Dual Exhaust Systems on 1972 and 1973 Chrysler models with 440 engines Question

[polarus]

There is no left side C body HP manifold in 72, I had to use a B body HP manifold on my 72 Polara.

 

[CBODY67]

A point of curiosity . . . I recall seeing where TTI needs the casting numbers from the exhaust manifolds being used so they can clock and angle their front pipes accordingly, so is Waldrons using the application for the car (with the correct manifolds on them) as their guide or otherwise?

Just curious,
CBODY67

 

[marko]

There is no left side C body HP manifold in 72, I had to use a B body HP manifold on my 72 Polara.

thanks for the info, @hergfest also advised me that his 74 WA patrol car had only 1 HP manifold.
i do have HP manifolds so i should be able to make things work if the waldron's exh is made for HPs

 

[MJFUR]

I used TTI dual exhaust for my 69 Chrysler 300. They did ask for the HP manifold part numbers to make the correct bends.(Various year HP manifolds can be used.) The exhaust fits like a glove, no cutting or bending needed. It's nice to get some quality parts for a change.

I've not dealt with Waldrons before, but the prices look comparable.

 

[saforwardlook]

I ordered a single exaust setup for the Eldorado through Waldron. Quality pipes fit great but the muffler was a real POC. Sound is horrible, just a loud drone. Getting that muffler replaced this spring.

Did you opt for the original factory quiet muffler or mild imposter or ????

I used TTI dual exhaust for my 69 Chrysler 300. They did ask for the HP manifold part numbers to make the correct bends.(Various year HP manifolds can be used.) The exhaust fits like a glove, no cutting or bending needed. It's nice to get some quality parts for a change.

I've not dealt with Waldrons before, but the prices look comparable.

On my 70 Chrysler 300 with a 440HP engine in it (my avatar car), I also ordered an exhaust system from TTI for it and it too installed very well and had all the correct orientations with the HP manifolds but the pipes themselves were not exactly formed just like the originals but they fit and worked well. The mufflers they supplied were more noisy than I liked but tolerable. They also needed to know the exhaust manifold numbers to get the flange orientations correct and the angles.

I would prefer, however, to go with Waldrons this time to get the correct factory looking pipes but mostly because I want the mufflers to be as quiet as stock, that they alone offer to my knowledge. The TTI exhaust system though was very high quality and easy to install.

 

[CHARLES374]

The 225hp 440 and 245hp 440 are much more than an exhaust. It is a different carburetor, different camshaft and the HP exhaust manifolds, in addition to dual exhaust.

What year(s) did they offer these ? HP motor E86 ?

 

[CBODY67]

To me, the KEY orientation is "How different?" Certainly, both engines had ThermoQuads on them, was the HP version of more cfm? More than the engine really needed, even on the normal version, I suspect. The base camshaft had already been a bit upgraded from the old 256/260 4bbl cam, so not as much difference between the newer "standard cam" and the HP cam. Certainly, it would make a difference, but just how much of that extra 20 horsepower was in the cam and the exhaust being dualled? ALL of these things would generate different part numbers, but just how much real "at the tire" difference did they make in real world horsepower? Can't forget any multi-inlet air cleaners, either! Certainly the auditory and sensory experiences of the HP motor would be nicer than for the normal motor, I suspect.

Now, IF you really want to see your head spin, compare ALL of the factory specs between the 1964 383/330 motor and the 1970 383/330 motor. Which advertised horsepower is more accurate? Then put the 383/335 motor into the mix (which NHRA factored upward to about 345 horsepower for THEIR classification purposes). Then as side issues, look at carburetor cfm, the outlet size of the earlier exhaust manifold exits, manifold shape, and torque converter "tightness" compared to the 1970 383/330. Plus cyl head ports and such.

Lots to ponder . . .
CBODY67

 

[6PKRTSE]

I have dual exhaust with Walker mufflers on my 74' New Yorker with a 440. Nice rumble but yet nice and quiet also.

