Exhaust
manifolds, thermal wraps, mufflers and headers
(Click on image for larger view)
The factory exhaust manifold is adequate for most applications, with a little porting work it's a good piece to work with. TAFT and LRE sells ported ones that flows 28% better than a stocker.
Garry McKissick has a home-made header you can check out on his website here.
Design and Fabrication's race header kit. (717-337-3250)
Mopar Performance had a header planned and even announced that one would be for sale, but the product was pulled due to the fact the turbos were falling off the engines! Price was in the $400 range and was only good for 4-5 hp.
Quality
of flow is just as important as quantity!
The ported exhaust manifold combined with a large exhaust system provides the largest gains to be had in a Chrysler Turbo car. A minimum of a 2.5" system should be used, a 3" mandrel bent is preferred. Muffler design is very important in a turbocharged applications, you need a muffler with the least amount of backpressure. This cannot be stressed enough!
Straight through
designs with no baffles or louvers to obstruct the flow are the best.
Flowmaster or "path" mufflers should be avoided if possible. Check
out the backpressure chart below to see how some popular mufflers perform
in a backpressure shootout.
(click for larger image)
The Ideal Exhaust
system for a 2.2 Turbo powered car would be a 3 inch mandrel bent system,
no catalytic converter, a straight through muffler and a ported exhaust
manifold.
The Best.
Dynomax Ultra Flow and Hooker Super Competition Mufflers
The Good.
Edelbrock RPM Series Muffler
The Not-Recommend-For-Turbocharged-Applications.
Hooker Aero Chamber and Walker Super Turbo
Last season we started on the journey to faster e.t.'s in a buddy's '87 Shelby Z. A full 3" exhaust w/ Dynomax race magnum muffler & no cat netted quite a large noticeable gain over the 2.5" catless Dynomax Super Turbo equipped exhaust.
A word of warning on thermal wraps.
On my turbo cars we had wrapped the exhaust manifold and turbo. Now Thermo-Tec notes this is a bad thing (wrapping the exhaust manifold) and they are correct. It results with a warped, cracked exhaust manifold that flexes so much it snapped the #1 exhaust stud right out off the head...and barbecued the turbocharger too. Proceed at your own risk!
Now that doesn't mean you cannot use the wrap in other areas! On my Daytona the exhaust system around the fuel tank is wrapped to keep the heat from the exhaust from warming up the fuel, learned that from an old timer who raced SCCA.
