2003-2004 Mach 1 Modifications
This write-up is a summary of modifications for the 2003-2004 Mach 1 Mustang. Bolt-on modifications in this write-up are defined as a modification that is an upgrade to an already existing part. Suspension upgrades are parts that may or may not be on your car already, help the handling of the car, and help launch the car with minimal problems. Power adders are defined as parts or chemicals that can be used to additional power that is not seen on a stock Mach 1 Mustang. Some of these modifications can be used on the 99-04 Mustang V6, GT, Bullitt and Cobra, but may not so be sure to double check if you own one of these other types of Mustangs. Lastly, this write-up is not the end-all be-all of guides for modifying your Mach 1. It does not include all modifications by all companies, but can be used as a guide when starting to modify your Mach 1. On a side note, if you plan to reach 400-450rwhp (closer to 450) please take extreme caution as our motor’s rotating assembly components typically don’t last much passed 450rwhp and need to be upgraded if more power is wanted.
Bolt-Ons
Cold Air Intake/Ram Air Intake (CAI/RAI)
Cold air intakes draw air from the passenger side fender well and increase the amount of air that is drawn through the throttle body. The air that is drawn from the fender well is more condensed (colder) than the ram air intake, but it eliminates the functionality of the Shaker.
The ram air intake increases the amount of air just the same as a cold air intake but the air is drawn from the engine bay so it will naturally be warmer than that of the CAI. The upside to the RAI though is that it keeps the Shaker system functional so some of the air coming to the air filter actually is cooler. JLT and C&L both make CAI/RAIs for the Mach 1.
Headers
Aftermarket headers allow more air to flow from the engine which in turn increases efficiency and horsepower. The amount of air you want to flow from the headers is up to you as there are three types of headers you can buy.
Long tube headers allow the most air to flow from the exhaust and give the biggest increase in power. However, they relocate the O2 sensors which in turn make them illegal on public streets. And an aftermarket midpipe or a modified stock midpipe is needed to connect the headers to the catback. American Racing, Kooks, BBK, MAC, and SLP all make long tube style headers.
Mid-length and shorty style headers allow a gain in horsepower, but not as much as the long tube style header. These headers are legal for street use though and an aftermarket midpipe is not necessary to buy with these headers. Bassani, and JBA make aftermarket mid-length and shorty headers.
Midpipe (X-Pipe, H-Pipe, Prochamber)The midpipe connects the headers to the catback parts of the exhaust. There are three different styles of midpipes and they are named by their shape. Each has its own unique sound. Apart from the three styles there are two types of each of these midpipes. There is the catted midpipe and the off-road or catless midpipe. The off-road (o/r) midpipe is less restricted than the catted midpipe which allows it to produce more power, but it is illegal for use on public streets because it eliminates the catalytic converters. If you are planning on a turbocharged system look into what turbocharger kit you want before buying a midpipe. Turbochargers require modifications to the exhaust manifold which sometimes renders the stock midpipe useless.
Catback
The catback is the final piece to the exhaust puzzle. Deciding on which catback exhaust system you buy will be up to you. Most of these produce the same power and the only difference is the sound that they produce. Bassani, Borla, Flowmaster, MAC, Magnaflow, Pypes, SLP, and Steeda all make their own catback system.
Water Pump
The stock water pump on the Mach 1 is a mechanically driven water pump. Stewart Components makes a direct replacement for the stock water pump (2-3 washers are needed to space the bolts though). The Meziere Electric Water Pump eliminates the need to pump coolant mechanically which creates more power than the Stewart pump, because the engine doesn’t need to turn the pulley on the pump as it is powered by the battery.
Driveshaft (Aluminum and Carbon Fiber)
FRPP makes a light weight aluminum driveshaft which reduces rotational mass allowing for a small horsepower gain, allows the car to move through the RPM band faster, and is stronger than the stock driveshaft. The carbon fiber driveshaft takes everything the aluminum driveshaft offers just a bit further as it is even lighter than aluminum and stronger. The only downside is that the carbon fiber shaft is considerably more expensive than the aluminum driveshaft. PST makes carbon fiber driveshafts.
