Looks nice. Keeps spiders out of your engine. Lightens your wallet so you get an increase in performance.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

There is less surface area on the inside than the outside.

Donaldson Power Core filters are hands down the best technology on the market right now.

Show me the dyno numbers.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

Measure the static pressure downstream of the filter, and correct for Mr Bernoulli to establish how much flow losses you are getting with whatever you've got right now. (Bernoulli means that the static pressure in that duct will always be less than static pressure outside, and there is a theoretical minimum that can readily be calculated if you know the dimensions and a reasonable estimate of the volume flow rate and temperature.)

A scangauge monitoring MAP and IAT while driving was sufficient to convince me that the stock air intake system on my car is not worth changing. Only thing worth doing is occasionally replacing the (stock) air filter element when it gets dirty.

I agree abou filters, but a cold air intake can be beneficial if it is done right.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

Yup, and monitoring IAT with a scangauge will tell that tale, too.

I was actually somewhat surprised by what I found. In my car, the air filter and intake duct is built into the plastic engine cover and the whole deal is surrounding the cylinder head and valve cover. I expected heat soak with the engine stopped, and indeed it does. But after restarting, within a couple of minutes the IAT is indistinguishable from ambient temperature.

Plastic doesn't conduct heat well, and additionally there is insulation with a reflective material applied to the underside of it where it is otherwise facing the cylinder head. It heat-soaks from engine heat when there's no airflow anywhere, but once it's running, evidently whatever heat makes it through the reflective layer and the insulation layer and the plastic of the housing itself, isn't enough to make a meaningful difference.

Perhaps a different design might let the engine draw in cooler air for the first couple of minutes after a hot start ... but that isn't enough of a benefit to interest me.

I suppose the aftermarket intake ducts don't need to be taken off in order to do anything with the engine underneath (e.g. spark plugs) ... but the stock intake duct is only attached with a couple of screws and a couple of hose clamps; removing it to get to the spark plugs once ever 100,000 km is hardly enough of a challenge to bother doing anything about it.

I have to agree with the others. Air filter alone will rarely give any significant improvement over stock, unless you're pulling a hell of a lot more air through it than standard. The claims about velocity etc are believable enough, which is the main reason why OEM setups normally use a panel filter.
A cold air intake, or a redesigned intake tract, can show some improvement in some conditions; again, usually not enough to justify the cost unless your engine is heavily modified.

There was a time when engine designs were sloppy, and something simple like an improved air filter would boost performance. That time is long past IMHO.

Aftermarket intakes and air filter arrangements come into play when you are taking an engine to power levels significantly higher than the original. At higher air flows the demands change.
For stock (or near stock) set up it is usually hard to beat the OEM system.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

If you ever feel inclined to change the air filter, measure the pressure drop across it with a water filled U tube. That may reduce your enthusiasm.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

Increase noise / sound may be a significant "benefit" of aftermarket systems.

I'm always amazed at what others can sell and the ideas they come up with. Much as I enjoy engineering, I'd love to be the guy that made millions selling a gimmick like this and working for amusement rather than income.