duels on stock 225

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carfan

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My 69 WSS still has it's original exhaust system on it and the rear portion over the rear-end is starting to have more in common with Swiss cheese than a tailpipe and I want to add the other side and cross over as far up as I can( it has one tip and I would like both). first question is: I noticed that the gas tank is offset, was the tank for a car with duel exhaust different? Next: What small V8 used a dual system that was smaller than 2.25.
You can buy 2.25 parts but it just seem over kill on a stock 225. This car only has 80,000 on it and is bone stock and I'd like to keep it as stock looking as I can.
Thanks,
Larry
 
Tank is offset on either single or dual exhaust. Cant offer any info on sizing. If I were doing a \6, even if I was using header or dual manifolds I would combine to 1 pipe and use 1 low restriction muffler, then not sure about split (not much room after muffler to do a split before axle). I think full duals on an inline 6 just sounds too weird.
 
I agree it sounds like a motorboat had headers with duals all the way ,not good.
 
diymirage said:
is it dutra who makes manifolds for true duals?
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yes, Doug Dutra, if he is still doing them. I'm not sure, some googleing would be in order.
Instructions to do your own on slantsix.org
 
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RogerRamRod said:
I think full duals on an inline 6 just sounds too weird.
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To each his own. LOVE the sound of my Dutra Duals with 2" pipes all the way back. On the highway, it sounds like a WW2 fighter plane to me. Old Jags sound good with inline six's and duals, too.

Seems all most folks wanna hear is a V8 these days. Heard one, heard 'em all. Every engine sings it's own song.

vm
 
RogerRamRod said:
yes, Doug Dutra, if he is still doing them. I'm not sure, some googleing would be in order.
Click to expand...
jkeff said:
I agree it sounds like a motorboat had headers with duals all the way ,not good.
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One reason for wanting to stay with stock mufflers is to keep the sound down and was thinking of crossing somewhere around tranny cross-member.
I was surprised that at Idle with the stock resonator tip it sounds the same as a v8 ( before all the holes)
 
I've owned Slants, Fords,& Jeep inlines and loved them all, but prefer them through a single pipe. Bagger Ultra Glide through a 2>1 Thunderheader, same deal.
 
Mine did have cherry bombs on it with a H cross on it. It sounded great at idle just giving it gas it sounded like someone was gargling.
 
Dutra Duals are still a thing, yes—a very, very good thing. Pipe size and muffler: Yep, pick 'em carefully; loud exhaust is fun for a couple days, then it gets old in a hurry.

I like 2" pipe off of each of the two exhaust manifolds, into this wye connector, 2-1/4" pipe from there to this muffler. It's in Walker's QuietFlow SS premium OE line, all stainless steel (which is nice for durability), made for the '01 Jeep Cherokee 4.0 so it's easily got the flow capacity for a healthy 225 and it's tuned to keep an inline-6's exhaust from droning, has a 2¼" inlet and outlet (can easily step down to a 2" tailpipe). The inlet has a 2-bolt flange meant to bolt directly to the outlet of the Jeep's catalytic converter, but there's plenty of length to the input pipe that the flange can just be sawed off in 5 seconds at the exhaust shop (or get this unflanged one. It's got the 4¼" × 9¾" housing, muffler shell 20" long, so it'll be a bit of a tight fit in an A-body, but it will fit.

2" tailpipe with resonator. If I'm rich, I like a Flowmaster HP2 stainless unit with 2" in and out. It's 18" long, which is a workable fit behind most A-body quarter panels. If I'm broke, I like a Walker № 17198 4" round can-type unit, 2" in and 2" out, with offset outlet next to a proper hanger bracket.

Speaking of that, whatever muffler you wind up with, make sure to use very soft hangers. The hook-and-O-ring type, for example. Today's popular "rod and rubber box" type transmits a lot of noise to the passenger compartment.

(Tailspout outlet 45° or greater downward.)
 
slantsixdan said:
Speaking of that, whatever muffler you wind up with, make sure to use very soft hangers. The hook-and-O-ring type, for example. Today's popular "rod and rubber box" type transmits a lot of noise to the passenger compartment.
(Tailspout outlet 45° or greater downward.)
Click to expand...

Excellent info as always, Dan. Thanks for the help. I'm about to do the exhaust on mine as well, and I've got a true dual Dutra Duals setup I'll be running, so this is quite helpful.
 
Occurs to me I answered a question other than the one that was asked -- I posted a recipe for a 6-into-2-into-1 system, which is optimal for most purposes; you get a giant benefit from the Dutra Duals without drawbacks of duals all the way to the back of the car. But if the goal is maximum (or particular) exhaust sounds, then basically just do the same thing except delete the wye connector and × 2 on the pipes, muffler, resonator, tailspout, etc. A \6 through duals without a crosspipe sounds very "rappy" up through the gears, which is fun (until it gets old).
 
These are very square-bodied cars that tend to create low-pressure areas behind them. With a straight-out-the-back tailpipe you're pulling exhaust along with you, which is (at best) unpleasant. With a down-discharge tailpipe, the exhaust hits the slipstream and doesn't get pulled along.

This is related to the reason why station wagons have side-(and down-)discharge tailpipes; the rear body shape of the wagon tends to create a BIG low-pressure area right behind it, so it really drags exhaust along, which is extra-dangerous because of the openable tailgate glass.
 
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