It's true a hose transporting cold air to the air filter box makes the engine run faster. I've experienced it for years, but I also got the impression that it needs more gas (in my case LPG)...
As for the reniflard, if you were to change it now, what would you choose: the original Citroen stuff, the British replica, or the Belgium kit?
Thanks for your advice

Well I haven't had problems with the cpd valve I had on an old 2cv a few years back, I've not tried the UK made version and based purely on my budget (nothing) and the equipment I have at my disposal I would replace the rubber internal parts on a standard Citroen reniflard with silicone. If I had more cash to spend on my car I would probably just buy new standard reniflards.

banjo,
in the absence of 'before and after' test results, guess I'm going to 'buy and try' one of these things.
I don't hold out much hope though, as a valve designed for use with a liquid doesn't usually function all that well with a gas, particularly if it's required to operate at a frequency approaching 100 Hertz.

I'm sure that someone posted about a similar check valve on another forum, that one seemed to work at tickover but not at higher rpm where it's needed most...

ken

( p.s. Anyone else recognise the 'new breather' pictured on this BMW airhead site?
http://www.bmwscotter.org/procedures/oi ... ervice.htm )

yes whats the prize?


DSC00346 by Sean602, on Flickr

OK, anyone using the Belgium kit (which I guess can be changed numerous times, and this way becoming less expensive) feels is is a good option? I was told the new Citroen reniflard doesn´t last long...

Thanks Joolz!, i'll stick with stunts. My brother did use to call me penis fingers when he first saw me working on a car, he reckoned I f@*ked everything I touched... I guess it still applies to the calculator


Thats the idea, and it does work, especially on smaller engines like ours, but it is not noticeable until around 90mph And thats on a tuned ram intake, not one that has a fan that forces air sideways instead of backwards (which is very effective mind you) who's main purpose is to feed the cylinder heads and sometimes vent the brakes.

Here is what the superbike legends say: http://www.sportrider.com/tech/146_9910_ram/index.html
and there is lots of good stuff at Autospeedon this, all based around increasing intake efficiency, but without real HP/performance gain info.

I think the Dyane type "supercharger" intake is a great mod for a 2cv, I would argue it's the cold air induction that makes a marked improvement as opposed to a ram air effect.

I still amazes me how much air internal combustion engines pump... 903litres a minute @ 3000rpm from a 602cc engine, think about what the tappets are doing at 6000rpm, they be dancing!!!

Harley

Has anybody got a known buggered reniflard they'd be able to post to me? I'll pay postage etc. I'm tempted to assemble one of each, with a manometer and see which are most effective and do a proper instruction thread with decent photos and dimensions of the refurbishment process.

Or isn't it worth it?

I wouldn't mind sending my reniflard to the UK, but wouldn't it be too expensive to post? I live far away, in Portugal...

Russ there's one on that engine I gave you.. ??

Who says there's no noticeable difference under 90? I once 'tuned' a Special which wouldn't go over 65mph with its noisy little pancake filter sat atop the carb. With some trunking and an old filter box from an old Peugoet with a ram box low down feeding the air, the difference was obvious from 60 onwards - right up to 95-100. Removing the ram box lost 5-10mph top speed. I was surprised at how spectacularly well the setup worked - however I did tune the lengths for the best result.

The cooling fan blows the air sideways, you're right, and directly into the sideways tube which is welded onto the fan housing on a Dyane. I thought perhaps it was just colder air which improved things - so I removed the ram effect with the pipe facing downwards, then replaced it and removed the fan and tried it (briefly!). There was a discernable difference, improving with the connection to the fan housing for the ram effect then more again when the fan was fitted with the slight blower effect. When you've as little as 30hp, every little improvement helps.