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airfilter


gvy

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Hi,

2 years ago I installed a K&N airfilter in the original airbox of my S2.2.Not cheap but at the time I considered it as a good investement. It can be cleaned and regreased. It lets the engine breath more free....

A week ago I did maintenance and I decided to also clean the K&N filter. Since I did not have the right oilspray to regrease it after the clean, I decided to provisionally put in my old paper airfilter, because I wanted to drive the esprit to a meeting the next day. To be honest, The S2.2 is never a silent car inside the cockpit, but with that classic paperfilter things became considerably quieter and the sound is more pleasurable and less harsh. I cant feel any drop in power or torque. My car has a pleasant sporty exhaust sound with the ss SJ 4 in 1 exhaust and without the resonator. The K&N only added harshness and loudness.

So I decided to buy and install a new Mann C4373/1 paper airfilter instead of replacing the cleaned K&N. Happy with it. Sometimes one can better stick with standard parts. Moreover, a classic paperfilter protects the engine better than a cotton gauge high flow air filter.

Opinions?

Geert

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Upgrade today to remove Google ads and support TLF.

Good feedback, Geert, it's something I am (was?) expecting to do. 

Youve say you've removed the resonator....that's the big round box feeding the air intake, yes?

So where does your intake air now come from? Have you rigged up the ram air mod, or are you still pulling warm air from the boot space (which is the current setup on my s3).

TIA, Dave

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Dave,

I ment the exhaust note of my S2.2 became sportier since I renewed my exhaustsystem "from original cast iron manifold-resonator-muffler" to " SJ-sporscars 4 in 1 Stainless Steel manifold - muffler", So the resonator is that small mufflerpart between manifold and muffler.

The intake , I left complete original except from the K&N filter inside the airbox. So now I went back to a normal dry paperfilter inside the airbox, so complete original.

Geert

 

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  • Gold FFM

I also found the K&N to make my SE a bit noisier, just as it did in previous cars. But I do like it, because it makes the turbo more noticeable.

I have made many mistakes in my life. Buying a multiple Lotus is not one of them.

 

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Filip,

It must be nice to hear the Turbo doing its work. ( I have no turbo),

On my car, I loved it for a while , but when doing highway miles at a constant 4000rpm, it gets boring real fast. I have an english RHD car, and the intake is situated right behind me. With the K&N it is as if I hear the cilinders pumping :o

It is also known that the S1, S2, S2.2 cars were noisier inside then the series from the S3 to the S4S cars. Engine vibrations because of the original Chapman strut system they say? The early esprits got a bad reputation because of the noise and the S2.2 912type engine with its longer stroke was even worse then the 907 2l engines of the S1 and S2.

Maybe We could measure dB's in our cars at a certain highway speed to compare.

 

Edited by gvy
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Interesting Philip. I have the K&N and agree that the noise is greater but I love it with the 4-1 manifold. At least on the inside it makes the 4 pot sound like a V8. I also agree that there is no real noticeable  performance difference and I fitted mine for the same reason, so that I didn't have to keep replacing the paper filter.

Pete

Pete '79 S2

LEW Miss September 2009

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  • Gold FFM

Geert, mine is RHD to, so I understand what you're saying about the intake being right behind your head. Especially in summer, with the window open. My previous SE had a custom exhaust and was considerably louder. I like the fact that the K&N adds a bit and makes it sound less civilised. Both had a K&N and ram-air mod. Anytime you wanna compare the cars, just let me know, would be nice to see your S2.2. ;-)

In my Defender, with the airbox in front of the driver, the noise did bother me a bit. But worth it being able to clean the filter after offroading instead of constantly replacing the paper element. In the Range Rover it doesn't make a difference, too much insulation.

Filip

I have made many mistakes in my life. Buying a multiple Lotus is not one of them.

 

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  • Gold FFM

I've not got the k&n - but according to my boy - with the ram air - it's massively noisier on dry by.

bit noisier in the cabin as well - but better than any noise that may be on bbc radio 1

does the k&n add any real performance you guys ??

Only here once

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Treated myself to a K&N filter as my mate got me one for £30 to replace the old paper one.

Seemed like the car deserved it but it's in bits at the moment so haven't driven it with the new one yet.

Be nice to know its breathing easier even if there's no performance lift.

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Not worth starting anything now...🍺

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Hi

No performance lift according to these guy's : https://www.youtube.com/watch?v=PAIxeQUSg-Q

I did not put mine on a dyno , so I can't really say, BUT strangely enough it feels as if it pulls up better with the paper filter. But this can be a distorted image, because by the dampenend noise inside the car, when flooring, it seems the engine has to do less effort to pull forward .  For me , the paper filter stays.

