Lotus Elan and Lotus Elan Plus 2 Forums

Had my plus 2 a few months now,having sorted main mech problems,touch wood...and being happy with general bodywork and such,im moving on to little things now.Engine runs lovely so dont want to upset things but do like the looks etc of K&N type filters as opposed to usual original set up..anyone any experience of changing to these,if so any problems with carb set up? type of filters to use?

All my Louts cars, Climax and Twinks have K&N, if for no other reason the sound!!

They just bolt on, no carb changes for me in any way, easy to maintain/clean, only issue is the throttle cable anchor on the Twink.

Go to the K&N site, good info and price there.

personally i have fitted a K & N style cone airfilter in the nose cone,, you still get the louder induction roar whilst still giving a quieter cabin on A roads/motorways, also no need to mess with the throttle return or engine breather in the airbox, also with the filter in the nose still, the engine gets supplied with cool, therefore denser air, without the restriction of the standard effort.

just ny twopennyworth!!

Mark

Nice one Alasdair - totally agree about the sound! I was considering this very thing last night. Could you / someone tell me more about the impact on the throttle cable anchor and the breather return? Photos would be great if anyone has some.

Thanks.

Sean.

alaric wrote:Nice one Alasdair - totally agree about the sound! I was considering this very thing last night. Could you / someone tell me more about the impact on the throttle cable anchor and the breather return? Photos would be great if anyone has some.

Thanks.

Sean.

try a PM to Matt on the forum, he has removed the K&N set up from his car and fitted the original spec airbox, the breather was fitted into the rear of the rear K&N if i remember correctly, I cant remember what the throttle return spring set up was though. Matt will have detailed pictures and possibly still has the filters so could send you pics/dimensions if needed.

Mark

Rocket
K&N filters have been discussed a few times, and the choices are as follows:-

Fit a K&N in the original air cannister. I have not found an ideal size to fit having trawled through the K&N website and talked to the company.
Also the problem with the original air cannister is it is too restrictive and sits in front of the radiator.

For racing a pair of K&Ns are bolted straight to the carbs. This is very noisy with massive induction roar and a lot of owners find the noise too much on a road car.
Bolting straight to the carbs means you remove the air box back plate which has the throttle bracket on it so you need to fit a throttle linkage that mounts onto the top of the carbs or make a bracket up. You also will need to do something about the engine breather that vents into the back of the airbox.There has been talk about taking hot air from behind the radiator with this system, when the car is moving it should not be a problem but when in slow moving/stationary traffic it might become an issue.

The final option and the one I went for was a remote filter. This basically replaces the original air cannister. I designed and made up a mounting bracket so the original trunking can fit straight onto it and the filter just bolts on.
On my Sprint I positioned it on the inner wing in front of the radiator,so it is a nice tidy installation (picture on my website) . In this position it does not sit in front of the radiator restricting air flow and also being higher up stays cleaner as it is not so exposed to muck from the road. As you are still using the airbox bolted to the carbs you do not have to do anything to the throttle or engine breather.
There is a slight increase in induction noise but not excessive.

K&Ns are worth fitting, I can only really comment on the system I fitted, but myself and a few other owners using this system have noticed the engine responds and revs much cleaner.

Cliveyboy

useful info thanks to you all..i have dug into archives..fire risk pops up a lot?

I too use cliveyboys system to catch cooler air and made a simple bracket to secure the K&N filter in front of the rad. Clives bracket looks much nicer then mine. I was motivated by the current exchange rate. Sounds great when you get on it and is quiet at low revs. It also seems to rev easier. It does not increase the fire problems any more then the original set up.

sarto

I implemented the Cliveyboy setup as well, with my own brackets. You can't see the brackets, and in any case, when the bonnet is on, you can hardly see the air cleaner. The photo shows the location (on an S2) with the bonnet removed. There is a bit more induction noise with the bonnet off, but with the bonnet on I hardly notice a difference.

Hello
I had to fit K&Ns to improve the air intake to lower the CO2 emmissions to an acceptable level here in France
I cut (close youir ears anyone who thinks original is best) the air box to leave a plate with the bracket for the linkage, and then sandwiched this between two gaskets between the carbs and the K&Ns. Lovely Sound , I only wish my wife would agree!
Personnally I didn't like the duct and the restriction in the airflow to the radiator

Get cutting !!!!

Terry

Thanks for the piccies - very useful. I'm still undecided - waiting to hear back re prices.

All the best.

Sean.

Does anyone have the product number of a suitable K&N filter for a +2, mounted a la cliveyboy?

UBoat
You can in theory use any K&N filter with a big enough surface area. The trick is mating it upto the flexible trunking and fixing it to the car.
It depends on your budget and practical abilities.
For ?50 you could buy a filter and make up some brackets and adaptor, Alternatively spend more and buy the complete kit ready to fit.

Cliveyboy

OK, thanks!

This is what I used on my S3 Coupe';

Air-box Hose Mighty Flow 3-19/32 X 32-1/2
Cone filter K&N RE-810

Plumbed into a stock carburator air box. I had vacuum pods and found no issue with finding a suitable mounting location.