Replacement of air filter with ram pipes and sock filters.

[skodajag]

I'm thinking of replacing the air filter box on my series II with some so-called "ram" pipes fitted with sock filters. Are there any obvious dis/advantages of doing so? I'm assuming it will run a bit weaker and the carbs will need retuning, but hopefully retaining the original needles....All suggestions and advice appreciated.

[Heuer]

You can use an ITG filter which will fit over the original inlet pipe's. Check out the Rob Beere web site for details or do a search here for ITG in the upgrades part of the Forum. You will need different needles but these are usually supplied with the filter.

[Tony]

I think it depends on why you are doing it. If it is for performance, I do not believe they will make a difference and you will end up with a lot more induction noise which can be tiresome on long journey and at high speed. In my opinion performance is about lots of small changes which compliment each other and are in balance.

If you are doing it because you like the looks, the idea or your old box needs replacing then that is a different matter and is a pesonnal choice which is fine.

[Heuer]

Tony is, of course, totally correct. Unless your engine has been upgraded in some way the ITG style filters will be more for looks than anything else. There will be a considerable increase in induction roar (the standard system is both a filter and silencer) which is great for knocking about local roads in summer but if you intend to do long tours you may want to consider putting the standard system back. Having said that I regularly do 3,000 mile tours and I have the ITG filter, albeit with an uprated engine. http://etypeuk.com/forum/viewtopic.php?t=165

[skodajag]

I'm inclined after all to leave well alone. I was vaguely assuming that trumpets plus a modern filter would improve engine efficiency, albeit only slightly, but if not it aint worth the expense. Thanks to all of you: this is a terrific forum.

[christopher storey]

The original setup is in fact very, very efficient . It minimises turbulence in the inlet tract, which is very important with SUs as their accurate calibration of depression and, therefore, mixture strength depends upon the airflow past the piston being relatively untroubled. A classic of example of where people got bitten by this was in 1275 BMC A series with a single HD6 carburetter , where substituting socks for the carefully designed filter made the piston whizz up and down unpredictably, with a total loss of calibration and, therefore, of power. Because of the awful noise it made, however, the same people were utterly convinced that their MG metro was 10 times faster. Furthermore, the other great advantage of the E type's system is that it draws cold air from the duct which the two trumpets face, rather than hot air at underbonnet temperature. This can be worth something like 2 or 3% in power terms.