 

[marko]

here some pics from the 74 chrysler manual showing some 440 & 440HP spec differences and the exhaust layouts of single & dual 440s

 

[The_Eagles’_Nest]

To me, the KEY orientation is "How different?" Certainly, both engines had ThermoQuads on them, was the HP version of more cfm? More than the engine really needed, even on the normal version, I suspect. The base camshaft had already been a bit upgraded from the old 256/260 4bbl cam, so not as much difference between the newer "standard cam" and the HP cam. Certainly, it would make a difference, but just how much of that extra 20 horsepower was in the cam and the exhaust being dualled? ALL of these things would generate different part numbers, but just how much real "at the tire" difference did they make in real world horsepower? Can't forget any multi-inlet air cleaners, either! Certainly the auditory and sensory experiences of the HP motor would be nicer than for the normal motor, I suspect.

Now, IF you really want to see your head spin, compare ALL of the factory specs between the 1964 383/330 motor and the 1970 383/330 motor. Which advertised horsepower is more accurate? Then put the 383/335 motor into the mix (which NHRA factored upward to about 345 horsepower for THEIR classification purposes). Then as side issues, look at carburetor cfm, the outlet size of the earlier exhaust manifold exits, manifold shape, and torque converter "tightness" compared to the 1970 383/330. Plus cyl head ports and such.

Lots to ponder . .

1972s had Holley 4160s, 1973s had ThermoQuads.

 

[CBODY67]

Now, look over in the transmission section and see if there are any stall speed specs. In the '78 FSM I have the stall speed specs look like something out of a drag racer's dream.

Thanks,
CBODY67

 

[marko]

Now, look over in the transmission section and see if there are any stall speed specs. In the '78 FSM I have the stall speed specs look like something out of a drag racer's dream.

Thanks,
CBODY67

from the 74 FSM

 

[saforwardlook]

from the 74 FSM

View attachment 584756

View attachment 584757

It appears things changed in 1974 at least with some of the C body applications...................................

 

[CBODY67]

When I got a '78 FSM, which was ATF oil-wicked, that was the first time I recalled seeing factory-spec stall speeds in detail. Knowing that, in general for similar applications, that the 10.75 would be higher than the 11.75 converters. But when I saw those factory 440HP stall speeds hit right at 3000rpm, I was shocked that they were that high. Especially as everybody perceived they needed an aftermarket converter for their "hot rods". BTAIM

ONE other reason that I figured out these looser converters might be needed, from what I read decades ago, was that in the decel parts of the IM240 driving cycle, the looser converters would not inversely-load (as in keep engine rpm higher during decel modes, letting it return closer to idle speed during engine braking times) the engine, making it a bit easier for the engines to get past their emissions testing. Possibly @saforwardlook might have something to add to that subject?

Now, these looser converters ALSO can make it more difficult to drive the cars for best highway fuel economy, too, especially IF the highway cruise speed rpm is below the stall speed of the converter. Back in the 1980s when all of the OEMs were having "parts warehouse clearance sales" to the dealer network, I scored a '79 THM350C transmission assy for my '77 Camaro, knowing that (at that time) a good THM350 overhaul would be about $200.00. I got the '79 Z/28, Corvette L82 spec trans assy (with converter) for that price. Which had the lockup V-6 converter in it. I had already observed that Z/28s had a looser converter in them than a normal 350 did. Those Z/28s also had 3.42/GR70-15 axle-tire size combinations, too, whereas the normal 350 Camaro would have 2.56/FR78-14 combinations. In order to get more ground clearance for the front valence panel, I put P225/70R-15 Z/28 take-offs on my car, so it ran 2000 rpm at 62mph. With that looser converter, it required a steadier foot on the throttle to get close-to-prior highway mpg figures (in the time of 55mph national speed limits!). I still do not have the converter lock-up hooked up.

When I was looking at '76 Cordobas, I wanted one with the 400HO motor, but also wanted a 2.71 rear axle ratio rather than the standard 3.21, for a couple of highway mpg more. PLUS real dual exhaust with no converters under it. But that dream was not to happen, NOR finding very many, at all, cars with that combination, W23s, and bucket seats, either. BTAIM

Back to the above charts. Notice the difference in 2-3 WOT upshift speeds for the 440-440HP compared to the normal 400-440 WOT upshift speeds. This will probably be due more to the differences in rear axle ratios more than anything else. 3.21 (usually) on the HP and 2.45/2.71 on the normals. Seems like the non-HP engines had stall speeds a few hundred rpms nigher in the '78 list, with the HPs being about the same as the '74 list?

