Critter

mods in the sig if it makes any difference, i've been thinking about getting cut-outs right after my collectors to uncap every now and then when i want the car to be excessive.

this is mostly due to the fact that every time nascar races start the zoom in and you can hear the audio of the cars. so i have thought about this because it is cheap and can be put back to quiet it.

i have heard that it will burn up valves or possibly tear something up. is this true? i realize that it will be super loud, throw fumes all over the place, possibly get me a ticket, give me a headache, rattle the car to pieces, and scare small children. but thats the point of having a hot-rod sometimes right.

Critter

also i have done a search and have a question related to what injuneer said:

The problem with running open headers depends on the location of the O2 sensors. If they are in the collectors, the air backwash will cause them to read "lean", and the PCM will be adding fuel the engine doesn't need, causing it to run very rich.

You don't need "backpressure" in an exhaust system. Make believe you never heard that word.


how far back do you need to be from the o2's to prevent this?

Daniel6718

probably at least 8 inches after the o2

Projectz28

The only thing it will tear up is your ears

Honestly no. It wont hurt anything.

I have heard this also about placing the O2's back a bit to prevent the air backwash also. honestly I have a real hard time believeing it. Anything off idle and you not going to have any air going back into that header. No way, no how. I give the benifit of doubt for idle...

I wouldnt put the O2 at the very end of the collector if you have room behind them, but i tend to believe that as long as they are a few inches back you should be good.

BTW, I'm with you on the back pressure. You do not need backpressure to make more tq/hp... If that were the case then every race car in the world would be running mufflers I picked up over 20hp and 30 tq Across the entire rpm range, on a dyno, by opening my cutout