In this blog post, we go over what wiring needs to be adjusted when installing a rotated turbo kit in your Subaru. Common kits come from manufacturers like ETS, Perrin, MAP, Full Race, or P&L
Installing a rotated turbo on your Subaru can make a lot more power. It can also create a simple problem: The factory wiring may no longer reach.
Why Does a Rotated Turbo Change the Wiring?
A factory Subaru turbo sits in a specific spot behind the engine. A rotated turbo setup moves the turbo to a different position. This is usually done to make room for a larger turbo and different intake and exhaust piping. Moving the turbo can also change where other parts need to sit.
That may include:
- Boost controller
- Mass Air Flow sensor, also called the MAF
- Throttle body or intake piping
- Front O2 sensor
You do not always need to extend every one of these. It depends on how your rotated turbo setup is built. The best time to check is while you are putting the engine bay together. Before pulling on a connector to make it reach, stop and see if an extension is a better solution. iWire offers Extension Harnesses for your engine bay wiring so you can get that rotated turbo working and get back to driving.
You Must Switch to Speed Density Tuning.
With a rotated turbo setup, you will most likely remove the stock MAF sensor, so you MUST switch to speed-density tuning. More about what speed density is here. It's easy to switch from a stock MAF to a speed-density setup. You'll install an IAT sensor near the throttle body, then use one of iWire's Speed Density Wiring Kits so the new sensor plugs into the stock harness at the correct location. Reach out to your tuner to see which iWire kit they recommend for your specific project.
Why Not Just Cut and Extend the Factory Harness?
You can cut wires and make them longer, but every cut adds another place where something can go wrong. Plus, some of the sensor wires are shielded, so simply cutting and extending them can lead to sensor noise issues later.
An extension harness lets you add length without cutting up the original engine harness. This makes it easier to change the car later. If you remove the rotated turbo setup, you can unplug the extension rather than undoing changes to the factory harness.
Don't Forget About Heat and Wire Routing
A rotated turbo can also put very hot parts in places Subaru never intended. That means wire routing is just as important as wire length. Make sure that when routing your wires, you keep them away from sharp edges and heat sources such as turbo housings, exhaust manifolds, headers, downpipes, wastegates, and other hot exhaust parts.
iWire Extension Harnesses
Click on the links below to learn more about our extension harnesses. They are made with high-quality tefzel wire and high-temp sleeving, so they will withstand the harsh engine-bay environment.
Boost Controller Extension Harness
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