Thanks, @marko, for posting the transmission specs pages of the '74 FSM!

CBODY67

 

[6PKRTSE]

I have had numerous 73, 74, 75, 76 Chryslers (Seven total over the years). All with 440's and all had dual exhaust, but one 75 wagon. It had a single exhaust.

 

[saforwardlook]

ONE other reason that I figured out these looser converters might be needed, from what I read decades ago, was that in the decel parts of the IM240 driving cycle, the looser converters would not inversely-load (as in keep engine rpm higher during decel modes, letting it return closer to idle speed during engine braking times) the engine, making it a bit easier for the engines to get past their emissions testing. Possibly @saforwardlook might have something to add to that subject?



CBODY67

I believe that given the engine was under some load during the driving cycle ahead of a decel, the converter would be at least at normal temperature and under decel conditions there would be an excess of air to help the warm converters effectively eliminate any excess decel HC or CO emissions.

One takeaway from seeing these charts is how do they compare to calibrations of converters in the earlier years? The numbers presented seemed unusual from my experiences with earlier model Chrysler engine calibrations and given that these engines were greatly detuned in terms of compression and power output (no thanks to the "lean burn" garbage either) plus even higher mass of the formal vehicles at least, these numbers are suspect for application to earlier vehicles....................

 

[CBODY67]

I would suspect that the torque converters from the 1964 and prior era were tighter than the '74+ specs. "Tighter" with respect to their quick response to throttle inputs than similar Ford or GM vehicles. It was noted that for the '65 model year, Chrysler allegedly loosened their torque converters a bit to decrease "Idle Creep". CAR LIFE magazine tested a '65 Satellite 383 4bbl in this respect, at a drag strip, clocking it at 7mph through the traps.

On my uncle's '63 Polara 318 2-dr hardtop with TF, I was amazed at how it responded to throttle, off-idle, with a "punch" to make a quick lh turn in traffic. It just went . . . no hesitation or anything. Our '66 Newport 383 was similar.

Back then, especially, IF you wanted something looser in torque converters, you got one of a smaller diameter than what you had. Which was usually from a six-cyl engine with the same automatic transmission. Until the factory hot rods became popular, nobody worried about "stall speed" as if you really wanted to have "street cred", you had a 4-speed anyway. UNTIL the aluminum-case TF came out. Having a 4-speed also meant there was no torque converter loading on the engine at idle, which a looser torque converter might minimize a bit, which would be needed with a hotter camshaft, usually.

My uncle traded-in a '59 Impala on the '63 Polara. They liked to go to New Mexico to the horse races, but the brakes in their Chevy were not up to the mountain driving. He was advised by friends to buy a Chrysler product as "Put it in '2' and not use the brakes" in the mountains. A testament to the TorqueFlite converter's tightness, I suspect. Seems like there is a video showing a '57 Chrysler going down a test track hill, in "D" at idle, compared to a GM competitor? The GM got their way first.

Enjoy!
CBODY67

 

[patrick66]

The '73-'74 Imperials were all, for certain, single-exhaust systems only. There really is little room under the car to route a dual system. The muffler placement is relatively easy, But from that point back, getting a symmetrical dual setup installed is impossible, due to the placement of the fuel tank. Your exhaust and tailpipes will be of uneven length.

I went through all that in my old '73 four-door Imperial back in 1998. I had an ace exhaust bender/fabricator do up the car back then, and it was a work of art; considering it all had to be custom.

Below is that very same car in around 2018 or so, in KS. That was quite the Imperial!

 

[Boydsdodge]

The '73-'74 Imperials were all, for certain, single-exhaust systems only. There really is little room under the car to route a dual system. The muffler placement is relatively easy, But from that point back, getting a symmetrical dual setup installed is impossible, due to the placement of the fuel tank. Your exhaust and tailpipes will be of uneven length.

73 C bodies have plenty of room and the frames have the provisions for tail pipe hangers on both sides.

 

[patrick66]

73 C bodies have plenty of room and the frames have the provisions for tail pipe hangers on both sides.

The Imperial does not, rest assured.