High Performance Air Filter

[CAR4TWO]

At my first inspection of the engine air filter today, I found it to be made of paper. I was hoping to find it made of cotton at least but it isn't. Looking online, I found no one makes a high performance replacement yet . When they do, I'll buy one.

[HTMLSpinnr]

This car doesn't breathe that much in comparison to high performance cars. Unless you're running WOT, I doubt you'd see much difference.

[CAR4TWO]

If it were cotton, I would not bother with it. Paper on the other hand can be very restrictive. K&N Air Filters can be cleaned and reused so they can last a very long time. I have always noticed a difference in performance with K&N Air Filters.

[jestoy7]

Measure your air filter and see if the dimensions compare to the Gen II or another Toyota. You could be the first with a K&N on your Gen III.

[wave_slider]

Originally Posted by CAR4TWO

At my first inspection of the engine air filter today, I found it to be made of paper. I was hoping to find it made of cotton at least but it isn't. Looking online, I found no one makes a high performance replacement yet . When they do, I'll buy one.

I would like to purchase one eventually. I haven't checked yet, but normally you change out the air cleaner filter at 30k or 2 years. Amsoil has IMO a better air cleaner filter than K&N. Instead of cleaning, drying, and re-oiling the filter, you just use a vacuum to clean it. Much easier and re-usable like the K&N. Amsoil makes quality products.

[F8L]

Originally Posted by CAR4TWO

If it were cotton, I would not bother with it. Paper on the other hand can be very restrictive. K&N Air Filters can be cleaned and reused so they can last a very long time. I have always noticed a difference in performance with K&N Air Filters.

The difference in HP between a new standard filter vs. a K&N is rarely measurable let alone noticable with the "seat of pants" meter. Most people suffer from the placebo effect when it comes to minor "performance" parts. I've spent a lot of time on a dyno and the numbers don't lie. 5HP is very rarely noticable and that is about all you ever get from a filter swap unless your original filter was filthy and highly restrictive, in which case, any new filter would have provided a boost in performance. Even on high performance cars like the 98-2002 Camaro LS1 (280-310rwhp stock) you would only see about a 5-13rwhp difference with a swap to a K&N AND intake system. The K&N alone was worth very little.

From a money savings standpoint the K&N makes sense, especially if you are buying full price Toyota filters but from a performance standpoint with regards to the Prius I would wager $100 you cannot feel a HP difference between a quality filter and a K&N.

[David Beale]

Be aware there is some controversy re the effectiveness of K&N and other cloth filters. Some have tested them and found they pass fine dust, particularly in industrial applications. I've used them in the past (but so far not in Pearl) and didn't notice anything getting past but my tests wouldn't be hard to pass (paved road driving most of the time).

While a little more restrictive, a paper filter does work very well. They just put more filter area in to keep the restriction under control.

As already posted, Prius engine rarely runs at full RPM, usually cruising along below 2K RPM (by design). This requires very low volumes of air. Note also that the max. RPM the engine will see is also not high (5000 for the GII) so air volume requirements may not be that great.

[stream]

Originally Posted by F8L

The difference in HP between a new standard filter vs. a K&N is rarely measurable let alone noticable with the "seat of pants" meter. Most people suffer from the placebo effect when it comes to minor "performance" parts.

from a performance standpoint with regards to the Prius I would wager $100 you cannot feel a HP difference between a quality filter and a K&N.

Agreed.

[jestoy7]

I am going to buy a K&N for my Prius not because of the increase in power or mpg (because we all know it will be negligible) but because it can be reused.

On my turbo Eclipse however, the K&N did help a lot but that is because I run twice the amount of air that a naturally aspirate engine does.

Can someone confirm the size of the Gen III?

[PriusLewis]

Originally Posted by F8L

I've spent a lot of time on a dyno and the numbers don't lie.

Same here. However, I find I keep falling off the rollers. How do you manage to stay upright when you're running on those things? I bet one of those loggers who roll logs in the water would produce good numbers. At least they could stay on the roller. If you use a 4WD dyno, do you use your feet on one roller and your hands on the other? lI'd fall flat on my big belly if I tried that! Do performance shoes increase the dyno numbers? Which shoe do you find to provide the best traction on the rollers? Do you just attach the safety chains to your belt, or do you have a harness? Do you monitor RPM (Running-shoe-hits Per Minute) and speed to calculate HP (Human Power)? Do you calculate speed in feet per second? I only have 2 feet - more feet might be an advantage. Hmmm, now I'm hungry for a foot-long hot dog. I think I'll run off to lunch.