free hit
counters
Air filter - Induction/Turbo/Chargecooler/Manifold/Exhaust - The Lotus Forums Jump to content
Sign in to follow this  

Recommended Posts

With the recent thread on oil change regularity I thought I might raise a similar topic on air filters.

First I would not run a paper/cardboard filter, the car inducts from outside in the air stream, so if it’s raining the air filter will get wet, soggy paper/cardboard will distort and not do it’s job.

I fitted a K&N filter as soon as I had the car, but what surprised me when I next serviced it, only just over 2,000 miles later, was how much dirt it had collected, (never been off tarmac) so I got the cleaning kit and duly cleaned it. That certain crisp induction sound returned straight away.

So this is now a job I do every 3-4 months.

Share this post


Link to post
Share on other sites

Upgrade today to remove Google ads and support TLF.

Here in the UK we'll be digging them out every 3-4 days if this carries on.

Share this post


Link to post
Share on other sites

Whilst doing everything else I decided to clean MY K&N air filter, now when I come to re-oil it I forget which side to apply the oil ?

One side id straight filter the full length, the other side is divided into 2 windows, which side do I put the oil on, then which way round do I put it back into the car ? :help:

Share this post


Link to post
Share on other sites

Doesn't matter - the oil is absorbed by the filter medium sandwitched between the mesh jsut make sure it's liberally covered.

Share this post


Link to post
Share on other sites

OK. My turn.

My S4 is fitted with a K&N reusable filter. The part # is 33-2011. However, looking at the website this filter is listed for a bunch of esprits finishing at the 88 2.2L carb model. It does not list an air filter for my car. Oil, yes. Air, no.

I don't think the PO knew it was fitted as he had service work done by a garage and it has come out bone dry. I had looked at it once before and stoopidly did not do any research so it went back in as dry as it came out.

That will be fixed this time.

Does anyone know if this filter is ok for a '94 S4?

Thanks,

Michael

ps. Roger, the K&N website mentions 21ml as the oil amount for the filter I have so I reckon that would be the same for your filter. You can find it on the K&N website.

Share this post


Link to post
Share on other sites

Personal view - if it fits int he hole and it filters all the air without leaks then it's fine - however you must oil it ASAP

It won't be filtering anything smaller than bees out which will not do the turbo compressor any good....

Infact if it's been dry for a while I'd replace it, the cotton may be damaged and filtering compromised.

Edited by Rich H

Share this post


Link to post
Share on other sites

K&n 33-2784 for an S4 and S4s

Share this post


Link to post
Share on other sites

I've said it before, but happy to say it Again: take that K&N (or Sparco of Greenfilter etc.) off and throw it away. It does not perform as good as a standard paperfilter. I bought a new one, oiled it lightly and drove around. Then went to the rollers and tested it: some ponies lesser. I then cleaned it out, and oiled it Again. Same result. And the guy operating the testbed told very clear that I should never use K&N and the likes, as they allow harmfull particles into the turbo (or compressor), acting as a grinding paste. He have been turbotuing and compressortunig cars for more than 30 years. He also showed me destroyed blades etc.

I use a standard paperfilter now and onwards. Period.

I've also seen for example Laverda motorcycles having their new DellOrto internals destroyed pretty fast with 3 small K&N air filters. Naturally I also use standard paper airfilter on my bike as well.

Even on my 1:6 petrol driven 26cc rc buggy, there's an K&N airfilter (and similar). I grinds Down the carb, piston rings and cylinderwall pretty fast compared to the standard oiled foamfilter. Seen it myself. I so use K&N air filter oil on the RC buggy as it Works well on the standard foamfilter and a tuning foam air filter. I have been using their air filter oil for many years.

Lotus designed a drain so Water would not reach the paper airfilter in the airbox. It Works.

Each to his own.

Kind regards,

Jacques

  • Like 1

Share this post


Link to post
Share on other sites

 

On 3/23/2018 at 22:07, Jacques said:

I've said it before, but happy to say it Again: take that K&N (or Sparco of Greenfilter etc.) off and throw it away. It does not perform as good as a standard paperfilter. I bought a new one, oiled it lightly and drove around. Then went to the rollers and tested it: some ponies lesser. I then cleaned it out, and oiled it Again. Same result. And the guy operating the testbed told very clear that I should never use K&N and the likes, as they allow harmfull particles into the turbo (or compressor), acting as a grinding paste. He have been turbotuing and compressortunig cars for more than 30 years. He also showed me destroyed blades etc.

That is quite a sweeping statement, especially coming from a dyno expert..  I don't doubt he has experienced what you have stated but I do feel we have to ask why..   I have been running this type of filter for many years with repeated dyno test sessions and periodic turbo inspection overhauls, this has all been part of the development to test modifications and components on the Esprit.  After 10.000 miles, aggressive testing on dyno and dirty British roads with a 4'' ram air system , we found no signs of ware on the S182 turbo when returned for interim inspection to manufacturer.. In fact they gave it glowing report.  So not sure why your guy was having so many problems..   The other point you make about reduction in power on your Esprit being systematic with the filter change to the K&N type,  again very strange .. The point being, you state in your experience you believe it lets lager partials of dirt though , In which case will be less restrictive and have higher flow capability.  The high flow capability is what the manufactures promote and will only enhance performance ...  Personally in the situation you have I would be exploring the flow dynamics and and tuning parameters on the engine as a whole rather than focusing on the filter.. 