And above all, it protects the engine better and that is not relative, but a fact.

 

Geert

Edited by gvy
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22 hours ago, gvy said:

Hi

No performance lift according to these guy's : https://www.youtube.com/watch?v=PAIxeQUSg-Q

I did not put mine on a dyno , so I can't really say, BUT strangely enough it feels as if it pulls up better with the paper filter. But this can be a distorted image, because by the dampenend noise inside the car, when flooring, it seems the engine has to do less effort to pull forward .  For me , the paper filter stays.

And above all, it protects the engine better and that is not relative, but a fact.

 

Geert

Don't get too distracted by isolated chatter on air filters.  They all work as part of a designed system.  With most modern cars and computer modelling, the OE paper filter will provide the full air flow required to match the engines performance capability..  Fitting a sports high flow filter will have no effect as the air flow restriction lies elsewhere within the engine..  Hence no change..

What you have experienced with your Esprit air filter system is the same situation.. that is why you do not get any noticeable performance benefit...  However the design of the paper filter does have better sound / pulse suppression qualities. This in turn will make the engine quieter , so feels smoother , but more from a psychological front.

The paper filter does have a finer filtration ability, as a result will clog quicker. So more regular maintenance is required.

The above applies mainly to the N/A engine with much lower induction volume. The turbo versions provide a completely different set of parameters.  They are using the same design air filter with a much larger induction volume. To service this, the turbo is sucking on the filter which creates heat and looses performance.. An upgraded high flow air filter will benefit this system especially on full boost volume and lag reduction.  Ram air introduction has shown improvement as it pushes air against the filter which reduces the turbo suck. Both used together can improve the VE moving the restricting element to next area on the induction system.

I have found During extensive dyno testing, gains can be made by using modified induction and filtration on the turbo Esprit  

hope this help clear some of the Myths              

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  • Gold FFM

Dave - I expected nothing else from you - now feel far more fully informed and enlightened. May well have a go with a k&n filter in the new year.

the ram air did give a slight improvement of mine - I thought it resulted in the turbo spinning up slightly faster and boosting a bit more rapidly. Loads and loads more noise - always like the sound so doesn't bother me - I don't like my women quiet either !!

Only here once

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I think you guys are missing the point here.

K & N filters simple trap more dirt and flow more air than paper especially when carrying any load of dirt. That is why they use the on the 1000 mile Baja race cars almost exclusively. Paper wouldn't make it. Same on the helicopters in the desert storm.

All use K&N.

All the hot rod guys I know swear by them and all the performance shops sell a ton of them. They are guaranteed for a million miles and you don't have to waist paper ever again on an air filter.

Same reason I use the  "System one" oil filtration system on my Lotus's hot rod engine.

I went to extreme detailing all components having this engine custom built with a cost of over $7,000 back in the early "90s. I simple wouldn't use paper ever again but that is just my way of looking at the cost of owning a car like this and wanting to keep it maintained to the highest level as it is quite a major investment.

 I think these products both make for more power and mileage. Certainly, engine life will increase the K&N air filter. So does synthetic oil but that is another subject.

There is plenty of proven performance data to prove that paper is not the way to go for performance. But, if you are just looking to quiet the harshness and noise of the Lotus 907 engine then maybe a paper air filter is best for you.

I think that the harshness is heard more, because there is a larger flow of air (at all speeds) and increasing airspeed, would increase noise and raise the level of audable harshness

Some of loudest, db tested noise level producers are accomplished with compressed air. I think it applies in this case with the testimony given here.

Colin Chapman didn't have the money to properly R & D this engine so two of the characteristics are simply that, it is noisy and harsh. IMHO, it was almost the death of the company and if not for two outsiders (at different times) coming to the rescue Lotus, I think that Lotus cars may have gone the same sad way that their F1 team went, of which I had been a fan since 1962 when Jimmy Clark entered the picture with Lotus.

btw, I use K&N and synthetic lubricants on all my rigs. Gas cost too much so this is one way to cheat gas prices and with all of the other benefits it has,  to me, is the only way to go. .

 

atb,

 

Richard

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Hi Richard,

Your statements are very...eh...definite.

I have the K&N filter for 2 years now , but I choose the paper one.

You say K&N traps more dirt. I do not agree. And yes, in the dessert or other long time extreme conditions, you probably are better of with a good K&N filter system, because things are really extreme and a paper filter, which will trap more fine dust, will simply clog in no time. But that does not mean K&N traps the dust better. It just won't clog that fast.

In normal road conditions, the way I use my esprit, The paper filter is way finer and will protect the engine better . And excuse me if I think in a road GT car, cockpit noise is an important issue. If you read the books about esprit, you will know, that in its time , lotus engineers were struggeling with the issue to make the esprit S1, S2 and S2.2 more quite and civilised. I can state first hand now ( since  2 weeks), that the K&N is not helping here.

