Equal-length exhaust secondaries

I think this warrants its own thread. I'm not the first to do this on a 3800 but I am in the middle of an experimental exhaust project so I'll keep adding into this thread as I get things accomplished but today was a good day for my ears.
Most of us on rivperformance, these days, aren't doing performance builds on our beloved rivs like 5-15 years ago but I wish I knew about this much sooner.
So it's pretty well-agreed upon that the FWD 3800 is pretty unsoundly when uncorked. That's why I did up a whole mess of different exhaust systems and eventually went back to quiet as possible as of recent. You watch a bunch of these youtube videos of RWD cars - especially australian vehicles with the same motor and they sound pretty cool loud - like a really aggressive high performance 6 cylinder purr. Why the difference? It's 100% exhaust piping length. The cylinder banks have about the same length of piping before they join together. Our transverse layout means the front bank has significantly more pipe length before it can meet up with the rear bank (something to the tune of 3 feet). This affects exhaust pulse phasing and with our unequal length secondary piping, we get paired-up pulses that sounds kinda cool at idle but goes way sour with rpm. By the way, keeping the two exhaust banks totally separated for the whole exhaust system sounds just as bad as the stock unequal configuration. I guess it's a matter of effectively two 3-cylinder motors not sounding very nice either. But if you get the lengths right and merge them together, it sounds cool. I bet you could go more fancy and do a kind-of bundle of snakes and tune each primary on a individual basis and get it even better but that's outside my ability so I'm just looking to get the bank to bank lengths evened out.

First thing to do is just buy a set of Pacesetter style headers. The copies are a lot easier to get than the O.G pacesetters these days but doesn't matter either way. You can get them in 304 stainless for about $500 or mild steel for about $150. They are w-body headers but the main point is unlike any other header design I've seen, those keep the two exhaust banks separate at the upper downpipe region of the exhaust system. The kit includes a 2-1 junction that you slip on and the the rest of the actual downpipe connects to that. The trick is the move that 2-1 junction much farther back in the exhaust system and add piping to the short exhaust secondary bank however you can within the packaging constraints of the car to make the two banks pretty equal.

This is about where I'm at. I installed the headers on an otherwise totally stock 99 riv. I also got a whole DIY exhaust builder 16 piece piping kit for about $120. There's a number of things I need to work out later such as the oxygen sensor placement & the trans dipstick tube interfering with the header crossover pipe but for now, my mission is tuning the pipe lengths and packaging.


first setup that gave me a result I was after (really just literally throwing pipes together out of the box)
The muffler sorta merges the two not quite like an x-pipe (there's an open space in the middle of the muffler) but I wanted to see if I could make it work for neatness.







All exhaust leaks and stuff aside, this is dangerously close to sounding awesome

Sounded good.

EXCEPT FOR THE DAMN DOG RUINING THE AUDIO.

Don't get me wrong, I love dogs but if your trying to make a sound video, put him/her in the house.

BTW, I'm surprised at what those Stainless Headers cost now. All this info just further pisses me off that I let the car go.

That does sound pretty good!

Wow. That does sound pretty damn good. That's a lot of work for a sound.....

perhaps for better fit run the exhaust in parallel from the headers and at they make the short side loop back along a Y and a couple bends to one two-inlet Flowmaster... ?

The dog is my neighbor's. He barks at everything.

I got this together to a driveable point. With the one muffler pictured its really tame at idle but wow it picks up big time with some throttle. When I go forward with it, I'm probably gonna add another removable straight-through muffler at the back. It sounds really good if you drive with some aggression and get the engine to sweep through the range a bit rather than like the stock tune wants - upshifting early and lugging the car. This would be right at home on the green riv. I'm wanting more rev's and not getting them haha. On the white one, it sounds so much faster than it goes.. Blipping the throttle sounds awwwesome

I have pics and some little video clips but I'm leaving for a vacation in a few hours so I'll have to do it later. I'm doing too much lately

I got the compilation of driving clips done finally. Now I'll work my track videos from last year maybe lol

Hey Codith, been a long time.

