Toby S Posted April 13, 2019 Share Posted April 13, 2019 Hi AllI have a 1992 1400 K series Supersport - Currently has a K&N cylinder air filter around 7 inches long 10 inch diameter which sits at the front of the engine bay in the nose cone and its looking pretty shabby (may well have been the original - cars done 36,000 miles) so I'm thinking changing.Looked on K&N website and there's more universal filters than you can poke a stick at - However I've seemed to have found one which looks a direct replacement.However now the questions:- Cylinder filter or cone - seems to be a very similar one which is cone shaped (same length, diameter and flange diameter) - has anybody any experience of both and can advise whether there is any difference in performance During my googling, I found an article testing the induction resistance of performance filters and the foam Pipercross and IFG filters seemed to come out very well (less resistance than the K&N one tested albeit the K&N tested was a smaller filter) - has anyone tried the Piper cross of IFG or any foam filters - any comments on performance Does anyone have any other recommendations Given the position of the filter (just behind the radiator, sitting on the offside of the car close to the side of the nose cone) - has anyone tried putting a vent/air intake hole in the o/s side of nose cone in an attempt to improve air intake of colder air - I've always wondered whether it would make any discernable difference in performance. Am I just thinking too much (whatever you do won't make any significant difference) and I should just get the direct comparable one (and probably a life !!)Main use of the car is fast road blatsCheersToby Link to comment Share on other sites More sharing options...
elie boone Posted April 14, 2019 Share Posted April 14, 2019 By a refurbishment set from K&N these filters are perfectly serviceable. Link to comment Share on other sites More sharing options...
rj Posted April 14, 2019 Share Posted April 14, 2019 Am I just thinking too much (whatever you do won't make any significant difference) and I should just get the direct comparable one (and probably a life !!)Yes :-p Link to comment Share on other sites More sharing options...
Jonathan Kay Posted April 14, 2019 Share Posted April 14, 2019 Given the position of the filter (just behind the radiator, sitting on the offside of the car close to the side of the nose cone) - has anyone tried putting a vent/air intake hole in the o/s side of nose cone in an attempt to improve air intake of colder air - I've always wondered whether it would make any discernable difference in performance.This keeps cropping up for both combustion and cooling. There are several attempts in the archives including a description and photographs of a fully ducted Seven.It looks very likely to me that both could be improved. But it never seems to catch on, and there are usually good reasons for that...Jonathan Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted April 14, 2019 Leadership Team Share Posted April 14, 2019 There were a couple of mods that were the norm for the 1400 Supersports with the forward facing throttle body ...1. To reduce the intake temperature fashion a simple ally plate that will direct air over the radiator to the air filter, I've not got any pictures and not sure whether you'll understand my description ... it's a simple angled plate, the horizontal part at the bottom sits over the radiator and passes far enough back to tuck under the filter, the angle forms a 90 degree vertical section that passes up the engine side of the filter and forward again over the radiator, adding some rigidity. Trim the top of the vertical section so that it's close but doesn't touch the nose cone. Hope that makes sense!2. If you remove the air filter and open the throttle fully, unless it's already been modified you'll notice the butterfly doesn't open fully because there's a limit to the cable travel due to a fixed stop. Most people file the stop away slightly to allow the butterfly to open fully.3. The air filter is a bespoke part - the rubber mounting face is angled slightly to orientate the filter correctly. It would be unusual for a K&N filter to be beyond service life, is it so bad that it can't just be cleaned properly and re-oiled?Stu. Link to comment Share on other sites More sharing options...
Toby S Posted April 14, 2019 Author Share Posted April 14, 2019 Cheers for the suggestions guysI think at this stage I do a clean and re-oil and see how I get onStu - I saw a similar thing (home made air box) on Alcester racing sevens website http://www.alcester-racing-sevens.com/heat_management.htm which sound pretty similar to what you were saying and agree it might be worth thinking about, although I'm not sure there is that much clearance between the radiator and the nose cone, and their's seemed to stop at the radiator (I'd thought you'd need to do a hump back bridge effect over the radiator with the aluminium to get any real ait scoop effect). Alternative I suppose would be to enclose and either side vent through the side of the nose cone behind the radiator or do an air scoop out the top behind the radiator, I suppose - I've seen a couple of air scoop bolt on mods on a few performance sites but there not that cheap - key I suppose is deciding whether it will make a significant diff to performance before spending the cashYour point on the butterfly in the throttle body is a good one - did that a couple of years ago and it made a noticeable difference at full throttle so to anyone who hasn't done that already.RJ - Like your thinking - which went through my mind when I was typing the original query Regards Link to comment Share on other sites More sharing options...
Recommended Posts
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 accountSign in
Already have an account? Sign in here.
Sign In Now