Product Review: K&N Drop in air filter

[Big Z]

Vehicle: Suzuki Swift Sport
Year: 2009
Mileage: 24k km
Product: K&N Panel Air Filter
Website: http://www.knfilters.com/
Purchased From: Quickbits by Andy Clarke, Curepe.
Reviewer Bias: None
Perceived Reviewer Bias: None

Sample Image from K&N website



Impressions:

Engine was definitely quieter, and more willing to rev.
Acceleration in the upper revs was better. No discernible change in lower rpm torque.
Definite increase in power.
I have had similar results in a 2007 Toyota Corolla.
Granted, the comparison is an old OEM filter to a new K&N, I have never noticed an improvement like this in other vehicles with just an air filter change, using paper filters only.


Verdict: Highly recommended. Definitely worth more than the investment.

Note: I have been informed by a local dyno operator that the K&N filter is good for up to 3 whp on the SSS. My quick eval seems to corroborate this.

[Parvin]

I've heard that the cleaning kit residue/oil will somehow cause problems with the relevant sensors in that area ... I believe the Airflow sensor ?

[wagonrunner]

^
through over-application.

a light spray, and should be completely dry before use. if it stains your fingers, it will do the same to the sensor

[Big Z]

Its very common for end users to over oil their filters when servicing.
The procedure and amount of oil needed is well documented by K&N.
This is generally the cause of most issues.

[Parvin]

So just like medicine ... follow the prescription.

Scene

[bushwakka]

placebo effect ftw

[thegtiman]

Vehicle: Suzuki Swift Sport
Year: 2009
Mileage: 24k km
Product: K&N Panel Air Filter
Website: http://www.knfilters.com/
Purchased From: Quickbits by Andy Clarke, Curepe.
Reviewer Bias: None
Perceived Reviewer Bias: None

Sample Image from K&N website



Impressions:

Engine was definitely quieter, and more willing to rev.
Acceleration in the upper revs was better. No discernible change in lower rpm torque.
Definite increase in power.
I have had similar results in a 2007 Toyota Corolla.
Granted, the comparison is an old OEM filter to a new K&N, I have never noticed an improvement like this in other vehicles with just an air filter change, using paper filters only.


Verdict: Highly recommended. Definitely worth more than the investment.

Note: I have been informed by a local dyno operator that the K&N filter is good for up to 3 whp on the SSS. My quick eval seems to corroborate this.

I conducted a controlled dyno test for airboxes modified and unmodified for:
K and N Panel filter
New OEM filter element
No filter element

There was naff all improvment between the 3 conditions.

The benefit of such a filter is consistant filteration over a much longer time that an OE filter element. And when it gets dirty, just wash and reoil, Job done.

[bushwakka]

^well said......i can't believe u waste money on debunking that tho....i call a bluff lol

[Big Z]

Note: I have been informed by a local dyno operator that the K&N filter is good for up to 3 whp on the SSS. My quick eval seems to corroborate this.

I conducted a controlled dyno test for airboxes modified and unmodified for:
K and N Panel filter
New OEM filter element
No filter element

There was naff all improvment between the 3 conditions.

Conflict!!!! Which one is righter? lol.

[bushwakka]

^the latter.....local dyno operators dunno wtf they talkin abt

[Big Z]

But I felt and heard the difference in the two vehicles that I have equipped with K&N panel filters...

[bushwakka]

^doing 2 runs (one run for the K&N filter and one for the stock) cannot be held as proof of anything

i have done dyno runs with the exact same setup, nothing changed, and the dyno figures were all different....i wud say the spread was 8-9 hp and the same in torque......

thus, it is very difficult if not impossible to measure 3 hp difference on dynos like we have here.....
it wud need to be done in a lab

[belalegosi]

thus, it is very difficult if not impossible to measure 3 hp difference on dynos like we have here.....
it wud need to be done in a lab

beat me to it.
It would be difficult to measure 3whp on any car dyno really.

2nd the need for an engine dyno to debunk this myth.

washable filters ftw though

But I felt and heard the difference in the two vehicles that I have equipped with K&N panel filters...

you felt and heard what you needed to justify your product

[Big Z]

you felt and heard what you needed to justify your product

Strange... I don't sell K&N filters!!

[Alpha_2nr]

thus, it is very difficult if not impossible to measure 3 hp difference on dynos like we have here.....
it wud need to be done in a lab

beat me to it.
It would be difficult to measure 3whp on any car dyno really.

2nd the need for an engine dyno to debunk this myth.

washable filters ftw though

Indeed. I was under the impression that the "repeatability" error between successive runs for most dynos could be as much as 3-5 whp?