I don't know if I'm being brilliant or retarded, but isn't the reason for the lousy exhaust sound from our 231/3.8/3800 motors because the General cheaped out and built a V6 on a V8 engine line?

By definition V8's naturally fit a 90-degreee configuration, and V6 & V12 motors fit 60 degrees...  I always figured that was the reason my exhaust sounds like crap @ 2000 RPM - which seems to be the speed that the damned PCM likes to keep it around town!   ARGHHH

I believe you're right, mark. A 90° "V" sounds better as a V-8, not so good as a V-6. Even a 60° V-6 does not usually sound "good" compared to inline configurations. VW made a V-6 in the '90s called "VR6" using a 15° "V". It was essentially an inline, and had a great sound. I-4 and I-6 engines inherently have a pleasing note, and a V-12 is basically two I-6s sharing a crank, so that explains that.

But everything is improvable, and exhausts can be tuned to emphasize or attenuate certain frequencies, so even a 3800 can be made tolerable, or even enjoyable with some experimentation. 3800 turbos sounded pretty good in the GN back in the '80s!

Oh, Hi Aaron, I thought you'd retired...  Glad I'm wrong.
Yes, we are in agreement.  As a kid I even remember my old man smog-passing a slant-6 with (california)-illegal headers because he liked the sound!

I know the VR6, but I've never actually heard/ridden/driven one.  They actually came out in 2 angles (I thing they tightened it up to 11 degrees in the 2nd version) and they built them until quite recently.

My mother - of all people- had a Turbo Regal, but it was as quiet as the Rivi with its own "dual" exhaust...  I only remember waiting until June for that big ol' Garrett T3 turbo to spin up (connected to a Q-Jet, no less.)  

Ha, I drove a Dart with 225cid Slant-6 in college. That car was quiet as a mouse, and a very smooth power delivery with copious amount of torque!

My friend had a '90s Corrado w/VR6 and a K&N cone on the intake. He let me drive it a few times. I believe the harmonies were emanating from the intake. That thing just howled like a race car.

Turbos are some of the greatest mufflers ever invented. There are not many reasons I would prefer a turbo over a blower, but the exhaust sound is one.

I'll go along with that, except for the fact that our 90-degree V6s just sound like crap @ 2 grand... 80>

AA wrote:

Ha, I drove a Dart with 225cid Slant-6 in college. That car was quiet as a mouse, and a very smooth power delivery with copious amount of torque!

I know you didn't say something good about the Dart . . .

Jack the R wrote:

AA wrote:

Ha, I drove a Dart with 225cid Slant-6 in college. That car was quiet as a mouse, and a very smooth power delivery with copious amount of torque!

I know you didn't say something good about the Dart . . .

Darts were not bad cars especially the 1971.  They were kind of awful in 1974.  See https://www.allpar.com/cars/dodge/dart.html , it's entertaining.  A better description of relevant Chrysler engineering is in the description of the 1960 Dart (you can find that easily on the Allpar site if interested).

Quote :

I know you didn't say something good about the Dart . . .

It was a terrible car with a good engine.

Until the smog made it gutless AND thirsty the slant-six was a great engine.
As for the Dart, at least they made the coupe a whole different & attractive body in the Sport & Duster...
(Anyone remember the "Conver-Triple"? I think it was a Sport body with with a crank sunroof & fold-down rear seats. Thus, it was a sport coupe, a 'convertible' and a useful wagon. I wanna' say I've also seen that body with a rear-glass & trunklid 'hatchback' like the later Novas.)

AA wrote:

Quote :

I know you didn't say something good about the Dart . . .

It was a terrible car with a good engine.

Uncle Tony has two of them -

Ahh, the Dart and the Disguster.

Loved the slant six. When well maintained and solid lifter's (early models) adjusted regularly they would last a long time.

They were good efficient commuter cars of the time. Unfortunately the sheet metal was so thin they rotted out quickly here in the northeast with all the salt used in the winter months.

