new m3
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new m3
http://www.bmw.ca/ca/en/newvehicles/mserie.../engine/v8.html
how did bimmer make this setup reliable enough cause i doubt these lawers tune their cars every morning.
how did bimmer make this setup reliable enough cause i doubt these lawers tune their cars every morning.
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whats the difference between the butterflies and the ones for our cars. did bmw build the engine for them or do they have a kind of air box around them. i dont see why they are a pain for the s2000 but they put them in a luxury car. i thought they are loud?
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"ITBs allow each cylinder to aspirate equally, and in the most efficient way possible,"
"In a conventional plenum manifold, some cylinders are farther from the throttle than others, thus air has to travel different distances and along different paths to reach the cylinders." Aftermarket exhaust manifold companies always tout the benefits of "equal length runners" in the exhaust, so why not in the intake too?
Another problem inherent to the conventional single-throttle manifold in naturally aspirated applications is the pumping loss each cylinder incurs while 'pulling' air into combustion. "Collectively, ITBs offer a larger throttle area than would be practical to use in a single-throttle application," he explains. "So air can flow more easily through each throttle without having to be stretched through a smaller, shared single throttle, when 'pulled' into the engine."
Additionally, ITBs allow the user to custom-tailor power and torque production characteristics. Just as air most efficiently travels into an engine along a port-centerline, it is 'pulled' into an engine at the most efficient velocity through the smallest sufficient opening, at a specifically decreasing cross-sectional area. Without a lecture in fluid dynamics, this means that in custom applications, runners of ITB systems can be changed in length and width to maximize efficiency in power production for the desired part of the powerband, and to better complement the engine's intake ports. The ITB's horn-shaped runner design allows the desired cross-sectional area to be better realized than a plenum manifold could-very important to naturally aspirated engines.
Improvements in flow with ITBs also allow the addition of much more aggressive cams than can be used in conventional manifold situations. "Our ITB kits have made gains of as much as 40 whp to an otherwise stock S2000's mid-range, with over 20 whp top-end, and as much as 70 whp with cams,"
"In a conventional plenum manifold, some cylinders are farther from the throttle than others, thus air has to travel different distances and along different paths to reach the cylinders." Aftermarket exhaust manifold companies always tout the benefits of "equal length runners" in the exhaust, so why not in the intake too?
Another problem inherent to the conventional single-throttle manifold in naturally aspirated applications is the pumping loss each cylinder incurs while 'pulling' air into combustion. "Collectively, ITBs offer a larger throttle area than would be practical to use in a single-throttle application," he explains. "So air can flow more easily through each throttle without having to be stretched through a smaller, shared single throttle, when 'pulled' into the engine."
Additionally, ITBs allow the user to custom-tailor power and torque production characteristics. Just as air most efficiently travels into an engine along a port-centerline, it is 'pulled' into an engine at the most efficient velocity through the smallest sufficient opening, at a specifically decreasing cross-sectional area. Without a lecture in fluid dynamics, this means that in custom applications, runners of ITB systems can be changed in length and width to maximize efficiency in power production for the desired part of the powerband, and to better complement the engine's intake ports. The ITB's horn-shaped runner design allows the desired cross-sectional area to be better realized than a plenum manifold could-very important to naturally aspirated engines.
Improvements in flow with ITBs also allow the addition of much more aggressive cams than can be used in conventional manifold situations. "Our ITB kits have made gains of as much as 40 whp to an otherwise stock S2000's mid-range, with over 20 whp top-end, and as much as 70 whp with cams,"
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Per Wiki:
As with most M engines, the S54 again had 6 independent throttle bodies and this time electronically operated throttles (drive-by-wire throttle with no cable). Of interesting note the Double VANOS system used on the E46 was developed with Honda Motor Co.
As with most M engines, the S54 again had 6 independent throttle bodies and this time electronically operated throttles (drive-by-wire throttle with no cable). Of interesting note the Double VANOS system used on the E46 was developed with Honda Motor Co.
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From: Vilano Beach, FL
Originally Posted by 21k,Sep 18 2009, 07:11 AM
whats the difference between the butterflies and the ones for our cars. did bmw build the engine for them or do they have a kind of air box around them. i dont see why they are a pain for the s2000 but they put them in a luxury car. i thought they are loud?
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Originally Posted by 21k,Sep 18 2009, 01:46 AM
http://www.bmw.ca/ca/en/newvehicles/mserie.../engine/v8.html
how did bimmer make this setup reliable enough cause i doubt these lawers tune their cars every morning.
how did bimmer make this setup reliable enough cause i doubt these lawers tune their cars every morning.
Anything that requires aftermarket engine tuning is going to have mixed results because most tuners know jack shit about tuning a car and virtually none of them can tune to the same degree of precision as a major manufacturer.
many production cars have ITBs from the factory, though most are higher end cars. Virtually every sport bike has ITBs.
They are not particularly loud on the BMW engines because there is still a common plenum which muffles much of the sound.
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From: Tampa Florida
Originally Posted by Mr.E.G.,Sep 18 2009, 04:49 PM
ITBs have a reputation for being unreliable because you typically hear of them on car forums in the context of an aftermarket setup. Aftermarket ITBs require a significant tune to account for the difference in air flow than the car had when it ran a typical intake manifold.
Anything that requires aftermarket engine tuning is going to have mixed results because most tuners know jack shit about tuning a car and virtually none of them can tune to the same degree of precision as a major manufacturer.
many production cars have ITBs from the factory, though most are higher end cars. Virtually every sport bike has ITBs.
They are not particularly loud on the BMW engines because there is still a common plenum which muffles much of the sound.
Anything that requires aftermarket engine tuning is going to have mixed results because most tuners know jack shit about tuning a car and virtually none of them can tune to the same degree of precision as a major manufacturer.
many production cars have ITBs from the factory, though most are higher end cars. Virtually every sport bike has ITBs.
They are not particularly loud on the BMW engines because there is still a common plenum which muffles much of the sound.
