Exhaust cut outs

[Grey Vw]

Are AMAZING! I went for a drive up and down the street with the cut out closed and could barely spin the tires in 1st. A little later after working on the festiva I opened the cut out and some guy down the street said go for it. I launched in 1st, spun and shifted to second and spun a lot more(WOT since i'm not at the track) while on my drag radials. My first time making some real smoke

Even with a turbo back 2.5" exhaust, no cat and a muffler the cut out made a huge difference open on the "tire spinning dyno" and it's only 1.5" big.

It's super ghetto. Just 2" of 1.5" ID pipe welded onto the bottom of the downpipe with a plate I cut out to close it and two wing nuts holding the plate on. Cost $1.50 since I had to buy the bolts and nuts.

The track doesn't open for four more months but I think i'll be running mid 13's regularly. Thats pretty much it, i'm just really excited.

[festyfreak39]

thats awesome take some pics !!!!!! kinda trying to visualize it but i cant

[pyrothehitman]

yeah pics please, i dont fully understand what you are talking about.

[Aaronbrook37]

http://www.dmhperformance.com/ecutout.htm

There's some info and a picture of an electric setup. Imagine having that hooked up to a dashboard switch... that'd be so intense. Basically it's a valve you can install in your exhaust so that you can have a "track ready" exhaust at the flick of a switch (if electric) or turn of a valve/lever (if mechanical). The idea is that the car remains street legal, convenient to drive, and not too noisy from Monday to Friday... but that you don't have to go through the pain of uninstalling a street exhaust every time you head to the track.

You can sort of think of it like a separate wastegate dump tube... only for your entire exhaust rather than those times when you're rocking out high boost. Of course, you can't cut out the weight of a cat-back system when you're using a cutout... but the convenience factor is so great for grocery getter monster cars. And indeed... the power improvement levels are dramatic by comparison... assuming you can handle the noise and the welding required to install this sort of thing.

They're a little bit controversial though for two main reasons. The first is because they often times leak if the setup isn't kept in good condition or well constructed... I've seen many shabby junkyard chop'n'welds that just leak exhaust gas and create noise most of the time. Another concern I've read about somewhat across the Web is that people tend to get in a little bit of trouble with the authorities because they will get greedy on the highway sometimes and open'er up for a rip or two. Obviously, with a sleeper or slammed car, it's going to be practically impossible for a police officer to identify you have a cutout installed... but it's good to stay conscious of the fact that driving around the boulevards and grocery store parking lot with your dump tube open is a pretty dumb idea.

One popular system I've seen is that people convert throttle bodies into the valves, because they are often the same/similar size. Thus, people will hook up a throttle body to a splitter pipe... and from there, all that needs doing is either to turn the butterfly valve into something easy to switch/turn or to hook it up to a small lever in the cabin somewhere alternatively. That's a remarkably cool way to do it in my opinion... especially considering how affordable B3 throttle bodies are.

[Rocketman]

[Advancedynamix]

^ Matt, I think I saw one of those in a head shop in Vermont once! Where do you put the screen? Lol. That's pretty creative! I like it!

[Grey Vw]

thats awesome take some pics !!!!!! kinda trying to visualize it but i cant

yeah pics please, i dont fully understand what you are talking about.

I'll get some pics and maybe a video up tomorrow but i'll tell you guys right now it doesn't hold a candle to an electronic one or even a throttle body one but it works!

[Rocketman]

^ Matt, I think I saw one of those in a head shop in Vermont once! Where do you put the screen? Lol. That's pretty creative! I like it!

The bowl bolts to the flange at the top!

My goal with the system was to have a active, cabin controlled exhaust. But I did *not* want a cutout- so I have a muffler "bypass" if you will, I wanted it to all exit the same place.
There's a big difference in volume and tone, especially WOT. I'll have to get a video of it sometime. Much more agressive open, it's 2.5" mandrel bent from the turbo back. Big performance difference as well, turbo is much more responsive and breathes so much more in upper RPM. I suspect part of that is my 90° junction to the muffler.

[Grey Vw]

Better late then never. The reason it's dirty is cause I broke one of bolts coming out of the driveway straight instead of sideways and had to weld another on.

And I can weld good it's just that my $80 welder can't do thin stuff unless it's thick to thin.

Reallyyy ugly

[bhazard]

Holy homemade, Batman!

[zoom zoom]

First time hearing of this concept, yours looks decent and gets the job done, +rep for effort!

[festyfreak39]

haha i knew what an exhaust cutout was, i just wanted to see what on earth got done as per his description.

[bhazard]

I put a 2.5" summit cutout in mine, after the flex pipe, but before the 2.5x30 glasspack I put in at the same time. Pretty easy to reach too. Works well. Costed more than his though.

[festyfreak39]

a buddy of mine had one on his fully fully fully bulit race gas 15-1 comp neon and he rigged it up with a throttle body and a cable hidden in the glovebox

[kumalaba]

nice job grey vw!