Under Drive Pulleys (UDPs)
Under drive pulleys reduce the amount of power needed to power systems on the car which frees up more power to be put on the street. The Mach 1 comes stock with an under driven alternator so UDPs are not considered to be as good of a mod as they are on GTs. They are also linked to, but not proven to cause oil pump failure in Machs. Steeda makes UDPs that are harmonically balanced and are considered to be safer than the piggy-back style UDPs.
Short Throw Shifter
The short throw shifter is a replacement for the stock shifter in Mach 1’s with the Tremec 3650 (manual) Transmission. This mod allows a driver to shift into a gear with less effort by not having to “throw” the handle as far and find the gear easier than the stock shifter. MGW, Pro 5.0, and Steeda Tri-Ax are all types of short throw shifters that are available for the Mach. In this writer’s opinion, if you race your car at all this should be one of the very first mods you do to your Mach because of the T-3650’s trouble of shifting into 3rd gear.
Throttle Body (TB)
The throttle body allows more or less air into the intake and is controlled by the gas pedal. BBK and Accufab both make a twin blade throttle body that increase the amount of air into the intake. However, most owners of Machs will say that an aftermarket throttle body is not necessary until a power adder is added to the car as the stock throttle body flows well or a stock part.
Clutch
An aftermarket clutch will be needed if big power is produced on a manual Mach 1. Centerforce, SPEC, RAM, and Fidanza all make clutches for the Mach 1.
Flywheel
An aftermarket flywheel made from aluminum or billet steel is another upgrade for the Mach 1. An aluminum flywheel will allow the engine to rev faster due to a decrease in rotational mass. This also allows for a few horsepower to be gained from the addition of this mod. Centerforce, SPEC, Fidanza, and Ford Racing all make aftermarket flywheels.
Intake Spacer
The intake spacer is often confused among non-Mach owners with a throttle body spacer. This part is placed under the “lid” of the intake. This part increases the overall volume of air that can be in the intake and is the only part in the bolt-ons section that is not on a stock Mach 1. Paul’s High Performance and Roy on the Mach 1 Registry (2003-2004 Ford Mustang Mach 1 Owner's Club & Registry Website) both make spacers for the Mach 1. These spacers claim to have a 2-3rwhp gain along with a gain of 10lbs of torque.
Gears
Ford Racing Performance Parts and Motive both make gears for the Mach 1. Gears allow a car to accelerate faster (or slower). Machs come with a 3.55 gear ratio stock which is the highest of any 99-04 Mustang. Many Mach owners switch to a 4.10 or 4.30 gear ratio while some upgrade to a 3.73, but the 3.73 isn’t that big of a step up from the stock gearing. A majority of drivers consider a gear swap to be one of the best “bang for the buck” mod you can do.
Suspension
K-Member
The stock K-member or cross member on the Mach 1 is heavy and bulky. Aftermarket companies made K-members that are not as big, stronger, and lighter than the stock K-member. Sometimes a K-member is needed for a turbo setup or long tube header install. UPR and Maximum Motorsports both make an aftermarket K-member.
A-Arms
Like a K-member the A-arms are upgraded for strengthening purposes. Maximum Motorsports and UPR make after market A-arms.
Caster Camber Plates (CC Plate)
Caster camber plates are required on aftermarket K-member kits and more aggressive lowering springs. If you don’t buy CC plates with an aggressive lowering spring you won’t be able to align your car properly. MM, Steeda, and UPR all make CC plates.
Lowering Springs
Lowering springs do just what their name implies. They lower your car to get better handling and make the car look better. Mach 1s come with a mixed B-spring stock so don’t buy B-springs thinking you are upgrading. FRPP, Steeda, MM, and H&R all make aftermarket springs.
Subframe Connectors (SFCs)
Subframe connectors reduce the amount of flex your chassis encounters while driving resulting in better handling and launching of your car. Maximum Motorsports (MM) and UPR both make SFCs.
Upper Control Arms (UCAs)
Upper control arms allow your car to handle and launch better than the stock UCAs. There are two types of UCAs you can buy. Solid upper control arms are a direct replacement for the stock UCAs while adjustable UCAs require some tweaking. Adjustable UCAs are considered to be better as you can adjust the pinion angle to get the affect you want from your suspension. MM, Steeda, Granatelli, BMR, MMR, and UPR all make after market control arms.
