is an air pump. And enabling it to pump more air is how we make power. But why is it always the airbox?

 

What makes you think the stock intake in inadequate? Have you performed pressure drop measurements? Not being condescending, just curious where you are coming from.

 

Simply coming from seeing so many people replacing the stock one with an aftermarket unit. Wondering why. Is it just for looks and sound? or is the factory unit not up to the task?

I don't have any data. That's why I am asking.

 

I'd like answers to that myself. My system is still stock, so before I do anything, I'd really like to know...

 

Probably 90+% of OEM vehicles built today have a very efficient intake system, and going with an aftermarket system gets you very little. OEM engineers have many other factors they need to consider when designing an intake system, and power/efficiency are some of them. They also need to account for sound and manufacturability.

 

No significant power gains to be had relative to the price for a full cold air intake system. I just put in a $50 aFe dry filter and get that nice whooshing sound when i let off boost. And maybe 1 mpg or so better, but I have no concrete evidence of that.

Why airbox? Probably the easiest to get to! Much easier than changing the internals of the engine, that's for sure.

 

I suppose I should weigh in on this since I spent several years designing air intake systems for Ford and GM. njaremka is right; there are a lot of considerations in play. No. 1 is noise, and not just the absolute level - the spectrum matters too. Most aftermarket CAI systems would be considered commercially unacceptable for a modern car - some might even fail pass-by tests. Most things that reduce noise will increase restriction to some degree and the OEs have different "budgets" for what they will accept. In truth, at the levels we are talking about, the impact on performance is negligible. The effect of restriction is not linear, there is a dynamic component (tuning) as well, and some restriction can help power in the lower ranges. I have seen dyno charts on some well-known aftermarket brands, and usually you see that there is no improvement, and sometimes some harm, below about 5,000 rpm. You might see several hp improvement at 7,000 rpm; good for bragging rights, but not much practical use. Even full race engines don't operate at redline all that much of the time. There are a bunch of other things to consider - one you may not have thought about is snow-packing. If the intake isn't suitably baffled it's apt to pack solid in blizzard conditions and shut you down cold (literally). No, we're not idiots, at least not most of us, but we do operate under different constraints than you do, so you may prefer different solutions.

 

...also keep in mind that an Automotive Engineer's main goal is not to squeeze as much power from an engine. It's to get the most power while also meeting noise, efficiency, reliability, emissions, and safety requirements.

An aftermarket company can come along and make a part that might give you a little more power, but at the cost of adding more noise, or some other thing that might not be acceptable for a production vehicle rolling off of the showroom floor.

 

Yes.

And the same goes for aftermarket exhausts. Funny how it's one end and the other.

 

Couldn't agree more. Thank you. I have not found anything that can backup HP claims.
I have personally never drank the Coolaid on the CAI trend. Most of my cars (9) predate the trend as well. I would like to see a vendor or 3 chime in with some info that would sway me into sending them some $$. But if they are just for looks and sound (as I sarcastically implied, and as you explained) than I will spend my $$ elsewhere.

 

Another good subject. The only tri Y design header I have seen is the OBX. The tri Y is a great header for midrange torque. And it is half the price of most others. Anyone have any data to back up a 4 to1 header design on the Mini S?

 

There have been a few 4-2-1 headers for the MINI over the years. The OBX is probably the most popular because it's the cheapest and almost identical, to put it nicely, as the SuperSprint header which preceded it. What's not identical is the quality, fitment, and a revised taper in the pipes at the flange on the head, but these issues are often overlooked because of the price and performance. The SuperSprint is usually around $8-900, but recently on sale for $640, and the OBX is around $330.

I think the pipes were pinched down because of fitment issues with the OBX, but there are still recent posts of installation issues because of the clearance regarding the welds. Here's the latest post I've seen: https://www.northamericanmotoring.co...d-welding.html

 

Factory air boxes aren't made to be super good. They are made to fit the price point of the target market, and keep intake resonance to a minimum so Grandma won't keep bringing it back to the dealer saying it is making a funny noise.

Same as everything on the car. Made to the price, made to be as inoffensive as possible and still meet target speed / power / attitude targets for the intended market.

James

 

Living and driving at an altitude of 6,500 ft., the first modification to my last 3 MC's (over 13 years) has been a cold air intake. Just to survive entering the Interstates. The normally aspirated MC (non turbo) has "0" power at this altitude and driving in sport mode helps slightly. Even the MC sales manager verifies this. My 2015 MCS is not as affected as much, but its performance increased with the intake. Years ago, my wife's Jaguar XJS had an altitude switch located in the trunk. Nowadays, computers make it easier but even they have "average" parameters.

 

noise, case in point my 135i's intake wraps around from the turbos to the other side, replacing this gives nice gains but adds a lot of turbo noise

 

Wonderful reply, thank you!

 

Aftermarket is even more conscious about price point (and more willing to sacrifice quality). Just check eBay.

 

Worked with engineers and architects during my construction career. There are good ones and bad ones. It would be logical to assume the auto industry is the same. I remember the Fiero spark plug uproar as you had to remove the engine to change the plug. I did not have to do that with my Mini but I did have to remove the front end to change a simple O-ring.

My JCW is pushing over 130 HP/Liter, today's 4 cylinder Boxster is pushing 150 HP/Liter. These engineers are not stupid. To accomplish what they do in today's world of class action lawsuits, crash standards and emission controls is just amazing.

 

Amen. Always been a fan of European engineering. The group of people that designed the MINI did such a great job with it, it made me wonder why everyone seems to toss out the airbox. I've read where people claim a 10hp increase, although I cant find any data to back it up. Maybe they took a filthy plugged up stocker out felt it with the butt dyno.

 

The guys at mini ripped my intake from being too lazy during all those warranty filter changes to remove the intake completely. Thanks Ralph Schomp. Then after checking the stock turbo and finding the shaft moving I upgraded to a KO4, bigger intercooler, intake muffler removed and noisemaker capped off + a tune and a ported-ceramic exhaust and hi-flow cat. The intake pipe on the turbo was bigger than stock so I turned to Alta for a metal pipe only to discover that the pipe is too small for the new turbo. Alta wouldn't assist and I didn't want to return the turbo. Solution = hacksaw. I cut the end of the Alta pipe off and connected it to the turbo with a silicon reducer and clamped everything together. It's not perfect but it gets the air to the turbo.

What I think is needed for these kind of mods is a creative machine shop that is willing to make things for a fair price. I am not sure that everything needs engineering. Sometimes a little craftsmanship and an open mind work better. DR.