Aftermarket air filters

[Gjk]

I am looking to replace the standard paper element filter with an aftermarket item. There appears to be a few alternatives on the market. Can anyone share their experience of fitting one as I have read that the K&N panel filter used to have a metal frame but, due to copyright issues they can now only offer a “floppy” panel. Having read the LEW write up on installing said filter and not be able to suitably attach the rubber seal, I do not wish to start using silicone to seal it up.

PNM offer a Green Cotton filter but I don’t know if the seal ring is either required or a pain to fit like the K&N offering.

ITG offer a replacement filter and from a picture I found online it looked to have a metal frame thus making the installation of the seal viable but, I haven’t found anywhere that stocks the filter.

Any help or pointers much appreciated.

[jonwat]

30 minutes ago, Gjk said:

ITG offer a replacement filter and from a picture I found online it looked to have a metal frame thus making the installation of the seal viable but, I haven’t found anywhere that stocks the filter.

SJSportscars 

[drdoom]

FWIW, I spend time regularly reviewing a forum hosted in America for petrolheads, numbers of whom are well informed tuners, and the K&N type filters are considered to be poor in terms of filtration.

[Gjk]

Thanks @jonwat I found that. 👍

Thanks @drdoom, K&N is out the question now.

Has anyone fitted the Green Cotton filter? And if so, is the sealing rubber an easy fit?

[Jacques]

I bought a new K&N with the metal frame, long ago, and it was not a good design, as it clogs up badly quickly and some engines do not like the filter oil. Some people spray too much of it, and it's worse still. No oil on it, and it filters badly, letting too many particles into your engine, that should best have been left out. I spoke to two different tuning companies, with many many years of experience, and they showed me dead turbos and dead (especially) compressors, that died too early because of the K&N's filtration. Won't ever use it and on a former car I had a green filter. seemed to be the same as K&N. I also used  Sparco filter. Same story. Use  a standard paper filter is my recommendation. These filters are not for street driving, but for racing use, and that is another ballgame, with fewer miles and far more service.

I rolled it on a propper Dyno, trimmed, updated and by a super experienced operator, and he showed me the results: a little more on initial new installation, but once it gets washed with their special filter soap and reoiled, it's less ponies than a standard new original paper filter. Note: original paper filter, not aftermarket.

I rolled it three more times and that was indeed the results. I then installed a new original paper filter, and voila, all ponies were back in the stable, same goes for Nm. And the curves.

That is my experience and my observations + recommendations from two of the best tuners here in Denmark.

My car in question is a Lotus Esprit Turbo SE, 1990. Both in standard trim and when tuned. Plus my former car, plus my Corrado G60 that I stil have.

Same could be said about oil filters.

Up to you of course. Want a better trim? Talk to Dave for example, about getting rid of parasitic power losses etc, or just read his thread on making more power on his SE.

Kind regards,

Jacques

[Gjk]

Cheers Jacques, many thanks for the information. I was going on Dave’s recommendation to fit a decent free flowing filter to compliment the “ram air” mod. I don’t believe the manufacturer claims between cleaning and reconditioning timescales. TBH aftermarket filters need cleaning far more often.

It is far to easy to over oil any aftermarket filter that requires it. It is very hard to judge how much is enough, and usually what might be thought enough is in fact far to much.

From your comparison testing I have food for though. I plan to carry out the ram air mod but currently I still have a paper filter so, I’ll see how that goes first.

[Escape]

I have good experiences with K&N. Installed in the Range Rover because is goes off road so it's nice to be able to clean it instead of having to replace. And they can handle water ingress a lot better, a paper filter can collapse when wet and choke the engine. Not relevant on an Esprit of course. I did install one in my Turbo SE as well and it has done about 100k km. Cleaned and oiled (within reason) a couple of times and seems to do the job. No problems fitting it either, the rubber edge takes a bit more effort to squeeze in but sits nicely. I'll probably keep using K&N, or similar like ITG.

