Hey guys, so like many of you, I've been infected with the customization virus. Yeah, thats right, I'm like a crack head when it comes to doing stuff to my car. Gotta get my fix! Lately my pockets have been pretty light and my withdrawls have been getting severe. So I took the chrome rings off the grill, but I need more.

So I want to take off my exhaust from the flexpipe back. I know its illegal, I know its loud and its only going to be gone a day or two. Something to satasfy my craving. My question is: backpressure.

I know a lack of back pressure can cause burnt valves. (though I don't know how or the tech aspects) Is there any way to remedy this? On muscle cars you could put a washer on? Will my valves be fine for a day or two?

What about exhaust temps? I know the gases are super hot and I was wondering if it could damage my undercoating/anything else. I don't want to catch fire.

Finally, CO2. I really would like to be concious while driving. Is venting exhaust directly under the car (i.e. exhaust removal) a problem? Windows up? Down?

I've heard of a few people doing it. Sounds like fun. Live in a cul-de-sac so I wanna **** off the neighbors haha. Any cautions/pointers welcome.

 

Ehh I'd be careful. My dad did something similar on one of his old trucks and it turned into a bit of a mess. He hacked off the exhaust aft of the headers, then bolted glass packs up to the headers. The straight pipes started melting his floor, and the exhaust fumes (especially sans cats) gave him problems when sitting at red lights.

Also, being a 454 it was obnoxiously loud and he got several tickets before putting a full exhaust back on the car.

That said, TheRussian has straight pipes on his 1.8 and it sounds bad *** lol.

 

Your specific concerns about backpressire are a non-factor. With essentially no exhaust system you'll have virtually none. You should be concerned with noise and fire. Even a turbo four will be loud with nothing but the turbine to keep sound down. And you will be blasting heat on the underside of the car in a big way, not to mention that, with no cat to quench it, you have the possibility of popping fire on fast, high-rpm shifts. It's a cool effect at night of course but not the safest way to treat things on the vicinity of the dump end of your downpipe.

 

The turbo itself causes back pressure between it and the motor.

The thing you will notice is that you will pretty much lose all your low end tq on the K03. This is because you are changing the back pressure behind the turbo so much that when the exhaust flow hits the turbo the path thru the wg will have a larger drop in resistance vs the tubine path so more of the exhaust will bypass the turbo and the Ecu can not adjust for this change.

 

Cool, thanks guys. Devil: I think you've got a couple things wrong. I know I won't have pressure, thats what I'm worried about. I will have a cat. It goes Compressor|Cat|Downpipe|(Flexpipe)

So for heat, should I throw up some layers of aluminum foil on the car's underside at the exit?

And thanks mike, I kinda thought the turbo would keep my engine safe. The lack of pressure wont affect it right? and I assumed it wouldn't operate quite the same.

 

The lack of no back pressure behind the turbo will just change how its spools up and change the power band.

You can always put a turn down on the end of the down pipe so that exhaust is forced down toward the ground or toward the side of the car. Basically just like I run on my car all the time since it is only used at the track.

 

Yeah, I don't want to do that. This is a temp thing. Just to "feed the beast" as I said.

So I did it! Very fun. Instead of taking the whole exhaust off I just zip tied the pipes sleeve back off to the side. Sounds throaty and muscley but not a good kind. Low RPMs sound nice but high sound like a missing exhaust. Probably going to replace tonight because cops here are dicks. It sounds like a diesel with a huge turbo.

 

No offense dude, that's not modifying, that's hacking. Using zip ties to hold a hot exhaust is not the brightest idea. I would definitely put the exhaust back on before you die of CO poisoning or a car fire.

 

If possible get an audio/video clip before you put it back together, or catch on fire lol

 

If you pull "back" the sleeve that section isn't exactly hot seeing that the opening is now before it not after. So basically the hot exhaust gas is exiting before the wire tie.



kayakman13 - if you want to run open dump when you want to have some fun but still have a full exhaust for those normal days on the street, here is what you want. This is my old exhaust setup which is just sitting in my garage now.