Installing a J37 Magnesuim Intake Manifold onto J32A2 or other J-series with 3-outlet heads

Swapping the throttle body over

To do this manifold swap, normally you would change out the manifold and the throttle body. This can be tricky because the normal J37 throttle body is a DBW (drive by wire) unit and the stock throttle body on older J's is cable-actuated (with a throttle cable).

You can actually re-use your stock throttle body if you want to do this swap, using a specific adapter. That is a P383 adapter found here.

 To fit an aftermarket throttle body you also need this adapter plate and bracket kit:

• P2R B-Series Throttle Body on J32A2 Intake Manifold Bracket/Adapter Kit, P362
• P2R "B-Series" Throttle Body Adapter, J30A/J32A2 cable throttle body (to install on a J37 manifold), P383

We have  made this convenient package for you, including a manifold, throttle body, butterfly delete parts, and all the gaskets and adapter pieces needed to install a J37A intake manifold to a J30/J32, especially a J32A2 engine:

HTSpec J37 Magnesium Intake Manifold and Throttle Body Package, Honda J30/J32 Engines (For Thottle-Cable Chassis)

Other things to know

Relocating the IAT sensor is needed. The IAT (intake air temperature sensor) is normally mounted in your stock intake manifold, but the new J37 manifold does not have a port for it. This is a custom installation. There is one recommended way to do this and that is to make a hole in your intake tube and install the IAT by either threading it in or with a grommet. You will want to install it near the throttle body inlet, a convenient place maybe a few inches away.

The stock manifold has a butterfly valve that you probably are going to delete. This part acts like a bypass valve that changes the manifold shape at different RPM to give a balanced performance for road use.

When you take off your stock manifold you are removing the built-in valve. The J37 does not have a valve built-in; the valve is part of the "top plate" assembly.

We can provide a new top plate with the J37 manifold that will add the butterfly to a J37 setup, but most people delete the butterfly valve because on the newer cars the actuator is fully electronic with different ECU control logic than the older cars use, and therefore actuation with an older computer cannot be easily accomplished. An external, 3rd party-switching mechanism would be needed, and this introduces a whole new layer of complexity to the project which is arguably not worth the trouble.

For this reason, you will need to get a top plate that DOES NOT have a butterfly valve in it (we sell those with the manifold package) and simply leave the old solenoid plugged in and disconnect the actuator cable. If you leave the solenoid plugged in, you won't get a CEL.