Hi. Im going to be getting dual exhaust pipes put on my 63 Pontiac Catalina 389 soon, and i was wondering what would be the best pipe size. And since my Dad wants me to put mufflers on it, what would be the best glasspack, how long, diameter, etc.? And what would be the best location for them, and the pipes to end? Anything i missed? Thanks for your help, -Joe The Doo Wop Kid
I'd say 3 inch pipe and the shortest smittys yon can get (not sure what the real length is) and make sure that you get em' as close to the headers as possible.
3 inch? whoa thats a tad large. those are all good questions up there but you forgot one vital bit of info, what do you want it to sound like!? all the same parts put in different arangments are going to sound different.
I agree,if they'll fit. A friend switched from 2.5" to 3 " pipes with the same style mufflers and what a difference in sound !!! A Catalina's a pretty long car,it's going to take a lot of pipe and a lot of bending. Make sure the shop can handle it before you decide.
Don't forget to install a cross-over pipe (sometimes called an "H-pipe") between the duals, near the front u-joint. It'll balance the exhaust pulses, reducing the noise and helping your low & mid-range torque. 3" pipes are pretty big for a street car. I suspect many shops don't even keep that size in stock and would have to special order it. 2 1/2" is far more common. Hope this helps.
If you are using the stock cast iron manifolds, they are 2" flanges. A good muffler shop can neck down 2-1/4 and use the 2" flanges before flaring the pipe. A 2" stub piece can be welded inside the 2-1/4" pipe. Most glasspacks have a 2" louvered core that will serve as the bottle neck in the system. They will be perfectly fine for a street racer that's not trying to squeeze every tenth of a second out of his ride. You don't need 3" pipes on the street unless you are winding up big cubic in. engines to high RPMs. You'll probably have better low end throttle response with the smaller pipes. IMHO bigger isn't always better.
i agree, and realy what sound do you want becuase the three inchers are going to sound muscle car while smaller pipes might get you some rap it your going for a cruiser
thats what I keep telling my wife Go with the 2.0 or 2.5 pipe 3 inches is going to sound like a muscle car.
i almost forgot if you really want it to rap run 2-1/2 all the way backe then find the smallest tips you can.
thanks for your help guys. i just want it to sound bad ass, and not get pulled over, since its going to be my daily driver. and right now its just the stock exhaust manifolds, dont have enough money to get some 69 pontiac headers for it, since i hear those are the best for them. -Joe The Doo Wop Kid
pretty far i have: -shortest mufflers, located closest to the motor? -2.5 inch pipe, 3 inch makes it sound louder/deeper? -a cross bar (H bar) connecting the 2 pipes near the front u joint? but then what do i do if i have to take the tranny out? anything i missed? thanks, -Joe
you still havnt realy said what you want it to sound like other then "bad ass" you want a deep rumble or a cruiser rap? if you give a better idea of what sound you want im sure we can give you a golden recipie to get it on the cheap but "bad ass" could be anything. as far as the cross over i think its a combination between creative placement or just drop the exhaust to get the trani out
I remember a post a few months ago about getting one "glasspack" longer than the other. So you would have one 30" and one 21" for example, I'd like to try that on my next project. If it were my car I'd go with the 2 1/2 pipes. and run bellflowers too ha ha
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