ISR Performance - Top Feed Injectors - 1000cc- (set of 4)

Our 1000cc top-feed injectors, sold as a balanced set of four. The matched injector for our ISR top-feed fuel rail and intake manifold combo on SR and 4-cylinder applications, and a universal drop-in for any compatible top-feed setup.

What It Does

Delivers 1000cc of flow per injector for serious power builds. Every set is flow-matched within 2% variation across the transitional, low, and linear pulse-width ranges, so all four cylinders fire consistent fuel even at low duty cycle and idle. Stainless steel internals make these E85-compatible. High-impedance design works with most aftermarket ECUs without needing a resistor box. USCAR connector style is the modern standard for aftermarket pigtails.

Fitment

Universal top-feed application. Designed to match our ISR top-feed fuel rail and intake manifold combo on SR-based builds, and fits any setup that accepts the specifications below.

Important Note on Connectors

These injectors use the USCAR connector type and do NOT include pigtails or connectors. Plan to source pigtails separately if your existing harness uses a different connector type (factory Nissan side-feed harnesses do).

Specifications

• Flow rate: 1000cc
• E85 compatible
• High impedance
• 48mm height
• 14mm upper O-ring
• 14mm lower O-ring
• USCAR connector type

What's in the Box

• 4x 1000cc top-feed injectors
• Injector O-rings
• Injector flow data sheet

Product Details

Brand: ISR Performance

Part Number: IS-INJK48441004

Type: Top-Feed Injectors

Flow Rate: 1000cc

Connector: USCAR (pigtails NOT included)

Impedance: High

Height: 48mm

O-Rings: 14mm upper, 14mm lower

Internals: Stainless steel (E85 compatible)

Flow Variation: Within 2% across transitional, low, and linear pulse-width ranges

Application: ISR top-feed fuel rail / intake manifold combo (SR-based builds); universal drop-in for any compatible top-feed setup

Sold: Balanced set of 4 (with O-rings and flow data sheet)

Related: IS-INJS-550-4 / IS-INJS-550-6 (side-feed alternatives if you're not converting to top-feed)

Legality: Off-road and competition use only