Exhaust recommendations

[Exidous]

Mine is all stainless and closes on vacuum. Just like the vette setup it's loud for the split second until vacuum comes. Then you flow it and it auto opens up once I go over 50-75kPa. That's all uncontrolled. With the MS3 it will be a piece o cake to control. Looking at the ultimate for all sorts of extra controls.

[Cobranut]

That's good for it to cycle on startup.  It'll help keep it from accumulating carbon and sticking.

[Exidous]

It's great for keeping it clean. Just don't try to explain the initial startup to my neighbors. 

[petawabit]

totally forgot I had this thread up.  For now, it's sound a little more tame, now that I got the car back, but will reevaluate when I get more of the quirks worked out and driving it more.

[MPbdy]

What vacuum valves are y'all using?

[Exidous]

Check out Ali Express and search for stainless vacuum valve 3" or w/e size you want. Make sure to pay attention to operation. Some rest closed and vacuum opens them and some vise versa. You want one that's open without vacuum.

They are measured in mm and won't slip fit. But you can butt weld them.

Or you can go with spracing and pay their stupid ass Supra prices of $400+. But the fit and finish is much higher. Mine (cheapo) operates smoothly.

I would also like to update my post about how loud dual 2.5" with dual 2.5in/out 4" round body magnaflows. Initially it was obnoxious. Terrible drone to the point of inducing a headache. About 3-400 miles later and it's totally transformed. Down right tolerable. The cam click bugs me more and that's with the valve open. The mufflers really had a huge break in. Even the drone is significantly reduced. I'm still going to add a muffled x-pipe from magnaflow. Curious how much hp I'd lose over the normal car pipe that's in there now.

[MPbdy]

I doubt a muffled X-pipe would lose any power at all.  2-3 hp at most from the increased friction of a perf tube instead of straight.

Does your valve rattle or anything?  Some of the cheaper ones aren't as tight fitting I've heard.

What does anyone think about actually placing the valve in the exhaust stream after the xpipe in one bank?  Essentially if you had dual 2.5" exhaust... it'd be dual 2.5" into x-pipe and when the valve was closed it'd be like a Y into a single 2.5".

When you hammer it the valve would open and it'd flow as normal.  I know the valves are very responsive.  With some back pressure in front of it I don't think the car would hesitate to fill the exhaust and start flowing.  For spirited driving you could just force the valve open.

I imagine the single 2.5" would quiet things down a lot...

[Exidous]

The valve is on one side on my setup. It doesn't rattle at all. Was pretty well made. No slop and smooth movement.

As a note, look up a 1/4 wave branch resonator if you aren't familiar with them. It's not as efficient as a properly implemented resonator but I have my valve 1/4 the wavelength of where I was getting drone. About 2100rpm or 153hz. Which comes out to about 25". I have the valve 25" from where the exhaust splits in the x pipe. Worked pretty well.