Creeps and Leaks

Boost creep and a power steering fluid leak are my biggest concerns on the car at this time. When I originally bought the car, it was equipped with a brass manual boost controller zip tied to the radiator fan, which I’ve since replaced with an AEM boost controller. The new AEM controller not only provides an adjustable boost solution, it also serves as a more accurate boost gauge than the decades-old analog gauge that was previously installed.

Unfortunately, the new gauge has only revealed a previously unknown issue. While the previous gauge showed that the car reliably made a very consistent 14psi of boost pressure, the new gauge shows that this number was nowhere close to accurate. In fact, the previous controller was providing well over 20 pounds of boost and that pressure was consistently climbing as the throttle stayed open. After installing the EBC though, and tuning it all the way down to zero restriction (running the wastegate at spring pressure) the climbing boost was still present. Even with the controller completely bypassed, it turns out the wastegate just can’t keep up.

As I’ve mentioned previously, closer look at the turbo on this car reveals that it was taken from an EVO 3. This turbo is nearly identical to the eclipse’s 16G but has a larger compressor wheel. This turbo is connected to a 3 inch turbo back exhaust which allows it to flow like crazy.

I first suspected that the car’s waste gate actuator may not have been working correctly so I removed it for some inspection. While the unit is sealed and can’t be examined internally, it appears to work as intended. Still, I’m not ruling out replacing it with a new adjustable actuator from kinugawa in the future. At this time though, my suspicion is that the wastegate simply can’t flow enough exhaust to spool down the turbo. I know there are some options like wastegate porting which I’ll look into once the engine is out of the car and I can better understand the shape of the turbo itself, but for now my solution is to just take it easy on the gas pedal.

As for that power steering fluid? The steering rack is coated in the stuff, from end to end. It’s not a notable leak in any one location and I haven’t had to add fluid, but the seals are certainly gone. So, one more seal and gasket kit goes in the shopping cart.

Cheers!