Quieter exhaust
#1
Quieter exhaust
howdy,
Ive got a 3" bore turbo to backbox exhaust on my 93WRX with no restrictions.
Im looking to quieten it down for day to day driving as my neighbours are going to lynch me because I leave for work at 6am on my early shift.
Ive searched the threads on exhausts/backboxes and im wondering that as my exhaust system is 3" bore can I use a 2.5" bore backbox or would that restrict power? ( I have'nt seen a 3" bore backbox with a lot of sound deadening only 2.5" bore ones)
my backbox at the mo has hardly any sound deadening...4" tailpipe 6" diameter backbox!
cheers peeps
Ive got a 3" bore turbo to backbox exhaust on my 93WRX with no restrictions.
Im looking to quieten it down for day to day driving as my neighbours are going to lynch me because I leave for work at 6am on my early shift.
Ive searched the threads on exhausts/backboxes and im wondering that as my exhaust system is 3" bore can I use a 2.5" bore backbox or would that restrict power? ( I have'nt seen a 3" bore backbox with a lot of sound deadening only 2.5" bore ones)
my backbox at the mo has hardly any sound deadening...4" tailpipe 6" diameter backbox!
cheers peeps
#5
Ive spoke to a few 'custom' exhaust people and they've said that a middle resonator won't fit due to the fact that ive got 3" bore pipework...basically theres no room to weld it in without it catching the bottom of the car.
Strangley enough they're more that happy to make me a middle section from 2 1/4" bore pipework for £150 ......2 1/4" bore? yeah right, "thats what we fit to all scoobies" came the reply....
Better backbox with more sound proofing I think.
Strangley enough they're more that happy to make me a middle section from 2 1/4" bore pipework for £150 ......2 1/4" bore? yeah right, "thats what we fit to all scoobies" came the reply....
Better backbox with more sound proofing I think.
#7
I do have a bung for the backbox which I have'nt fitted yet but im gonna have to on my early shift before the neighbours go mad.
Only problem is that I need something permanent and ive heard that the bungs restrict performance...not good
Only problem is that I need something permanent and ive heard that the bungs restrict performance...not good
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#10
Hi There
Hyperflow do a product called Active Exhaust System. These are made in Australia were you get a ticket for having loud exhaust systems. The Active exhaust is basically an electronically controlled throttle body in the exhaust stream. By creating back pressure in the exhaust by reducing its effective cross sectional area the noise of the exhaust is reduced. The computer supplied with the system continuously moniters the back pressure via its own map sensor and varies the butterfly to give the same back pressure in the system whatever the throttle positoin is. So effectivley you set the noise level you want and the system takes care of the rest. You can swicth it off in the cabin if you want or have it constantly modulating mapped to throttle position or exhaust back pressure. If using throttle position its quiet on part throttle untill you floor it, then its fully open and causing no restriction. These systems are now bieng fitted as OE on Jag,Lambo,corvette to name a few, but Hyperflow is the only effective system available to the aftermarket. Its an excellent product for track day use with the ever decreasing noise levels we have to abide by and eliminate the need to change back boxes etc.
cheers, Andy
Hyperflow do a product called Active Exhaust System. These are made in Australia were you get a ticket for having loud exhaust systems. The Active exhaust is basically an electronically controlled throttle body in the exhaust stream. By creating back pressure in the exhaust by reducing its effective cross sectional area the noise of the exhaust is reduced. The computer supplied with the system continuously moniters the back pressure via its own map sensor and varies the butterfly to give the same back pressure in the system whatever the throttle positoin is. So effectivley you set the noise level you want and the system takes care of the rest. You can swicth it off in the cabin if you want or have it constantly modulating mapped to throttle position or exhaust back pressure. If using throttle position its quiet on part throttle untill you floor it, then its fully open and causing no restriction. These systems are now bieng fitted as OE on Jag,Lambo,corvette to name a few, but Hyperflow is the only effective system available to the aftermarket. Its an excellent product for track day use with the ever decreasing noise levels we have to abide by and eliminate the need to change back boxes etc.
cheers, Andy
#15
Thanks for the replies guys.
STI Ben,
mate id love to take you up on the offer but mine is a powerflow jobbie that a friend of a friend did for me ( a bit of a foriegner late one evening for £100) so its a bit rough around around the edges...no disrespect to Powerflow but the guy who did mine could'nt bend 3" perfectly. Does the job though
STI Ben,
mate id love to take you up on the offer but mine is a powerflow jobbie that a friend of a friend did for me ( a bit of a foriegner late one evening for £100) so its a bit rough around around the edges...no disrespect to Powerflow but the guy who did mine could'nt bend 3" perfectly. Does the job though
#16
get a standard STi muffler and have it re flanged to fit the 3 inch centre pipe.
or get a 2.5 inch inlet muffler, and same deal, flange it to the 3 inch system.
a number of people over here in oz are starting to run 2.5 mufflers on 3 inch systems, because they get better performance out of it, particularly mid range.
plus they are generally quieter on the road.
MY99-MY00 STi mufflers are great though, i have one and it flows awesome and is very quiet, still nice and growly when the pedal is pushed though.
or get a 2.5 inch inlet muffler, and same deal, flange it to the 3 inch system.
a number of people over here in oz are starting to run 2.5 mufflers on 3 inch systems, because they get better performance out of it, particularly mid range.
plus they are generally quieter on the road.
MY99-MY00 STi mufflers are great though, i have one and it flows awesome and is very quiet, still nice and growly when the pedal is pushed though.
#17
get a standard STi muffler and have it re flanged to fit the 3 inch centre pipe.
or get a 2.5 inch inlet muffler, and same deal, flange it to the 3 inch system.
a number of people over here in oz are starting to run 2.5 mufflers on 3 inch systems, because they get better performance out of it, particularly mid range.
plus they are generally quieter on the road.
MY99-MY00 STi mufflers are great though, i have one and it flows awesome and is very quiet, still nice and growly when the pedal is pushed though.
or get a 2.5 inch inlet muffler, and same deal, flange it to the 3 inch system.
a number of people over here in oz are starting to run 2.5 mufflers on 3 inch systems, because they get better performance out of it, particularly mid range.
plus they are generally quieter on the road.
MY99-MY00 STi mufflers are great though, i have one and it flows awesome and is very quiet, still nice and growly when the pedal is pushed though.
I'm jealous !!
#20
I think ive sorted it.
At the mo im using the exhaust bung to quieten it down on my early starts for work.....really kills power though.
Im looking at a G-sports 3" exhaust or a HKS hyper 3" exhaust ....the G-sports is £50 cheaper though.
Obviously I know HKS are the dogs danglies but does anyone know if G-sport are any good?
cheers Nathan
At the mo im using the exhaust bung to quieten it down on my early starts for work.....really kills power though.
Im looking at a G-sports 3" exhaust or a HKS hyper 3" exhaust ....the G-sports is £50 cheaper though.
Obviously I know HKS are the dogs danglies but does anyone know if G-sport are any good?
cheers Nathan
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