Exhaust Cut Outs

[64nailhead]

I'm in need of an exhaust cutout, either electric or vacuum/boost activated. I've looked at a bunch of the prefabbed setups, but I don't think they will work for me. I have a question that I'll come to in a moment. It appears that most of the cutouts are not in the direct flow path of the exhaust which implies that full exhaust pressure is not hitting the flapper. Most of them appear that the direct pressure is designed to go through the full length exhaust piping and that the exhaust pressure will be relieved by the shorter cutout path even though it is not a 'straight shot' to the cutout. Do you think it will work if I have the cutout being in th edirect path of exhaust pressure?

The setup that I would like to do is to run a 2 1/4" pipe to the rear area and maybe include a muffler lol. It would be attached via a double slip joint so that it would allow for quick and easy removal and reinstall at the track. I would weld in the 2 1/4" pipe into a 4" down pipe that has the cutoff on the end of it. I can supply a pic if needed for a better idea of what I'm trying to accomplish. In a nutshell, I would like to put the electric cutout on the end of my 4" dump that's about 3 1/2 feet behind the turbo.

The entire reason for this for extended trips of more than an 1 or so only because it's loud and I'd like to listen to the radio without ear plugs.

 

[jlcustomz]

Many cutouts are flappers machines into a flat plate with a 3 or 4 bolt mounting pattern. you can get matching sized plates to weld up to your own pipe however you'd like to have it, inline if you want. Would be minimal flow restriction.
I won't sit here & tell you how you should design your system, just that you need to make your own pipe or have a shop make for the valves that are available.
Made my own manual cutout valves from other things before. One was inline on true duals just after an x-pipe, which in shut position turned exhaust into single y-pipe 2 into 1 effectively.
If you're needing to be cheap & don't mind a few minutes swapping, you can put a flat solid plate between 2 flanges to cap off.
Vacuum valves are full open on startup or acceleration, not always the ideal thing with most not being adjustable. Personally not sure what electric brands are best. I'd prefer a quality cable operated part, never saw a quality premade.

 

[motorheadmike]

A 2.25" pipe is going to be silly restrictive and won't make regular driving even remotely enjoyable. I would strongly suggest a 3" pipe just for routine use, just put a good muffler on it. You are going to have to decide if you want a passive or active system. Passive being you and a switch, or active being one that is triggered by manifold pressure or magic pixies from the ECM or the like.

If it is track/scumbag neighbour time only then the passive system works fine - I have them on the wagon and TBSS. QTPs on both.

However, the active system could be more effective if you are either forgetful or doing a lot of aggressive driving. The problem is timing it to where it doesn't choke out power (ie. using RPM and manifold pressure thresholds) - hence the larger pipe run to the back. The vacuum operated units are pretty limited in this regard.

Those are my thoughts.

 

[64nailhead]

I can make it open whenever I want based on either a triggered output and a manual switch also (both). That way I can't forget.

Mike, I was looking at 2.25' because I have a crap ton of it and some double slips in 2.25" I thought tht for normal driving and cruising 2.25 is more than big enough for a 5.3, but you could correct - it might be way to restrictive.

jlcustomz, I'm really wanting something that I don't have to unhook manually. I was looking at a budget electric unit from Amazon, Jegs or Summit, When at the track I'll plan to pull all of the 2.25" stuff off just for weight.

 

[81cutlass]

I bought a 2.5" boost actuated valve off fleabay for the wagon. They don't seal all that great but it allowed me to run 2" pea shooter stock exhaust and then dump open when the boost came in

 

[64nailhead]

I bought a 2.5" boost actuated valve off fleabay for the wagon. They don't seal all that great but it allowed me to run 2" pea shooter stock exhaust and then dump open when the boost came in

Any pics?

 

[81cutlass]

I ordered it off eBay and it took 7 weeks. Loud valves make the same thing but charge 5x as much. I ordered the wrong one at the time and got a vacuum actuated one and had to flip the diafram to make it boost so I ran the pipe plug for a short period.

I just Y'd it off the cat delete pipe.