Exhaust Kit or Pay a Pro

[fury fan]

If you have a lift and a weekend, and some skills/patience, it can be done at a decent savings.
PLUS - you can make sure it all fits high and tight, the way YOU want, not the way some disinterested guy decides to do it.
Blocks of wood and under-hoist prop-supports are a huge help. Insert the wood between pipe and car, mash it up, and make pipes meet.
A single prop with a car-width 2x4 can hold both pipes from 1 location.
Some things you tack-weld on teh floor, some things you weld in as you go.
You install the tailpipes first, then everything else is Promontory Point.
Plan 2-3 steps (and cuts) ahead.

BUT - don't do it unless you have another car to drive to the parts store, or to drive to work on Monday while you await more pipes/bends from Summit!

I've done the last 5 cars myself at a buddy's on his lift. 68 Fury, 70 300, 65 300, 2 Lincoln Mark 7 LSCs (5.0 HO engine) and a 88 Dippy copcar.
#1 was Summit X-pipe with TTI tails.
#2 was Summit X-pipe with Flowmaster 2.5" B-body tails.
#3 was TTI H-pipe and Flowmaster 2.5" B-body tails.
#1 thru 3 were all 2.5" throughout.
Those were all mandrel-bent except the X-pipe setups required 2 15deg crinkle-bends outboard of the trans.

#4-5 (the Lincolns) were done with Summit Mustang GT cat-back kits and 2-1/4" home-fabbed tailpipes (from individual bends).
#6 (the Diplomat) was 2-1/4" Summit X-pipe and individual bends for the tailpipes. They dumped under the quarterpanel ala 66-67 Chevelle.

I used a Summit X-pipe kit (2 of them, to get some extra long-bends) and TTI tailpipes.
A-B-E-body kits are narrower, as the exhaust cutouts are symmetrical about the driveshaft, while the C-body is symmetrical to the width of the car.
So those would be easier to fab at home.
The Summit kit isn't long enough to fit the crossmember cutout on the driverside, so some extensions are needed.
But - you're fabbing most everything under the floorpan - so what's 1 more splice?

The headpipes actually turned out to be very easy, the correct angle-cut on them got them shooting rearward, and I got both cuts with little fuss.
The TTI tailpipes didn't fit very well. Folks rave about them, I didn't have good luck.
The Flowmaster B-body pipes were much better, and are what I would use on any future C-body.

I had considered some years ago to take off one of my systems and measure the angles, buy some custom bends, and tailor a Summit kit to be a near-bolt-on for a C-body.
Make a welding fixture off of my system to lay the new pipes in to weld certain pieces together, and weld bolting flanges in strategic locations, to make it all UPS-shippable.
Have ball-flanges hit the centerline of the crossmember widths so that a guy could hook up flexpipes to his existing exhaust and have a muffler shop finish it.
But - I never have time to pursue all the ideas my brain concocts.

I found 2 threads I did on the Drydock on car #1, priddineer 19 years ago.
Must've done an OK job, they are all still on the car and only needed 1 gasket change on 1 header flange.

My X-pipe thread:
Forums / Performance Tech / Hedman shorties, X-pipe kit, TTI tailpipes - C-Body DryDock
My Hedman #780-70 shorty header review:
https://cbodydrydock.com/e107_plugins/forum/forum_viewtopic.php?22001.0

 

[mgm1986]

@fury fan - Thank you! I will take a look through these threads. Very curious about this approach as I do have access to a lift and a friend who is a welder by trade.

 

[493mike]

I'm assuming those are electronic cutouts you have added there? How well do they work and for how long? Does rust start to keep the motors from allowing the ports to open?

Yes. Doug's brand and top of the class-in my opinion.
Mike

 

[493mike]

Is that a Gear Vendors overdrive? What has been your experience with it? Would you do it again? And what car is this beautiful exhaust mounted on?

