In the April 2003 issue of MM&FF we covered the installation of ProCharger's P1-SC supercharger on our resident '90 Mustang GT. As far as project cars go, we haven't bothered to give this one a name yet, but we've continued to modify it with a Cobra R four-wheel disc brake upgrade from Ford Racing. With 330 hp at the wheels of the little mare, we definitely had to do something about the stopping situation and the FRPP kit worked like a charm.
This time around we've decided to chuck the stock shorty headers in exchange for some long-tubes, but we didn't stop there. We also needed to get the pony in compliance with the state of New Jersey's emissions requirements and we accomplished that with a set of high-flow catalytic converters. Lastly, the venerable Flowmaster mufflers and stock cat-back pipes were traded for a true 2.5-inch cat-back system.
Choosing an aftermarket exhaust can improve both the sound and performance of your pony, and with what we hope to do with it in the future, we looked for an exhaust upgrade that wouldn't be a restriction later on.
When it comes to exhaust tones, just about every manufacturer has its own unique signature. The best way to choose one that you like is to go to your local cruise-in or better yet, visit a Fun Ford Weekend or NMRA event. Listen to the cars as they do their burnouts. Listen to them go down the track and then head to the pits. Find the cars that sound good to you and then find out what they're running. Granted you might like the sound of a big-block Pro car, but running open headers on the street really isn't an option, not to mention that 4-inch collectors and 2-inch primaries probably aren't the best setup for your bolt-on street car.
Our pony's combination is somewhat unusual at this point. It's a stock five-liter from intake to pan, but we're cramming 10 psi of boost through it with some help from ATI. Someday, we would like to get some nice cylinder heads and a hotter camshaft, but for now she's mostly stock. We do have an intake manifold on the way and with all of these parts, we're expecting a power output in the neighborhood of 400-450 at the rear wheels. With those plans in mind we decided to go with long-tube headers and a full 2.5-inch exhaust system.
The long-tube headers we selected are from Bassani (PN 5092R), are chrome plated and retail for $731.50. These optimum-length, 14-gauge carbon steel tubes are mandrel bent and step up in size from a 1 5/8-inch diameter to 1 3/4 inches. This stepped design keeps exhaust from reverting back up the tube and the smaller sized tube off the head maintains torque, while the larger tube downstream aids horsepower. The individual tubes slip-fit into Bassani's exclusive "Extractor Collector," which induces a scavenging effect, further improving performance. The headers come with instructions and all necessary parts for the installation from bolts to gaskets and even antiseize.
Bassani has a new line of exhaust components called BX, which replaces Bassani's standard, stainless steel tubing with mild steel construction wherever possible to reduce the cost and price of the part. We used a BX shorty X-pipe (PN 50933R) equipped with high-flow catalytic converters. With New Jersey vehicle inspections being the brutal tests that they are, we averted potential problems by going with the proper cats. The BX X-pipes are mandrel bent and made from aluminized steel for corrosion protection. Our '90 GT was already running an off-road X-pipe, and we happen to like the change in tone that occurs when using one, so that is why we chose the BX unit.
MM&FF's Procharged Pony has...
MM&FF's Procharged Pony has quite a few miles on her, but still runs like a top. We began the exhaust installation by removing the spark plugs. If your wires are not marked by cylinder, do it as you remove each plug.
Moving below, we sprayed the...
Moving below, we sprayed the nuts and bolts with a penetrating oil and then unbolted the cat-back and X-pipe.
This tube from the air pump...
This tube from the air pump must also be removed. Bassani supplies a new one along with clamps and hoses to connect it.
In order to maximize future gains in horsepower, the stock 2.25-inch cat-back system had to go. The kinks and bends that aid in installation on the assembly line simply have no performance in mind. To remedy this, we opted for the BX AFT-CAT exhaust system.
The Quiet Thunder kit features aluminized mandrel-bent 2.5-inch tubing and Bassani's "Composite" construction mufflers. The mufflers feature durable Stainless Steel internal construction housed in a 16- gauge aluminized steel case. For 1987-93 Mustang GTs, order PN 5093GT5, which sells for $531.25.
On the passenger side, remove...
On the passenger side, remove the mass air elbow and if you still have them, the emission lines that run to the air pump. This will give you more room to work and you'll need it.
Since Bassani includes all of the clamps and bolts needed, installation is a snap. Ball and socket connections eliminate the need for welding and also offer excellent sealing characteristics. The step headers come as separate tubes, but instructions are included and tell you which order to install them in. Once you have them loosely hung, you can slip on the collectors and then the ball and socket flanges that connect them to the X-pipe.
