ISR Turbine O2 Housing - Nissan RB20/25 Swapped 240SX

The ISR Performance Turbine O2 Housing is a turbo outlet / O2 housing for RB20DET and RB25DET engine swaps into the 1989-1998 Nissan 240SX (S13 and S14). 3 inch diameter outlet, double-welded inside and out to prevent cracking, with a brushed finish. Specifically designed to clear the LHD steering rack and bolt up to a SR20-style downpipe when running ISR swap mounts.

What It Does

The factory RB20DET and RB25DET turbo outlet is restrictive and routes the exhaust toward a JDM RHD chassis layout, not a US-market LHD S-chassis. This ISR turbine O2 housing replaces the factory unit with a 3 inch flow path designed around the LHD steering rack clearance issue that's the most common headache on US RB swaps, then transitions to a standard SR20-style downpipe so any 240SX SR20 downpipe and catback work downstream.

Bang-for-the-buck power gain on any RB-swapped S-chassis build, plus it cleans up the turbo-to-downpipe transition that's usually custom fabbed.

Critical Fitment Requirements

This is built specifically for RB20/25 swaps into a 240SX using ISR swap mounts.

• RB20/25 engine swap into US S-chassis (LHD)
• ISR Performance RB swap mount kit required for guaranteed fit
• Designed to use SR20-style downpipe downstream
• Designed to clear the LHD steering rack

Installation Notes

• Re-uses factory OEM turbine housing studs and nuts
• May require slight clearancing of the bellhousing or flange due to the 3 inch diameter

Specifications

• 3 bolt flange thread pitch: M10 x 1.5
• Bolt length: 1 3/4 inch
• Finish: Brushed
• Construction: Double welded (inside and outside) to prevent cracking

Fitment

• 1989-1998 Nissan 240SX (S13 / S14) with RB20DET or RB25DET swap on ISR mounts

What's in the Box

• 1x ISR Performance RB20/25 turbine O2 housing
• 1x 3 inch 3-bolt gasket
• 1x 6-bolt gasket
• 3x Exhaust studs
• 3x Nuts

Re-use OEM turbine housing studs and nuts.

Product Details

Brand: ISR Performance

Part Number: IS-O2-RB25

Type: Turbine O2 Housing (Turbo Outlet)

Vehicle Fitment: 1989-1998 Nissan 240SX (S13/S14) with RB20DET or RB25DET swap

Engine: RB20DET, RB25DET

Drivetrain Restriction: LHD chassis only (designed around US steering rack clearance)

Required Companion Part: ISR Performance RB swap mount kit

Downpipe Compatibility: SR20-style downpipe

Outlet Diameter: 3 inch

Flange Thread: M10 x 1.5 (3-bolt)

Bolt Length: 1 3/4 inch

Construction: Double welded inside and outside

Finish: Brushed

Installation Note: Re-use OEM turbine housing studs / nuts; may require slight bellhousing or flange clearancing

Sold: Housing with gaskets and exhaust hardware

Legality: Off-road and competition use only