Lower Control Arms (LCAs)
Lower control arms help tremendously over the stock LCAs. They allow your car to handle better and launch better than the stock arms to help reduce 60’ times on the track. Like upper control arms there are two types you can buy in the solid and adjustable versions. MM, Steeda, Granatelli, BMR, MMR, and UPR all make after market control arms.
Front and Rear Sway Bars
Sway bars are used to help stiffen the chassis in order to help with handling and launching the car. MM and UPR both make aftermarket sway bars.
Power Adders
Before I begin on power adders please talk to a qualified mechanic and/or tuner when applying a power adder. If one of these mods is added to a car it may end up being a catastrophic mistake if not applied correctly.
Superchargers
A supercharger is a mechanically driven power adder. It uses the engine to power a blower that forces air into the intake to produce more power than under normal conditions. There are also two kinds of superchargers for use on the Machs. The twin screw/roots style supercharger sits on top of the intake and under the shaker. This type of supercharger creates instantaneous power and it lasts throughout the power band. Kenne Bell is the only manufacturer that makes a kit for the Mach 1 however Eaton superchargers can also be mounted to fit.
The centrifugal supercharger acts like a mechanically driven turbocharger. The power created by the supercharger is “lagged” and builds up as the car goes through the RPM band. Vortech and Procharger both make kits for the Mach 1.
Turbochargers
Turbochargers pull exhaust gasses from the engine and send them back into the intake in a compressed form like a supercharger. The turbocharger does not require the engine to physically power it in order for it to work so there is no parasitic loss. The downside to a turbocharger is that there is lag, but it creates an extreme amount of power once it has spooled up. You can mount a single big turbo or a twin turbo setup on your Mach 1 to increase your power. HP and Hellion both make kits to fit Mach 1s.
Nitrous Oxide
Nitrous oxide (NO2) is laughing gas, but it is also used to chemically increase the power in a car. There are two different kinds of nitrous systems. There is the wet kit and dry kit. The dry kit sends nitrous oxide directly into the intake via the fuel injectors. The wet kit is sprayed into the intake. What system you want to use is up to you and you should do more research than what is provided in this article to decide what system you should use and how much horsepower you should add to your engine before adding it to your car. NX, NOS, and Zex are all reputable companies that make nitrous kits for Mach 1s.
This write-up is a summary of modifications for the 2003-2004 Mach 1 Mustang. Bolt-on modifications in this write-up are defined as a modification that is an upgrade to an already existing part. Suspension upgrades are parts that may or may not be on your car already, help the handling of the car, and help launch the car with minimal problems. Power adders are defined as parts or chemicals that can be used to additional power that is not seen on a stock Mach 1 Mustang. Some of these modifications can be used on the 99-04 Mustang V6, GT, Bullitt and Cobra, but may not so be sure to double check if you own one of these other types of Mustangs. Lastly, this write-up is not the end-all be-all of guides for modifying your Mach 1. It does not include all modifications by all companies, but can be used as a guide when starting to modify your Mach 1. On a side note, if you plan to reach 400-450rwhp (closer to 450) please take extreme caution as our motor’s rotating assembly components typically don’t last much passed 450rwhp and need to be upgraded if more power is wanted.
Bolt-Ons
Cold Air Intake/Ram Air Intake (CAI/RAI)
Cold air intakes draw air from the passenger side fender well and increase the amount of air that is drawn through the throttle body. The air that is drawn from the fender well is more condensed (colder) than the ram air intake, but it eliminates the functionality of the Shaker.
The ram air intake increases the amount of air just the same as a cold air intake but the air is drawn from the engine bay so it will naturally be warmer than that of the CAI. The upside to the RAI though is that it keeps the Shaker system functional so some of the air coming to the air filter actually is cooler. JLT and C&L both make CAI/RAIs for the Mach 1.
Headers
Aftermarket headers allow more air to flow from the engine which in turn increases efficiency and horsepower. The amount of air you want to flow from the headers is up to you as there are three types of headers you can buy.
Long tube headers allow the most air to flow from the exhaust and give the biggest increase in power. However, they relocate the O2 sensors which in turn make them illegal on public streets. And an aftermarket midpipe or a modified stock midpipe is needed to connect the headers to the catback. American Racing, Kooks, BBK, MAC, and SLP all make long tube style headers.
