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Modifying Your Wastegate actuator rod: Performance mod on a budget

With a couple of turns of the wastegate actuator rod, you can boost your Volvo’s performance—but you have to proceed with caution. Learn how to tweak your wastegate actuator rod with field-tested advice from other DIYers.

The Cheapest Performance Mod

The 4.4 Motronics (94-98) can handle up to 3+ turns but you don’t want to do that. You will actually get too much boost almost off the line and in bad weather can be a bit scary.

Wastegate rod adjustment diagram. Earlier boosting when shortening the wastegate rod.
Earlier boosting after shortening the wastegate rod

JDS60R » VADIS provides the adjustment procedure and proper setting for each car. You will find they all come set differently from the factory. I like to check the setting when buying a used car.

Just post which car you have and someone with VADIS will respond. If you set it at the factory setting the cars become lots of fun to drive.

You are setting the minimum boost level the turbo will be running at while the car is running with no gas pedal input. This amount of boost is always on. When you hit the pedal it then boosts up to its psi limit. For example – On some cars that produce 12psi max the wastegate setting is to hold 5 lbs of boost. This means when you accelerate from idle you immediately have 5psi of boost. If you turned it up to its max of 12psi you would have 12psi boost too soon and it would bend rods etc. Even if it doesn’t do this the first time it will stress/destroy the engine soon.

As mentioned earlier going over stock setting will do bad things. At the proper setting you get great response , great mileage and great longevity.

Do a stage 0 by checking the turbo control valve’s operation (usually not working up to spec), set the cam pulleys properly, replace the plugs, filters , fluids and set the wastegate. These cars, properly tuned, running on top shelf synthetics are lots of fun.

Wastegate rod on a 15G turbo
Wastegate rod on a 15G turbo

Does This Make My Volvo Have More Boost? Nope.

rbodor3 » Turning the entire thing isn’t really that big of an issue. Yes it should have a cotter pin thru the WG valve and the end of the WG actuator arm.

A common mistake is the misconception that boost = power which is not always true.

Even if you raise boost pressure your power can stay the same. By raising boost with a stock car (specifically, the exhaust) you’re really going to just be creating more backpressure, heat, backfire, even reverse the direction of the turbocharger compressor with too much backpressure (which will of course destroy it), early detonation, and high peak boost with low drop off. Even if you do this correctly and build boost earlier, the ECU will recognize this and retard timing if stock. So basically by building boost earlier you don’t do much of anything unless you’re trying to build it up to come on sooner.

By changing the WG actuator you’re not increasing your boost, you’re just deciding when you want it to come on. By tightening it you have it come on earlier – which with the completely stock exhaust system can and has lead to bent rods and detonation.

If you aren’t sure what the names of the turbo parts are, you shouldn’t do this without a boost gauge. In fact, don’t do this without a boost gauge ever unless you know what you’re doing.


Modifying the Wastegate actuator rod…

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