Also, I used the same filter on a Swift Sport, and noticed zero difference IMHO....but...I have no figures to back that up <shrug>.....so I can't categorically say I'm right.

Benefit to me would have been the fact that the K&N was re-usable.

[bushwakka]

^yea, initially i was hoping for a gain of some sort.....but i have contented myself with the fact that its a good purchase based solely on its re-usability

IMO.....that should be the only selling point of this product....

[Chemical]

Waste of time IMHO..was throwing oil onto the MAF on my wife's corolla. K&N denies ANY form of this happening to the MAF. Flowing more air means bigger dust particles entering the engine.

[bushwakka]

^^higher airflow does not mean that....

did u use the specified amt of oil on ur filter? i always use no more than the specified amount....i have taken out my MAF and looked at it....have not noticed any oil film on it

[thegtiman]

thus, it is very difficult if not impossible to measure 3 hp difference on dynos like we have here.....
it wud need to be done in a lab

beat me to it.
It would be difficult to measure 3whp on any car dyno really.

2nd the need for an engine dyno to debunk this myth.

washable filters ftw though

Indeed. I was under the impression that the "repeatability" error between successive runs for most dynos could be as much as 3-5 whp?

Also, I used the same filter on a Swift Sport, and noticed zero difference IMHO....but...I have no figures to back that up <shrug>.....so I can't categorically say I'm right.

Benefit to me would have been the fact that the K&N was re-usable.

2-3bhp is what professionals would call "noise". Further 2-3bhp@ what rpm. The vehicle accelerates due to torque. BHP numbers good for bench racers.
I did 60 tests on a proper Dyno Dynamics 450DS with OEM control standards to ensure repeatabilty. In the end the factory airbox was made to perform as good as a cone unit and with new OE paper element, without and with K and N panel.
Vehicle was driven to the dyno with OE panel filter and modified air box and then back to the owner with the washable filter in modified airbox. I could detect no diffference.
If you service your vehicle at recommended intervals then a washable filter is a good investment. But for power and torque...do not believe the hype.

[A172]

wtf is 2010 and men still talking bout "power and acceleration gains" with drop-in filter LMAO

[Big Z]

Removed.

[thegtiman]

Original sticky post from ClubGTi.com where I am known as "Toyotec".
Title- How to make your Golf MK3 16v breathe on a budget.
Day one testing 25 runs back to back.

Testing using VW Golf Mk3 16v.

So you have bought a MK3 16v in stdish form and you are eager to experience "the fury". Before going out on that loud pedal you start to read the threads on ClubGTi. Then the question comes...What filter is the best?
Well yours truly decided to find out and to do that, it was essential to team up with the good guys at Streamline Garage, in London, to use their newly installed 2400BHP AWD Dyno Dynamics rollers
to validate the typical air induction combination you would find on a MK3 today.

These methods can be applied to most airboxes found on other engine types.

First of all I would like to thank eatonMK2, VWsingh and cs98sss4 for the use of the specimen/victims in this study and of course Theo@Streamline for letting me loose on his dyno to perform the 25 tests back to back

Now let the testing begin!


The vehicle used in in this test is a 95 plate MK3 16v called N7NDO. It has a STD ABF engine with 113K miles. The only small mods are, ported throttle and matched inlet system.


The filter configurations that where tested were;
Open throttle-body ( thanks to the factory speed density digi 3.x system)
Std VW airbox w/OE filter
Std VW airbox w/K&N panel
Piper pod filter
Modified VW airbox top half, STD bottom half
Modified VW airbox complete.





Each configuration was tested at least 2 times.
The ambient air temp was 19 deg C.
25 tests were run.

After safely strapping down the vehicle on the rolls, the air ducting and and filter box were removed and the first power run was conducted.


The throttle duct and the STD top half of the air box were installed and placed in line of the dyno fan.


With the STD top half already in place, the standard panel filter was then compared to a K&N filter in the STD bottom half. A genuine VAG filter was used.

This was later removed and a Piper cross pod filter was installed and then tested.


Lastly a modified airbox, which had the OE tapered velocity stack modified and in its place a larger diameter and more bell mouthed unit, was tested with the standard bottom half and then a modified bottom half.


Not one to focus on just peak power points we shall study what happened to the torque as ultimately this would affect peak bhp points if one follows the mathematical formula BHP=TQ*RPM/5252. I will state the peak power developed in concluding.

