Anyone got any links or clues as to how I can run my exhaust quiet for on the roads and silly loud on the track? Im running a bung at the moment, but want adjustability and in car control of some kind. Any ideas?
Like this? Apexi-USA - Exhaust Control Valve (ECV) Somebody makes a different version that varies with how much revs you give it too.
Yeh something like that, although not too sure how much of a negative effect that would have with serious back pressure. I think ive found what I need though, just expensive; [ame=http://www.youtube.com/watch?v=K7jGYnhbQQU&feature=player_embedded]YouTube - Varex remote control muffler.[/ame]
That's a really cool system. I've had a butterfly valve in the exhaust before, and it did reduce volume, however it also massivly reduced power to a worrying level, so that diverted exhaust flow system is a really cool answer to the problem.
on an old car i had,i fitted a y piece to the exhaust before the silencer with a throttle body on the end, then it was operated by a cable into the car. so you just pull the handle and get lots of noise. only downside was it didnt seal 100%.
"guerilla exhaust systems" they do them here in holland, basicly you run 2 pipes with a valve to switch between pipes. or get an apexi valve.
Varex is 313.10 delivered to my door... Not bad at all. Just about to order one for the FD, so ill let you know how i get on.
I have a dyno sheet somewhere of an S14 running one of these and then without. It caused massive back pressure even at its most open point.
I don't see how that's possible. Once open it's hardly any restriction at all. Closed, yep sure - I can see it causing some significat back pressure. But in reality, I dont want to go racing with the valve closed. Just pootling around town off boost when thr bacon is about and in/out of my driveway. The one I am ordering is a 3" in with a 4.5" tip. I can't see the valve restricting it too much when open
actually if you were worried about every little performance gains,,, then even with it fully open it would cause massive back pressure,,, as any sharp edges in the path of an intake or exhaust flow causes a venturi effect which leads to high turbulence. i have done extensive research on this on a flow bench. but since this is not F1 you should be ok as your daily driver because im sure even like this it flows way better then your stock system
Nah man I'm finally finished in Germany. Back in the UK full time now Is the Apexi valve ok then? I just think it will do the same thing as my bung and just cause massive back up, not actually allowing the gases to go anywhere Aparently it weighs 9Kg, so yeh pretty heavy! Also when I come to buy it i'm going to try and order it without that gimmicky key fob thing, or the control box, just wire it up to a switch - OR a volume control knob in the car
A bung is shit and produce massive backpressure, it just is stupid to fit this in a 3" exhaust; it restricts the flow MORE than an OEM exhaust. Apexi ECV is nice, although it has the same problem : closed even partially means you should just drive around and never floor the pedal. But it gets much quieter. A friend of mine is using it (was in fact, the backbox exploded recently so he made some other mods and it is not currently working. Not ECV related as the ECV fits between decat and catback), quite easy and ear friendly with it quite closed, and LOUD when open.