Yes. GV overdrive. I have purchased 2 of them with great results.
Car with 3" system:
Mike

 

[mgm1986]

Just got home from the exhaust shop. I found a local place that still bends and cuts custom exhaust. I ended up with a 2.5" front to back with Spelab cutouts and turbo mufflers and an X-pipe. I asked for an H-pipe but I guess they didn't have one.

Out the door it was $1250 for installation. I paid for the cutouts separately but they installed the pipe for me.

I was on the fence of doing it myself but my time has become limited and I didn't want to lose more of the driving season. It took them about 5 hours and includes a 1-year warranty.

Thank you all for the input and voting on the poll. I know the consensus was to DIY it but time got away from me.

I'll try to get photos but it's tough without a lift.

 

[UGW]

Out the door it was $1250 for installation. I paid for the cutouts separately but they installed the pipe for me.

I was on the fence of doing it myself but my time has become limited and I didn't want to lose more of the driving season. It took them about 5 hours and includes a 1-year warranty.

Just here to say there is nothing wrong with that! Working on our cars is fun, but it's not wrong to pay a professional if you have the means and want a job done quickly and correctly. A plumber and an accountant both have skills - it's not wrong to let the plumber fix the accountant's plumbing and the accountant manage the plumber's books.

 

[mgm1986]

After driving for a few hundred miles I could not stand the drone I would get in the car from 20-45 or so MPH, which is where we spend a lot of time cruising around. It was even worse with a car full of people which made conversation difficult.

I read about the theory behind the "Helmholtz" resonator but I didn't love the idea of adding more piping and hoping it would work. I also considered adding a length of pipe at the cutout flange and hoping that would work like a resonator pipe but again, more pipe and just didn't love the idea.

After buying several resonators I finally found one short enough that I could fit between the rear axle and the exhaust tip and still clear the springs and gas tank. This cut the drone by 50% or more, in my estimation, and is so much more pleasant to cruise at those slower speeds. Cause after all is said and done, if I want to wake the neighbors I can open the cutouts. But most of my driving is leisurely and should be near quiet.

I suspect a bigger muffler would have prevented the drone but with the cutouts the biggest they said would fit was the turbo muffler.

Final test will be the next cruise with four people in the car but I am optimistic this is the last time I need to deal with the exhaust.

 

[6PKRTSE]

I am not pro, but I just buy the mufflers and all of the mandrel bends, and straight tubing, make my own X pipes, mock everything up, tack in place and weld up all of my own exhaust systems for way less than TTI or any muffler shop.

 

[mgm1986]

I am not pro, but I just buy the mufflers and all of the mandrel bends, and straight tubing, make my own X pipes, mock everything up, tack in place and weld up all of my own exhaust systems for way less than TTI or any muffler shop.

That's awesome. A few folks suggested they do as well. Next time I may tackle the job myself; hopefully not any time soon!

 

[Gerald Morris]

That's awesome. A few folks suggested they do as well. Next time I may tackle the job myself; hopefully not any time soon!

I like QUIET, and have achieved it to a remarkable degree. A couple of my neighbors call Gertrude "the Tesla" for her whisper quiet creeping on these busted up paths. Originally, she came with a single 2.5" exhaust pipe running into a monstrous old Walker muffler, and had a 2" tail pipe. When that big muffler split open, I attached the dual 2.25" pipes I'd had on the same engine in our '66 Newport, complete with the mufflers. She still runs sneaky quiet, until I open the throttle enough for folks to notice.

I will likely invest in a TTI pipe set, or maybe Waldron's work one more time in some years, when I drop another engine into Gertrude. I'm researching the cost/benefits of sundry headers, and TTI makes a nice kit for that. If I adopt headers, the super quiet running of my engine will be gone, so it will have to be for some substantially higher powered plant than the stock family ride 383 we currently enjoy. I really like a quiet ride, but I also like the sound of good, well tuned headers helping a high powered V8 gulp down plenty air and fuel to SMOKE those rubber doughnuts! A 2nd gear scratch can be quite the thrill.....

 

[CBODY67]

If you are looking for a bullet-proof quiet HP exhaust system for your car, it can PURELY be "cut and try". Each engine has its own harmonics in the exhaust system, although some are similar enough (stock cams and such) that there seems to be a huge "quiet spot" of sorts.

