Exhaust Bypass ?

[FeNder]

heya ppl ,
ive came across some of those for sale , short piece of 2.5 piping with an actuator activated butterfly , only opens at WOT ,
as my exhaust isdifferent to the starlets , got like 2-3 90 degree bend till the back , wouldnt this be a good idea , bypassing on full throttle kinda like having a side exit , but sounds quiet on normal driving ?

[FeNder]

^^

[turbojim]

i no a few lads runnin these in drift cars on the road so they dont get in the shit wit cops and it works well but i always thought it just cut the exhaust size down so less gasses got thro

where did you find em?

[FeNder]

salvage place has got them off various bmw models like 325/330s and lots of diesel cars , apparantly stock on those .

[turbojim]

oh rite cool well these ones are aftermarket they are opened and closed manually inside the car with a lever

[FeNder]

lever is interesting , those other ones take a vacuum source from the inlet mani i suppose , was kinda bulky though !

[turbojim]

ah rite as far as i no these are tidy ones they just fit onto your exhaust and you weld it in place

[durmz]

the dahlback golf has this sorta setup, runs near 900 bhp ,restrictor in the exhaust, but a pipe that goes around it when full whack, wonder how this'd work

[Monkfish]

If I'm reading this right, you're basically on about the sort of exhaust valves Aston Martins run, yeh?

Below a certain RPM, the valve is shut and the full system is used. Above a certain RPM, the valve is opened and the majority of the exhaust system is bypassed, resulting in an uncaged hell/sex noise.

Not sure what the benefits of this would be on the majority of Starlets, but I see no reason (apart from the legality issues) why you couldn't do something like that.

[FeNder]

spot on ! astons in particular yes ,
for starlets those wanting side exits but no noise all the time would be benefecial ,
for me as the rolla has got a restrictive path for the exhaust pipe , so better bypass

[350ep70gr]

Many bikes use this systems from 90s till today. The trick is you can have the benefits of the small diameter pipe and the big diameter pipe just by tricking with the baterfly. Usually those butterfly for bikes run by an ecu with a motor inside wich switch the thotle in a specific rpm. For doing this in a car in my eyes you should done two rr runs one close one open and compare the diagramms to see where during the rev you need to open.

Chris

[adi271087]

http://autospeed.com/cms/title_Butte...2/article.html
i was looking at this a while ago

[tersplat]

I'll be running one of these leading to a side exit on the tercel once the motor is done, utilize the full exhaust when you want to be quiet and avoid problems with the police, and when you want faster spool and more scare factor, flip the switch and it opens a butterfly valve in a y- pipe, to hear the difference, click on the link. The TBSS is the one with the cutouts.

http://videos.streetfire.net/video/V...-vs_681948.htm

[FeNder]

i think this one ive got here only operates via vacuum like turbo actuators / wastegate flaps , not motorised , would this still need any further map adjustment or so ?