Congratulations to vtecmec for winning May/June's Lude Of The Month, with his DIY Turbo BB1 build.
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ram air geekery
- mercutio
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that depends on what figures he has started with a ported and polished head will flow more air and therefore the figures will change if he is using cylinder volume as a measure then the figures will be pretty static over all engines @A1ex doesn't show his working out
bristol_bb4 wrote:ahhh a 5th gen, i love 5th gens
Dino wrote:I loves the 5th gen really.... just dont quote me on it...
4thgenphil wrote:Mines 4 1/4 unches mate, sorry
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- NafemanNathan
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OK, so as stated at the start, I’ve assumed no losses in friction from the piping or from the resistance of the air filter.
I’ve also assumed that it’s a smooth linear flow. I've taken the internal flow characteristics of the head into consideration, think of it more up to the filter / throttle body.
The calculation was pretty basic. I’ve taken the displacement of the H22 as 2157cc’s, so for every 1000rpm the motor gets through 2.157 cubic meters of air.
I’ve then take the speed in each gear per 1000rpm, so in 4th at 5000 rpm with an M2B4 box it’s doing 77.7 mph. I’ve then converted the speed the car is doing into meters per minute and multiplied it by the surface area of the intake pipe based in the internal diameter.
That then gives the volume of air being forced into the air pipe at any given speed, which can then be matched against the engine rpm for the speed giving the flow of air which is being forced into the intake vs the air the engine needs.
So if the value is <100% the engine is sucking air in, if the value is greater than 100% air is being pushed in. The %age value shown is then the volume difference between what is trying to be pushed in and what the engine needs. There should be a way to use this airspeed to calculate its effect on the air pressure and density but I couldn’t be arsed to look it up
I’ve also assumed that it’s a smooth linear flow. I've taken the internal flow characteristics of the head into consideration, think of it more up to the filter / throttle body.
The calculation was pretty basic. I’ve taken the displacement of the H22 as 2157cc’s, so for every 1000rpm the motor gets through 2.157 cubic meters of air.
I’ve then take the speed in each gear per 1000rpm, so in 4th at 5000 rpm with an M2B4 box it’s doing 77.7 mph. I’ve then converted the speed the car is doing into meters per minute and multiplied it by the surface area of the intake pipe based in the internal diameter.
That then gives the volume of air being forced into the air pipe at any given speed, which can then be matched against the engine rpm for the speed giving the flow of air which is being forced into the intake vs the air the engine needs.
So if the value is <100% the engine is sucking air in, if the value is greater than 100% air is being pushed in. The %age value shown is then the volume difference between what is trying to be pushed in and what the engine needs. There should be a way to use this airspeed to calculate its effect on the air pressure and density but I couldn’t be arsed to look it up
PAW rebuilt 98 prelude 228bhp & 171lb/ft R.I.P.
PAW rebuilt 01 ATR 238bhp & 164lb/ft sold
Monte Carlo Blue 02 S2K
PAW rebuilt 01 ATR 238bhp & 164lb/ft sold
Monte Carlo Blue 02 S2K
- mercutio
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its only over your head if you let it be
bristol_bb4 wrote:ahhh a 5th gen, i love 5th gens
Dino wrote:I loves the 5th gen really.... just dont quote me on it...
4thgenphil wrote:Mines 4 1/4 unches mate, sorry
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- NafemanNathan
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hahaha I didn't say I was suicidal!
...Ok, so after reading it all again, twice, the conclusion I have come to (whether right or wrong) is that everything said so far is speculative mumbo jumbo that would only be true in an ideal world of no friction, no resistance and possibly no gravity, which we don't live in, soooooo (and with absolutely no offence intended @A1ex) is all this actually meaningless??
...Ok, so after reading it all again, twice, the conclusion I have come to (whether right or wrong) is that everything said so far is speculative mumbo jumbo that would only be true in an ideal world of no friction, no resistance and possibly no gravity, which we don't live in, soooooo (and with absolutely no offence intended @A1ex) is all this actually meaningless??
- mercutio
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pretty much
bristol_bb4 wrote:ahhh a 5th gen, i love 5th gens
Dino wrote:I loves the 5th gen really.... just dont quote me on it...
4thgenphil wrote:Mines 4 1/4 unches mate, sorry
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