[edinlr]

The My 2015 issue has a test on page 76 where they compare the Sprint Filter, the MWR, K&N, Pipercross, DNA, & BMC. They tested them on a Superflow flow bench at the University of Wales. There were 3 types, at the top were the single layer polyester like the Sprint. Then the woven cotton filters and the worst were the oiled sponge filters. Hello operator, connect me with Sprint Filter.....stat!

 

[Turtle1000]

I have never used any air filter but stock on my 10+ dirt and street bikes. It use to be so I didn't have to rejet carbs. Not sure what my reasoning is now. Probly cuz I'd rather not trade performance for protection. My filter was reached at 2100 miles. It wasn't TOO bad but was a little buggy... I live in the boonies

 

[selenap]

For me that FAST BIKES air filter test fell short. It does seem to suggest polyester filters flow more and filter better than Gauze and even more so than foam.


BUT, why the heck didn't they test the stock filter and show where it rated in the rankings of all the filters tested?


That to me, not testing and showing how the stock filter ranked next to all the aftermarket filters ruined the entire test.

 

[Ryder]

Agree, testing the stock filter should have been the first thing they did, and then move on to the others.

Having a baseline to go off of for comparison is key. People need to see the value and difference.

 

[selenap]

Check this out. This air filter test that showed how far superior the sprint filter was, has one more interesting twist.


This filter test covered 2 full pages in FAST BIKES magazine, pages 76-77.


I read both pages, sat the magazine down, and when I picked it up again later and turned the page, guess what was on the backside of page 77?


Yep a FULL page advertisement for Sprint Air Filters. Coincidence? I doubt it.


Those sprint filters might be as good as claimed, but as thick as they look I find it hard to believe they flow so much "more" air than either of the 2 brand of 'Race' filters, that are slightly even filters at all.


Lack of posting the Stock filter results and the surprisingly odd Full page Advertisement of the test winning Sprint filter on the very next page makes me doubt the validity of the entire test.

 

[edinlr]

I agree with all of the above comments. I know a couple people in the magazine business and they will do anything possible to sell ads. If a product had good reviews, that is a natural to get someone to advertise with them. If anyone reads Race Engine Technology, whenever there is an engine story, you can count on ads from the camshaft, piston, and valve train suppliers to follow. I have had to deal with air filters for HVAC a lot over the years and they are very similar to our filters. There is a trend to go with these "V" shaped patterns so that instead of a single flat surface, the material is done in V shaped ridges and essentially doubles the filtering space. If there is anyway to increase the filtered area it makes sense that it will allow more air flow. Yes, I would have preferred a test with a comparison of the stock filter, but I am guessing the manufacturers have (hopefully) done their homework and have tested their own product against the stock filter. In reality they have probably tested all of their competitor's products and have tried to improve on them. If not, why go to the expense of developing a product if you will get shot down in tests like this.

 

[GoFaster]

The other thing is that the normal pressure drop across any decent air filter is a tiny change in air density, i.e. a minuscule change in mass air flow. The pressure drop across the filter could have a significant effect on carb jetting but EFI will just see the current air density and compensate. Bottom line is that any decent air filter will make little difference in power but there can sure be a big difference in filtering. There is usually little wrong with staying stock.

 

[selenap]

Found this picture on Sprints website, looks 100% identical to the one in the Fast Bike test. The difference is, on this graph the worst performing filter is actually labeled OEM Stock where on the Fast Bike graph it is labeled as the Pipe Cross filter. The also have some of the other filter names switched around in order of how they finished in the Fast Bike test, even though the graphs are both identical.


hmmmmm

 

[GoFaster]

For comparison in the above chart ... Let's pretend for a moment that the dimensions of that filter ("frontal area") are akin to the H2. We don't have enough information to know if that's the case. If they had presented this chart properly and non-dimensionalized the flow rate (basically, correcting it for the "frontal area" of the filter in order to obtain what is properly called the "filtration velocity") we would have been able to figure this out properly, but in the absence of that ...

The H2 will draw approximately 200 litres per second of air at full load = 424 CFM.

If you cross that over into the chart above to try to back-calculate how much pressure drop there would be across the filter at that flow rate ... it's not even on the bottom of the chart.

