Which Mufflers? Crossover?

Just scored the exhaust manifold that I was missing for my CJ-6 w/304. Now I am ready to get rid of the fenderwell headers, and go back in frame w/duals exiting behind the rear tires. I will eventually end up with Edelbrock Shorty's, but since they are pricey, and the manifolds are free, why not. Manifolds are a proven setup anyhow.

Anyways, I was wondering which mufflers y'all have used and either recommend or don't recommend. Me personally, I prefer a deep throaty sound. I don't care for the glass pack, "braaaaaat, braaaaat" sound. I was thinking of the flowmaster hushpower since they are small, but I have never heard them, or read up on their performance potential. What about the other flowmasters? I know their classic 40 series is pretty loud, which I don't mind, but they can also sound "tinny," if that's a word. They've also got their off-road series. I want something deep and throaty. Brand doesn't matter....I need a combo of fit, sound, performance, and some durability.

Also, given the tight space in a CJ, do I have room for a crossover or H-pipe? I know that a crossover isn't necessary, but I would like to if it's possible. I'm not sure the extra wheelbase of the CJ-6 helps...shouldn't the crossover be as far forward as possible? If so, I would have the same clearance issues as a CJ-5.

Anyhow, and advice?

Thanks!

 

Well, the original pipes have a crossover. I'd think you could use the same route that the original pipe uses for your crossover.

I'd use two OEM style mufflers. I'm pretty sure there's enough room to put the PS pipe to the outside of the transfer case. I have seen inside-the-frame duals, but it's been too long to remember any details. In back of the TC, the two sides are a mirror of each other. The OEM pipe goes over the rear axle and comes out at the rear corner.

 

I used these.

http://www.holley.com/50054FLT.asp

They actually came with some parts when I bought the Jeep. Normal noise level at idle, sound great when you open it up. I've only got a 4.3, manifolds and duals, the 304 might be louder.

 

I just bought a new muffler for my 302 swap. Summit doesn't list many mufflers that will actually fit between the frame and the driveshaft. I finally settled on a Thrush Welded and it barely fits. I had a set of Flowmaster 50's from my Camaro that really looked small enough to fit and they weren't even close.

 

I got some turbo tubes from my local garage, look just like a class pack but not that nast loud. I actually put glass packs on first, the pulled them and put these on. They sound great when you get on it, but not anoying. They where around 4" x22" long 2 1/2" pipe. Ran duels on my 3b. manifolds with mufflers tucked up in frame rails behind Dana 18 and piped out behind rear wheels. Really happy with it.

 

So, it sounds like width is going to be my limiting factor. I found the specs on the Hushpowers, and it sounds like they should fit, but they are a bit pricey ~ $300 for the pair + the cost of the exhaust system. They are stainless, but dang!

I'm curious about the "turbo tubes" that Windyhill scored....time to do some more research.

Thanks everyone!

 

I ran the Thrush welded (offset in /offset out), under 30$ each from Jegs, fit was fine once I rotated them to about a 45 degree angle (high spot to the center line) just behind the skid plate,plenty of clearance. I'll try to get some pics on.Nice and quiet at lower rpm's but still a very aggressive sound. I just ran turn downs until I decide where I want to run the dump tubes,,,have been thinking in front of the rear tires like the Army HMMWV's.

 

I'm running stock manifolds into glasspacks with no h-pipe on mine. I don't think its too raspy sounding. I love the way my jeep sounds, and have gotten compliments. But anyway, I have a lot more room underneat sinc i'm running only the underseat fuel tank.

I dont think the Crossover/x-pipe/y-pipe/H-pipe is necessary. It may get a slightly better sound and performance, but its alot of work for minimal returns IMO.

 

My dad ran dual pipes into glasspacks on his fullsize Jeep pickup for years. It sounded mean. Really tough, not tinny or raspy or anything. But then again, that truck has a lot more wheelbase and those pipes were pretty long. Never bothered with crossovers and didn't seem to miss them.

 

The crossover is a performance issue.

Consider the SBC firing order:
1-8-4-3-6-5-7-2
The two banks are evens and odds. If we look at the LHS (odds) that's
1-0-0-3-0-5-7-0
and RHS
0-8-4-0-6-0-0-2
it's clear that the exhaust pressure in each side of the exhaust will go up and down over each cycle (two revolutions). Ideally you'd like each cylinder's exhaust to be pumping against the same back pressure as all the others, but with the V8 layout that's not possible without connecting opposite banks somehow. The crossover pipe helps to even out the pressure on each side during each cycle.