Mid-length and shorty style headers allow a gain in horsepower, but not as much as the long tube style header. These headers are legal for street use though and an aftermarket midpipe is not necessary to buy with these headers. Bassani, and JBA make aftermarket mid-length and shorty headers.
Midpipe (X-Pipe, H-Pipe, Prochamber)The midpipe connects the headers to the catback parts of the exhaust. There are three different styles of midpipes and they are named by their shape. Each has its own unique sound. Apart from the three styles there are two types of each of these midpipes. There is the catted midpipe and the off-road or catless midpipe. The off-road (o/r) midpipe is less restricted than the catted midpipe which allows it to produce more power, but it is illegal for use on public streets because it eliminates the catalytic converters. If you are planning on a turbocharged system look into what turbocharger kit you want before buying a midpipe. Turbochargers require modifications to the exhaust manifold which sometimes renders the stock midpipe useless.
Catback
The catback is the final piece to the exhaust puzzle. Deciding on which catback exhaust system you buy will be up to you. Most of these produce the same power and the only difference is the sound that they produce. Bassani, Borla, Flowmaster, MAC, Magnaflow, Pypes, SLP, and Steeda all make their own catback system.
Water Pump
The stock water pump on the Mach 1 is a mechanically driven water pump. Stewart Components makes a direct replacement for the stock water pump (2-3 washers are needed to space the bolts though). The Meziere Electric Water Pump eliminates the need to pump coolant mechanically which creates more power than the Stewart pump, because the engine doesn’t need to turn the pulley on the pump as it is powered by the battery.
Driveshaft (Aluminum and Carbon Fiber)
FRPP makes a light weight aluminum driveshaft which reduces rotational mass allowing for a small horsepower gain, allows the car to move through the RPM band faster, and is stronger than the stock driveshaft. The carbon fiber driveshaft takes everything the aluminum driveshaft offers just a bit further as it is even lighter than aluminum and stronger. The only downside is that the carbon fiber shaft is considerably more expensive than the aluminum driveshaft. PST makes carbon fiber driveshafts.
Under Drive Pulleys (UDPs)
Under drive pulleys reduce the amount of power needed to power systems on the car which frees up more power to be put on the street. The Mach 1 comes stock with an under driven alternator so UDPs are not considered to be as good of a mod as they are on GTs. They are also linked to, but not proven to cause oil pump failure in Machs. Steeda makes UDPs that are harmonically balanced and are considered to be safer than the piggy-back style UDPs.
Short Throw Shifter
The short throw shifter is a replacement for the stock shifter in Mach 1’s with the Tremec 3650 (manual) Transmission. This mod allows a driver to shift into a gear with less effort by not having to “throw” the handle as far and find the gear easier than the stock shifter. MGW, Pro 5.0, and Steeda Tri-Ax are all types of short throw shifters that are available for the Mach. In this writer’s opinion, if you race your car at all this should be one of the very first mods you do to your Mach because of the T-3650’s trouble of shifting into 3rd gear.
Throttle Body (TB)
The throttle body allows more or less air into the intake and is controlled by the gas pedal. BBK and Accufab both make a twin blade throttle body that increase the amount of air into the intake. However, most owners of Machs will say that an aftermarket throttle body is not necessary until a power adder is added to the car as the stock throttle body flows well or a stock part.
Clutch
An aftermarket clutch will be needed if big power is produced on a manual Mach 1. Centerforce, SPEC, RAM, and Fidanza all make clutches for the Mach 1.
Flywheel
An aftermarket flywheel made from aluminum or billet steel is another upgrade for the Mach 1. An aluminum flywheel will allow the engine to rev faster due to a decrease in rotational mass. This also allows for a few horsepower to be gained from the addition of this mod. Centerforce, SPEC, Fidanza, and Ford Racing all make aftermarket flywheels.
Intake Spacer
The intake spacer is often confused among non-Mach owners with a throttle body spacer. This part is placed under the “lid” of the intake. This part increases the overall volume of air that can be in the intake and is the only part in the bolt-ons section that is not on a stock Mach 1. Paul’s High Performance and Roy on the Mach 1 Registry (2003-2004 Ford Mustang Mach 1 Owner's Club & Registry Website) both make spacers for the Mach 1. These spacers claim to have a 2-3rwhp gain along with a gain of 10lbs of torque.
