Exhaust butterfly valve control. See pic

[Dealer Xing]

http://easyfinder.atnext.com/images/next-photos/EasyFinder/519/640pixfolder/X519-01K/01K-01.jpg

Don't have much detail about this but it is supposed to provide more flexible powerband given that you have large exhaust.

[t2000gts]

that's identical to the Apex'i ECV...i wanted one in conjunction with a Kazuma, but it's not available in the states and i dunno how you'd go about installing it. looks like it requires some welding.

[oldster]

Originally posted by t2000gts
that's identical to the Apex'i ECV...i wanted one in conjunction with a Kazuma, but it's not available in the states and i dunno how you'd go about installing it. looks like it requires some welding.

It looks like it would just bolt between the two exhaust flanges.

[Blk00SS]

Originally posted by Dealer Xing
http://easyfinder.atnext.com/images/next-photos/EasyFinder/519/640pixfolder/X519-01K/01K-01.jpg

Don't have much detail about this but it is supposed to provide more flexible powerband given that you have large exhaust.

It's a Exhaust Cutout :)

[oldster]

Originally posted by Blk00SS


It's a Exhaust Cutout :)

Are you sure? Looks more like an inline device that opens or restricts exhaust flow through the system. :confused:

[Gaps]

Both Yamaha and Honda use a similiar setup on some of their streetbikes. Variable backpressure is used to create a more flexible power delivery. Open for high rpm and restricted for low of course. Im guessing it would do very little to improve a Celica with its trick valve gear doing much the same job. I believe the Honda version is manipulated by a signal from the ECU to give best performance....2 stroke MX bikes have been running valves in the exhaust like that for years too where they are very effective at widening powerbands

[Jards88]

I think that it does a similar job to the Australian VariFlow system, except that this one is obviously manually operated.

See the following 2 Autospeed articles for details.

http://www.autospeed.com.au/A_0883/page1.html
http://www.autospeed.com.au/A_0893/page1.html

[platnm]

Gaps is right. With the powerband the celica has a large exhaust will only benefit top end whereas there is not enough backpressure down low hence the butterfly valve. it always varies backpressure through the rev range when its needed. the new model bmw's have it. check the twin exhaust tips of a new 328 and u'll see one tip has this valve from factory

[t2000gts]

how much will this quiet down say a kazuma? can you have it closed for normal driving, and open it over 3000rpm or something? but it'd still let plenty of exhaust through...so you'd still lose some low end, wouldn't you? while completely unbolted doesn't take away low end (from dynoes and butt-dynoes).

i've been looking for an exhaust cutout forever. i got one that's cast-iron, that completely redirects exhaust gas flow from the pipe to the muffler to into the air. 'cept noone welds cast-iron here. i wonder if i still have it. cost like $20. bah. i should've found that out before.

[platnm]

i'm not sure exactly how its set up to work. what i posted earlier is the theory behind it but how different manufacturers use it im not sure. ive heard rumors that the celica has one, but im not sure where it is. i have a suspicion that if the celica has one it might be up near the manifold. i think that after-market butterfly valve is supposed to replace the factory one if u upgrade ur exhuast and get rid of the factory b/fly. who knows, if the exhuast manufacturer knows what they r doin u might not even need it - depends on ur set up. dont hold me to it, thats what i heard. better of asking some one who knows what they're doin with exhuasts for our cars.