The X-pipe features the proper factory hangers, as does the cat-back system. This makes installation for these parts a simple disassemble/reassemble deal. The tailpipes offer plenty of clearance around objects like the gas tank and upper control arms. Which keeps things rattle-free.
In the instructions for the headers, it mentions that some modifications may be necessary, but we found no issues that needed correcting as far as the headers were concerned. The long-tubes do relocate the O2 sensors farther back and, for this, Bassani recommends pulling the wires out of the harness to gain the needed length. We needed to re-route the "low oil" level sensor, which runs with the O2 sensor in the same harness. This seemed rather tedious, as re-routing the harnesses required quite a bit of Zip Ties to keep them out of the way of the headers. Get yourself some O2 extensions and be done with it.
The Bassani headers and BX exhaust system sounds great and fit well. We had hoped to bring you some updated track and dyno results, but the stock replacement clutch that was installed a few years back isn't really happy with the 300-plus rear-wheel horsepower and said "Uncle" more than once when shifting into fourth gear at the strip. Therefore be sure to check out our next installment of our Procharged pony for the details.
Apply more penetrating oil...
Apply more penetrating oil here and then unbolt the header. If your car is stock, you may also have to remove the engine hook that the factory leaves on the headers.
The driver's side has a little...
The driver's side has a little less clutter. The dipstick will mount back in the same location when you're done.
Out comes the stock shorty...
Out comes the stock shorty header.
Use a good razor blade or...
Use a good razor blade or better yet, a real scraper to remove the old gasket material. Clean the surface with brake parts cleaner or something of that nature.
The difference is fairly obvious....
The difference is fairly obvious. The Bassani piece has only one thing in mind and that's performance. The stock shorty purportedly features 1.5-inch diameter tubes, but they are pinched and crimped all over the place, consequently impeding flow. The stock O2 sensor usually mounts about 5-inches or so past where the mid-pipe connects to the header, so comparing the Bassani header, you can see that you'll have to do some re-routing.
Bassani makes sure you have...
Bassani makes sure you have everything you need to install their exhaust system. The header gaskets that are used feature stainless steel plates and replaceable graphite inserts.
The instructions will tell...
The instructions will tell you the order in which to install the header tubes. On the driver's side, you have to install these two that wrap around the steering column first.
The "Extractor Collector"...
The "Extractor Collector" slips on and is secured by two bolts, one on each side. We had to do some minor sanding on the ends of the tubes to get them to slide in smoothly. If you have to do this, make sure you don't take too much off otherwise they may leak.
As mentioned previously, the...
As mentioned previously, the oil dipstick goes right back into position. You may have to tweak it just a bit to get it to slide on the bolt.
Ball and socket flanges enable...
Ball and socket flanges enable you to bolt up your X- or H-pipe just like with the stock system.
Diameter wise, the two pipes...
Diameter wise, the two pipes are the same, but Bassani uses a slightly different "X" chamber, and we also have the new high-flow catalytic converters on.
We tightened the clamp on...
We tightened the clamp on the collector after estimating its position. We then loosely secured the X-pipe to it.
We're pretty sure the inside...
We're pretty sure the inside of the old mufflers look just as bad. You won't have that with the BX piece as the internals are made from stainless steel.
Once you have removed the...
Once you have removed the stock tailpipes (either by saw or by torch), you can install the new ones. With the larger diameter, we found it necessary to remove the wheel and lower the axle. The tailpipe is secured at the factory hanger locations.
While under the car, support...
While under the car, support the muffler and slide on the tailpipe. Leave the clamp slightly loose so you can adjust the tailpipe as needed.
Sometimes the hangers on the...
Sometimes the hangers on the transmission mount become bent. We used a jack and some wood to protect the pipes and then pushed the X-pipe up until it was in the proper position.
Once you have all of the pipes...
Once you have all of the pipes and tubing lined up, you can tighten all of the clamps.
Bassani also supplies these...
Bassani also supplies these polished stainless steel tips for a nice finishing touch.
Hanging down is the "low oil"...
Hanging down is the "low oil" level sending unit that we removed to re-route the O2 sensor and harness. We would recommend getting a set of extensions instead.
Bassani includes a new air...
Bassani includes a new air pump tube along with high-temperature hoses to connect it.
Another job completed, but...
Another job completed, but an ailing clutch has prevented us from bringing you solid results. Be sure to check back as we will have drag and dyno tested our supercharged steed and plan to give you all of the performance figures.