Which is healthier for a n/a engine - more air or colder air? in other words - for a non s (no intercooler) would a CAI which got air from under the hood be helathier for the engine than the stock air box since the engine could breathe easier?

Also, which type of filter is healthier for an engine - traditional paper, gause/cotton or foam. Once again - is it helathier for the engine to get more air through a k&n type filter or cleaner less oily air from a paper filter?

 

I've read many tests that show consistently that more air = more particulate into the engine, regardless of what type of performance filter you have. I believe from what I've experienced and read that colder air is more beneficial in a turbocharged car. While I might want a performance intake and exhaust, I may end up choosing to leave my MC stock because I intend to keep it for a long time, and paper filters are definitely better at their primary job, that is filtering air.

 

I would guess that cold air is still better. And I only say that because it feels like I've got more pull when it starts to get cold in the fall.

....Or maybe it's because I swapped to winter wheels and they're lighter...

 

I think that "More air" is somewhat synonmous with "cold air". At the heart of it, you want more oxygen molecules to burn more of the gasoline. Whether you get more oxygen from removing restriction in the intake path or from increasing the density of the air (ie making it colder), it's sorta the same in the end.

I'm sure the temperature of the air does change the combustion a little, but I don't have the experience to say how much difference matters and how much is negligible.

 

How do we really measure what's healthiest? If anyone has problems with their CAI, I'd like to hear about it.

I've bought about 20 mods in my my 1 month old Cooper. I know, I'm possessed. Details at https://www.northamericanmotoring.co...ad.php?t=59429

Of all the mods, I'm happiest with my K&N CAI. It's $220 retail, $140 at Ebay. Install was a breeze, it looks good. Performance is very noticeable. And the sound is incredible! The performance improvement is definitely noticeable with a more deliberate pull throughout the powerband. The sound is completely normal up to 3000 rpm and then it snarls like a rabid dog to 6000 rpm.

You know what's not healthy is me just revving the engine all the time just to hear the snarl. I would give up my Borla at this point before I give up the CAI. It's such a worthy mod.


Videos with CAI and Borla

http://mtbr.com/author/photos/cooper/mvi_5742.avi

http://mtbr.com/author/photos/cooper/mvi_5747.avi

francois

 

If you attack the worst bottleneck first, you'll get the best benefit. Not to familiar with the base cooper, but there's significant constraint in the air path on the S. IF you don't fix that, you wouldn't get all the benefit from other things that get put on the car.

And the post about density is pretty much on target. Density creates power. With the exception that temp creates detonation.

Matt

 

I prefer K&N

 

You make me want to buy one :P

I've got a question tho, wouldn't an exposed filter like this be subjected to spray and dirt? I mean, the engine bay does get dirty water and stuff like that in it from day to day driving.

 

Cold air definitely makes a big difference, but I think there's a limit in that after a certain point the benefit stops. The main thing is that hot air from the summer makes my car slower. While cooler air from the winter, fall, and spring makes the car peppy. However, I've found that very cold winter air doesn't help any more than cool spring and fall air.

Of course more air is good too, but I think there's a limit as to how much can be sucked into our non aspirated 1.6 engines. The bottleneck is the head. Getting a freer flowing head helps a lot, and takes better advantage of a freer flowing intake (and exhaust too, and header too). But in my experience, the cold air makes a considerable difference.

 

Cold air, definitely.
A non-pressurized system can only process so much flow. Once you reach that theshold, it doesn't matter what you have going on, you are against a wall.
What is contained within that flow can make all the difference in the world.
Cold air is more dense and contains more oxidant (O2).
Once you hit the flow threshold, colder air will give more power than warmer air. Simple fluid dynamics.

 

You want more cold air!

More for more power, cold so you don't get detonation.

That is, until the injectors can't keep up.

Matt

 

With a given volume cold air is more air.

 

But then, you just get larger injectors.... The need to mod can become insatiable.... Before you know it, you will be where the S starts out....

 

The answer is yes.

Or to be more specific, what you want is more air mass. The amount of fuel you can burn, and therefore the power produced, is determined by how much air mass is available to mix with it.

If you can remove restrictions in the intake path and flow more air at the same temperature as originally you'll get more air mass.

If you can draw in the same amount of air but cooler, and therefore denser, you'll get more mass.

And obviously combinations of the two will work too. Underhood temperatures in modern cars can be very high, so it's generally good practice to avoid drawing intake air from there if at all possible.

Neil
05 MCS
96 M3

 

It has been my experience that more is good how ever if you combine the 2 the result is extreme to say the least. Because of the limited options for the non-s enthusiast, i have been experiencing with intake mods. Currently i have installed an "s" hood and have diverted the outside air as sort of a ram system. It has been my findings that colder is better in this application. i am currently working on an electronic cooling device much like the plug in cooler one would put there beer in. the current issue is the amperage it requires to operate

 

If you want to get a real cool blast, you could set up something like what the Ford Lightning did one year.... USe the AC to cool the air charge. They did it in the intercooler of the supercharged v8. but in theory, the same could be done for ambient air. But watch the increase in turbulence.

one thing you may want to try is the eRAM, it's a 1000 CFM axial fan. It's caught a lot of crap in the electric supercharge thread, but it should be good for about 1 psi or so......

http://www.electricsupercharger.com/

Matt

 

Yes, as said here, colder air is denser, thus is more air..... equals more power! More air means more oxygen, which is flammable so ignites and creates power!