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Triumph TR6 - K&N Air Filters

Rick C., in a previous thread you described how you've unstalled the 3" K&N air filters on your TR6. Did you have to make any modifications to fit it in the very tight space between the carbs and the wheel well(not sure that's the right term)? Also has anyone used the Carburetor Ram Stacks listed in the Moss catalogue for use with those filters? Do they add anything besides cost?
J.T. Cruz

I once read that the K/N conversions for modern cars is a bunch of BS as it draws in air from the surrounding engine compartment. This warm/hot air is not ideal for peak performance to the colder denser air from outside...perhaps why race cars have air scoops.

As the article put it, 'in today's horsepower wars don't you think that the automotive engineers would strive to find every bit of horsepower for their engines deemed by their marketing people'

One thing for sure is that it certainly changes the sound of your engine and with the added noise it makes you feel that you have more power...isn't psychology great? Hmmm that explains why a newly washed and waxed car seems to run better!!!

You may gain a fraction of a hp more but at a very high cost/performance ratio. I would think that money is better spent in saving for a hotter cam or increasing compression or portting and polishing.

Steven--Most modern cars have the air to the air filter ducted from outside the engine compartment. I have done the same with my TR6 using the old twin-snout filter housing with hoses run through the radiator shroud. You are correct that the cooler (denser)the air the better for performance. Interesting that later TRs had cutouts in the housing essentially pulling air right above the exhaust manifold. I understand this was done to ease emissions.

Rick O.
72 TR6
Rick Orthen

I am aware that modern cars have some sort of airbox or snorkle that draws in outside air (in the case of my Acura CL) what I was commenting on is the K/n conversions that replace all the stock stuff with a tube and a canister type of filter that sits inside the engine bay. Their claims of +15-25bhp seems a bit far fetched as it goes against common sense of drawing in colder denser air.

I have a later TR, perhaps I should seek out an older air cleaner with the twin snouts and duct them to the front??

Hey guys I have K & N filters on both my 72 TR6 and my 99 VW Jetta VR6. Yes the TR6 does draw air from inside the engine compartment but other than Rick O's conversion I don't think there is much of a way to improve induction. The K&N in the 6 is superior because they are able to draw air from all around the filter rather than just the little inlets in the stock box, there is an increase in air flow that is evident as soon as you touch the throttle it breathes much easier. The VW installation does get rid of the duct that runs into the front most area of the right side fender well but the improvement in breathing is readily apparent. Not 25hp but at least 10 the noise it makes at full thrust is very inspiring to say the least both vehicles it was well worth the money.
Regards, Keith
KBD Dixon

One point to note is that the engine can not breathe any better if it can not blow any better. Intake and exhaust are linked and the vacuum of air through the system.

Like I said earlier the increase in sound is a psychological 10bhp

Keith, do you have the 3" K&N's and did they fir without modification?
J.T. Cruz

J.T.,My K&N's are 1.75 inches thick by 5.75 inches diameter no problems at all with fit they came thru TRF. Steven, yes some of the horsepower gain is psychological but the stock VW breather is like having a bad case of asthma by comparison, 10 hp is probably on target without exhaust mods in that car. However I do not think that the TR6 gains any at all it just seems to breathe easier,ie:throttle response is much better.
Regards, Keith
KBD Dixon

I have added the K&N (TR6) Internal Ramstacks (85-5040) to the inner rear part of the K&N air filters. These are supposed to assist in inducing air flow. Results ??? ...I know they're there.

Just noticed u asked me a question..DUH!....sorry.
The answer is yes the 3" chrome faced K&Ns fit just fine. It is a little more difficult to wax and polish that area of the wheel arch though. I agree with Keith..the stock air filter cover allows air into the front carb more so than the rear. Does this cooler denser air really make a difference to a 100BHP engine? I do not think so. I think it is more an issue of air "freely" being allowed to get to the carb throats. The best way to allow no air restriction is the use of ram pipes. But we have no filtering of the air. For a race car, fine, for our cars no...we want air filtration. Rick O; Your comment on the addition of extra slots in the OE filter housing is true. In fact the pipes on the front where also removed and the holes slotted bigger. reduce emissions..yes we now have a lot more air being allowed into the carbs. The point here is that the housings where altered to allow more air to the carbs. K&Ns claim of more HP may be exagerated. They do claim there filters are less restictive than others...more air to the carbs. I am learning here that there is a ram stack available for the K&Ns (MOSS took me off their mailing list). Will it help....I do not opinion is..I do not think so. It is more important to have a larger filter surface ( 3" compared to 1.75"). Simply, more air is allowed to enter.

Does any of the breathing mods in this thread make a significant difference in performance to us owners of stock engines? I do not think so. But whatever we do as a mod, does have lots of psychological benefit.
Rick C
Rick Crawford

Rick C, Are we supposed to wax and polish your wheel archs? that is love! ...or does this also improve the air flow to the carbs? :)

Spend time making love with your significant other..don't waste time polishing the wheel arches around the engine or within time it will be self love only.

Hey can not be that lonely :)

Ignatius and steven
So from what u are both saying I should not tell u that I also wax and polish the underside of the boot and bonnet.oops..sorry..forgot to mention the a and b posts and the doors. You will both be glad to hear that since it is difficult for me to turn my car over, I do not wax and polish the frame (though I must say it looks good in semi-gloss black).
Ignatius, I am surprised at u to think it was love. Ofcourse it is for better air flow to those shinny chrome K&Ns :)
And steven, Lonely...Man do you have it all wrong! You would not beleive the things I have to do to keep "MY MYSTRS" and my wife happy! :)
Rick Crawford

Hey Rick,

I only wish that I did not have other things to fix/maintain and could start polishing odd places on my TR. Well, my list is getting shorter, so hopefully before the end of summer we can figure out a way to polish the underside.


Rick C. Thanks for the response, finally. 3" K&N's it is! I'll just have to put up with the hassleses involved with waxing that part of the wheel well. I believe the psychological effect will be worth the investment tho' the actual increase in HP may be more imagined. (used to run a '55 Chevy with dual quad carbs in my youth...when those babies were really sucking air the car sounded as if it would FLY!) Who needs Viagara?
J.T. Cruz

Bet u wish u still had that '55 Chevy EH? The 3" K&Ns do look sharp on the Strombergs
Ignatius, if u feel it is absolutely necessary to polish the underside! If u do figure out how to do it, then next time u come to Ontariario, come to Toronto and help me do mine:)
Rick Crawford

Steve DeLisle, Dracut, MA

One additional point regarding K&N's. I've used them on various cars including BMW's, a Miata and TR's. The filters get clogged (dirty) after a very few miles (2-3000). You really should clean and re-oil the filter with each enginer oil change. That's the only way that you'll get semi stable performance out of the filter. Not for this thread necessarily, but you need to be careful on modern engines to not over oil the filter after cleaning as the oil will foul the mass airflow sensor.


Steve DeLisle

This thread was discussed between 31/05/2002 and 28/06/2002

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