CBE w/no or least drone?

Rockcrawler

Import, not contesting what you looked up and derived from it. My original source is a well known 30 yr Cummins Engineer who was involved in significant heavy equipment testing using historical oil analysis from scheduled PM on a fleet of equipment having run the oem micron spec filters. K&N asked the customer if they could demonstrate a cost savings on the fleet by use of washable filters. They did save considerable money on the filters. but the oil analysis went to **** with substantially more dirt in it drastically changing the oil change interval and erasing any savings.

This is not urban legend, spoke to the horses mouth. It's become well known in the offroad and diesel truck world.

NOW that was ten yrs ago and if K&N was smart they would have altered their product to perform more admirably. Maybe they have. It's simpler for me just to verify oem micron ratings regardless of brand.

all that said, sleds and boats don't even use air filters. Most of us spoiling our cars don't see a lot of dirt roads, but, it used to be relevant..... and me still be relevant for some.... so i shared, eyes wide open. Forgive the hijack.... motor on

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2009 silver sport, 6MT touring and nav, 8700 miles when I got it, "almost" a daily driver now... bone stock aside from tint and Gemini CBE, PC'd Rays black stardust and running 275/295 DWS rubber

Red__Zed

I always laugh when people use that chart as an example of "misleading graphs"

The general assumption with most of these data presentations is you have some understanding how to read scale. They aren't going to show it from the perspective of 0-100 because it would be unreadable.

If you want a "fair" way to look at it, take a look at this:

Your 96.8% efficiency on the K&N maps to just shy of a 3.4 sigma process...you are talking 32,000 defects per million opportunities.

Compare to the AC Delco at 99.93%, and you have a ~4.7 sigma process, a mere 700 defects per million opportunities.

In this case, your "defect" is a piece of crap that shouldn't be there (ie, dust, dirt), and you might be surprised at the high number of "opportunities" that appear over the course of a drive.

You can debate all day whether or not an 45 TIMES the crap getting past the filter is a big deal or not all day (and I won't bother because it isn't worth my time), but trying to downplay the number as "just 3%" is misleading. "Just 3%" was the difference between a Motorola that almost went out of business in the 80's, and the Motorola that was a major player in the 90's. Percentages are inherently misleading when viewed by most people, especially regarding high-capability processes (like filtering). We could, of course, illustrate with DPMO, but I imagine those results would appear even more skewed.

Red__Zed

Double post...

Red__Zed

Hell, no need to imagine. Here you go

ZMan8

nice.
So where does the stock air filter fall in on this chart?

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2010 370Z 40 Anniv., 6 MT | Fast Intentions | Swift Springs | SPC | Z1Motorsports | JWM | Redline Oils | 35% Window Tint
2015 Mazda6 | 370ZChicago: Chicago Area Cars & Coffee

Red__Zed

I unfortunately do not have access to any data surrounding the stock filter

ZMan8

Would my logic be correct in that an air filter that has the lowest DPMO also is more air restrictive (therefore not providing the typical gains seen from dropin filters (k&N filters since they are most common on this forum)

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2010 370Z 40 Anniv., 6 MT | Fast Intentions | Swift Springs | SPC | Z1Motorsports | JWM | Redline Oils | 35% Window Tint
2015 Mazda6 | 370ZChicago: Chicago Area Cars & Coffee

daisuke149

generally. There could be a filter with a very low DPMO but also has a high flow... but then again things like that would probably cost more than people are willing to pay and so no one bothers to make one. Its all possible..

P.S i would assume the stock filter has a low DPMO and also doesn't flow very well... because as much as we want to believe otherwise, Nissan won't put a filter in there that could cause engine damage and thus have them to pay out on a warranty fix. They will be overly cautious to protect their money.

Red__Zed

often but not always

things get even trickier when you start comparing "real world" loaded flow numbers for the filters. That's a topic for someone with more schooling than me.

m4a1mustang

Love it.

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ImportConvert

Well...I ordered the filters, too. I will research it further, but the smooth bellows or whatever are g2g.

richiivu

I have ARK DT-S exhaust, there is practically NO DRONE on highway. It sounds great on WOT, however its pretty quiet, its distinctively louder than stock exhaust, but not a dramatic change. The tone/note has a really nice low grumble/growl.

Romulus1

Yes honestly, are you trying to tell me what I can and cant hear and how to perceive things? I didn't notice much in mine. It IS a subjective issue. I'm not fan boying my set up, i had several and i liked them all but for the price i recommend FI if youre spending 1200 on and exhaust as its a quality product with quality customer service.

People can hear different frequencies of noise that others cant so it would affect some more than others. Which goes with if you cant hear something how do you say it is or isnt there? So I stand by it. You may hear it and it bother you, I do not and it doesnt. Subjective

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chii370

I guess if your hearings been damaged that much then yeah, your right. Generally speaking 99% of humans hear in or around the exact same freq range. Otherwise there wouldnt be a thing called a hearing test, it would give completely inaccurate unacceptable results every single time for each different person. Its subjective to a point of TOLLERANCE is more to the point. How high is your "annoying" level. But common sense comes into play too. We are talking about if you can hear it or not, not if it bothers u. Drone is a physical provable occurance that could be monitored if one so chose. Aka how much NOISE its making in cabin at speed in a constant tone. If you cant hear that...i dont know what to say.

Romulus1

So basically yes, you are telling me what I perceive. I will continue to stick with, with my set up, casual conversation was 100% easy to carry on with who ever was in the car with no yelling over cabin noise or complaints about the "drone" even on 4-6 hour trips. I guess the 1% of the 100's of owners that comprise this exhaust all have severely damaged hearing. Good talk brah


Also note, I never attested to that exhaust by itself. I always point out that mine is paired with art pipes so mine made almost no noticible drone.

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11 SR 370Z Sport 6MT - Sold
03 Escalade AWD - Sold
13 Silverado LTZ Z71 Crew Cab