>>>>>The airbox experiment we will be conducting this Sunday will be on OrdinaryDaves 2001 Scrambler 500 4x4. Both Dave and PADZZ will ride it with each airbox configuration, and I will be changing the airbox configuration between each test without telling them how it is set up each time. When all is said and done they will each rate the airbox configuration test runs from 1 to 4 in both acceleration, and trail ability.<<<<<<


Did you run any of the tests before you swapped out the the standard silencer for the White Brothers Muffler?

 

Very interesting! It reminds me of the time when our family tried to get more performance out of a Honda 450Es by the installation of a Southern aftermarket high performance kit which added another intake hose for the airbox to supplement the increased flow of a K&N airfilter and an aftermarket pipe and muffler.

Guess what? Those engineers at Honda did not leave any free horsepower laying on the table and no increases were to be had.

The air box intake, exhaust system and cam were all perfectly matched and any changes to the intake or exhaust reduced performance and made the engine run lean. If the leanness was removed and optimal temperature operating conditions restored performance again dropped.

The preferred outdoor operating temperature range was so narrow that the machine had to be rejetted like a two stroke for ambient temperature changes. This tuning went on for days and in the end the machine was returned to its stock state of tune which happened to be the best. The extra inlet to the airbox was plugged, waterproofed and
the high performance parts were sold at a flea market.

So it would appear that the airbox on a polaris 500 engine is indeed a tuned portion of the induction system.

I have always been amazed at the fuel economy of my Magnum 500. 25 mpg is no problem under a wide variety of operating conditions. Now I know why, the engine is drawing only enough fuel for the load put upon the engine. With a properly functioning CV carb we can't dump in too much fuel. So what's left? Just the exhaust restriction?

Thank you for the report and the objective research.

I have noticed that documentation for performance claims as of late is sorely lacking by the aftermarket companies such as HPD, Hot Seat, AAEN, Dyno-Jet, White Brothers, Super Trapp etc., etc., etc.

Most reviews are seat of the pants subjective opinions by some obscure writer with a published pen. Extolling the virtues of whatever in visceral terms which you know can be trusted. Right?

I would really like to see more dyno charts and elapsed times over established standardized distances from these so called purveyors of performance.

But... I realize that the Monster Truck Crowd wants pictures of "Big Air" rather than emperical data so .....

 

JUST A THOUGHT BUT HAS ANYBODY TRIED TO HOOK UP A VACUUM GAUGE TO THE AIR BOX TO SEE WHATS GOING ON INSIDE. THAT WAY YOU WOULD KNOW JUST HOW MUCH OF A CHANGE IN VACUUM THERE IS BETWEEN A STOCK AND A MODIFYED AIR BOX.

 

I just did Rick Ritters airbox mod to my 00 Xplorer 400cc,are you guys trying to tell me that it should perform worse than stock,or does this just apply to the 4 strokers?
Bill

 

3TV,
Thanks, it does make sense that the airbox works in restricting the amount of air to move.
My question then is what about the stock airfliter vs the K & N or UNI? Is the airfilters' restrictions taken into this equation?
More tests?
Thanks again for the posting and testing.

weetoots

 

Only 4-strokes Bill. I did that mod to my Scrambler and I could literally "feel" the difference. Before the mod it fealt like my quad was "holding it's breath". With the mod it fealt like one of those Halls commercials...where the airways just start flowing!

Brian

 

Yeah that only effects 4 strokes well just the Scrambler 500 or any other bike that uses a CV card because it is vacum activated I think that is why it needs the restriction for the vacum to help run the carb but if you put a diffrent carb on it might work if it was not for the machanical fuel pump that needs vacum also.
I could be wrong but this is what I think happens

Have a good one

 

3TV
I was a little disapointed and surprised at the outcome of our test sunday.all the work you put into altering those air box lids just to show that the stock one works better than a modified one.I was hoping for a better outcome so as to get better performance.Im bummed.I did enjoy the ride after the test with PADDZ however.That 400ex really scoots,every time we took off 3TV was in front leading and PADDZ was in front of me.Almost every time we came to a stop it was me behind 3TV.Definatly not due to a lack of power on the 400ex,but due to the lack of traction around corners in the new 4-12 inches of snow,it was fun to watch PADDS totally sideways around each turn.For those of you that think you can go anywhere a 4x4 quad can go if you just keep your speed up just ask PADDZ.THANKS FOR THE SHOW PADDZ. And yes my 500 scrambler got smoked on the flat by the 400ex in 4 inches of snow with the ex violently swapping from one sid to the other.But when the snow got deeper to about 1 foot on the trail the 400ex was done and the 500 went around off the trail in 18 inches to 2 feet.MORAL OF THE STORY EVERY QUAD HAS ITS PURPOSE.Thanks for the fun day PADDZ & 3TV

 

Hey, that was fun. Snow may not be the best enviroment for the 400EX but I thought I hung in there pretty good. If my tires had a bit more bite I think I would of done better. Atleast when I did that 180 I didn't take out one of those cows in the process. Then again I did work up quite an appetite. 3TV...I'll bring my K&N next time just to see how you like it. That was alot of fun and I was impressed with the power of the Scrambler; can't go wrong with the reverse and 4X4. Has just a tad bit more than my 335 (yeah, right). Just keep me in mind when you're doing thses blind tests...or rides or anything for that matter. Had alot of fun.

 

One last thing....I was somewhat suprised that the stock quad had as much, if not more power than the one with the WB slip on. The WB does look a lot better though...and sounds better of course. Maybe go up another size on the main?? Now that you have all the jewlers tools the switch should be simple .