As much as we’ve complained about noise ordinances in the years since “back in the day,” people are finding noise just isn’t cool anymore. Open headers may free up horsepower, but torque and your hearing suffer as a consequence. Racers are learning there’s torque hidden in those silencers. Companies such as Flowmaster, Magnaflow, Hooker, and others are discovering more horsepower and torque through advanced muffler design and pipe-sizing technology. Fortunately, the aftermarket offers a huge variety of complete exhaust systems for all kinds of vintage Fords, which makes selection and installation easier. Not all off-the-shelf systems are a great fi t. In fact, you probably need the expertise of a good exhaust shop to install just about any system because nearly all of them require some kind of tweaking to achieve proper fit.
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Summit Racing Equipment’s website offers excellent advice on how to design an exhaust system. It suggests first knowing what size pipe to choose once you get past the header collectors. Summit also advises knowing the difference between a crush bend and a mandrel bend, which affects exhaust fl ow, before you buy an exhaust system. Crush bending causes flow restriction along the way. Mandrel bending provides a smooth journey and it looks better. Always go with an H-pipe or X-pipe dual-exhaust system (balance tube) for improved scavenging and better sound. Without a balance tube, performance suffers and you wind up with an exhaust system that sounds like a popgun at the tailpipes.
FPA long-tube headers are a true Tri-Y design with four-into-two-into one cleanly alongside the block and bellhousing with a ball/socket collector.
The FPA ball/socket collector design eliminates header gaskets and the pesky nature of threebolt disconnection. Installation is simple and easily performed by any reputable exhaust shop. Jet Hot did the ceramic coating on this FPA header. And remember, if you’re going to dyno your Cleveland, wait to have the ceramic coating done until after dyno testing. Extreme heat fogs the coating.
This is an FPA header collector prior to Jet Hot coating. What makes the FPA header a good value is cost, craftsmanship, and fit. You may order them in the raw and clean them up, then have them Jet Hot coated. You may also use a high-temperature exhaust paint with a tolerance of up to 1,700 degrees F. Pop for the ceramic coating; it will last the life of the header.
Right sizing includes the exhaust system having a balance tube between sides. Pipe size is everything to torque mostly. If you go too large, you lose torque. Go too small and you lose horsepower.
Pipe sizing must be consistent throughout. If you have 2¼ or 2½ inchers, it must be this size from header collector to tailpipe. Flowmaster muffl ers are among the best in the industry. They deliver great throat. If you go with Delta Flow 40 or 50 Flowmasters, that resonance is gone, accompanied by cabin quiet.
National Parts Depot offers the most extensive line-up of exhaust systems for vintage Fords in the industry. You may combine these systems with a wide variety of aftermarket mufflers depending upon pipe size desired. Which Flowmaster muffler you choose for your Cleveland project depends on desired performance and noise levels. Remember, noise isn’t cool anymore; mellow and throaty are.
Aluminized or Stainless
Another item you don’t think about enough is material. Stainless or aluminized steel? Because exhaust systems are more a work of art these days as well as functional, additional thought has to be given to material and aesthetics. Aluminized exhaust systems are more affordable; however, they are more susceptible to corrosion as time passes especially if you live where humidity is high. If appearance is important to you, you can ceramic coat headers and pipes. However, it is very expensive. The beauty of ceramic coating is color choice including a natural metal finish if you desire. Ceramic coatings such as Jet Hot can withstand temperatures up to 1,700 degrees F. If you’re going to dyno test your Cleveland, remember ceramic coating doesn’t like the extreme heat of a dyno pull. It fogs badly.
Factory mufflers offer quiet, but quiet comes at a price—impeded scavenging. You want backpressure, but not too much. Much depends on cam profile as well as pipe size and muffler baffling.
Though you rarely hear about this subject, it is important. Exhaust system seams need to be welded, which gets rid of noise issues. It also keeps backpressure consistent.
One of the largest exhaust system challenges is header flange and gasket security. The key to gasket security is header bolts that stay tight. Stage 8 (PN 8912) locking header fasteners are tightened and locked so it is impossible for them to become loose.
Equal-length shorty headers offer improvement with an open exhaust at high RPM, but have never really been proven effective for the street in terms of horsepower gain. Go with a more conventional header for the street.
For all the hype over step headers, there’s no real evidence they improve power significantly for the cost and the complex nature of their manufacture.
If your budget allows, stainless steel is the best choice for an exhaust system because it will last the life of a restoration. Although stainless is corrosion resistant, it is not corrosion proof. It can rust in pinpoint locations if not cared for.
Not much attention is paid to exhaust tips, but they do affect performance to some degree. You want exhaust tips that are not restrictive, such as small quad-tips or those louvered first generation Mustang trumpet tips. Both are quite restrictive though they’re at the end of the system. GT trumpets have never been much on sound quality nor are original rolled-tip quad tips.
Written by George Reid and Republished with Permission of CarTech Inc
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