Date: Tue Jul 26 08:22:36 1994 From: jgd@dixie.com (John De Armond) Subject: Re: aeroquip for webers >Ok, my curiosity is piqued, John. I thought that K&N's were supposed >to be the trick thing to use for air filtering? Also, do you have any >good ideas about routing a duct to the windshield cowling? Would it >make that big a difference in terms of hp? (or any at all?) K&N is simply the company that spends the most ad dollars and therefore gets the most attention. I learned my very expensive K&N lession over 20 years ago when I was actively building racing engines. K&N had some contingency money available so I replaced our Filtron (Oiled foam) filters on our motocross bikes with K&N. An engine that would normally last 10-15 heats was completely trashed by dirt before the first one was over. Frankly I've never seen such massive filter failure. Figuring it was a fluke, I tried it again at another race. Same result. Massive wear, grit all over the intake track - trashed engine. Lesson learned. The K&N that came on a used Z I bought awhile back is exactly the same construction as the 20 year old filter still somewhere in my junk collection. K&N follows a familiar path. Lots of hype, lots of advertising dollars which effectively buys them good press, and an excellent no-questions-asked warranty. A warranty that pays people off to keep 'em quiet. One can get away with a lot on the street simply because there isn't much dirt under normal conditions. But off-road is another matter. There is an easy test of a filter that you can do. Simply thoroughly clean the air cleaner housing and the carb intake. Then coat it with a very thin coating of light grease. A portion of any dirt that gets through the filter will be trapped in the grease. Run it awhile and then feel the grease. If it is gritty, the filter isn't working. It will be gritty with a K&N. There is simply no better filtration media than paper. The very best filters, HEPA filters, used to catch sub-micron particles in nuclear plants and hard disk drives, is simply a very refined paper. If the paper element doesn't flow enough air, install a larger one. The only time I won't use a paper element is when there is a possibility that the filter element can become wet. Then I'll use oiled foam. For REALLY dusty environments such as dirt tracks and off-road racing, I'll do like every other mechanic and use a foam prefilter over a paper element. As far as picking up air under the cowl, you can simply go through the firewall above the partition that separates the cowl space from the interior. I've done that with stock carb setups. Depending on how far the horns of the webers stick out, this may or may not be easy. John |