2003 Ford Mustang Cobra Exhaust Kit - Pipe Scream

Cobra exhaust manifolds changed between the naturally aspirated '02-and-earlier cars and the supercharged '03 machines. From this view, only the EGR fittings are noticeably different.

Flip over the manifolds and the increase in the runner volume and outlet dimensions is obvious. The '02-and-earlier headers won't cover the ports in '03 heads.

JBA builds all its header flanges from 31/48-inch-thick material. The shapes are laser cut and quite accurate. The slits give the laser an entry and exit point and allow for flange expansion.

Built from 409 stainless steel and ceramic-coated black, JBA's Cat4ward short-tubes are compact designs. Installation is thus easy by modular standards. These went on our test car in 211/42 hours. The advanced enthusiast might want to tackle this job at home without a hoist. It'll take longer than 211/42 hours, though.

Something we've never seen before-the short pipe and flange on one side is reinforced with a pair of struts. This reduces warpage.

To mate with the stock H-pipe, one header has a ball flange, the other is flat. JBA supplies the flange bolts, but they are not welded by JBA. It is highly recommended that you tack these bolts in the flange, otherwise you'll use up a big favor from a buddy while he holds the bolt heads and you take care of the nuts.

Clearance is always tight on modular headers as this dimpled flange attests.

JBA supplies the one gasket for the flat-header-to-H-pipe flange along with header-to-head bolts. The stock studs are discarded to allow more working room.

Standard-composition header gaskets are supplied with the Cat4ward units.

Here's a set of big boys-JBA's 131/44-inch midlength headers. These are done in uncoated 409 stainless steel. That's the same stuff Ford uses, and as with stock 5.0 headers, the material turns a dull brown and won't polish to a shine. It doesn't rust either. The part number is 6625S, they fit '97-'03 Cobras, and, as with all JBA headers, they feature a Firecone welded inside the collector to help smooth the merging gasses. Pricing was not available at press time.

Laid next to short-tube headers, the midlengths are clearly longer, but not as long as standard long-tubes. Wouldn't you know it-the quickly available short-tubes were an odd 5.0 part with a J302 bolt pattern and huge 131/44-inch tubes. Talk about an odd-ball header-these are old "big-badge" headers, in JBA-speak, due to the rodeo belt-buckle-sized E.O. number plate.

Not a production part at JBA, this is the prototype 3-inch high-flow cat piece used in our final test with the red convertible. The two expensive aftermarket cats provide equal or better emission reduction than the stock four-cat arrangement, except that having the cats farther away from the exhaust manifold means they take longer to heat up and become effective. This H-pipe is also plenty loud compared to a stocker, and we wouldn't recommend anything similar for daily commuting.