Dual Exhaust

ScottG wrote:


Also, CARB is not only Ca. Many states accept their EO numbers for aftermarket parts.
Keep in mind that some day all states may require testing.

True, I believe there is 12 states now that follow CARB standards.

When I did the "duals" on my 2000 Chevy, towing a 5th wheel, wife really did not like the exhaust drone even though the pipes pointed out to the sides. Looking back now, I would have to say it was a throw back to youth type of action that wasn't worth the noise, cost and very little HP gain. Also, you throw away the stock muffler which is very long life these days.

mowermech wrote:

ScottG wrote:
You can do anything you wan't after the cat (also you cannot change the configuration of the cat(s)). Anything before and including the cat is a federal no-no unless the new part has a CARB no.

CARB is California. I live in Montana. I don't care about CARB.
In fact, my Jeep won't pass CA emissions testing because Genright didn't get the CARB certification for the 30 gallon gas tank. Everything ON the tank is OEM, but the tank is different.
Montana doesn't care.

Well first off, the post wasn't directed at you.

Also, CARB is not only Ca. Many states accept their EO numbers for aftermarket parts.
Keep in mind that some day all states may require testing.

wmoses wrote:
If this is a Tow Vehicle (which I assume given the forun the thread is in) then exhaust drone could be a significant nuisance problem on any trip longer than 1/2 hour (for me) and with not much bang for the buck, the OP may wish to reconsider this "uprade". If it is not a problem then the CAT-back solution is the way to go, although typical gains would be of the order of 15 hp and may be in an rpm range that is not noticeable, depending on driving style and conditions. The upgrade woul dbe more for sound effect.

True in many ways. the best fix for exhaust drone in the cab, Is to run the pipes out the SIDE. Running them out the back lets the sound bounce off the trailer, and back into the cab. Running out the side, There is nothing for them to bounce the sound off of, Also running them out the side prevents exhaust from being sucked back into a bed cover should you ever put one on.

If this is a Tow Vehicle (which I assume given the forun the thread is in) then exhaust drone could be a significant nuisance problem on any trip longer than 1/2 hour (for me) and with not much bang for the buck, the OP may wish to reconsider this "uprade". If it is not a problem then the CAT-back solution is the way to go, although typical gains would be of the order of 15 hp and may be in an rpm range that is not noticeable, depending on driving style and conditions. The upgrade woul dbe more for sound effect.

ScottG wrote:
You can do anything you wan't after the cat (also you cannot change the configuration of the cat(s)). Anything before and including the cat is a federal no-no unless the new part has a CARB no.

CARB is California. I live in Montana. I don't care about CARB.
In fact, my Jeep won't pass CA emissions testing because Genright didn't get the CARB certification for the 30 gallon gas tank. Everything ON the tank is OEM, but the tank is different.
Montana doesn't care.

You can do anything you wan't after the cat (also you cannot change the configuration of the cat(s)). Anything before and including the cat is a federal no-no unless the new part has a CARB no.

I think maybe it can be done but is a complex and expensive operation probably not worth it for the gains. You probably know that duals from the muffler back are pretty much fake and just for looks although I did it just for fun on a Chevy truck. You might gain a few horsepower but it's mostly for looks. I think the sound and a little less backpressure comes from the muffler used and not by having 2 pipes.

As long as you retain the cats and the O2 sensors, you can cut out the factory "Y" pipe and fab up a 'true dual' setup... You'd want to incorporate an "H" or "X" pipe between the new dual pipes and not use too large a dia piping.. Something like 2.25".

But, it won't really gain you all that much, except for maybe the sound... If it was me, and you still want the dual tailpipes, go for the single in/dual out muffler as mentioned above and you will save yourself a lot of headaches in the future... ;)

Good luck!

Mitch

Single in dual out muffler...