Ultimate Exhaust? Electronic Cutout Dual Exhaust

[cloudasc]

As we all know there are times when backpressure in the exhaust is good (low rpms), and other times when no backpressure is good (high rpms).

Well normally we go for a big exhaust to allow the engine to expell exhaust gasses at higher rpms (like when racing), but sacrifice low end (which we use for daily driving). This is my understanding, feel free to correct me if I'm wrong.

Well I was thinking of a way to have the best of both worlds, while still keeping things quiet. Then a light bulb went off in my head, and I thought, why not use a electronic cutout that is rpm activated (say the same time the iabs open up, like what you use to go open header at the push of a button). This way, when your driving around town, or cruising at low rpms, you are only using a single exhaust, and then when you WOT, your using a dual exhaust.

This could easily be applied to both NA and BOOST applications.

Besides the increased cost and fabrication required for a dual exhaust, is there any other downside, or would it truly be "the best of both worlds" (for daily driving, and for racing)

Thanks in advance for your input

[mndude07]

I think it would be more beneficial to get a single exhaust with an appropriate piping diameter such that you retain some midrange power, and then just get a cutout that dumps into the open air. You would see more gains by dumping the exhaust into open air than into more piping, the setup would be cheaper, and would weigh less. Besides, you'd have to make sure that the cutout isn't opening and closing as you shift while your revs rise and fall.

Your setup is a large factor of what size piping too.

Personally, I think that a 2.5" mandrel bent system with an e-cut out would really be the best of both worlds for a built F22 or h22....n/a that is.

[wherm]

that's such a cool idea! I've seen the electrical cutouts before but never thought of putting a relay on one to make it rpm activated. Just think about how VTEC would scream if the relay was activated by the Vtec solenoid (I mean in general)! Great idea! I say go for it, but just do a normal 2.25 or 2.5 exhaust to keep the city driving quieter. If you have an exhaust dump there's not much need for dual pipes.

[cloudasc]

I was actually thinking more along the lines of a dual 2.25" Exhaust System, when both are open it would be like a 3.25 to 3.5" Exhaust. The weight of the extra tubing and mufflers is a good point, but I think the gains could outweigh the extra weight, unless it was a track car. From a daily driving standpoint, i think the gains seen might be worth it. Plus it would give you more control over your exhaust then you currently have, so you could "tune" it rather easily in case of future mods require it. This is with a 200+ flywheel hp NA F22ax, or equivalent motor in mind. You could always go dual 2" for less power in mind, or even bigger, but this is as an example. Thought I would throw it out on the table.

Also keeping the noise down is a primary concern (cops don't like noise), my motor already turns heads from 2-3 blocks away (when WOT), and I still have the stock a1 exhaust and air-box... lol

[J3wman]

As we all know there are times when backpressure in the exhaust is good (low rpms), and other times when no backpressure is good (high rpms).

Well normally we go for a big exhaust to allow the engine to expell exhaust gasses at higher rpms (like when racing), but sacrifice low end (which we use for daily driving). This is my understanding, feel free to correct me if I'm wrong.

Well I was thinking of a way to have the best of both worlds, while still keeping things quiet. Then a light bulb went off in my head, and I thought, why not use a electronic cutout that is rpm activated (say the same time the iabs open up, like what you use to go open header at the push of a button). This way, when your driving around town, or cruising at low rpms, you are only using a single exhaust, and then when you WOT, your using a dual exhaust.

This could easily be applied to both NA and BOOST applications.

Besides the increased cost and fabrication required for a dual exhaust, is there any other downside, or would it truly be "the best of both worlds" (for daily driving, and for racing)

Thanks in advance for your input

maserati makes something like youre talking about, when you press the sport button the exhaust diameter increases (idk how but it does) and you get better hp at high rpm and a louder sound.