Restrictive Air Filter Assemblies

[Oversize]

Anyone else think about the fact that a good portion of the K Jet air cleaners are completely ineffective? That can't be good for airflow or power....

 

[Andrew280SEL]

I'm not technically knowledgeable enough on the matter to say either way, but I have considered going the K&N aftermarket route in the past. Supposed to be better.

 

[sean sherry]

I would think that an Air Cleaner plonked on top of an engine and drawing hot Air from high up in the Engine compartment can't be very efficient irrespective of the type of filter element.
On the 107 SLs fitted with a 110 DOHC Six Mercedes located the Air Cleaner low down to the side of the Radiator to avoid this issue.
My understanding is that for every 2% rise in ambient Temperature , an Engine losses 1 H.P.
Jaguar did the same thing with their E Types with the Air cleaner on the side of the Engine drawing cool Air.
Both our modern cars a C Class and a Mk V11 Golf have cold air intakes , std.

 

[CraigS]

It is interesting with my Ranchero. It was a California car, and as such, they have stricter emission standards than the rest of America. On all other US State versions, the air cleaner ends at the snorkel in much the same way as the 450SEL does, drawing warm/hot air from the engine bay. My California version Ranchero however continues the snorkel through a concertina hose to a plastic duct that draws cold air from the front of the car beside the inner guard.

 

[BenzBoy]

I would think that an Air Cleaner plonked on top of an engine and drawing hot Air from high up in the Engine compartment can't be very efficient irrespective of the type of filter element.
On the 107 SLs fitted with a 110 DOHC Six Mercedes located the Air Cleaner low down to the side of the Radiator to avoid this issue.
My understanding is that for every 2% rise in ambient Temperature , an Engine losses 1 H.P.
Jaguar did the same thing with their E Types with the Air cleaner on the side of the Engine drawing cool Air.
Both our modern cars a C Class and a Mk V11 Golf have cold air intakes , std.

In that case why don't manufacturers draw in cold air from the air-conditioning unit? They already use the air-conditioning to cool fuel lines in some models ......
Maybe it's not necessary but it's a question to ask.
Regards,
Brian

 

[sean sherry]

Question ,Brian.

what happens to the room temperature when the Fridge and Freezer Doors are left open ?

 

[abl567]

Nothing Sean, because the evap coil and condensor coil are then in the same space so heat transfer just goes round and round in circles, if an evap coil was placed inside an air intake duct it would indeed cool the air charge. I vaguely recall a set up in some car that cools the fuel supply when the air is on to prevent vapour lock and subsequent hard/no starting

Edit: Just read Brian's post and note he mentioned the fuel cooling

 

[Michel]

Obviously Mercedes-Benz woke up to the fact with the W126 series (V8) drawing air from the front of the car.

Here are some pics.

The ideal would be to have air ducting from the lower end of the grille.

 

[Andrew280SEL]

I believe Oscar once did a custom cold air induction setup on his 350SE, years back.

He reckoned he could feel the difference in response and performance. Obviously you won't be gaining a heap of horses for free, but if there's any improvement to be had and you don't mind a bit of fiddling/custom setups, it can't hurt.

 

[BenzBoy]

Question ,Brian.

what happens to the room temperature when the Fridge and Freezer Doors are left open ?

In my house nothing happens as everything is climate controlled - and very precisely at that.

The ML cools the fuel lines as do a number of Jaguars. I imagine cooling the air could be done quite simply by bleeding some of the air from the HVAC box through to the air intake. That it is not done seems to indicate that the gains might be too small to be of consequence.
The Spirit draws the air from inside the front wheel arch but I have had to put in an extra filter to stop dog hair clogging the paper element.....relevant during moulting season.
Regards,
Brian

 

[abl567]

Obviously Mercedes-Benz woke up to the fact with the W126 series (V8) drawing air from the front of the car.

Here are some pics.

The ideal would be to have air ducting from the lower end of the grille.

They knew long before the W126, all W108/109 cars have a cold air intake, from the lower part of the grille on the right side in front of the radiator.
This and the factory air filter/intake system has been proven to be superior to aftermarket K & N filters/pods by a past member of the M-100 group on the drag strip, with back to back runs. The factory set up was quicker and faster in the same atmospheric conditions every time

 

[sean sherry]

Yes, K & N are only in the business of selling Filters. Full stop. I would back the Mercedes Engineers any day. They could have just as easily designed a simular Filter to K & N. Now I wonder why they did not.

 

[sean sherry]

Ah yes , the heat transfer does go round and round but add in the heat generated by the electric motor and the room heats up ... No ?

 

[abl567]

Ah yes , the heat transfer does go round and round but add in the heat generated by the electric motor and the room heats up ... No ?

Spot on Sean, energy cannot be created or destroyed, only converted from one form to another

 

[abl567]

And while I have my pendant hat on, the passage of air through a air filter is only ineffective if it does not clean the air, i believe the question is about efficiency, which, given the external static pressure of a adequately designed automotive air intake system relative to the work done by a healthy air pump (engine) at 18" of vacuum, is insignificant.
Aftermarket air cleaners such as K & N pod filters are all about increased induction noise giving the impression of increased performance

 

[Andrew280SEL]

Interesting about the K&N filters vs stock. Probably not a bad thing, as an aftermarket unit might look a bit odd on a Benz

 

[Oversize]

I think you guys have missed the point! My observation was that the hump in the middle of the housing to clear the divider is effectively blocking 1/3 of the element surface area!!

The design does not draw air from the top of the engine but along side it, above the exhaust manifold (which is probably worse)! Cold air is definitely worth the effort and on a 6.9 there are several options. Something interesting which I forgot about (until I saw one today) is the RH guard intake duct on a W124 diesel....

I've heard the same about K&N filters and the quality isn't as good as a MB or OEM one.

 

[Oversize]

Here's a pic:

 

[CraigS]

The best conversion I have seen was to go the other way and draw the air from the ducting/grill below the windshield. The air cleaner was ducted into the firewall, allowing it to draw down cold air from the grill.

 

[Oversize]

Ahhh yes but that involves a structural mod which would require approval from an Engineer