One friend had a '70 Swinger 340 with a well-finessed stock-spec engine. He put some Flowmasters on it after they first appeared locally. With a hotter-than-stock "Purple Stripe"-series cam it was louder than it should have been. Not obnoxious, but LOUD. Another friend had a '69 Road Runner 440 6-Pak car, with an OEM-style muffler pair on it. Same thing. Too loud, but not obnoxious. They swapped mufflers and BOTH cars got quieter with no change in performance!

I had a GM car I put a Test Tube on to replace the allegedly restrictive bead cat converter. It was louder than what I wanted. In looking at specs, an E-body 383 dual exh resonator (under the rear seat) was the same length. I got a "fit kit adapter" for the test tube and put the resonator in place of it. I inspected the resonator and it was merely a straight pipe with slashes in it, in the oval-shaped body. I hoped for the best, as it did not appear to be capable of much! I was shocked that it amde so MUCH difference! Stock OEM-level quiet with a little V-8 burble in it. One reason I don't like to deviate much from stock, OEM items.

Just my experiences,
CBODY67

 

[Big_John]

I suspect a bigger muffler would have prevented the drone but with the cutouts the biggest they said would fit was the turbo muffler.

They didn't want to look.

My #2186 1968 Cadillac muffler next to the Turbo muffler that came with my TTI system.

Caddy muffler on the left.

 

[Gerald Morris]

If you are looking for a bullet-proof quiet HP exhaust system for your car, it can PURELY be "cut and try". Each engine has its own harmonics in the exhaust system, although some are similar enough (stock cams and such) that there seems to be a huge "quiet spot" of sorts.

One friend had a '70 Swinger 340 with a well-finessed stock-spec engine. He put some Flowmasters on it after they first appeared locally. With a hotter-than-stock "Purple Stripe"-series cam it was louder than it should have been. Not obnoxious, but LOUD. Another friend had a '69 Road Runner 440 6-Pak car, with an OEM-style muffler pair on it. Same thing. Too loud, but not obnoxious. They swapped mufflers and BOTH cars got quieter with no change in performance!

I had a GM car I put a Test Tube on to replace the allegedly restrictive bead cat converter. It was louder than what I wanted. In looking at specs, an E-body 383 dual exh resonator (under the rear seat) was the same length. I got a "fit kit adapter" for the test tube and put the resonator in place of it. I inspected the resonator and it was merely a straight pipe with slashes in it, in the oval-shaped body. I hoped for the best, as it did not appear to be capable of much! I was shocked that it amde so MUCH difference! Stock OEM-level quiet with a little V-8 burble in it. One reason I don't like to deviate much from stock, OEM items.

Just my experiences,
CBODY67

Some detailed volumetric measurements, optimized for the performance band you seek help make a decent first pass at optimizing for both quiet and High Performance. That's how the old engineers at Ma Par, GM and Ford did it during the Golden Age, using naught but their slide rules, cigars and martooneez. I kept that lovely old single exhaust system off Gertrude, as it might come in quite handy in a few years.

It helps when you know the actual bore dimensions, combustion chamber volume and such, especially if designing custom header tubes, allowing for the precise amount of gas ejected on the exhaust stroke, and the dimensions of the intake system in the bargain. The more data here in the initial investment will pay off. Where exactly should one place an "H" or "X" pipe? Do you want constructive wave addition to more rapidly eject gas, or something to cancel the waves into a smoother, more laminar and thus quieter flow out? Fun stuff! Come to think of it, I now get WHY the cigars and martooneez were necessary. All those First Order calculations, then WHOOPS!, somebody plussed where a minus was needed while dealing with some wave function in Fourier space..... When using tables and slide rules, translating the calculus to Fourier and laPlace likely would have been used on a regular basis, then likely put in a big reference Table. Yes, empiric Truth still is THE TRUTH, after all the number busting, BUT, the work up front CAN HELP....