a "what would happen if" thread

[IanSzgatti]

what would happen if you tried to split your exhaust in two starting at the downpipe...pretty much after the flange... i mean cut the downpipe to a tri-angulated tip, and then welded up you two pipes to it? (using 3100 and 3400 engines for scenario)

first and foremost im thinking oxygen sensor issues... obviously theres one stock downstream, not to mention even if there was two downstream there would still only be one upstream.

Now you could make it without being emmisions compliant easily, but it would be more interesting to try to use brains to over-come OBD2 problems... 02 sims? parralell circuits with some kind of voltage altering resistors?

im not so sure that even if you could work it out it would be benificial... i mean, the exhaust manifolds are still the same size, it's not like thats different... but i guess im wondering how much faster they could dump out into a dual pipe set-up. humor me, i am an automotive slut, i'll concider anything.

[geldartb]

im pondering setups for my own car right now

one would be which ill prob end up doing is picking up a fuel cell or a gto gas tank(basically a fuel cell) and putting that in the trunk and eliminating the gas tank underneath the car and putting a flowmaster 80 and having it dump before the tires on both sides.

another one which i recently thought up would be Y it off the down pipe where the catback pipe would bolt up. I would Y it off and use to glasspack or similar style muff's and again have it dump out before the rear tires.

both of the setups would retain the stock style downpipe setup. rear O2 sensor is useless and i have it eliminated in the pcm anyway.

[bszopi]

Umm... it wouldn't dump any faster, because your downpipe is still your restriction. You also have to look at finding room for 2 cats, 2 mufflers, and space to route 2 pipes over your rear axle. The oxygen sensor issue would definately not be my first concern.

[Mr_Efficiency]

If you were going to do that, why not just run two seperate exhaust's off each manifold and run true duals.

I run 2.5" and have the cat, 18" of pipe, cherry bomb, glasspack and then split into two (glasspack had two exits) and went out to the tips. I split it before the rear tires and ran the pipe under the gas tank and between the rear lower control arms. I made a little heat shield to protect the gas tank, I might get some header wrap for that area as well but no problems so far, its been like that for over a month now, my exhaust is almost touching the tank.

Clearance wise its fine now, might get a little low when i lower the car but you will never fine a straiter exhaust. I have no bends from the cat back except for one on each side were it comes off the glasspack each pipe makes a 30* bend and goes to the rear bumper.