[Jacques]

I too have done the ram air mod on my SE, and I rolled it and it gave a little more Nm and like 2 ponies. I should add, that the test bench we set up so that there was a lot of extra air flow along the sides of the car, trying to simulate real life fast speed airflow. I am sure high speed airflow will be greater numbers.

How about making better tubing for the intake in other materials?

Regarding engines with these kind of filters, there is less of a chance to wear something down earlier, if it is not an engine with pressurized build.

It's all up to you. I've seen enough dead engines to steer clear. In fact I'll just toss my two near new filter out (K&N), so it won't do any damage to any engine in the future.

Kind regards,

Jacques

[Gjk]

56 minutes ago, Jacques said:

How about making better tubing for the intake in other materials?

I have ordered some silicone hose sections and an aluminium joiner after reading @MrDangerUS’s thread. This means I will retain all the OEM parts should I wish to revert back to the original factory spec.

The elephant’s trunk would be the next part to be addressed. Having read a few threads on this forum it seams the hose can be re manufactured using aluminium tube, a silicone elbow and a couple of silicone reducers.

I not in the market for more ponies just better drivability, so it may well be that a paper element filter is perfectly sufficient for my needs. I just want to know what other users had experienced.

 

[Chillidoggy]

I bought a PNM Green filter, but it didn't fit the filter housing. It's still in the garage somewhere.

As ever, there's a lot of hot air spouted on the subject by keyboard warriors on forums around the globe, their only measure being marketing claims from manufacturers, and an arse-dyno. The only sure way with any mod is to prove it on a proper rolling road dyno, as in Jacque's case above.

The ram air mod as suggested will increase induction noise, especially with the windows or moonroof open, trust me on this one. If noise = more power, then it's a winner. But I'm not aware of any post-conversion dyno results.

[Gjk]

Thanks for the heads up on the Green Cotton filter not fitting @Chillidoggy. That’s two off the list now. So it’s paper v ITG.

I’ll start with the paper filter and see how it goes. Like I said in my last post, I’m not after more power just more response from what I already have. If making the air flow into the engine smoother results in better throttle response then I’ll be happy. Obviously after turning attention to the intake side of the engine the exhaust will be the next on the list but at present I don’t have the £1700 odd quid for a Alunox manifold. 

Only after sorting the exhaust manifold would it really be worth while putting it on a dyno, just to synchronise everything.

[Chillidoggy]

I moaned to Pete at the time that it didn’t fit inside the air filter box, and unless the size has been altered subsequently, I’m surprised he’s still listing it. As I recall, I tried to trim it, but wasn’t happy with it, and reverted to the Mann K&N lookalike.

[tomcattom]

I have the ITG ProFilter on mine and had no issues with fitment whatsoever. I just had to remove the rubber trim thingy (technical term that ) from the perimeter of the OE filter and transfered it to the edge of the metal frame on the ITG item. Filter itself was a special order item through Demon Tweeks.

[tomcattom]

6 hours ago, Gjk said:

The elephant’s trunk would be the next part to be addressed. Having read a few threads on this forum it seams the hose can be re manufactured using aluminium tube, a silicone elbow and a couple of silicone reducers.

Are you referring to my intake tube? If so I am intending to get it off the car this winter while I do other work on the car to refine my design and make a jig to enable my friendly fabricator to make more if there is interest.

[Gjk]

Thanks @tomcattom for the info about the ITG filter. At least I now know it is a direct replacement without having to faff around to make it fit.

I did express an interest in a group buy of your elephant trunk replacement tube when you received the first carnation from your fabricator (IIRC it was in your rolling restoration thread). I am still interested but, I appreciate that there would need to be a minimum production number to make it financially viable.

[tomcattom]

There won't be a minimum order required, the fabricator can make one-offs but if there is more interest it will bring the cost per unit down; plus less faff for me making one trip to the fabricator for a batch rather that lots of one-off trips!

