For those keeping score, the link in the last post is a copy of the Spicer test.
I can. Four times as much dirt as a 99% filter.I can only imagine how much dirt a filter with 96% efficiency is allowing through.
Plus the fact that they work better. Win/win.This is why the manufacturers spec cheap $15 throw-away paper filters and even with those, folks don't change them out.
Did you see where it says, "A filter with a 98% efficiency rating would pass roughly twice as much dust as a filter with a 99% efficiency rating, so what seems like a small difference is actually quite a large one." ?
I can only imagine how much dirt a filter with 96% efficiency is allowing through. Also, with K&N filters, their efficiency is based on the requirement that the filter has been cleaned and oiled as designed which, in my experience, most people don't do. They either bathe the filter in oil or miss a bunch of sections, etc.
Ed
OVERKILL said:Let's look at the dirt passed and time to restriction limit data.
The duration of the test was 60 minutes and during that period, the amount of dirt passed by the Donaldson unit was 0.4g.
The K&N passed 7g of dirt within 24 minutes and hit the restriction limit.
If we break this down to g/minute passed, a simple metric, we can perhaps gather some clearer data comparing the most efficient filter in the test, which also loaded up the slowest, and one of the least efficient.
1. Donaldson PowerCore: 0.0067g/min loading rate
2. K&N oil cotton gauze: 0.2917g/min loading rate
This means the Donaldson is 43.5x more efficient. Ignoring the loading limit, if we just look at the performance within a 6 hour window:
1: Donaldson PowerCore: 2.4g of dirt passed
2. K&N oiled cotton gauze: 105g of dirt passed
That's a HUGE difference.
The Donaldson would have to be run for 262.5hrs; 11 DAYS to pass the same amount of dirt as the K&N, or, looked at from the other direction, the K&N passes in 8.2 minutes what it takes the Donaldson 6 hours to pass.
If max filtering is what you want yes. If you want max flow then no. Simple.Plus the fact that they work better. Win/win.
If max filtering is what you want yes. If you want max flow then no. Simple.
"Max flow" is only really beneficial at WOT with ECU controlled engines ... where racer's gas pedal lives a lot.
Correct - again, some want max flow, some don't care. All good. Funny, go over to enthusiast forums/FB pages and nobody talks about the downsides of K&Ns or other high flow filters (in general of course) b/c it's all about slightly better performance at the expense of slightly less filtering. All what you are after with your vehicle."Max flow" is only really beneficial at WOT with ECU controlled engines ... where racer's gas pedal lives a lot.
Or go crazy and upgrade both!And even then, just upgrade the airbox. I'm quite sure the one for my 6.4L flows more than enough for most FI hot 4-pots, and if not, get one from Hellcat/Trackhawk or diesel.
Or go crazy and upgrade both!
View attachment 26254
The MK7 Golfs have a closed box that gets air from a front duct above the radiator/grill. It's a good system but has been proven to be more restrictive to flow (flow bench testing) than the open style intake I have. The issue is - your vehicle is NA, mine is turbo'd. Sure, that air is a little warmer entering the turbo (again, shown many times in testing on my platform) vs. the stock closed intake but it's leaving the turbo very hot and then being cooled by the intercooler before hitting the throttle body. I am about to have a larger intercooler installed to help out with all of this and performance in general. Folks go on an on about "hot air intakes" but the fact, intake air temp isn't the only factor here and overall flow also is critical especially on modified/tuned turbo cars. The better question is: does the increase in intake air temps outweigh the reduction in flow? Can't know without some dyno pulls and dragy times. I had modified the stock intake by removing the accordion hose and blocking off the pass thru duct on the p. side as well as opened up the d. side for more direct flow to the filter. That had shown appreciable flow increases over stock (again, flow bench tested w/data) but it just won't touch these larger open intakes. Believe me, I've done the homework including some of my own intake temp data logging etc.
Yes, turbo motors aren't as sensitive to intake restrictions but do benefit from opening them up (whether open or close intake) which typically reduces the waste gate duty cycle on the turbo which has been shown in logging on my car/engine many times over. Several aftermarket outfits do offer closed intake systems (same as mine but with an enclosure) so a bit of the best of both worlds I suppose. Your comment regarding flow vs. air temp is correct - but only if the closed system flows the same and in my case , it does not (chart shows the air flow of the stock system at the bottom with the highest performing intake system at the top by MST - a large intake ("cone filter on a stick") with a metal shield at the filter. This argument is a near daily occurrence on other forums/FB pages for the VWs. The logging I did with an under hood temp sensor placed at the filter showed that in highway driving, I am getting effectively ambient air at the filter b/c of the flow through the engine bay. Around town, I get an increase in temps to the turbo over the stock box which clearly does provide insulation against the hot engine bay - makes sense in both counts. I've never seen dyno or 1/4 mile data that supports a significant decrease in power running an open intake. When it's boost season (fall/winter), none of this really matters anyway does it? Finally, don't forget the best thing about open intakes on turbo cars....all that whooshi whooshi pssssh psssh noise! Enjoy your truck, I'll enjoy my wagon.Right, mine feeds a 475HP 6.4L V8 that's naturally aspirated, a turbo motor is much less sensitive to air intake restrictions since it isn't relying on atmosphere, so an airbox similar to mine should be more than sufficient unless you have surpassed my HP level and then there's the 707HP Hellcat/Trackhawk airbox option (assuming they'd fit).
And yes, colder air always makes more power assuming you aren't restricting, so I can't see feeding an engine hot engine bay air, then further heating it in a turbo and then trying to shed some of that heat with an intercooler being better than a setup that flows the same but starts with colder air.