Author Topic: TUNING Airfilters/Airboxes/Panel Filters.. The Defining Thread...  (Read 39549 times)

Offline bored_Welsh_lad

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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.[;)][/QUOTE]


For a more updated version check out this thread..

Clicky
« Last Edit: 07 February 2012, 20:28 by boneybradley »
Mk3 Golf Gti:Full Milltek system and Decat,K&N filter,mk2 Cam,-1.5 degree camber shims, borbet a's, toyo proxies,hot tuning coils, brembo vented discs, greenstuff pads...Soon to have Eaton Power

mk3 16v 5dr Gti,mintex extreme pads,drilled/grooved discs,lowered,cat back powerflow system,omp panel filter with modified airbox,debadged grill, started prep for spraying, lots to come :D

Bumper Vents :D

Offline hyland770

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Re: Airfilters/Airboxes/Panel Filters.. The Defining Thread...
« Reply #1 on: 13 September 2009, 10:27 »
you bastard, why couldnt you have done this 48hours ago before i did my induction kit!!!!  :grin: class write up though fella!

Offline bored_Welsh_lad

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Re: Airfilters/Airboxes/Panel Filters.. The Defining Thread...
« Reply #2 on: 13 September 2009, 10:48 »
you fatherless son, why couldnt you have done this 48hours ago before i did my induction kit!!!!  :grin: class write up though fella!

I cannot take the benefits for the results here..they were produced by Toyotec.. i also told you a panel filter is better than an "induction cone" before you bought 1 lol..
Mk3 Golf Gti:Full Milltek system and Decat,K&N filter,mk2 Cam,-1.5 degree camber shims, borbet a's, toyo proxies,hot tuning coils, brembo vented discs, greenstuff pads...Soon to have Eaton Power

mk3 16v 5dr Gti,mintex extreme pads,drilled/grooved discs,lowered,cat back powerflow system,omp panel filter with modified airbox,debadged grill, started prep for spraying, lots to come :D

Bumper Vents :D

Offline Khare

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Re: Airfilters/Airboxes/Panel Filters.. The Defining Thread...
« Reply #3 on: 13 September 2009, 11:26 »
So modified box and paper filter better? Something went wrong.

I still reckon foam filters are better than paper filters, bear in mind foam filters need 500 miles to be "run in" for them to be fully effective as they have a heavy layer of oil to start off with.

V. good write up though dude :afro:

Offline bored_Welsh_lad

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Re: Airfilters/Airboxes/Panel Filters.. The Defining Thread...
« Reply #4 on: 13 September 2009, 12:21 »
So modified box and paper filter better? Something went wrong.

I still reckon foam filters are better than paper filters, bear in mind foam filters need 500 miles to be "run in" for them to be fully effective as they have a heavy layer of oil to start off with.

V. good write up though dude :afro:

I didnt do the write up, i have copied it because i know people would rather see it here than click the link..

He says in the thread that the standard filter was brand new and thats where theres issues as it flows so well when brand new.. whereas after 10k the filter is shagged...

Mk3 Golf Gti:Full Milltek system and Decat,K&N filter,mk2 Cam,-1.5 degree camber shims, borbet a's, toyo proxies,hot tuning coils, brembo vented discs, greenstuff pads...Soon to have Eaton Power

mk3 16v 5dr Gti,mintex extreme pads,drilled/grooved discs,lowered,cat back powerflow system,omp panel filter with modified airbox,debadged grill, started prep for spraying, lots to come :D

Bumper Vents :D

VW BUSH

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Re: Airfilters/Airboxes/Panel Filters.. The Defining Thread...
« Reply #5 on: 13 September 2009, 12:29 »
Fcuking excellent, Shove an 8v on there and soon will be able to close this debate forever :grin:

Offline justalex81

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Re: Airfilters/Airboxes/Panel Filters.. The Defining Thread...
« Reply #6 on: 13 September 2009, 13:32 »
so if i have this right if i modify the air box in the same way done in the tests, and then add a K & N filter will i get even more bhp and torque than any of the test set-up's ?

and would that improve further if i run a cold air intake into the original box?

Offline bored_Welsh_lad

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Re: Airfilters/Airboxes/Panel Filters.. The Defining Thread...
« Reply #7 on: 13 September 2009, 13:38 »
I would expect a cold air feed to be of benefit.. long term a K&N is better than  a paper filter, although the results dont show this well as the paper filter was brand new..

If you want advice on this i would go to the link at the bottom of the initial post i made..
Mk3 Golf Gti:Full Milltek system and Decat,K&N filter,mk2 Cam,-1.5 degree camber shims, borbet a's, toyo proxies,hot tuning coils, brembo vented discs, greenstuff pads...Soon to have Eaton Power

mk3 16v 5dr Gti,mintex extreme pads,drilled/grooved discs,lowered,cat back powerflow system,omp panel filter with modified airbox,debadged grill, started prep for spraying, lots to come :D

Bumper Vents :D

Offline Shady Pioneer

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Re: Airfilters/Airboxes/Panel Filters.. The Defining Thread...
« Reply #8 on: 13 September 2009, 17:23 »
Great write up chap, it can stay stickied for some time and when I get a chance I'll add it to a Bible somewhere in the maintenance section :)

Offline Ess_Three

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Re: Airfilters/Airboxes/Panel Filters.. The Defining Thread...
« Reply #9 on: 16 September 2009, 07:19 »
So modified box and paper filter better? Something went wrong.

I still reckon foam filters are better than paper filters, bear in mind foam filters need 500 miles to be "run in" for them to be fully effective as they have a heavy layer of oil to start off with.

V. good write up though dude :afro:

Foam filter where?
In the airbox or as a cone?

Funny that toyotecs results line up with what I've found over the years.

Sadly, the amount people have their wallet lightened by in buying their noisy, bling induction kit is proportional to the placebo effect of the benefit they think it gives.
Sadly, the Dyno, and physics, suggests otherwise.

The only other test I'd have liked to see would have been a foam/K&N panel filter tested in the best airbox set-up, back to back with a cone filter.

Reducing my Golf count by the week....
..but gaining motorcycles.