A while back I asked what the metal pipe that connects into the rubber "Y" tube at the AAC valve was for.
This is the one which runs from the back of the block to the back of the thermostat housing but does not connect to anything. (Air wise)
Well. after careful considerations , I decided to remove it.
I also replaced the "Y" tube with a couple hoses and a 90DEG elbow.
So far, I've been running the '92 like this for 7+ days and have had NO adverse effects from it.
16585 was completely removed.14860N was replaced with an "L" assembly.
So far I'm pleased with the decision, but I'm keeping a watchful eye on it to see if it effects anything adversely.
G50 AAC Hose Deletion
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Q45tech
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Re: G50 AAC Hose Deletion (anlasak)
The closed pipe is an acoustic shock absorber length diameter tuned to attenuate some vibration/oscillation in the coolant system. say when thermostat opens/closes or an air bubble goes thru the system. Probably necessary at the high rpm the pumps run.
Ever seen water pump cavitation failure? The fins get knocked of the pump.
Be assured engineers don't waste money on adding something that is not necessary to solve some problem. Every 10 cent item must go thru a proof to accountants [multiple times] that it is ABSOLUTELY necessary as every $1 of cost gets multiplied by 12 and results in adding $12 to the MSRP.
That piece probably represents $50 added to the cars retail!
Redesign without knowing the engineering behind parts is almost never a positive thing on performance or RELIABILITY!
The IAC system [fixed amount of bypass] and the eclectronic pulses of air bypassing the throttle plate are necessary for precisely contro rpml at idle and to compensate for engine load changes and to act as a dash pot when throttle lift occurs at speed to keep engine from dying.
The ecu controls the duty cycle in fairly precise 5%increments allowing 20 steps of increasing air.........changes can result in changes......up to a point the ecu with O2 sensors is smart enough to try to fix modifications with what downsides is unknown. At idle the O2 sensors are ignored and iy takes 2-5 minutes for them to warm up at cruise so without feedback the ecu uses whats preprogrammed into memory. PHYSICAL changes can result in odd reactions.
Why change oem design when you don'tn have the technology to measure changes.
Not sure a human can feel engine changes that are less than 10%?
Ever seen water pump cavitation failure? The fins get knocked of the pump.
Be assured engineers don't waste money on adding something that is not necessary to solve some problem. Every 10 cent item must go thru a proof to accountants [multiple times] that it is ABSOLUTELY necessary as every $1 of cost gets multiplied by 12 and results in adding $12 to the MSRP.
That piece probably represents $50 added to the cars retail!
Redesign without knowing the engineering behind parts is almost never a positive thing on performance or RELIABILITY!
The IAC system [fixed amount of bypass] and the eclectronic pulses of air bypassing the throttle plate are necessary for precisely contro rpml at idle and to compensate for engine load changes and to act as a dash pot when throttle lift occurs at speed to keep engine from dying.
The ecu controls the duty cycle in fairly precise 5%increments allowing 20 steps of increasing air.........changes can result in changes......up to a point the ecu with O2 sensors is smart enough to try to fix modifications with what downsides is unknown. At idle the O2 sensors are ignored and iy takes 2-5 minutes for them to warm up at cruise so without feedback the ecu uses whats preprogrammed into memory. PHYSICAL changes can result in odd reactions.
Why change oem design when you don'tn have the technology to measure changes.
Not sure a human can feel engine changes that are less than 10%?
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elwesso
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Re: G50 AAC Hose Deletion (Q45tech)
Tech, how does that tube have anything to do with the cooling systme, since its hooked up to the IAC?
Re: G50 AAC Hose Deletion (Q45tech)
As usual Tech, you are a smorgasborg of information.
How would that tube prevent cavitation since there is no direct physical exchange between the coolant system and the secondary air system?
How would that tube prevent cavitation since there is no direct physical exchange between the coolant system and the secondary air system?
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Q45tech
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Re: G50 AAC Hose Deletion (anlasak)
Which pipe are you speaking off, one is for one thing and the other another.
Is their any difference between acoustics in water and air other than the speed of transmission and attenuation. Simple College Physics.
The same could be asked of the tuned dead end tubes in the intake design prior to air filter. Most know they are to tune [smooth ] peak system responses.
Whenever a steady state system suddenly changes states [sudden opening or closing of throttle]...........shock waves are created and there will be an audio frequency change and a sudden trough in amplitude. These waves can cancel and reinforce the tuning.
Study the sound frequency of the air entering the engine [4 pulses per rpm].......43Hz at 650 rpm, 133 Hz at 2,000 rpm 266 Hz at 4,000 rpm, etc.
Measure the length of these various closed end pipes and determine the tuning frequency = rpm they are designed to fix/protect.
Is their any difference between acoustics in water and air other than the speed of transmission and attenuation. Simple College Physics.
The same could be asked of the tuned dead end tubes in the intake design prior to air filter. Most know they are to tune [smooth ] peak system responses.
Whenever a steady state system suddenly changes states [sudden opening or closing of throttle]...........shock waves are created and there will be an audio frequency change and a sudden trough in amplitude. These waves can cancel and reinforce the tuning.
Study the sound frequency of the air entering the engine [4 pulses per rpm].......43Hz at 650 rpm, 133 Hz at 2,000 rpm 266 Hz at 4,000 rpm, etc.
Measure the length of these various closed end pipes and determine the tuning frequency = rpm they are designed to fix/protect.
Re: G50 AAC Hose Deletion (anlasak)
UPDATE: Its now been 800+ miles/ 11 days and no side effects so far from deleting the $30 hose from the system.
I'm happy so far, but will continue to update this thread as to any issues that might arrise.
I'm happy so far, but will continue to update this thread as to any issues that might arrise.
Re: G50 AAC Hose Deletion (anlasak)
June 16, 2006anlasak wrote:UPDATE: Its now been 800+ miles/ 11 days and no side effects so far from deleting the $30 hose from the system.
I'm happy so far, but will continue to update this thread as to any issues that might arrise.
No problems so far, at least none which are evident.(And I've been searching!)
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maxnix
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Re: G50 AAC Hose Deletion (anlasak)
Thanks for reporting back.
Have you measured the duty dycle of the IAC valve at idle?
Have you measured the duty dycle of the IAC valve at idle?