Performance Parts

Players in Need for Speed: Underground are allowed to modify their vehicle's performance by purchasing performance packages. Each performance package must be unlocked in Underground Mode by completing specific events. These packages are usually unlocked by completing tournaments.

Every package is categorized as Street, Pro, and Extreme. The latter offers the highest performance increase. Players may also select between various brand packages, which do not have any difference in performance between them.

Street Performance Packages

Engine/Exhaust Package
Content	Brand Packages
Cold Air Intake System Cat-Back Exhaust System Replace Headers	Package 1: AEM, Aerospeed, DC Sports, Injen Technology, HKS USA Package 2: NEUSPEED, Jackson Racing, HP Racing, Stillen, Venom Package 3: Skunk2 Racing, Borla, A'PEXi, GReddy Package 4: 5Zigen, Skunk2 Racing, A'PEXi
Increases Acceleration	Unlocked after completing Challenge #6.	Price: 500
Drivetrain Package
Content	Brand Packages
Short Throw Shift Kit Shifter Stabilizer Kit Replace Clutch Lightened Flywheel	Package 1: Arospeed, Clutchmasters, Stillen Package 2: NEUSPEED, DC Sports, ACT Package 3: Jackson Racing, HKS USA, Stillen
Increases Top Speed	Unlocked after completing Challenge #6.	Price: 500
Tires Package
Content	Brand Packages
Street Performance Tire Package	Package 1: Toyo Tire Package 2: Yokohama Package 3:Kumho Tires
Increases Handling	Unlocked after completing Challenge #6.	Price: 500
ECU & Fuel System Package
Content	Brand Packages
Performance Chip	Package 1: Jackson Racing, Venom, Stillen Package 2: AEM, GReddy, Skunk2 Racing Package 3: A'PEXi, Jackson Racing, Stillen
Increases Acceleration and Top Speed	Unlocked after completing Challenge #9.	Price: 1,000
Turbo Package
Content	Brand Packages
Stage 1 Turbo Kit	Package 1: HKS USA Package 2: GReddy Package 3: Stillen Package 4: A'PEXi Package 5: Turbonetics
Increases Acceleration	Unlocked after completing Challenge #9.	Price: 1,000
Brakes Package
Content	Brand Packages
Street Compound Brake Pads Steel Braided Brake Lines Cross Drilled Rotors	Package 1: AEM, Stillen, Brembo Package 2: KVR Performance, NEUSPEED, Jackson Racing Package 3: Arospeed, HP Racing, Wilwood Engineering
Increases Handling	Unlocked after completing Challenge #38.	Price: 2,000
Weight Reduction Package
Content	Brand Packages
Remove Rear Seats Remove Interior Panels Remove Spare Tire	Sparco
Increases Acceleration and Handling	Unlocked after completing Challenge #14.	Price: 750
Suspension Package
Content	Brand Packages
Sport Performance Springs and Shocks Strut Tower Bar	Package 1: Arospeed, Eibach, HKS USA, Stillen Package 2: NEUSPEED, Skunk2 Racing, Apex Springs, Bilstein Package 3: H&R Springs, KONI, KYB America, HP Racing, A'PEXi
Increases Handling	Unlocked after completing Challenge #14.	Price: 750
Nitrous Oxide System Package
Content	Brand Packages
Dry Shot of Nitrous Oxide	Package 1: Nitrous Express Package 2: NOS
Increases Handling	Unlocked after completing Challenge #14.	Price: 750

Pro Performance Packages

Engine/Exhaust Package
Content	Brand Packages
Mild Camshaft & Cam Gears High Performance Throttle Body High Flow Intake Manifold Larger Diameter Flowpipe	Package 1: AEM, Jackson Racing, A'PEXi, GReddy, Venom Package 2: Arospeed, NEUSPEED, Skunk2 Racing, Borla, Injen Technology Package 3: DC Sports, HKS USA, HP Racing, Stillen Package 4: Scorpion Exhausts, Henshin Auto, DC Sports
Increases Acceleration	Unlocked after completing Challenge #30.	Price: 1,000
Drivetrain Package
Content	Brand Packages
Limited Slip Differential High Performance Clutch	Package 1: ACT, NEUSPEED, Arospeed Package 2: Jackson Racing, Stillen, HKS USA Package 3: HKS USA, NEUSPEED, Jackson Racing
Increases Top Speed	Unlocked after completing Challenge #30.	Price: 1,000
Tires Package
Content	Brand Packages
Pro Performance Tire Package	Package 1: Toyo Tire Package 2: Yokohama Package 3:Kumho Tires
Increases Handling	Unlocked after completing Challenge #30.	Price: 1,000
ECU & Fuel System Package
Content	Brand Packages
High Flow Fuel Pump Adjustable Fuel Pressure Regulator Replace Fuel Rail Replace Fuel Filter	Package 1: Venom, AEM, GReddy Package 2: Stillen, Jackson Racing, Skunk2 Racing Package 3: A'PEXi, Stillen, Venom
Increases Acceleration and Top Speed	Unlocked after completing Challenge #38.	Price: 2,000
Turbo Package
Content	Brand Packages
Stage 2 Turbo Kit w/ Intercooler	Package 1: HKS USA Package 2: GReddy Package 3: Stillen Package 4: A'PEXi Package 5: Turbonetics
Increases Acceleration	Unlocked after completing Challenge #38.	Price: 2,000
Brakes Package
Content	Brand Packages
Large Cross Drilled Rotors Race Compound Brake Pads	Package 1: AEM, NEUSPEED, Jackson Racing Package 2: KVR Performance, Stillen, Wilwood Engineering Package 3: Arospeed, Brembo, HP Racing
Increases Handling	Unlocked after completing Challenge #38.	Price: 2,000
Weight Reduction Package
Content	Brand Packages
Replace Rear and Side Windows with lightweight polycarbonate Replace Front Seats with Lightweight Racing Seats	Sparco
Increases Acceleration and Handling	Unlocked after completing Challenge #48.	Price: 1,500
Suspension Package
Content	Brand Packages
Front and Rear Sway Bar Front and Rear Tie Bar Upgrade Bushings	Package 1: HKS USA, Stillen, Skunk2 Racing, KONI Package 2: Arospeed, NEUSPEED, Apex Springs, HP Racing Package 3: Eibach, Bilstein, H&R Springs, DC Sports, A'PEXi
Increases Handling	Unlocked after completing Challenge #48.	Price: 1,500
Nitrous Oxide System Package
Content	Brand Packages
Wet Shot of Nitrous Oxide	Package 1: Nitrous Express Package 2: NOS
Increases Handling	Unlocked after completing Challenge #48.	Price: 1,500

