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Discussion Starter · #1 ·
After looking at Marlons 155 i noticed how ineficiant the k+n looks .
It got me thinking back to my days as a biker.Suzuki had a bike with what was called a ram air system it basicaly force fed air to the carb.
So now to my plan.
Make a vent from the bottom of the front spoiler,funnel shaped,then pipe up to the filter then attach it to the filter sealing it instead of just blowing over it.My theory being that the faster you go the more air gets forced in the more power you get.
Am i fantasising here or is it possible,like i say i like a challange :rolleyes:
 
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Discussion Starter · #2 ·
Suzuki's Ram-Air system was a way of trapping air between the cylinder head fins. The cylinder head fins had a "roof" bit covering them, rather than being uncovered like regular bike engines.

It also squeezed the airflow through ever narrowing venturi, rather than just passing it along uniform-width cooling passages.

This had the tendency to speed up the airflow and in theory cool the engine more efficiently. It didn't have anything to do with the intake or supplying air to the carb's.

Anyway, your idea is still an interesting one.

The theory sounds great but airboxes are a bit of a black art - the air chamber is most efficient when it's still - F1 cars have a "ram-effect" airbox (that big hole above the pilot's head) but that's used to pressurise a pre-chamber. The airbox itself is connected to that, so that all that high-speed air does not enter the engine directly.

If I were you I'd leave the airbox alone but maybe run a big tube from it to a sealed (but "air-rammed") box.

There is a formula for the size of this box - something to do with the air vs fuel stoichometric ratio of 22:1 - a 2 ltr engine has 500cc's per cylinder so the box has to be 11 litres). Don't quote me but that's the gist of it. There's a handy gap behind the front bumper that'd hold an 11 ltr box.

Ralf S.
 
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Discussion Starter · #3 ·
Hi Shig

As I work with aircraft gas turbine engines everday at work I can hopefully explain what you are thinking about doing to the air box a little better.
The first thing is the stoichmetric mixture for engines is more like 15:1 (22:1 is running very lean). What you are looking for is a slight rise in pressure and a great mass flow of air in the inlet which would give you an increase in bhp. There is a good relationship between temp, pressure and velocity. As velocity increases both temp and pressure decrease. Like Ralf said you need to produce a larger airbox to slow the air down which therefore increase the pressure. Another advantage to a ram air charged car is the it reduces the air inlet temp which gives you denser air. The more air you can fit into the cylinder then the ecu injects more fule which of course gives you more bhp.

Hope this makes sense to you

Andy
 
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Discussion Starter · #5 ·
Hi Guys

I think i know what you mean.
correct me if i,m wrong
Could i put the filter in a sealed box and have a tube from below the radiator pressurising it

Regards Shug
 
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Discussion Starter · #6 ·
Yes you can.
Stick with me will I add some more. On gasturbine engines you want ram effect to supply the air for the engine. You don't want the engine to be sucking the air in if you catch my drift. So the more air you can supply to you air box the less air the engine has to suck in, and the air is forced in.
Remeber more air supplied the more fuel that is supplied therefore a bigger bang = more power.
I don't know if the next stag is possible because of the air mass flow sensors and the air intake temp sensor. Replacing all of the inlet pipe work with smooth pipe work (internally smooth) will also increase the amount of air supplied into the engine. Post a reply if you want how and why.

I hope all of this has information has got you thinking!

Andy
 
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Discussion Starter · #7 ·
Hi Andy
It certainly has got me thinking .Would
the area left once the air box has been removed be big enough.It looks like it could be sealed in.The oval hole at the front could feed the `box`.I want to know how and why

Regards Shug
 
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Discussion Starter · #8 ·
One thing to be careful of though is picking air up below the bumper, it would be awfully easy to vent a great deal of water through the filter and into the cylinder when the going got wet.

Steve
 
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Discussion Starter · #9 ·
Dude.... forget the airbox - it's been sorted by Alfa's engineers to work just fine.

The sort of air chamber I meant was a PRE-AIRBOX chamber, so instead of the airbox sucking air in from the atmosphere it is sucking from a pressurised chamber.

That PRE-CHAMBER is the one to pressurise, not the airbox itself.

Ralf S.
 
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Discussion Starter · #10 ·
I've been waiting for one of these periodic posts on air filters to mention this...

Anyway I was looking through my manual the other day and I found a reference to something called Exhaust Gas Recirculation. From what I could tell, in certain circumstances part of the exhaust gas is fed back through into the intake system! This helped the earth somehow by burning particulate matter or something like that.

I just wonder about all these people making the effort to get nice cold air into the plenum chamber when their car is conspiring against them but adding what I assume is hot exhaust gas into it.

If I have read this in the turbodiesel section I apologise as I no longer have the manual in front of me.
 
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Discussion Starter · #11 ·
Very true about the EGR. You can see it very clearly on a Q4, there is a small bore pipe that goes from the exhaust manifold around the timing belt end of the engine, and into the induction tract. However as I got a new exhaust manifold that didn't have the connection, this got blanked off on mine.
 

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HI

Are we talking about the 'breather' pipe ?

A lot of people make a filter on it instead of directing it into the intake pipework.

Rgds,
Eric
 
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Discussion Starter · #13 ·
stop messing and get yourself a supercharger..the correct AFR is 14/1 on petrol cars..the ecu knows how much air the system can flow if you chop up the inlet pipes without sorting out the ecu as well you may end up losing power not making it..a KnN filter might look good and sound loud but on its own you may as well pee in the wind and watch your fuel bill go up.
 
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Discussion Starter · #14 ·
Hi all,

EGR (exhaust gas recirculation) does indeed return a small amount of exhaust gas to the inlet manifold. The idea is that by diluting the intake air with exhaust gas, the air-fuel mixture will burn slower. This reduces the peak temperature of the combustion, which leads to a reduction in NOx emissions, since NOx is formed at very high temperatures only. And NOxes are BAD for the fishes in the sea and such.
It shouldn't significally affect the performance, as the amount of reciculated exhaust gas is quite small. An added benefit (I think) is that the reduced flame front speed delays the onset of knocking.

And Eric, the breather you mention vents fumes (blow-by, oil fumes) from the crankcase, either into the intake system (furry animal-friendly) or through the filter you mention straight into the nice clean air we all share with the other furry animals.
 
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