Does anyone have any good pics of dutra duals installed in a later duster/valiant with power steering? Im a little concerned with a 2 1/4 in exhaust pipe being able to clear the trans cooler lines and the ps lines. It is going to be a tight fit, would I maybe have to heat wrap the exhaust? I just want a few pics for the exhaust shop to reference on. Thanks

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'74 Duster 225 Super Six w/904
14" Cragar SS wheels

I don't have any pics handy, but it probably depends greatly on the experience of the guy bending the pipes.

My install was on a '72 Swinger with PS, PB, and auto trans, and I even had the heat stove/pipe up to the air cleaner for them to work around. They first told me they couldn't get the 2" pipes I was requesting through the limited space and would have to go smaller, but they ended up squeezing it in. I don't know about 2 1/4" headpipes... Maybe if they're really good? Or maybe if you're not using the heat stove.

Either way, are you sure you need dual 2 1/4" headpipes? A single 2 1/4" is usually recommended for slants without Dutras. If you think you need more than dual 2" headpipes, you may need to go with headers.

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vm

That's correct — there's no reason or benefit to use 2¼" headpipes with Dutra Duals. Use 2" headpipes.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I dont need 2 1/4 pipes, but I would like them for a deeper tone, but if they wont fit, then I will use 2" then. Im also still kicking around the idea of a V8 and I dont want to have to replace the entire exhaust again.

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'74 Duster 225 Super Six w/904
14" Cragar SS wheels

Then you should commit to one engine or the other before you do exhaust work. You'll need significant changes to the exhaust if you swap from slant duals to V8 duals anyway.

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vm

That is the worst logic for exhaust diameter choice I have ever heard. Dual 2 1/4 head pipes are usesless with the dutras. Especially if you use the modified rear casting,and not enlarge the exit. I thought the outlet of the Dutra is only 2"? Correct me if I am wrong. Truthfully, the only reason I run 2 1/2 head pipes is because that is the size of the exit on my header flange,then I Y the two pipes into a single 2 1/4 in pipe all the way out. A single 2 1/4 in. pipe(mandrel bent) will support quite a bit of hp for the 3.7 and even more for the 2.8 and 3.2L slants. Unless you run forced induction.

Dual 2 1/4 exhaust is going to murder that precious backpressure that our little slants use for torque,unless you are planning a serious build.Trust me you wont like it when you go to hit the gas and feel like you are driving a honda civic with 400 lbs of weight in it.I think you really wont like that bell tone drone you will get right around 60-65 mph either.

Would less than 2" headpipes be better for a street car? Sounds like the smaller head pipes are better for the torque, what is the smallest you would go with Dutras running into a 2.25 for the rest of the system? I always heard that small tube headers were better for the street so this makes sense.

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Grandpa's 1974 Dart Custom 4 door 225 auto, Aluminum Radiator, 1920 Holley.

My understanding is that the diameter of the exhaust moves the power band/torque curve up or down the RPM range (smaller pipe lowers the curve, larger pipe raises it). The consensus here at .org seems to be that 2 1/4" pipe for single exhaust is a happy medium.

I've sometimes wondered if my 2" pipe/Dutra Duals might be a little big for strictly street use on a slant, but I haven't noticed any ill effects. Also, my exhaust isn't mandrel-bent, so it's not TRUE 2" anyway.

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vm

If you are not running mandrel bends,then definitly run a larger pipe. If you have ever seen the compression bend that loops over the axle,you know what I am saying.


vynn3-

Your understanding is true to an extent.You must have enough power to make use of the backpressure drop you get from going to a larger pipe. So if you have a stock slant and put a 4 in. pipe on it,its not going to do anything with the power band but diminish it. If you have a 10-1 440 and you replace your 2.5 in exhaust with a 3 in. exhaust and put it on a dyno you would notice a raise in power,but not so much of a raise in tq,but the max TQ will be higher up in the RPMs.That has been my experience anyway.

Thats another point, no place around here mandrel bends pipes, the closest one is in nashville, which is to far. If I have to use 2" I will. The 2" single thats on it now has a pretty good pinch in it anyway.

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'74 Duster 225 Super Six w/904
14" Cragar SS wheels

TTI makes headers for V-8 mopars,and sell dual exhaust kits.All of their pipes are mandrel bent if I remember correctly.If you end up wanting to run a single pipe,maybe you could call them and see if they will sell you just the drivers side pipe.Then you just have to Y the Dutras into the single pipe and you are set.

My 73 Dart has a Dutra for the front 3 cylinders, modified stock manifold for the rear 3, and dual 2 1/4" pipes that go all the way back. Have PS, PB, column shift auto. Didn't have to reroute the trans lines or anything.

They will. I bought a 3" tail pipe from the for my car.

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11.02 @ 120.56
http://www.youtube.com/watch?v=EAxRmoDgsdY
Chassis dyno
http://www.youtube.com/watch?v=wd6hFGzLJMc

Nice. How much did they charge?