      There are many owners out there who have had these type of filters for decades , we are yet to get any direct reports of compressor damage as a result of using them . Further more many have reported a better performing feel to their engines after fitting..  If there was the massive evidence of resulting compressor damage as your dyno man stated, I would of expected  loads of compensation claims along with media outrage, none has come to my attention.!    So it may be a little early to make such sweeping remarks when evidence to the contrary is also available..  However it is important that manufactures installation instructions are followed so the filter can perform as designed. 

  I do not think there should be any reason for owners to panic about damage that may or may not have been caused by these type of filters when used correctly..  A simple visual check at next service should be enough to put minds at rest.. 

This post is in no way meant as a criticism  just a balanced response from another owner, as Jacques mentioned .... each to his own....

It is very important that we are aware of what Jacques experienced , thank you for sharing .      

  • Like 1

Share this post


Link to post
Share on other sites

I can supplement with that the surface area is smaller on the K&N compared to the paperfilter, and after driving for a period, the resulting area through which the air can pass is smaller still, being slowly more clogged (on both). Another area which can easily be corrected though, is the amount of filter oil used. It only have to be slightly lubed, not much.

On my other engine, there is a MAT sensor directly in the intake and this get's a thin oily film on it if lubed too much. This again can affect performance.

Kind regards,

Jacques

Share this post


Link to post
Share on other sites
2 hours ago, Jacques said:

can supplement with that the surface area is smaller on the K&N compared to the paperfilter, and after driving for a period, the resulting area through which the air can pass is smaller still, being slowly more clogged (on both). Another area which can easily be corrected though, is the amount of filter oil used. It only have to be slightly lubed, not much.

On my other engine, there is a MAT sensor directly in the intake and this get's a thin oily film on it if lubed too much. This again can affect performance.

I understand what you are saying , but there is far more to it than surface area.  Filtration and flow is a science in itself and some very clever people came up with the systems we use..  It is more to do with CFM and particle retention and duration.  The K&N panel filter is 40% more efficient than the typical paper filter why still retaining particles as small as 5.5 micro with 96% + retention..efficiency.   These figure come from the standard testing ISO 5011...  The particular retention is achieved within the fabric itself , where as the paper element uses just the surface , this is where people get confused.  It does in fact take longer to reduce the CFM  to a cleaning point than it would to replace a paper unit.. 

If oil gets on your MAT sensor then as you say that is incorrect over oiling not the fault of the filter unit.. 

However... We can not detract from the fact there are cheaper less effective filters that are copies of the higher end units.   These cheaper units may let through the larger particles which usually have to be circa 15 micros to do any significant damage . These could produce the symptoms that Jacques referred to...  

So always buy the proper kit and install correctly if you are going down this path.

Share this post


Link to post
Share on other sites

Simple question for a simple bloke like me.

K&N - bhp/performance gain ? Yes or no ?

Share this post


Link to post
Share on other sites

Barry, I think you will find that there are people who wants the K&N et al, and people who swear to paperfilters.

Here are mine. My point is, that all the K&N filters I've seen are not open after some miles. So have to be cleaned pretty often. It turns out to be diesel particles. The surface area on paper filters are much larger, and will take much longer to clogg. I am aware of cfm and other factors with regards to the intake path, without being able to neither calculate nor measure it ;) 

Kind regards,

Jacques

 

filters.JPG

Share this post


Link to post
Share on other sites

Barry, if there is power gain, you're unlikely to notice it. The inductions sound will change though.

I've run a K&N on my previous Esprit, as well as on several Land Rovers and other cars. My current Esprit came with a green filter of similar construction, which I kept. I've never experienced any ill effects on any car and certainly don't have indications the K&N clogs faster, but I can't claim any performance gain either. Changing a paper filter is easier than cleaning and oiling, and price-wise there is little difference over the years. So it's really down to personal choice. For the Landies, the K&N does have the big advantage it can resist some water, where a paper filter will collapse and clog. Less of an issue on the Esprit, though with the ram intake driving in rain will lead to a considerable amount of water being sucked in.

Just my 2cents.

Filip

  • Like 1
  • Thanks 1

Share this post


Link to post
Share on other sites

I'd have thought that, had the air filter been a restriction on power, Lotus would have willingly spent an extra £10 or so per car had they been able to gain a few extra BHP.   I don't necessarily mean gone to K&N type, I mean they'd have increased the size of the filter to get a bigger area. So I'm with Filip, in thinking it's a pointless exercise on a standard power output engine.

That said, when lots of other things have been done to the engine it may be that  the air filter becomes a restriction to the engine breathing, and so does matter. An example of that would be all the mods done by @Changes, excluding efficiency (which isn't great in a petrol internal combustion engine, and doesn't really vary a lot) he's got an extra c50% power (412 BHP IIRC compared to 264 standard SE or 300 S4S/sport 300), so that's c50% more air and fuel being consumed in the same amount of time, I can well imagine that the standard paper filter would have been a problem. It's most likely not a problem of restricting air flow to a material extent for the vast majority of us.

 

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  


×