Should I Add Long Tube Headers to My S550 GT?

A header is essentially a glorified, and performance improved, exhaust manifold. Bolting directly onto the cylinder head, the exhaust manifold is the first point of entry for the escaping exhaust gases.

In this case however, the stock manifold is a special piece. What makes it special? It is a turbo manifold. The exhaust valve opens, and the exhaust is spit into the manifold, but instead of travelling through the cat and out the rear (like is conventional), the exit end of the manifold is actually connected to the turbocharger, funneling the exhaust gases through the turbo.

The gases turn the turbo vanes (power the turbo), exit out the back of the turbo, through the downpipe and is then carried into the regular exhaust system and out through the tail pipes. 

However, because of the very short distance that stock turbo manifold is required to channel the exhaust to the turbo, there isn’t too much that can be done to optimize the pipes in such a short distance nor confined space. At this time, there aren’t any significant aftermarket offerings for a replacement turbo header. Perhaps later down the road we will begin to see aftermarket offerings, but only time will tell.

• The stock setup on the S5550 Mustang is completely emissions oriented, restricting the power of your GT
• Shorty headers are useful for tight engine bays, but if you're building a high revving Mustang, long tubes are a better option
• Long tubes are harder to install than shorties, but tend to see more power gains
• The aftermarket has made is so you can use headers while keeping your Mustang emissions legal

The start of any exhaust system is of course at the manifold. The stock pieces from Ford are a shorty style with a catalytic converter at the base of each collector. They do a good job (they support 420 HP from the Coyote!) but are very emissions oriented, meaning they are not 100% optimized for maximum power. Furthermore, having the headers dump straight into the cats (which are also right there to meet stringent emission requirements) is another source of restriction. All this to say, there is room for improvement.

With a Coyote engine – yes, they really are. Back in the 1960’s, a 5.0L engine would not be considered a huge engine. In today’s world, as fleet fuel efficiency standards close tighter and tighter, 5.0 of displacement is definitely on the larger end of what is available. With a healthy displacement of 5 litres, the Coyote engine is also pretty high-revving – red lining just under 8000 RPM. Large displacement high revving = high volume exhaust. High volume exhaust – sounds like the perfect scenario for long tube headers. The truth of the matter is that the Coyote engine responds very well to long tube headers. Again, power gains are on the top end of the spectrum, but said power gains are very impressive. It is not uncommon to uncork an extra 30 to 40 horsepower with a good set of long tube headers.

Without getting too deep into this argument, the quick and dirty of long tube versus shorty headers is as follows. Shorty headers feature smaller diameter primary tubes, and have shorter runner lengths before merging into the collector. They are great for space restricted areas and help power down low. Up in the higher RPM’s, however, they begin to choke out – especially on larger displacement engines. 

Long tube headers feature large diameter primary pipes that merge into the collector further down the exhaust stream than a conventional exhaust manifold. At low RPM (low exhaust volume), the larger diameter primaries slow the exhaust flow, losing torque over a set of shorties. On the top end however, long tubes are far superior. They can move A LOT of exhaust very easily – posing little restriction and drag on the engine as it spins faster, freeing up big power. In terms of installation, they are generally trickier to install and will take longer (accompanied by more swearing, too) but frankly, the bruised knuckles are fair trade for the gains.

Now, another important area to consider is emissions. ‘Emissions’ has been mentioned several times above, and is about to be mentioned a few more times. Historically, long tube headers meant ditching the catalytic converters in favor of an ‘off-road’ design. This is all swell and dandy, unless you live in an emission or smog controlled region. For those of us that do live in such a state, the aftermarket gods have come up with some pretty clever long tube systems that incorporate high-flow cats that don’t sacrifice much on the performance end but will still satisfy the sniff test.

We can bake our cake and eat it too. How often does that occur?

You get what you pay for in terms of header finishes. If you’re overall desire is power and efficiency, stainless steel or a ceramic finish is perfect. If you are primarily interested in showing the car off, a chrome finish works well.

The ceramic finish helps resist the heat created from the hot exhaust gases leaving the combustion chamber. Stainless steel is beneficial in that it will not rust out (which can happen to chrome and ceramic if they get chipped).

Generally speaking, the install is not difficult to perform. It's actually straight forward. However, it is time consuming and a tight fit. Short tube headers are generally easier as they take up less space, but that's not to say it they're any less time consuming as long tubes. 

It’s best to set aside a day or two to complete the install. Also, having a second set of hands is extremely beneficial not only to time, but getting the headers bolted up as well.

In summary, the basics of headers can be covered as such:

• Long tube headers give more power than rival short tubes, but need a new adapter mid-pipe
• Short tube headers give the same, mean sound changes that long tubes do
• Ceramic or stainless steel finishes are more beneficial towards power than chrome finishes
• While a tune is not fully required, it is highly recommended for optimal gains and benefits.

• Turbo exhaust manifolds like the EcoBoost have a valve to distribute exhaust gases to the turbo
• Unlike the V6 and V8 S550 Mustangs, aftermarket headers are nonexistent for the turbo models
• The EcoBoost downpipe feeds off the turbo and into the catalytic convertor
• Aftermarket downpipes provide better flow to help boost power
• Combining a downpipe with a tune will maximize your horsepower gains

So far, the exhaust has flowed through the exhaust manifold, through the turbo inlet and out the back of the turbo. At this point, the exhaust stream has entered the downpipe. The downpipe connects the outlet of turbo to the catalytic converter. It sounds like a pretty basic component; however the form and size greatly impact its function.

Like has been said many times before, stock pieces are generally not optimized to the fullest extent possible as they are designed with so many variables in mind (cost, cross platform compatibility, production tooling, emissions, fuel efficiency etc) that it simply isn’t possible to offer the maximum performance possible.

This same ideology applies to the stock downpipe on EcoBoost Mustangs. It is by no means a bad piece (Ford squeezed 310HP out of the motor!) but there is power left on the table, particularly if you plan on increasing the boost of the 2.3L.

Aftermarket downpipes are mandrel bent and larger diameter than stock. They offer less restriction and greater flow capacity. Both attributes go hand in hand when running an increased boost profile. Higher booster means more power, which means more exhaust to expel.

An aftermarket downpipe, in conjunction with a tune, can net 20-30 HP. If you are looking to upgrade your EcoBoost ‘Stang and plan on boost and tune modifications, a downpipe can certainly help.