I liked working on them. They were easy to work on and I made money doing just that back in the day.


EDIT: I just watched several of Uncle Tony's vid's. Or should I say as many as I could in one sitting.
He's so wired that I was feeling anxiety and needed to take a break. But I did subscribe for the future, when I have some more Klonopin to be able to watch without issues.
I like the guy and I used to be just as wired and eager to share info as he is.

Thankfully I grew up before You Tube and other social media sites.

Thanks for posting the link. It is fun and brings back a lot of memories from when I did that stuff in the 70's.

Some of the info is still applicable to the early Harley's I have when it comes to timing and adjusting the counter weights depending on the build specs of the engine.

Forgot to mention that I always considered the 318 the V8 version of the Slant-6... Great power AND mileage.

I only ever knew a single 340, (is it possible that i was a six-pack?) and was not impressed by my friend's 440 Six-Pack Superbird... To my foot, it felt like our 455 Toronado or 460 Lincoln could have blown it away from 0-60.

Rickw wrote:

Ahh, the Dart and the Disguster.

Duster's are expensive rides these days. As much or more than Hoovie's Bentley Azure which was supposedly owned by Jean-Claude Van Damme.

If you want mellow, Car Wizard is as mellow as it gets.


Eldo - I've got a 318 Charger. It's sloooow. Uncle Tony looks like he's having fun with his budget 318 Coronet build, and I'm tempted to copy what he did-



I see 4-500 hp 318 builds (usually turbocharged), which is all I should be driving in a car with no traction control without getting more high horsepower driving experience. People want to see a 440 pretty bad though, you almost have to have it. Or a new hemi.

Wow, Jack. I drove two Challenger 318s in high school - with the tiny 2-BBl carbs - and they mooooooved.... 80)

I watched the Bud Lindeman reviews for the 340 and 383 Challengers yesterday. The 383 is roughly as fast as the L67 Riviera. Maybe a little faster.

I love it Jack. Did the same guy test the 340?
Mark

I don't know enough about Bud Lindeman to say if it was the same driver for the 340 and 383 cars.

Eldo wrote:

Forgot to mention that I always considered the 318 the V8 version of the Slant-6...  Great power AND mileage.

I only ever knew a single 340, (is it possible that i was a six-pack?) and was not impressed by my friend's 440 Six-Pack Superbird...  To my foot, it felt like our 455 Toronado or 460 Lincoln could have blown it away from 0-60.

YES. A 70's Cuda with a 340 six pack/ 4 speed/  was one car I was the owners primary mechanic. I had many customers that I would perform maintenance and upgrades to their cars back in the 70's, before I moved to the Aviation trade in the 80's.

She, yes She, would call only me for all the maintenance that was required on her car. I kept it running real good and performed all the necessary preventive maintenance for her for a few years until I moved on. The 6 pack or Tri-Power required carb syncing / adjustments periodically to keep it running good and allow you to burn a lot of rubber. She, the owner, was very good at doing that. needed new rear tires at least twice a year. If I was only about 10 years older than I was I would have been sleeping with her. She was hot and knew how to drive.

I wish I had some of the special cars that I worked on for different people in my rented shop back then. I had that shop from the time I was 17 to 20 years old. 1976 to L 1979.

One of the cars I really miss is the Sunbeam Tiger. Essentially an Alpine with a ford 260 V-8 and a 4speed trans in it.
I converted that customers car to a 289 V8 with dual quad that it made it almost impossible to drive.
All you could do is drive it in a straight line, punch it, and hope you didn't drift to far into the opposing traffic.
It was a beast and I felt privileged to work on it and modify it for my customer.

He trusted me at such a young age. I always hoped I would be able to buy that car from him. But it never happened.
Instead he Gave me a 1972 Thunderbird with title as a gift one Christmas.

These are only a couple of cars I worked on back int the day, when I was young and trusted to work on somewhat wealthy peoples cars at the time.