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Triumph TR6 - Air Filter Test

While some of this should be intuitively obvious, it still makes for an interesting read....


Great article Steve. I have long been a K&N fan, particularly for the TR6, and halfway through reading it, I was wondering if I had been taken for a sucker all these years.

It seems to show up K&N in a poor light, but there are a couple of aspects which are not mentioned which I think are important for us as TR owners.

As the K&N is re-useable,the cost benefit profile is different to that of dispoable filters. Secondly, we are after high air-flow & volume for our cars, admittedly at the expense of protection, and I reckon the trade-off of "a bit more" dust in the combustion chamber is worth it. The fuel/air mix in our tractor engines is pre-set and any restrictions in the air available will result in a gradual richening of the mix.

I guess K&N's may be less appropriate for EFI cars as there is compensation for restrictions in air flow as the filter gets clogged. (and trucks as stated).
Roger H

Indeed an interesting article. Makes you think. I don't have the multi-thousand dollar test equipment, but from my perspective--Recently bought K&N replacement filters for stock air box. From a strictly drivers standpoint, I feel the K&N air filters have quickened the car, especially at higher RPM. Just a seat of the pants perception.
Hopefully this is not a result of the need to justify the expenditure.
T Cofer

all that's missing here (in the test) is a link to buy AC/Delco stock. I reject and am repulsed by the onslaught of "data". I'll keep buying crappy Fram filters (which thankfully wasn't even on the test) like I have forever, and, since it showed K and N's in a dim light I regard them with more merit than ever. This is anal retention with documentation.
Thanks Steve for posting, sorry for the rant...

p.s. people, don't forget to change your air filter when it's dirty......ok....that's all...
c.a.e. emenhiser

Does this really show the K&N in a bad light? Remember, it is like everything else out there. From a product engineering standpoint, everything is a compromise. You want better filtration, you will usually flow less air through the same nominal surface area. If you are willing to trade filtration for flow, then more "stuff" gets through. When do you need the most flow with your TR motor? When itís wide open throttle time...

Now let's think about the personal compromises we make with these cars. Do you use your TR as a daily driver? Then you might want to give up flow for filtration, same thing if you live in a particularly dusty area. Or are you like most TR owners these days and use your TR as a toy car? Carrying that a bit further, don't you tend to TRomp on the throttle a bit harder in your toy than in your daily driver just for the hell of it? Then you can afford to give up some filtration for flow (and a little more noise which almost always makes it seem quicker/faster) if you so desire.

Or are you at the far extreme like a friend of mine with what could very well be the world's scariest TR250 (a very nice car with excellent workmanship on his rebuild, but scary as it can be)? He drives the car maybe three or four times a year, runs no filtration at all because he elected to run longer air horns on his DCOEs and there is no good way for him to run filtration without butchering the bodywork.

So, what are you looking for and where do you make your compromise? Which filter is shown in a bad light is a largely function of where you are going in the decision making process. For the application in this test, K&N is not the best choice in my mind, but I can easily envision a set of test parameters where the AC filter would not fare as well. As stated in the originating post, "some of this should be intuitively obvious."

Besides, I dare say that even the sorriest filter used in this small and limited to one specific application test would make a better choice that the oil wetted mesh filters used the early TRs and even by VW into the early seventies.

This thread was discussed between 30/09/2005 and 01/10/2005

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