Hi Guys

I read this entire post and I just had to respond.

Been tuning 4 pots for 10 years in South Africa and this is my first Merc, wouldnt you know it? A 2001 C320 Auto. Couldnt afford a C32 at the time, but now with prices dropping in the same regions as the C320, it will DEFINITELY be my next car.

Getting back to the K&N vs OEM topic: like I said, I've tinkered with almost every car I've owned. The first mod I undertake is the exhuast and filter.

I read the entire article posted by the carcounsil: which also seems to be a bunch of tuners experimenting with filters on otherwise stock cars.

I would like to refer you to an old K&N supplement - I dont know if this ad was posted in the US but it was in all the South African Auto shops. When K&N first launched their product, a few select centres where the only place you could find the stuff, I'm talking early 90s here and one of the notes on the inside of the pack (printed by the "preferred" distribution channel) stated as follows: "Please ensure to adjust the vehicle's air/fuel ratio for optimum results"

Common sense prevails here - you see, with more air, you can add some more fuel to gain the exta HP. I'll try to explain this as simple as possible without going into the finer details so just bear with me, I'm going somewhere with this. I've personally done this test, I have an N6 qualification in Mechanical Engineering and this is how it went:

Stock Opel 200i 16V which here in SA is a zippy little FWD hatch (Vauxhall in the UK and I think Holden in Aussie)

First dyno run, air-temperature 23*C and engine temperature 86*C. Power at the wheels, 98kW and 186Nm torque.

Then removed airfilter and fit K&N replacement filter (pre-oiled) straight out the box.

2nd Run - air temperature still 23*C and I allowed time for the engine to cool and then idled it until exactly 86*C.
Power at the wheels, 99kW and 188Nm torque.

3rd Run, same temperature ranges but this time set the CO's 0.5% higher. Power now at 102kW and 193Nm torque at the wheels.

Total gain - 4kW and 7Nm torque.

I seen some rookies do the same thing, at another tuners dyno bay - I just watched in disbelief.

They where busy tuning an Alfa and ran the car on the dyno to get the benchmark power outputs. They quickly removed the stock filter, then without allowing the engine to cool down to the same temperature - ran the car for second time, this time with a performance filter. These 2 characters where quite a work of art. They looked at each other in disbelief and quickly removed the filters and returned them to the customer, explaining that the filters was "not well suited" to his particular car.

Did you know that when an engine is running, the water pump is turning, the fan is running and the engine cools down quicker?
After a dyno run, when you swicth off the engine, the heat is trapped and more heat builds up - thats why you have the most pressure in a system just after you cut the engine.

So the test of a true performer should be to insert your own exhuast probe, monitor engine and air temperature and test in exactly the same environments for a truely accurate measure of power. The customer cant feel this difference but it is there, rolling road doesnt lie.

So it the spirit of science, I've found that performance filters are only effective if you recalibrate the fuelling to accomodate the increased airflow.

Hope this all makes sense to you guys. Out of interests sake, I found that the K&N's work extremely well on 4 pots but the BMC offer a tad bit more on the large 6, 8 and 12 cylinder engines. I would also like to believe that each car is unique and each customer has certain requirements (One wants power, the other torque and you man in the street wants the in-betweener)

I'd rate K&N as a fairly competent replacement filter and once recalibrated, you will definitely realise a gain in the HP and torque departments over the stock paper elements.

I hope this is of some help to you.

 

OBDI and OBDII cars will adjust the fuel/air mix automatically. I agree, though. An adjustment is necessary to take full advantage of the extra air volume.

What's a "4 pots?"

 

Four Cylinders.

 

Oh. A four-banger.

 

You're right Lug, ODB cars do adjust the air/fuel mixture automatically for optimal efficieny, but they reference a data figure on the ECU as with anything.

I'm not talking abt essentially changing the air/fuel ratio here, I'm talking abt adding fuel under full load conditions. When you accelerate flat, the sport filter allows you to add more fuel and the system will automatically calculate the most desirable mixture to saefguard the engine and maintain good fuel economy.

I can see how that could have come out wrong, sincere apologies.

ciao

 

Hey guys, thanks so much for creating this thread!!!

I actually own a 01 C320 and was gonna change my air filter today! Very insightful discussion aside from some minor bickering

 

Sounds crazy, but i was watchin my gas mileage while driving w/ the old filters andi was averaging around 24.2 ish w/ my car. My car, 01 c320 sports, is listed to drive at 19 mpg in the city and 25 mpg on the highway. After I put in the new air filters i have been averaging around 25.4. Most my driving comes on the highway, but my avg speed (with city driving and what nots) is around 50 mph. I put in K&N air filters. The car sounds better and give me better gas mileage. I cant complain

 

The bickering comes with the forum we do it all the time.

 

It's interesting that I've happened upon these posts, but particularly your post. I have as recently as one month ago replaced my paper filters with K&N Filters. I have not noticed any huge boost in performance nor have I noticed any loss in performance because of them. Though I don't know "jack" about the efficiencies or deficiencies of either (paper or cloth), I have learned that they are washable. Perhaps, if we follow instructions we may not have problems, opposed to becoming chemists and engineers when we don't have license.

It is my hope that I don't incur any problems because of them, however, I do intend to economize because of them.

 

Hi Guys,

Happy summer time to you all..

FYI, I'm still running K&N's on my 2001 C320 since I first started this thread - and I'm pleased overall with the K&N's installed.

Plus points, slightly more meaty exhaust note (not annoying jap noise) -- Depth like Aston-Martin engines.

More torgue, I live in a city that has hills that compare to ROME and SAN-FRANCISCO and you DO notice the difference.[sm=gears.gif][sm=yeahsmile.gif]

If driven sensibly, on average - Better MPGs, better on the wallet!!

Finally - Lower maintenance costs as MB Stealership not "Pretending" to replace at the service intervals.

HAPPY DAYS

2001 w203 C320 - Elegance - Brilliant Silver - Black Leather - Premium MB Wheels - OEM Xenon HID - 2 x K&N Panel Filters


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