A classic Lotus Esprit is a GT, not a performance or track car, neither is it a helicopter or a jeep or hot rod . It simply is no better with a K&N filter. It is just louder, but no way more performant. So I really don't miss the point here.

I  dont state that K&N filters aren't any good in all the type cars you mentioned. They probably are. Except It is not because a performance shop sells them, they are in every car the best choice or even needed. One calls that marketing and K&N has done that job very well.

Geert

Edited by gvy
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  • Gold FFM

I have to agree with Geert. All the tests I've seen indicate the filtration of the K&N is not quite as good as most other (paper) filters. But during use, instead of clogging up, it retains much of it's efficiency and is claimed to even improve filtration. I've used K&N in all my cars, but never noticed either improved mileage or better power. The reason I use them is for the serviceability, even though it's a lot more work and just as expensive to clean and re-oil a K&N than to just put in a new paper filter. For me, the added noise is a plus, as I've said. And in my offroaders, I don't want to have to worry about paper filters clogging or collapsing when wet.

As for use in 'performance engines, you often see tuned cars with a K&N or similar straight onto the carbs or plenum./throttle valve. Which usually means the engine always breaths hot air that has passed through the radiator. Far from ideal, and yet advised and fitted by a lot of performance shops. So I wouldn't use that as a reference to quality.

Filip

I have made many mistakes in my life. Buying a multiple Lotus is not one of them.

 

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I could easily get more data but for what? Just doing a little research on this subject finding empirical data and not someones opinion says volumes to the Na-Sayers on K&N superiority over paper. Simply read below:

1)  https://www.youtube.com/watch?v=3DbkmThHYMs    Dyno test gave  +5.7HP with K&N over paper filter

 

2)  https://www.youtube.com/watch?v=mJW29eDZXzg    test shows K&N flows more air than paper filter.

 

3)  http://www.lsxtv.com/tech-stories/engine/dyno-test-4-kn-vs-aem-5th-gen-camaro-intake-options/  just replacing paper with K&N

·                                 K&N Panel Filter – Rear Wheel HP: 321.37 HP – increase of 8.4 rwhp

·                                 K&N Panel Filter –  Rear Wheel Torque: 338.5 Ft/Lbs – increase of 8.0 ft/lbs

 

·                                 Baseline Rear Wheel HP: 312.9 HP

·                                 Baseline Rear Wheel Torque: 331.5 Ft/Lbs

·                                 K&N Typhoon – Rear Wheel HP: 336.9 HP – increase of 24.0 rwhp

·                                 K&N Typhoon –  Rear Wheel Torque: 355.16 Ft/Lbs – increase of 23.6 ft/lbs


4)  http://mbworld.org/forums/c32-amg-c55-amg-w203/228514-my-c55-dyno-results-stock-filters-vs-k-n-s.html    

almost  +10 hp and + 14 ft/lbs torque over paper

 

5) http://www.mustangsandmore.com/ubb/Forum1/HTML/016727.html

 

Overview is:
Std Hi PO type assembly w/paper filter : 211.8 HP and 252.4 TQ.

No filter at all: 212.8 HP and 256.2 TQ.

K&N filter w/Xtreme lid: 214.1 HP and 253.9 TQ

 

.   So yes, my first post was definitive because there is so much data to prove that K&N air filters are superior to paper in every way, including flowing more air, making more power ( hp and torque on the dyno ) which is also an indication of more mpg and best of all trapping more dirt.  And another great reason to use it is because it is the last one you will ever have to buy. Say green!

 

 If all these are not reason enough for you to change over from paper then there probably never will be a reason good enough for you. But that is always a persons choice. 

 

Not sure who said that Lotus are simply GT cars and not high performance, I think I could easily get over 1,000 Lotus owners to disagree on that one including me.

Lotus stands for ultra high performance and always has since it's inception back in the 50's with Colin Chapman, who only built cars to support his racing cars. Many of his ideas went right into his street cars. If that isn't high performance then please tell me what is.

But for me, I have used K&N for decades with great results I think they are worth every penny.

 

nuf said

 

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Richard,

Thank you for the extended search. but no need to call me or other people over here ´´Na sayers´´ or ´´all missing the point´´.

You say :´´if all these are not reason enough for you to change over from paper then there probably never will be a reason good enough for you. But that is always a persons choice. ´´

I told here I already have a K&N filter and used it for the past 2 years on my esprit.I was happy with it. I recently changed over to paper again simply because there is no perceptible gain in performance and there is definitely a perceptible gain in noise inside the cockpit. That is in my car , because I am always cautious to generalize.

