AIR FILTER

It seems most on here think that so called performance filters such as K&M are a waste of money. The only good thoughts I have spotted are for ITG filters from Alive.
Am I falling victim to the hype or does anyone have anything good to say about them.
Just aquired the TD5 and its sporting an upgrade (turbo/intercooler/REMAP)

No better than a quality standard filter in my opinion, reason they sometimes perform better is that the air intake is often modified as well

I once drilled 2" holes in a 16v Clio air box and it sounded awesome, better than the aftermarket but it prob was worse for performance and economy due to drawing hot air from the engine bay,

K+N expensive but you can wash them, but there again you could buy a lot of standard ones for the same price

I have fitted K&N to vehicles that intended to keep for a long time, sometimes.
I would not fit one to anything that I was not going to tune slightly elsewhere. The only proviso being that I would fit a quality standard air filter, not all air filters are the same and some of the really cheap ones don't flow ait very well.

In real terms, a filter that flows more air with the same surface area, simply doesn't filter as well, which is the sole reason it's there.
No performance filter cleans the air as well as a quality paper filter, so for longest engine life, paper is the best way to go.

Nodge68 said:

In real terms, a filter that flows more air with the same surface area, simply doesn't filter as well, which is the sole reason it's there.
No performance filter cleans the air as well as a quality paper filter, so for longest engine life, paper is the best way to go.

Click to expand...

+1
If you look in YouTube, there's a video.. probably more than one.. of someone testing air filters with all sorts of particulate sizes and air flows. Standard paper filters are the most effective and don't have a big impact on air flow

@sofaboy, I use K&N's in all my cars except the Ninety. Unless an engine is of specific sporting ability there is no need for K&N/ITG type filters in a Land Rover, with the possible exception of running a V8. My 200tdi engine is modified in a number of areas, gasflowed head, new turbo, increased IC + some interesting other bits...but the filter is a bog std paper jobby. Even if I had a performance TD5 engine I'd still run paper filters and if more air volume is needed I'd up the size of the filter & housing.

Re' K&N's, they are very good filters providing they are maintained [cleaned & re-oiled annually]. I've been using them for 30+ years but one sees very little gain if just replacing like-for-like, and don't believe the internet hype re' after market/K&N/sports type filters...there's so much bo!!ocks out there. It's all about properly filtered Nett air volume into the engine that requires xxx cfm + kPa constant. By far the best way to achieve this to use an oversized air intake box and/or plenum prior to a properly balanced inlet manifold [and balanced head chambers]. K&N do have their very effective twin cone design filters with both inner and outer filter mesh - this provides oversized air volume through filter :. max vol + increased air velocity into manifold with correctly sized filter to inlet hosing in order to max' out air velocity = greater combustion efficiency = more suck/squeeze/bang/blow [I use this design on my 4.0ltr TVR Griffith engined MGB carefully calc'd for 1.5x cfm.pk with modified plenum and high scroll carbon trumpets]. But again, unless a V8 Land Rover there are few engines that would *really* gain from this upgrade when calc'd out.

landowner said:

No better than a quality standard filter in my opinion, reason they sometimes perform better is that the air intake is often modified as well

I once drilled 2" holes in a 16v Clio air box and it sounded awesome, better than the aftermarket but it prob was worse for performance and economy due to drawing hot air from the engine bay,

K+N expensive but you can wash them, but there again you could buy a lot of standard ones for the same price

Click to expand...

I bought a RRC V8 for trialling, it had K&N filters on when I bought it. A total faff with the amount of dust thrown around in the summer months, I was cleaning and oiling them every other month. The only reason I kept them on was I would have had to buy and fit the whole air system, so inertia cut in and I couldn't be arsed.

frog hopper said:

I bought a RRC V8 for trialling, it had K&N filters on when I bought it. A total faff with the amount of dust thrown around in the summer months, I was cleaning and oiling them every other month. The only reason I kept them on was I would have had to buy and fit the whole air system, so inertia cut in and I couldn't be arsed.

Click to expand...

Were they open or boxed in a filter housing? Imagine they'd be filthy if a trials RRC V8

v8250 said:

Were they open or boxed in a filter housing? Imagine they'd be filthy if a trials RRC V8

Click to expand...

They were open, just bodged on by the PO, sounded good though.

sofaboy said:

It seems most on here think that so called performance filters such as K&M are a waste of money. The only good thoughts I have spotted are for ITG filters from Alive.
Am I falling victim to the hype or does anyone have anything good to say about them.
Just aquired the TD5 and its sporting an upgrade (turbo/intercooler/REMAP)

Click to expand...

These vehicle came out of the factory in a standard fashion for a reason. The standard filter is more than adequate. That’s assuming they’re checked regularly to ensure they’re not blocked.

The k&n patter is that they can be washed. But it's a faff and no where as simple as it sounds. A new paper filter costs penny's. Use one and have a spare, takes moments to fit and back up to full efficiency.

Thanks guys

Air filters have come a long way in the last 20 years, we used to check or change them at service intervals (8 weeks/20k) now they get changed once a year (100k).
I think a lot of it is understanding how to flow clean/quality air to the filter minus all the dirt.

You cannot beat a fresh paper filter at regular intervals, well you can as an oil bath one is way better, but space is at a premium these days.

sofaboy said:

It seems most on here think that so called performance filters such as K&M are a waste of money. The only good thoughts I have spotted are for ITG filters from Alive.
Am I falling victim to the hype or does anyone have anything good to say about them.
Just aquired the TD5 and its sporting an upgrade (turbo/intercooler/REMAP)

Click to expand...

Not really seen them to give any improvement over standard.
We used to fit them to 4 cylinder motorbikes in the 80s, but that was more because they were less of a fiddle to fit to the back of the carbs than the standard air box.
Most of the bikes ended up getting rebores pretty often, so I doubt the filtration was all that good.
Some of my friends used to run with no filtration at all, or just a wire gauze over the back of the carb.
They used to get rebored even more often.