Extreme Performance Packages

Engine/Exhaust Package
Content	Brand Packages
Replace Piston & Rods Racing Camshaft & Cam Gears Port & Polish Heads Blueprint the Block Low Restriction, High Flow Headers Installed	Package 1: AEM, NEUSPEED, Jackson Racing, Venom, Arospeed Package 2: Greddy, Skunk2 Racing, A'PEXi, Borla, HKS USA Package 3: DC Sports, Injen Technology, HP Racing, Stillen
Increases Acceleration	Unlocked after completing Challenge #66.	Price: 2,000
Drivetrain Package
Content	Brand Packages
Six-speed transmission Lightweight & Strengthen Driveshaft	Package 1: DC Sports, ACT, NEUSPEED Package 2: Jackson Racing, Stillen, HKS USA Package 3: NEUSPEED, ACT, DC Sports
Increases Top Speed	Unlocked after completing Challenge #66.	Price: 2,000
Tires Package
Content	Brand Packages
Extreme Performance Tire Package	Package 1: Toyo Tire Package 2: Yokohama Package 3:Kumho Tires
Increases Handling	Unlocked after completing Challenge #66.	Price: 2,000
ECU & Fuel System Package
Content	Brand Packages
Stand Alone Engine Management Unit Replace Fuel Injectors	Package 1: Jackson Racing, AEM, GReddy Package 2: Stillen, A'PEXi, Venom Package 3: Venom, Skunk2 Racing, Stillen
Increases Acceleration and Top Speed	Unlocked after completing Challenge #80.	Price: 4,000
Turbo Package
Content	Brand Packages
Stage 3 Turbo Kit	Package 1: HKS USA Package 2: GReddy Package 3: Stillen Package 4: A'PEXi Package 5: Turbonetics
Increases Acceleration	Unlocked after completing Challenge #80.	Price: 4,000
Brakes Package
Content	Brand Packages
Large Cross Drilled and Slotted Rotors Four-piston Racing Calipers	Package 1: AEM, KVR Performance, Arospeed Package 2: NEUSPEED, Stillen, Wilwood Engineering Package 3: Jackson Racing, Stillen, HP Racing
Increases Handling	Unlocked after completing Challenge #80.	Price: 4,000
Weight Reduction Package
Content	Brand Packages
Replace Doors and Trunk Lid with Lightweight materials Cut and Foam Fill excess Frame and Interior components	Sparco
Increases Acceleration and Handling	Unlocked after completing Challenge #91.	Price: 3,000
Suspension Package
Content	Brand Packages
Coil Over Shock System with adjustable Pillow Mounts	Package 1: Eibach, Stillen, Bilstein, KONI Package 2: HKS USA, NEUSPEED, Skunk2 Racing, DC Sports Package 3: Arospeed, Apex Springs, H&R Springs, A'PEXi, HP Racing
Increases Handling	Unlocked after completing Challenge #91.	Price: 3,000
Nitrous Oxide System Package
Content	Brand Packages
Direct Port of Nitrous Oxide	Package 1: Nitrous Express Package 2: NOS
Increases Handling	Unlocked after completing Challenge #91.	Price: 3,000

Unique Parts

Unique parts in Underground can be won upon completion of TJ's time trial events. They can not be obtained elsewhere and allow vast improvements on performance.

Overall, three unique parts can be won, with the first one being unlockable after completing event #7.

The player gets the chance to select between an Engine/Exhaust, Drivetrain, and Tire package. All of these upgrades improve handling, except for the Engine/Exhaust package.

Yet another unique part can be won after completing event #27. The player may select a Brakes, Drivetrain, or Tires package for handling. TJ offers a Turbo and ECU package for acceleration improvements.

The final unique part can be unlocked after completing event #96. TJ will offer to the player the following items; Brakes kit, Drivetrain, NOS, Suspension, Turbo, and Weight Reduction packages.

Notes

• By installing an Engine/Exhaust package, the engine sound of a vehicle will be changed.