I was just always wondered if an electronic exhaust cutout can add power or not to a N/A car. I always thought that it sounds nice when it is opened. Im running a thermal full exhaust on my civic with a b20 in it. Ive done some reading and read that itll add some sort of power at an higher RPM. Who would want to buy and install if they didnt mean to add some sort of power anyways? Now for the big question. . . is it worth it or is it not? Buy it or forget about it? Any actual n/a drivers used this? Ive read alot using it on turbo applications but not much on a n/a car.

 

theres a muffler with the flap built in.

 

Yes but it's like 500$ IIRC. I think OP is talking about the that would simulate open header(or dp on a turbo car) which is a lot cheaper and easier to install. Haven't seen to many honda's with them but i know they're comon on "scooby's" and evo's

 

I have never seen it on a Honda in person but there are some on youtube. Supposing that you have a cat and muffler then yes it should be beneficial if you place it right after the header since your exhaust gases will avoid the cat and muffler.

This is just my thoughts though, anyone else with info?

 

Exactly what I was thinking about. With a flip of a switch you have instant open header (just like them boosted guys) but will it be beneficial to a n/a car. Ive seen some Hondas in the track with the muffler removed but I never really got the point why they would do it. Do they gain something out of it or is it just for the noise? If I was to get the cutoff id install it right after the header. Any more info would be greatly appreciated. Thanks.

 

depending how big you'r exhaust is. I've ran open header here and there(LOUD AF) I always notice better middle/top end, but feel a slight loss in low end. That being said i have a 2.36ID("2.5") skunk2 exhaust. so maybe im due for a better exhaust(I,H,E,IM,TB,head milled,cams). i'd say if you can find one for the right price or make one up you'r self why not.

 

this is called and "exhaust cutout". I can not see this being easy. The collector would have to be sacrificed on your header, unless you are able to make a custom pipe to move the cat further away from the collector. The easy way out , would be to remove cat and install a custom cutout/testpipe in place. good luck.

 

I wouldnt see a problem with it as long as your a "closed circuit" or "open" i get them mixed up. Basically if your not running any O2 sensors you should be fine. I see people running exhaust out there fender all day.

If you're obd2 and still using the down stream 02 sensor it would mess up the readings and may cause you to loose power.

If your obd1 you could just install like a foot passed the sensor, wouldnt get too close or still might mess up readings.

 

open and closed loop is what you're thinking of. Assuming OP is making the power to see a real gain from this set up he would be tuned on "open loop"(making the 02 irrelivant).

 

I tried so hard to remember that too haha.. Yes "Open Loop" is what I was referring to. At what point would you want to drop o2's on a N/a build anyhow? Seems relevant info to this thread.

 

you'll do better to install a quality glass pack with stainless packing, it's straight through so there isnt much restriction, your cutout is really only to generate power under full throttle at high rpm, it's mostly useful for the dragstrip, if you are going to run at the strip a lot, just design a quick disconnect for the exhaust, it's not hard to drop it at the track

 

but there is a noticeable gain when at WOT higher in the power band.

sparksman:it all depends on what basemap/ecu you'r running. my ecu runs on constant open loop i could give it to you then you would to so to say. when you get it tuned that's when the map becomes the most important thing for the car to base it's out put on.

(I,H,E,IM,TB,Head milled,S2:T2's)

 

uh...you never want to disable the o2 on a street car. when the ecu is in closed loop it relies on the o2 and various other sensors to maintain driveability. only in open loop will the engine run entirely off the ecu maps.

even on purpose built race cars you still want to run a wideband o2 of some sort to keep an eye on the engine.

 

I have one on my n/a b18c. Made 5whp and 4wtq more. Full exhaust is a apexi ws2

 

Im well aware of what it does and how to do it on my car. Im just entertaining the idea of how to make this idea work. I know for a daily driver, especially one that changes altitudes you want a o2 sensor.

Ideally maybe you would have a program like Neptune. Use a closed map for town driving, then use a different preset map thats an open loop while at the track with your laptop. Then you wont have problems when you push the button or drop the exhuast. Personally I think a wideband should be in every car regardless open or closed loop.

 

^don't think OP's car is built to the point for all that or he'd just run a 3'' exhaust and not worry about a gimiky cut out. on evo's and sti's it's easier as there are specific kits. but i see no need for it on a mild N/A street/track car 3''>EC

 

neptune and hondata have dual map feature that switches the maps with an input trigger.

you can also set up one of the outputs to open the butterfly at higher rpms