And yes my 912 engine is in perfect condition.

I am not impressed with the above data and it is in no way empirical. The first ones are plane commercial and no prove . I also know the K&N ping pong ball test. You really don´t have to persuade me as I already mentioned that K&N filters are ok and used in extreme conditions (sports etc) are doing what they say.

 

But  you cant convince me they trap more dirt then a paper filter.

Without naming brands, it is widely known that paper filters have better air filtration then gauge cotton ones and are dampening engine intake noise way better . It is also true that gauge filters flow better and dont clog up as fast and can be cleaned and maintained. Foam filters are sitting somewhere in between. And yes oil based gauge filters like K&N do filter better then dry gauge filters ,but not in comparison with paper filters.

So none of them is the better one. They just have different specs,pro and cons , and characteritics. Nothing black-white here. I tried both, explained my choice,asked other opinions, thats it

greets

Geert

 

Edited by gvy
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Surely it's pretty much impossible to make a cover-all statement about whether one type of filter is better than another, unless it's proven and fully quantified. 

K&N, fine, assuming it's suitably oiled (which is necessary) , but there are many different brands of paper filter, some will be finer than others, some will have greater air-flow resistance than other brands,and so it goes on. Each characteristic could make a tiny difference and all add up to that massive 1 or 2 HP difference on some Esprits, but perhaps more of a difference on a different Esprit with a slightly different setup. Personally I run K&N but don't know whether it makes for a better air-flow than a new paper filter. I'd only know if empirical data was available showing pressure differential for a given air-flow rate that;'s in line with what my car's engine uses.

 

I remember those POD filters, not from a car but a bike. I put one on a modified 100cc bike, it actually made the bike run too rich, I had to revert to foam and oil to get the bike to run better, the reason was that the bike was so modified that the small conical pod wasn't big enough, but may well have given more air flow than foam and oil at lower flow volumes. So it's very specific to application and environment.

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Andy,

I totally do agree with you.

As of the use of POD filters in a NA G esprit. In my opinion, this is not a good idea. Better stick with the original airbox, not sucking hot air from inside the engine compartment .As the engine gets hotter there will be a noticable drop in performance. I know they look good and performance shops love to sell them. And if choosen right and installed right they are ok, but not in an NA S1 S2  S2.2 S3 esprit under the glassfiber engine cover

Geert

Edited by gvy
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  • Gold FFM

In my experience K&N filters do look good, and for sure provide more airflow, but I don't believe they filter dirt and dust particles as well as a corrugated paper one. I have a K&N on my Esprit at the moment which was fitted when I bought the car, and to be honest, I'm thinking of reverting to a paper one firstly to lessen turbo noise, and secondly because my engine will live longer as a result as it's not ingesting as much dust. I'll forgo the extra 1 bhp for that.

Margate Exotics.

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This has been an interesting exchange of views regarding air filter design and practicalities.. some more passionate than others...

What does not change is that they are part of a design system to do a set job... Air flow rate and filtration ability are the measures of which filter is best for which engine.  The figures produced for marketing by manufactures and petrol heads will have us believe high flow filters make an engine more powerful... This is not the case.  However a filter that produces a flow rate less than 100% of an engines VE  can reduce its optimum power potential.  When this filter is changed for one with full capability then the engine can reach it max power output.  This is not the engine producing more power  just releasing its capability serviced by the filter.

Power figures attained on the dyno are with an engine at max VE ..Any deficiency in an air filter  can be measured and compared , as per examples posted by Richard..    As we rarely use max VE on the road you have to ask the question, how much difference does or will it actually make to my use of the car..

Paper elements supplied as OE will be as close to 100% engine VE as design practicalities allow. As most production cars rarely see max rpm any deficiency is not apparent. Even as the filter gets dirty the effects on a daily driver are negligible..  Only when an engine is used aggressively or measured for performance will the benefits of a high flow filter be appreciated.

Any quality tuned or modified engine will have an increased VE , as a result any OE filter will usually prove needing.. These are the instances where high flow filters come into there own, These top end units are generally marked with a BHP and flow capability so engine builders can match to engine spec... They also have a price tag to match.. do not confuse these with the OE replacement units..   The OE replacement units provide a great platform for the slightly modified engine and for those who wish to get the max from what they have.  Unlike the paper filters they require and oil film within the membrane to capture the smaller particles which would otherwise pass through, This will need servicing more regular than most owners are aware or do.

Saying all that i would still recommend a high flow filter for the turbo Esprit, in my opinion the OE unit is dated in comparison to engine spec.. Although direct new to new comparisons may show little gain on overall power figures, the response time and turbo spool up are noticeably in the mid range where used most..

     

            

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