2 inches of water gauge pressure across the filter (basically, the bottom of the chart ...) is 0.5% of atmospheric pressure. If you make the presumption that the engine's power output is in proportion to air density (which ought to be roughly true if all else were equal) then this is a rounding error, and the differences in pressure drop between filters become of no significance whatsoever in terms of power output. Too small to be of statistical significance if you did back-to-back testing.

Carbureted engines, where air filter pressure drop can affect the suction on the fuel jets and muck with the air/fuel ratio are another matter, but that's not what we are dealing with here.

 

[edinlr]

I know they speak English in Canada, but GoFaster was way over my head with his answer. I am not nearly smart enough to talk theory, much less in these measurements. I will check to see if the bike runs better with or without an air filter, and then fine tune from there. If there is no difference then on to something else. If there is 5 hp difference, then I have to see if an aftermarket filter can improve on the stocker.

 

[GoFaster]

<- mechanical engineer ...

 

[edinlr]

Well I hope no one (besides me) had their hopes up for a Sprint filter. I just got a message back from the company, "at the moment Sprint Filters do not make or have any plans to make a filter for this bike. Chris Parsons"


So the search continues for the best available filter.

 

[SilverbirdH2]

I went with the DNA...should be here this week.

 

[Sprint Filter]

Hello to all!
On Monday we will have the first sample of our air filters. First sample will be shipped to Brock's Performance to test and then we can start the production!

this is the mold for your Sprint Filer air filter

 

[edinlr]

Welcome aboard Sprint, thanks for listening to us, I cannot wait to try out your product.


As an additional suggestion to our new friends at Sprint, it would be nice if someone there (an engineer perhaps) could shed light on the air requirements for the H2. We have gotten into some pretty heated discussions about the size of the required opening for both the air inlet and the filter size. Some people claim that the H2 can never approach the H2R's performance because of the smaller filter size. Based on industry recommendations for filters, this does make sense. However, both the H2 and the H2R draw their air into the supercharger through a round opening that is approximately square inches. With H2's already making roughly 275 horsepower, how big of a holdup is this?

 

[Brock]

Welcome aboard Sprint, thanks for listening to us, I cannot wait to try out your product.


As an additional suggestion to our new friends at Sprint, it would be nice if someone there (an engineer perhaps) could shed light on the air requirements for the H2. We have gotten into some pretty heated discussions about the size of the required opening for both the air inlet and the filter size. Some people claim that the H2 can never approach the H2R's performance because of the smaller filter size. Based on industry recommendations for filters, this does make sense. However, both the H2 and the H2R draw their air into the supercharger through a round opening that is approximately square inches. With H2's already making roughly 275 horsepower, how big of a holdup is this?

"Some people claim that the H2 can never approach the H2R's performance because of the smaller filter size."

Zack Milholland, bike owner Chad S, myself and the rest of the proud staff of Brock's Performance will gladly dispute this claim

That said, we are happy to be working with Sprint Filter to bring even faster products to H2 owners.

Brock

 

[STRADALE]

I have the DNA installed. I'd be very interested in a back to back Dyno comparison for hp/TQ performance but just as interested in information that focuses on which filter/material is better at filtering fine material.

Some interesting info :
Brocks Performance: Sprint Filter Information Page

 

[edinlr]

"Some people claim that the H2 can never approach the H2R's performance because of the smaller filter size."

Zack Milholland, bike owner Chad S, myself and the rest of the proud staff of Brock's Performance will gladly dispute this claim

That said, we are happy to be working with Sprint Filter to bring even faster products to H2 owners.

Brock

I totally agree, for an undersized intake, Chad's bike did okay!

 

[Sprint Filter]

As told by Brock, yes..... the intake and the air filter is very little, too little...
We think that our new air filter could help more this marvellous bike! We have many different solutions and we will sent next week to Brock's to test some prototypes. Then we will decide together best solutions. We think that Brock's Performance is one of best tuner of the World, so you will have the #bestairfilter , as... usual!

In the meanwhile.... we are working also during this Saturday on your air filter!0000

 

[BobC]

Did the magazine article give any data on the effectiveness of the various filters at stopping the crap getting through?

This is MUCH more important on an H2 because the supercharger impeller is right after the filter. Grit, or anything else, will erode the rotor tips causing very expensive damage.