Looking at the plots for 4 conditions,
Open throttle - FlyBHP/TQ, AFR 1
STD airbox - FlyBHP/TQ, AFR 6
Pipercross Pod - FlyBHP/TQ, AFR 12
Complete modified airbox - FlyBHP/TQ, AFR 25



We can see that;

The torque deltas between tests is clearly evident post 4500rpm

The engine's PCM fuel calibration remains into closed loop control up to 4000rpm

Latter part of engine speed range the fuel mixture seems to be between open loop lambda and component protection lambda, this difference in AFR is correlated to torque development in tests

• There are torque improvements when running the pod filter over the std airbox, but this may not be real world as the pod filter was inline of the dyno fan. In real service the engine bay heat would be conducted by the alloy silver surface of the filter, heat up the air-charge thus reducing torque. This combination also resulted in torque hanging on for longer in the engine speed range. The shorter induction length may have contributed to this effect.

• The engine performed poorly when the throttle was open with any ducting. This may have been influenced by the hot air generated by the exhaust manifold just under the throttle.

• There was no improvement when the VAG panel filter was swapped with the K&N unit, but airflow through the OE item would deteriorate after 10000miles. There was no improvement without a filter in the box.
• The torque generation of the Pod filter was matched when the modified top half was attached to the STD bottom half

The best torque spread occurred when the complete modified airbox was installed

Test 1, open throttle body, resulted in the in the worse torque curve and had peak bhp measurement of 142bhp@6200rpm

Test 6, STD airbox, had improved torque range and resulted in 145bhp@6100rpm

Test 12, Pipercross Pod filter, improved the torque range further and resulted in a peak of 148.5bhp@6500rpm

My choice, Test 25, Modified air box and OE filter, improved torque even further than any of the other combinations and resulted in a peak power measurement of 151.2BHP@6200rpm


I have always been a believer of this type of modification and this is evident of what you will find on The WOLF R, the 3A 8v MK2 on MS and my 98 VR6. Goes to show that you do not have to spend loads of money on a shiny new induction kit if you apply some thought and modify the existing factory unit. The above modification only about 10 pounds was spent, vs 60-70 pounds on an induction kit. It makes a similar but refined sound as an open pod filter.
Hope this 10 pound modification inspires some to think next time you are about to shell out that hard earned.

Next steps,

• With the best air induction system now fitted, steps are on the way to optimize the ECU calibration.

• First a typical chip will be fitted to study the effect of how these items actually fuel these engines and how this correlates to the torque generation.

• As I am not a fan of desktop calibrations, the vehicle will be recalibrated on both fuel and spark over the entire speed load range.

Keep watching this space.

[Big Z]

^^^^^ Great article!! ^^^^^

[thegtiman]

No problem, glad to be of help.

[Alpha_2nr]

Excellent article thegtiman, and a good way to bring sound technical data to the table.

[~Vēġó~]

well done!!!

[thegtiman]

I should add, that in Trinidad, aftermarket std parts tend to be fitted to used vehicles due to the reduced cost. Some of these parts have reduced quality too and air filters fall into the catagory. OEs spend significant time researching the best trade off between filteration and pumping loss over time and today their filters, when new are as good as your best performance filter. I have tested this on several occasions and have found this to be the case.
Besides dyno test to test noise, if a a dirty pattern part was replaced with a K and N panel and an improvement could be felt when driving, then the same improvement would have been felt if the dirty pattern part was replaced with a new OEM paper element.
In general, filter elements from Greenstuff, Pipercross, BMC, HKS, K and N and so on do offer better filteration efficiency over time vs std OE filters, but in my experience, if your airbox is designed to reduce drive by noise, thus containing restrictors, then sort that out and your pumping loss will be reduced and the engine will breathe better, resulting in increased torque and better drive feel.
To validate this "improvment" then dyno testing, with a good operator, will be required and the test conditions controlled to reduce experiement noise. The test can commence and the myths can be busted.
I assure you on a 1000kg vehicle if there was a say a delta 9lbft increase in torque somewhere in the rev range, due to serivce, this would be felt through the gears at the rpm points where this is happening. But you would be very hard pressed to feel delta 1lbft@XXXXrpm range, which would occur naturally from one WOT or part load condition to the other.

Regards
Bitte haben eine guten Tag...

thegtiman.

[bushwakka]

^epic posting man, great way to lay things on the table

[Chemical]

thegtiman ... I feel you can talk to me whole day & night & I won't get bored to death.

BTW which country are you living in ?

[wagonrunner]

before the edit.

The vehicle used in in this test is a 95 plate MK3 16v called N7NDO. It has a STD ABF engine

i now understand the copy / pastes. no comprehension required.

DODGE