I just need to get my original off the car to be able to make a jig to make more from. I'd also want do a test fit of mine on other variants other than the S4s+Alunox to be sure it will fit. The Alunox manifold for exmaple makes the turbo sit nearer the rear of the engine, which I have designed for, but I haven't tested on one without the Alunox to be sure it still fits. It should be fine because of the silicone couplers at each afford a degree of adjustment, but I'd sooner test it to have confidence to say it will fit.

[snowrx]

I had a bad experience with the wrong size being listed for a K&N, it seemed to fit, but after running it a bit I found dust in the intake and saw that the rubber did not seal in the airbox on my '85 carbed G-car. I think there are two fitments that are close to the same dimensions, take care you check the size of whatever filter you get.

That said, most of the comments I see on the K&N style is they don't filter all that well, this from someone who's had them on many cars.

[Gjk]

1 hour ago, tomcattom said:

 I'd also want do a test fit of mine on other variants other than the S4s+Alunox to be sure it will fit.

I have an SE with standard exhaust manifold (well, standard everything to be fair) and I don’t mind being the Guinea pig for test fitment to another model, and I’m not a million miles away down here in Walton.

[Jacques]

Grahame,

You may also want to take a close look at the intake hose from the airfilter to the turbo itself. They are getting old, fragile and are known to collapse under more demand - more throttle. Idle is fine, but once you hit it, it dies out. Anyway, the larger turbo on the later cars, such as S4s and more so the Sport300 each have a bigger diameter hose for that purpose, and they are conical.

You will want the alunox tubular exhaust manifold. I have been running it for a few years now, and apart from the initial bad welding on mine, it works really well, both on a standard engine tune and a worked on engine. Really well. You should notice easier idling, cleaner running, and more power as well as torque. Roll it before and after and see the difference.

Do use some of the high temp grade k-nuts - not the darker cheaper version. They lock really well, and they last. They are smaller and makes it a LOT easier to get it on and off at a later date, if need be. Also use them on the 4 turbo studs. Well, I did and it works really well. I can now take by turbo and exhaust manifold off in around 1½ hour without bleeding knuckles, swearing and a pint. Just works so well. And they are lighter.

Do be aware of tubes running very close to the frame, so use a piece of exhaust wrap or otherwise to insulate, so the galvanized surface is not going bad.

The heat shield maze is easy enough to get on as well. No worries.

Kind regards,

Jacques

[Gjk]

Hi @Jacques. The past posts from @tomcattom were all about that said hose. After the hoses between the actual car intake and air filter inlet are changed I will be focusing on the air filter outlet to turbo hose (elephant trunk). I am still undecided on weather to use a paper or aftermarket filter element. I simply can not afford the Alunox manifold at the moment. I completely understand the benefits it would bring, just need to find some extra cash!

[drdoom]

Grahame, go with paper. They can be relied upon for good filtration, AKA engine life, and deliver the goods in terms of power. As their restriction is proportional to the air mass flow any purported improvement via aftermarket would be thus confined to the upper reaches of the power band and I remain unconvinced of meaningful gains in any case. Further to the point, engine response is felt rather more broadly and I would be seeking gains there via other means. 

Cheers

[Gjk]

Thanks for that @drdoom, it puts it all into perspective!

[Barrykearley]

You have to make meaningful changes to airflow to get the best from an esprit. This was explained at great depth by someone with far more knowledge than me. Start at changing the exhaust flow and then work on the intake. There are plenty of horses to be freed up.

[Jacques]

I second that.

Cheers,

Jacques

[tomcattom]

23 hours ago, Gjk said:

I have an SE with standard exhaust manifold (well, standard everything to be fair) and I don’t mind being the Guinea pig for test fitment to another model, and I’m not a million miles away down here in Walton.

If you're happy to do a trial fit then I'll let you know when I'm in a position to do so and we can arrange something.