Thread: Air Filter Tests - Teaser

Originally Posted by Tank

John, I do know that a modern well tuned naturally aspirated petrol engine has about 75% Volumetric Effiiency (VE), any motor of similar size that was Turbo'd or Supercharged would definitely have a higher VE. So at 1 Bar. that would mean 100% VE, wouldn't it?, Regards Frank.

Not necessarily. If we take the intake manifold pressure as 1 bar, even at this pressure, for the cylinder to fill to the same pressure not only requires there to be zero flow resistance past the valves (which is never the case), but a significant period of time for the pressure to equalise, as the mass of air has to be accelerated (although canny design can arrange for it to be still moving from the shutoff of another cylinder). So no, 1 bar does not necessarily mean 100% VE.

With supercharging (whether turbo or mechanically driven) there is no theoretical limit to the VE (although there are practical limits), and it can easily exceed 100%, and probably does in many installations.

John

Originally Posted by b50bsa

I've been here as a learner for as while. Looking for advice with non to offer. This thread allows me to do so. I was going to get explicit on this topic, but, I think a general link would be better. This site is great: Bob Is The Oil Guy - Powered by Motor Oil

been a member/poster there for years
If you look hard enough you'll find some 300Tdi and Nissan TD42T oil analysis results
There are some very good people there that really know their stuff (eg. Terry Dyson/Dyson Analysis, Molakule, Bruce 381) and a lot of people that know jack and sprout a lot of garbage, but a very good board if you take the time to glean the wheat form the chaff.
It's where I first learnt of Spicers air filter tests after he posted the results right after performing them a few years back. I read them, told Ben about them on another board we are both on and he confirmed the theory behind them. It's taken a few years and Ben to come home from Germany before he could do some test of our own on Landy filters.

Originally Posted by Xtreme

There should be some sort of grammatical ban on using Defender and door seal in the same sentence!

A new oxymoron to add to my list!

Originally Posted by b50bsa

I've been here as a learner for as while. Looking for advice with non to offer. This thread allows me to do so. I was going to get explicit on this topic, but, I think a general link would be better. This site is great: Bob Is The Oil Guy - Powered by Motor Oil

Nice first Post b50bsa

what a board

Any chance of testing a uni filter. As i have one of these and bought it because i was told of its ability to stop dust penetration. The shop i bought it from was a filter specialist and strongly advised me to stay away from k&n if i was going in dusty conditions they only advise in using the k&n on sealed roads.

Originally Posted by Pedro_The_Swift

Nice first Post b50bsa

what a board

need a few more Aussies on there to keep the Yanks honest.
Good board, but some there don't have a real good sense of humour when you take the **** out of them, and don't mention anything vaguely resembling politics or criticism of GWB or you'll get nuked by the mods. (and no, it hasn't happened to me, but one of the other Aussies, Sprintman, one of the very first posters on the board had to do time in purgatory for a few months as he upset a few.
I caused a furore once by posting a piece in the humour section that had a gentle dig at the US. If some of them could've laid their hands on me they would've lynched me A bit like top Gear the other night.....)