Since the exhaust we're replacing ended at the back axle, we knew there was a chance that the full TTI system could be slightly more restrictive since it included tailpipes. Even so, we figured the headers would definitely improve our stock 383's power numbers and were eager to see by how much. On the dyno, our Newport made a best pull of 209.87 horsepower at 4,400 rpm with the stock manifolds and hacked together 2.5-inch exhaust system. Peak torque was 286.56 lb/ft at 3,300 rpm, which is about right for a stock 383 measuring power at the back wheels. With our baseline established, we got busy removing our car's old manifolds and exhaust and installing the new headers and exhaust system from TTI.
We've installed TTI systems in the past, and have always found that if we read the included instructions, installation is easy. In fact, the only time we had a problem with TTI products was on a vehicle in which the engine was moved from the factory location, so it really was our problem and not TTI's. Luckily, the TTI instructions listed how to check for proper engine location and we quickly corrected the issue. Working on our Newport, we decided to install our headers first, which required pulling the engine mount bolt out and jacking up each side of the engine for clearance. As a test, we checked to see if the headers could be slid in without jacking the engine and they can't. Of course if the engine isn't in the car yet the headers can simply be put in place prior to engine installation, but in our case we jacked the engine up and installed them from the bottom per the instructions. It was a tight fit, and the starter had to be removed, but we got the headers in place in about an hour using a lift for the car and transmission jack for the engine. You could probably install the headers with jack stands and a jack, but the lift made the operation much easier.
Working from the rear of the car, we began installing the exhaust next and started with the tailpipes. TTI tries to utilize factory holes for hanger mounting when able, and on our Newport, the muffler hangers bolted directly to holes in the factory frame. For our tailpipes, we had to drill a hole in the side of each rear frame rail for the hangers, but this was the only fabrication necessary. Working forward, we installed our mufflers and H-pipe, and connected the system to the headers with the pre-bent and welded adapters supplied in our kit. For headers of different brands, TTI also has an adapter system to connect the headers to the exhaust. Because our car has an aftermarket rear sway bar, the tailpipes were too close for our comfort, but by shimming the sway bar mount we got adequate clearance. This isn't a TTI problem, just one of those issues you run into when utilizing equipment that the Chrysler never had from the factory, like a rear sway bar.
TTI offers a choice of exhaust tips, but since we prefer a factory look for this car we chose the stock-style turn downs. The turn downs (or tips) simply slide over the tailpipe and are held on with band-style exhaust clamps. The instructions say that for certain applications the ends of the tailpipes may need to be cut for proper tip placement, but the tips fit perfectly on our '69 Chrysler Newport. With the exhaust installation complete, it was back to the dyno.
One of the best feelings when modifying a car is getting to hear the sound of new dual exhaust for the first time. When we fired up the Newport we were impressed by the quietness of the car. Without the ticking of manifold leaks and noise of the loud mufflers the car was amazingly smooth and quiet. During the drive over to the dyno we were further impressed as we experienced no rattles and no drone at highway speed. And no fumes either which was an even better benefit.
Strapped to the Dynojet chassis dyno, we made two back to back dyno pulls netting nearly identical results. Horsepower was up by over five percent at 221.81, and torque was up as well at 297.99 lb/ft. This is an improvement of some 12 horsepower and nearly 12 lb/ft of torque, simply by installing an exhaust system that fits great and is far quieter than the exhaust it replaced. The 383 in our Newport is milder than even a stock 383 HP, with dish pistons and only 8.5:1 compression, but simple math tells us that replacing manifolds and exhaust on a more powerful engine would net even more dramatic results.
The Cash Outlay
|TTI Coated C-Body headers
|TTI C-Body 2.5 inch exhaust
|Silicone for Header Bolts
Run Date: 3/27/2012 10:54:05 AM
Run Date: 3/30/2012 9:10:27 AM
7 With the tailpipes in place the mufflers and then the exhaust pipes between the muffler
8 Since we used TTI headers, we simply bolted the exhaust to the headers using the suppli
9 Our exhaust fit nicely with no interference and plenty of ground clearance. The tailpip
10 We dyno'd our Chrysler on our Dynojet chassis dyno with the old exhaust and again with
11 Our stock, low-compression 383 gained 12 horsepower and nearly 12 lb/ft of torque by a