Three inch exhaust

[RCE1962]

I thought all factory hi-performance 409's came with a 2½ inch exhaust system?

Any of the 348-409 guys running 3 inch exhaust? ......Recommended?

What about type of mufflers/resonators and..... H-Pipes??

Tailpipes out behind the back bumper or turned down behind the rear wheel?....or something different?

RCE1962

[SS425HP]

The factory exhaust was 2 1/2" from the header to the muffler on the high performance cars. From the muffler on back, it was 2" pipe. There was also resonators on both sides. The original pipes turned down behind the rear wheels. Anything bigger than 2 " tail pipes cuts down on tire sizes you can use. The rear pipe runs alongside the wheel in the well. I was able to get 2 1/2" to the rear, but it takes time and fitting. 3" can be done, but you would have to exit it ahead of the rear wheels. Just not enough room over the axel for 3" and tires of today. I have seen one example of an X pipe done on one of these cars. It's not easy. There is really no place to do it. The one I saw was like a box that connected the pipes under the X in the frame. Looked to be very time consuming. I think mufflers are available. I have Magnaflow on mine, but they are loud. You can look right straight through them. There are stock types available, I think from Show Cars.

Hope this helpd

Fred

[dq409]

I`m using the Flowmaster 50 series and the sound outside is great with a mellow interior sound level. You can still carry on a conversation or listen to the radio.
Out the back, 2 1/2" pipes,,,
They also have a Hushpower II that is supposed to sound like a glass pack,,
Check out the link,,,,dq

http://www.flowmastermufflers.com/mufflers.html


.

[jim_ss409]

Here's the way I did the exhaust on my Impala. http://www.348-409.com/forum/showthread.php?t=1678 It was too loud at first so I added a crossover and that helped quiet it down alot. Later I added a couple of 4" truck exhaust pipes with a set of 3" race mufflers grafted on. http://www.348-409.com/forum/showthread.php?t=4446 That made it sound really nice. The tone was deeper and a bit quieter. Still later I added a set of 3" cut outs on to the 4" truck pipes. (sorry no pictures) This helped alot for drag racing because it's hard to hear your engine running with out cutouts when you line up beside a car with open headers. After all these modifications the exhaust system works well. I think my best time through the mufflers was about 12.6 @ 111mph. If I was doing it again I do it a bit differently though. First, if I was using cast iron manifolds, shorty headers or tri-y headers I would put a crossover pipe up closer to the front just ahead of the transmission pan. Fatride's car is done this way and it looks good and has lots of road clearance. I don't think you could do it with full length headers though becaust they end too far back. I would use the 4" expansion chamber again or maybe a large chambered muffler like a Flowmaster Delta Flow. I'd put that first muffler in about the same place the factory did but I'd try and keep it up as close to the floor as posible. Then I'd run 2 1/2" pipes back the rest of the way and maybe add a cheap glasspack muffler if it was still a bit too loud. I'd also add a set of 3" boom tubes at the very end just to deepen the tone.:D

[ratkiller]

I've found the guys at [www.burnsstainless.com] a wealth of knowlege about proper x=pipe and y-pipe flow knowlege. They have some really in depth white papers on matching the exhaust flow to the head flow and stroke movement of our engines.

Good stuff. Great guys to talk to, they'll refer someone in your area for installs too if you need.

[RCE1962]

All great information and links.
I read somewhere that the cast iron manifolds (header style used in ±1964-65) came out mid 1962, however, were any of these actually installed on the 62's or were they reserved for the later models? I'd like to stick to the cast version and I like the muffler choices given. I was curious about the factory exhaust set-up and now I know.

Now about those cutouts....I saw a thread with a link to solenoid operated cutouts. If thats possible for a quasi-stock exhaust system where would they be located best without too much or any of the solenoid hardware showing at street level?

The following link was borrowed from another thread and provided by walkerheaders.

http://www.mccordcg.com/mpp/mpp.htm

Ron

[MK IISS]

RCE1962: The '63 and later style high performance exhaust manifolds were part of a mid-'62 service package that essentially changed the '62 409 to '63 400/425 horse specs. The manifolds, cam, etc. could also be purchased separately. Last I knew there is a disagreement about '62s being factory built with the updated parts. In other words I don't think anyone knows for sure.

[64ss409]

I have a 62 engine, disassembled, that has is stamped T0409QB. I think I still have the exhaust manifolds that came with it. Is that late enough in the 62 production year to have the later manifolds if the factories did make the change? I can look at them this afternoon.
Ron

[jim_ss409]

I remember a post by Vern Frantz where he said that he hadn't seen any documented late 62's with the 425 hp equipment. The exception was the 63 style single point distributor, apparently they were installed on late 62's. I have seen a set of 425hp style service package manifolds, and apparently they were available over the counter by the spring of 62. So I wouldn't be surprised if some new car buyers that wanted the latest equipment might have got the service package manifolds installed by the dealer at the time if sale.
From a performance standpoint my guess is that exhaust cut outs, or a crossover pipe, would be best if installed about 48" from where the exhaust manifold meets the front cylinder. A header design program would suggest primary pipes of about 32" and a collector length of about 13" So, that's about 45" total, I just added 3" to the length for the front cylinder so that 45" would be the average length. I remember reading somewhere that the exhaust pulses will see a rapid change in pressure, caused by a cut out or a crossover, in a way that's similar to the end of an open collector. So, the best place to put it would be right where a tuned collector would end. Apparently, you use the same total length when you're dealing with cast iron manifolds. I think it's worth trying to find the right spot to install a crossover or cut out, or even a muffler that will allow the exhaust gasses to expand suddenly, like a Flow master. But here in the real world, we sometimes just have to put things where they'll fit. From what I read a crossover will usually add a few horsepower and always reduce the exhaust noise even if it's not exactly where it ought to be.

[MK IISS]

I did some more checking on the manifolds. The 63-64 style high-perf. exhaust manifolds that were released in the '62 service package were castings 3822923 (left) & 3822924 (right). These manifolds were not factory installed on production '62 or later 409s. They were over the counter or part of the service package only. The 3822925(left) and 3822926(right) manifolds, which also came out late in 1962, were the stock production units installed on the 63 & 64 400/425 409 and Z11s. These 925 & 926 manifolds are the ones that some claim were factory installed on the very late '62 409s.