Gears
Ford Racing Performance Parts and Motive both make gears for the Mach 1. Gears allow a car to accelerate faster (or slower). Machs come with a 3.55 gear ratio stock which is the highest of any 99-04 Mustang. Many Mach owners switch to a 4.10 or 4.30 gear ratio while some upgrade to a 3.73, but the 3.73 isn’t that big of a step up from the stock gearing. A majority of drivers consider a gear swap to be one of the best “bang for the buck” mod you can do.
Suspension
K-Member
The stock K-member or cross member on the Mach 1 is heavy and bulky. Aftermarket companies made K-members that are not as big, stronger, and lighter than the stock K-member. Sometimes a K-member is needed for a turbo setup or long tube header install. UPR and Maximum Motorsports both make an aftermarket K-member.
A-Arms
Like a K-member the A-arms are upgraded for strengthening purposes. Maximum Motorsports and UPR make after market A-arms.
Caster Camber Plates (CC Plate)
Caster camber plates are required on aftermarket K-member kits and more aggressive lowering springs. If you don’t buy CC plates with an aggressive lowering spring you won’t be able to align your car properly. MM, Steeda, and UPR all make CC plates.
Lowering Springs
Lowering springs do just what their name implies. They lower your car to get better handling and make the car look better. Mach 1s come with a mixed B-spring stock so don’t buy B-springs thinking you are upgrading. FRPP, Steeda, MM, and H&R all make aftermarket springs.
Subframe Connectors (SFCs)
Subframe connectors reduce the amount of flex your chassis encounters while driving resulting in better handling and launching of your car. Maximum Motorsports (MM) and UPR both make SFCs.
Upper Control Arms (UCAs)
Upper control arms allow your car to handle and launch better than the stock UCAs. There are two types of UCAs you can buy. Solid upper control arms are a direct replacement for the stock UCAs while adjustable UCAs require some tweaking. Adjustable UCAs are considered to be better as you can adjust the pinion angle to get the affect you want from your suspension. MM, Steeda, Granatelli, BMR, MMR, and UPR all make after market control arms.
Lower Control Arms (LCAs)
Lower control arms help tremendously over the stock LCAs. They allow your car to handle better and launch better than the stock arms to help reduce 60’ times on the track. Like upper control arms there are two types you can buy in the solid and adjustable versions. MM, Steeda, Granatelli, BMR, MMR, and UPR all make after market control arms.
Front and Rear Sway Bars
Sway bars are used to help stiffen the chassis in order to help with handling and launching the car. MM and UPR both make aftermarket sway bars.
Power Adders
Before I begin on power adders please talk to a qualified mechanic and/or tuner when applying a power adder. If one of these mods is added to a car it may end up being a catastrophic mistake if not applied correctly.
Superchargers
A supercharger is a mechanically driven power adder. It uses the engine to power a blower that forces air into the intake to produce more power than under normal conditions. There are also two kinds of superchargers for use on the Machs. The twin screw/roots style supercharger sits on top of the intake and under the shaker. This type of supercharger creates instantaneous power and it lasts throughout the power band. Kenne Bell is the only manufacturer that makes a kit for the Mach 1 however Eaton superchargers can also be mounted to fit.
The centrifugal supercharger acts like a mechanically driven turbocharger. The power created by the supercharger is “lagged” and builds up as the car goes through the RPM band. Vortech and Procharger both make kits for the Mach 1.
Turbochargers
Turbochargers pull exhaust gasses from the engine and send them back into the intake in a compressed form like a supercharger. The turbocharger does not require the engine to physically power it in order for it to work so there is no parasitic loss. The downside to a turbocharger is that there is lag, but it creates an extreme amount of power once it has spooled up. You can mount a single big turbo or a twin turbo setup on your Mach 1 to increase your power. HP and Hellion both make kits to fit Mach 1s.
Nitrous Oxide
Nitrous oxide (NO2) is laughing gas, but it is also used to chemically increase the power in a car. There are two different kinds of nitrous systems. There is the wet kit and dry kit. The dry kit sends nitrous oxide directly into the intake via the fuel injectors. The wet kit is sprayed into the intake. What system you want to use is up to you and you should do more research than what is provided in this article to decide what system you should use and how much horsepower you should add to your engine before adding it to your car. NX, NOS, and Zex are all reputable companies that make nitrous kits for Mach 1s.
