ISR Performance RamHorn Top Mount Manifold MVR SCH10 - Nissan SR20DET S13/S14

The ISR Performance RamHorn Top Mount Turbo Manifold is a Schedule 10 tubular top-mount manifold for the Nissan SR20DET (S13 and S14). T3 turbocharger flange, 44mm MVR wastegate flange, and thick Schedule 10 weld-el piping for serious durability. The geometry is purpose-designed to retain A/C and power steering on the SR20DET, which is rare for a top-mount manifold and a major win for street-driven swaps.

What It Does

Top-mount manifolds position the turbo above the engine rather than below it, which gives you better packaging for high-mounted intercooler piping, easier access for service, and visual presence. The tradeoff on most top-mount manifolds is that A/C and power steering have to come out to make room. The ISR RamHorn solves that problem with a specific geometry that routes around both accessories, so you can run a top-mount turbo on a street-driven S-Chassis without giving up A/C or power steering.

Schedule 10 weld-el piping is significantly thicker than typical aftermarket tubular manifolds, which means better resistance to thermal cracking and longer service life under heat cycling. This is the upgrade over the V3 bottom-mount SCH10 manifold for builds going top-mount.

Critical Specs

• T3 turbocharger flange (matches Garrett T3 and T3/T4 hybrid turbos)
• 44mm MVR external wastegate flange (matches TiAL MVR 44mm and equivalent external wastegates)
• Schedule 10 weld-el piping (thicker than standard tubular)
• A/C and power steering compatible

Recommended Companion Parts

To build a complete top-mount SR setup around this manifold, plan for:

• T3-flange turbocharger (ISR RSX3076 ball bearing, ISR RSX3582, or similar)
• External wastegate with 44mm MVR flange
• ISR O2 housing for top-mount SR20DET manifold
• ISR Downpipe for SR20DET S13/S14
• Oil restrictor (required for dual ball bearing turbos)
• Oil drain flange (GT Series with integrated -10AN)
• ISR Hot Side Top Mount IC Piping Kit (works with standard S-Chassis ISR intercooler kits)

Fitment

• Nissan SR20DET S13 (Redtop)
• Nissan SR20DET S14 (Notchtop and Blacktop)

What's in the Box

• 1x ISR Performance RamHorn top-mount turbo manifold, Schedule 10

Product Details

Brand: ISR Performance

Part Number: IS-SSHT-NS13

Type: Tubular Top Mount Turbo Manifold (RamHorn)

Engine Fitment: Nissan SR20DET (S13 and S14)

Construction: Tubular, Schedule 10 weld-el piping

Turbocharger Flange: T3

Wastegate Flange: 44mm MVR (external wastegate required)

A/C Compatible: Yes

Power Steering Compatible: Yes

Application: Top-mount turbo builds chasing serious power while retaining street accessories

Sold: Individually

Legality: Off-road and competition use only