sounds like this is what i want to go with... really want to be able to drive around mostly with the exhaust quite as stock.
where would the cutout be welded on? just at the end of the downpipe?
i would do the tb way, but first off, i want to be able to open close it while driving and in the car . wouldnt the tb leak a little bit when closed?

 

If you turn the "idle" screw all the way back it should pretty much close it completely, the closer to the muffler the less you'd notice a small leak. But if you put it right after the downpipe (right below your feet) you'll hear every little leak.

 

maybe its because,it looks like its coming off a header rather than a turbo downpipe, so its loud as ****?

 

So what are the downsides to tuning such a setup, I'd think a open downpipe tune vs. a very restrictive stock exhaust would be a huge difference.

 

yeah, so eliminate the restrictive stock exhaust.


It's not a fail to run a cutout off a header either, LT1/LS1 guys do it ALL THE TIME and it sounds amazing, especially when downshifting an auto-x course. My Z28 sounds like something the grim reaper would drive. Cutout also helps open the exhaust up and allow for better throttle response and faster decel.

I'm putting a cutout on my Miata this weekend (although wont have video of it driving, or anything significant to contribute to this thread other than this worthless post) and plan on putting it at the 45* bend the exhaust makes as it snakes its way past the diff housing. Best placement is at a bend, the "y" of a cutout will be much more efficient than when placed in a straight pipe.

If you put it under you/off the downpipe, plan on your interior (and you) smelling like exhaust until you get back under the car and remove the cutout. Also plan on wearing ear plugs while driving. Cutouts go BEHIND THE DRIVER for best placement, if that's after your cat: yank the cat, hollow it out, or get a high flow off JEGS for $50.

 

My enthuza 3" is ******* loud and I wear earplugs every time I ride in the car. If I knew about the throttle body cutoff i would have done that for sure.

 

Something I think some of you are missing w/ the throttle body cutout is 1 key factor....


Exhaust pipe is stainless or steel.

EVERY throttle body I've ever seen is aluminum.

Try welding an aluminum throttle body to a steel exhaust pipe.

 

Why dont you just stick a pipe off the end of it so it exits alittle farther down stream?

 

Had one for a long time, love it. Had one on my Subaru and had one on my Mercedes. Loved them all. As long as you set them up correctly, cutouts can be great for performance and convenience. IMO, set up the cutout nearer the rear of the exhaust, like right before the muffler, so that the noise levels and quality when the cutout is open is loudER and deepER, without being raspy, high-pitched, and annoying. This way, the exhaust is either DP>cat>resonator>cutout... or you could do what I always do--- DP>resonator>cutout... keeps it deep and growling without rasp.

Kevin