TD42 Split-Pulse Exhaust Manifold – SiMo Ductile Iron
Fits all GQ/GU TD42 engines (Silvertop or Blacktop), retaining the low-mounted turbo position to avoid major changes to intake and exhaust pipework. The turbo mount has been moved forward to eliminate the restrictive dogleg bend found at cylinder 4 on factory manifolds, freeing up room for larger dump pipes and a less severe angle past the firewall and heater hoses. It also makes plumbing an external wastegate back into the dump pipe near the turbo much easier.
The split pulse design delivers more drive energy to the turbine than a conventional merge-type manifold. Thicker walls and greater thermal mass hold heat in the exhaust gas for longer on its way to the turbine, meaning more energy reaches the turbine for the same amount of fuel. The result is a faster-spooling turbo, better efficiency, and more power and torque across your setup.
The manifold is compatible with a Turbosmart EWG 38mm external wastegate, which bolts straight on without compromising the split pulse design. A blanking plate and gasket are included at no extra cost if you'd rather retain your turbo's internal wastegate.
Important fitment note: This is not a direct factory replacement. Turbo position differs from the factory TD42 manifold, so factory and some aftermarket dump pipes won't bolt straight on. Some modification to dump pipe and intake pipework may be required. Contact us before purchasing if you have fitment questions.
What's included
- Pressed stainless steel turbine inlet gasket
- Choice of steel or Inconel 625 exhaust-to-turbo studs
- 316 grade stainless washers
- Copper coated German-made Wurth prevailing torque lock nuts
Options at checkout
- Raw cast finish, or HPC extreme-temp black coating (done locally by Thermal Edge Coating)
- Inconel 625 stud kit for manifold-to-head mounting (also available separately)
- Contact us for lead times on silver or other coating types
