So my friend wants to weld up some dual exhaust on my '92.

He wants me to do true duals, and I want to ditch the current cats and mufflers and throw on some Thrush Turbo Mufflers. (1 on each side)

We don't have inspections here in MN, so I was thinking of just ditching Cats altogether, but obviously I take into account the impact on the environment.

So I was thinking then I could add one high-flow cat to each side, but my question then is what do I do with the smog pump? Any way I could get it to work with both cats on each side?

 

I would just ditch the cats and save some money. They just make it quieter lol. Then you can forget about the smog pump too.

 

Yeah like I said that's what I was thinking. Sure would make things a lot easier and cheaper for me lol.

 

A modern 3-way converter does not require the air injection setup our trucks came with from the factory. Do yourself a favor, stick to a 2.5" to 3" single exhaust. it's much cheaper and will work just as well or better than a cobbled dual exhaust setup IMHO.

 

Ae true duals good for MPG or just power?

 

Most of the time it is just for looks and sound.

 

My dynomax fake dual system (it has one pipe between the cat and the muffler, then duals out the back) sounds pretty good, I must say.

 

Thanks, main reason for going true duals is to ditch the restrictive factory y-pipe setup.

Now that it sounds like I don't need the air injection, I might opt for cats as well.

 

I have done exhaust upgrades on two similar trucks, 92 150, 302, 5sp, 4x4, Gibson headers, fake duals muffler back, VERY small muffler, cat and air pump still there, sound is great, very surprised. Couple friends were surprised it was a 302 after a ride, they called 351. Other rig F-250, 460, E4OD, 4.11, Gibsons, pump and cat gone, 3"straight thru muffler, tail pipe out curb side before rear axle. Sweet noise and this thing really runs. To my ear the fake dual is a little better noise. Lose the pump and cat. Old cat can plug, had this happen, and the pump is just waiting to freeze up and leave you on the side of the road. On the other hand hard to beat the noise of real duals with long tail pipes. Not the best power but best sound.

 

I wouldn't even bother putting cats on the truck. I didn't put any on mine when I took the one plugged one off after I bought it. I just put a quieter muffler on. We don't have inspections over my way either, and as long as you don't have some ungodly loud exhaust, nobody will check it. There are a bunch of guys around here with straight piped dodge trucks that think they sound awesome, and at least one of them (out of 6 I believe) gets pulled over pretty regularly because he just stomps on it every time he takes off. But like was said before, a single 3" set up works just as well as a dual set up. But I like the look of duals myself. Especially if they come out behind the tires at a 45* angle.

 

I agree GNR that's why I want to go with duals. I wanted 45* tips out each side.

Adding cats is going to cost another $100 or so, cheaper to go without Lol. I was just looking under my truck though and it looks like the driver's side would need a lot of bends, especially since the transfer case is in the way.

 

Most true dual setups on these trucks cross over to the passenger side to clear the transfercase and transmission and then split before or at the rear axle. Its still two pipes, just routed on the same side. When I get my new system installed next summer, I'm just going to replace from the Y-pipe back with a new cat and a new muffler. One single pipe. Not a huge fan of dual's... We have inspection here....

 

Yeah A lot of times people run them down the passenger side, otherwise you really gotta tuck them up and away so they don't hang down so far. I wish I would have taken the front tank out of my truck instead of the rear (although the pump was junk in the rear and it was half rotted out) because I think it would be a lot easier to clear exhaust without that tank there too.