We’re back on track with modifying our race red 2011 Mustang GT 5.0.  Since our car’s delivery, it’s received a ton of testing and a few choice mods.

First up, we had to get the car down a bit, by installing Ford Racings 1” drop M-5300-P lowering springs.

We then promptly mounted up some Hoosier R6 rubber on 18x9” SVE wheels, and took our Brembo-equipped car to Tulsa, Oklahoma for some open track fun at the Mid America Shelby meet at Hallett Motor Racing Circuit.

Styling was augmented by installing a California Special Valance and Fog light kit, Roush 7-bar grille and a GT500 style rear spoiler.

The first step up the horsepower ladder was to install an SCT programmer.  Armed with nothing more than said programmer and a set of Mickey Thompson 26x10-15” ET Drag slicks on 15x10" Race Star wheels, it was off to the drag strip, where our 3.73-equipped 6-speed manual GT ran an impressive 12.23 at 111.5 in the heat of July here in Texas.

A Flowmaster Hushpower axle back was then added to uncork the GT’s exhaust, while dropping 20 pounds off its tail.

A RAM 2011 Mustang 5.0L Ram Force 9.5" Dual Disc Clutch kit solved our one-and-only mechanical failure; the, evidently common, OEM pressure plate dowel pin phenomenon.

To further scratch the horsepower itch, our GT received a STEEDA cold air kit, and the SCT tuner was loaded with a custom BBR tune.

So far, our combination of bolt-ons has resulted in a car that looks, handles, runs and sounds leaps-and-bounds better than it did stock.

The next episode in the saga was to install a set of headers.  We looked to Stainless Works for a solution.  Stainless Works is a manufacturer of high-end, 304 stainless steel header and exhaust systems and components.   Stainless Works’ headers are made from the finest materials available, to exacting specifications.  Their 2011 Mustang GT headers for the 5.0 Coyote engine feature 1 7/8” primary tubes, 3” X-pipe with or without cats, and 3” lead pipes that mate to the factory exhaust, or aftermarket systems with stock-style connections.  The 304 SS headers sport thick, 3/8” flanges and 3” slip-fit collectors.  The system replaces the factory manifolds, catalytic converters, and H-pipe with a superior performing, lifetime guaranteed, bolt on system.

I’ve got to admit, we cheated a bit on the installation.  We installed the headers while our transmission was out.  Pulling the transmission is not necessary to perform the header swap, but it did open up room to access some of the tougher-to-reach bolts.  This also gave us an opportunity to test whether the transmission can be removed and reinstalled with the headers in place.  It was to our delight that we discovered that the transmission comes out just as easily (if not easier) as it did with the factory headers.

Our early production Stainless Works longtubes did not include an X-pipe, but instead connected to our factory cat-back with 3" extension tubes.  All current Stainless Works header systems for the 2011 Mustang include an X-pipe in place of the earlier extension tubes.  The customer may also choose to purchase the headers without extensions, if a custom system is in the works.  We opted for the offroad version, but cats may be in our future to muffle the car’s tone a bit, and return it to street legal form.  The car is deafeningly loud with no cats and our previously installed Flowmaster Hushpower mufflers.  This is my only complaint.  Otherwise, the headers fit better than any aftermarket header I’ve ever used.  The thick flanges, combined with the 5.0’s improved 10mm header studs, are sure to hold gaskets in place and prevent exhaust leaks.  The headers don’t rub or vibrate on anything.  There is loads of clearance to remove the transmission, and there’s nothing in danger of being burned or banged against.  Ground clearance is phenomenal. 

The decibel meter says the car’s faster, but what about the butt meter?  Well, I was simply astonished by the improvement in performance that the headers offered.   I’ll have to admit, the large, 1 7/8” primaries on the Stainless Works long tubes scared me.  In pushrod 5.0 speak, that’s huge.  I was worried about a loss of torque from these sewer pipes.

Fortunately, my worries were unfounded. The car has more power everywhere.  The air-pumping ability of the Coyote motor must need those big primaries.  In stock form, the 5.0 didn’t induce enough power to lose traction without a deliberate effort.  Now, if the traction control is off, you can just expect to engulf the Pirelli’s in smoke in first and second gears.  Power is smooth and strong, all the way up to redline.

We’re excited to get the car on the dyno.  With the combination of modifications we have, the car should easily crest the 400 horsepower mark at the wheels.  

I’ve already been to the track with the headers, cold air kit and new tune, and I can tell you that the STEEDA cold air intake kit, custom BBR tune, and Stainless Works headers resulted in some serious trap speed, and equally shaved some et.  Our previous best of 12.22 @ 111.55 was blown out of the water.  With the newly-added STEEDA cold air intake, Stainless Works long tubes, and BBR tune, our GT ripped off a 1.54 60' time, blew through the 1/8th at 7.52 @ 94.95 and finished the 1/4 with a stellar 11.85 @ 114.95.  We're confident there's more left in the car.  We're still running the big 19" fronts, lowering springs, and otherwise stock suspension.  

Check out the installation of our Stainless Works long tubes, along with a sound clip of the offroad exhaust and Flowmaster Hushpowers.

Installation outline:

Before lifting the car, some work needs to be done up top.  Remove battery, battery tray, strut tower brace, cold air intake and engine cover.

The majority of your header install will take place under the car, so the next step is to support the vehicle on jack stands or a car lift by the body.  Do not support the car by the k-member, as partial removal of the k-member will be required for installation.

Once the car is safely in the air, remove the factory h-pipe.

Your next step is to support the engine.

We had access to these Ford engine lift hooks, and engine support.  If you don't have access to these tools, I've supported the engine on similar header swaps by the harmonic balancer or with an engine hoist.

With engine carefully supported, disconnect the motor mounts from k member, disconnect the steering shaft, and disconnect the plug to the EPAS module on the steering rack.  Then, unbolt the k-member and lower the rear of the k-member.  We took the time to mark the k-member's position with a felt marker to insure it was reinstalled in the same position.  Again, our tranny was out for our swap, so it looks a little more empty in there.  Removal of the starter may also be required during this step.  It's not necessary to completely remove the k-member.  Unbolting it and lowering it down at the rear is sufficient enough to gain access to the headers.  

 remove motor mounts and the factory headers

Reinstall the Stainless Works headers using factory hardware and gaskets.

Reinstall your motor mounts, jack the k-member back into place, connect steering rack, and steering shaft.

Install the Stainless Works x-pipe or extension pipes.

Once the car is back on the ground, reinstall the battery, engine cover, cold air intake and strut tower brace.

Once this is all done, check for exhaust leaks, load your custom BBR tune, and have fun with your added power and sound.