K N Filters ?

IME they're worthwhile in a racecar when you're looking for the last tiny edge, otherwise I've never felt the extremely small improvement is worth the hassle of having to wash/re-oil them.

You will get much better results performancewise if you fit a snorkel and more so a Mantec made one. Those specific snorkels have been tested by most members of the Camel Trophy Owners Club (you see all Defender and Discovery CT vehicles were fitted with Mantec snorkels) and we found that running the cars with the snorkel gave better performance, lower fuel consumption and much cleaner air filter elements when compared to running the cars without them. The solution is pretty simple. The Mantec snorkels are measured to also run with the V8 engines. Those engines required more air than the Tdi so with the Tdi there is no air restriction when compared to the engine's needs and to what the standard factory air intake position provides. In addition air from outside of the engine bay is much colder and cleaner so you get two birds with just one stone.

As for a more freely flowing air filter I can only comment about the previous type as used on Discovery 200Tdi engines and only with RamAir elements. It has made a difference and the most noticeable one was the ease with which the engine gained around 200 rpm at its rev band.

Hi Pantelis! Thanks for taking the time to share your thoughts with us, I have been thninking about fitting a Mantec snorkel on my Defender 110 TD5, and you convinced me! I also think about fitting a GKN overdrive to get the noise down. Greetings from Norway and best regards Reidar Otto

I'm a little wary of them. I ran one on a 2.25 diesel, no problems, after the hose from the standard oil-bath filter collapsed, and I was quoted a very high price for a replacement hose. I didn't notice any improvement.

If you're running an engine in standard tune, I'd doubt that the factory filter system is the limit. In these days of emission limits, the engines _have_ to get enough air.

Having said all that, a K&N will make more air available. And if you do something like fitting a bigger intercooler and upping the boost, it would be silly to ignore the air filter.

Reidar Hi,

Glad to be of assistance. If your Defender is mainly used on the road I would also suggest you swap the factory transfer box with a Discovery one. This will give you taller gearing and at significantly lower cost than fitting a GKN overdrive.

Take care Pantelis