Mazda Rotary Club

General => General Technical => Anything Engine/Performance/Tuning related => Topic started by: steevo on December 14, 2008, 07:23:43 PM

Title: electric exhaust cut out
Post by: steevo on December 14, 2008, 07:23:43 PM
Hi,
  Im having trouble finding a decent exhaust combo for my fd.
Its got a straight through 3"system with a nur spec r and it is TOO LOUD! , but flows so much more power than the tiger back box i had before that restricts flow at around 450 hp.
Trouble is im running big ports with a t04z@1.4 bar so really need a free flowing system.
I was thinking of refitting my original tiger back box but insalling a QTP exhaust cut out valve within the mid pipe section that i could wire up via a microswitch that would open the valve on wide open throttle only, giving me maximum bhp but a nice quiet exhaust at idle and low speeds.
Anyone had any experience of these valves? would it work? and would the valve open quick enough.
I dont do trackdays so im not bothered how loud car is WOT but need it to be quiet at low speeds.
Thanks...steve
Title: electric exhaust cut out
Post by: m1tch on December 14, 2008, 10:07:24 PM
I have seen some of these fitted, I mean aston martins have these sort of valves fitted for their cars for this reason :)
Title: electric exhaust cut out
Post by: pdtaylor18 on December 14, 2008, 10:22:08 PM
Agree with you there, these valves do work and you can get the manual type that work via a cable. Having a bung fitted will rob you of 30BHP or so and also cause a little bottleneck for the exhaust flow. You can fit a silenced midpipe that will not only still retain the output but also a little less noise.  Trouble is its a rotary and with big BHP cars comes with it the noise, we have to make a noise so they can stare at the car for longer !!