PRODUCT DESCRIPTION:
High Pressure actuator kit to replace softer unit found on the Hyundai Genesis 2.0T (2010 to 2012 model years) stock turbo. Allows more precise boost control and user can bypass the stock boost control solenoid and set boost to a fixed level between 12 psi to 15 psi. Holds boost much better all the way to redline. Can be used in conjunction with aftermarket boost controllers and/or stock boost control solenoid using proper tuning device. Stock actutor assembly is also shown (painted black)for your reference.

  



APPLICATION NOTES:
** Compatible with Hyundai Genesis Coupe 2.0T, model years 2010 to 2012 only **

The Hyundai Genesis Coupe 2.0T engine is new to the North American market (introduced during MY2010) is a relatively new tuning platform, and for some people, it's their first turbo car and tuning it can be tricky.

The HGC 2.0T engine incorporates a turbocharger that has closed loop boost. This means, during driving, the ECU actively observes and controls the boost curve across the RPM band depending engine temperature, gear used, as well, as load condition, all the time. The ECU is able to control and affect actual boost achieved via several primary control devices, namely the wastegate actuator, the boost control solenoid connected to the actuator, the diverter valve (also called the BOV or dump valve), the diverter valve control solenoid, and the electronically controlled throttle plate (drive-by-wire).

The ECU will generally refer to its boost control map (in its flash memory) in order to determine the proper amount of boost to run and electronically oscillate the boost control solenoid which in turn gets the wastegate actuator to regulate the turbo to make the proper amount of boost. The MAP sensor mounted at the intake manifold measures actual boost and tells the ECU if proper boost level measured is correct.

The ECU's current state of tune will have a "mapped range" of acceptable boost levels. The peak boost limit values are programmed into the ECU tables. In the event the ECU sees too much boost (via the MAP sensor) for a given driving condition, it will generate an "overboost" alarm within the internal ECU logic system. At this point the ECU may choose to command the boost control solenoid to run "less duty" is order to try to reduce the net boost to the engine. If that still does not cause boost pressures to drop within a range accepted by the ECU, the ECU at this point might command the BOV valve to go open via the control solenoid as an effort to bleed off the excess boost. If that still fails to reduce boost to an acceptable range, the ECU can command the throttle plate to close (even though you foot at full throttle position) in effort to prevent air from entering the engine and thus boost is reduced.

How does all this affect how I use my use of a "high pressure actuator" on the HGC 2.0T engine?

Answer: Please refer below to the reason we built this actuator and made it available.

What did we build the high pressure wastegate actuator as an option for the HGC 2.0T?

When we first took delivery of the our own HGC 2.0T for development, we observed that the engine's boost curve was quite erratic and boost was tapering off too much at the high RPM's. In addition, boost control appeared to be too "active". At the track, the lap times are quite inconsistent. On a cold run, the ECU always held back boost until the engine warms up. This coupled with the boost drop off in the high RPM's due to the soft wastegate actuator spring made the car very unpredictable to drive and results were far from predictable.

The stock turbo actuator on the HGC 2.0T engine is a low pressure 5 psi unit. This means base (minimum) boost under wide open throttle is 5 psi. If the ECU does not turn on the boost control solenoid to control boost, the net boost pressure observed is 5 psi. The biggest challenge for a low pressure actuator is to keep the wastegate closed at high RPM's. Due to the high amount of pressure inside the turbine housing, as RPM rises, the low pressure actuator has a hard time keeping the flapper door on the wastegate closed. As a result, turbine pressure is dropped when the flapper door on the gate is forced open, and boost drops.

The ATP high pressure wastegate actuator allows you to overcome the issue of boost drop-off at high RPM's. The high pressure actuator has a much stiffer spring that can keep the flapper valve on the gate shut at high RPM's and high exhaust pressure conditions. This means the turbo can theoretically hold more boost through the entire RPM band. There are two possible ways to use the high pressure wastegate actuator on the HGC 2.0T engine to tune or set boost:

Option 1: Fixed level Boost control. This involves using the actuator to dial in a fixed boost level. For example, you can adjust the actuator arm length to achieve 12 psi. It becomes the minimum and the maximum boost level and the turbo/wastegate combo is mechanically regulated to run 12 psi of boost every time you get on full throttle. In this scenario, you have to disable the ECU's ability to control the wastegate actuator via the boost control solenoid. This is achieved through routing the wastegate pressure signal hose directly from the side of the compressor to the wastegate actuator pressure nipple and bypassing the boost control solenoid entirely. You can leave the electrical plug to the solenoid plugged in, but NOT run the wastegate pressure/vacuum hose through the solenoid itself.

One of the biggest benefits of running a fixed boost control is predictability. Since boost is mechanically set, the target boost level is always going to be the same regardless of engine temperature, gear, or climate.

Option 2: Compounded high pressure boost control This involves leaving everything in the boost control system alone as is and then replacing the softer low pressure stock actuator with the higher pressure unit. This is NOT a recommended path. It creates a very unpredictable boost curve condition and can be very detrimental to the engine reliability. The reason is the ECU normally assumes that the actuator is a lower pressure unit with a 5 psi base. The boost mapping within the ECU also assumes that the actuator is a 5 psi base. Based upon that, the ECU oscillates the boost control solenoid at a certain frequency in order to achieve the target 10 psi boost. If you raise the base pressure to 12 psi, the same boost mapping (same frequency into the same boost control solenoid) will result in an exceptionally high boost level (upwards of 25 psi!).

How does the ECU react to changes to the wastegate actuator arrangement?

The ECU is very sensitive to actuator adjustments and has the ability to pick up the most minute changes. It's very easy to throw the ECU into an overboost condition and cause an internal alarm. When the alarm occurs, the ECU will induce both boost and throttle cut which will ultimately reduce both boost and power to the engine.

This is why some people who have installed the high pressure actuator into their vehicle and have actually seen negative results. The actuator commanded more boost, the engine starts to build more boost, but the ECU says it will not "allow" any more boost.

What is the fix?

The HGC 2.0T ECU needs a remap. Also known as a reflash or "tune". The parameters within the ECU needs to be changed to "allow" more boost under certain conditions. Certain upper limits have to be raised. Otherwise, with the ECU will be overly sensitive to any little change and will insert power reduction interventions anytime it sees "more flow". The HGC 2.0T engine needs this reflash more than any other vehicle we have seen in production. The stock ECU is just too conservative.

On our own development car, we asked PowerAxle to sell us a basic reflash to the ECU that raises the "peak boost limit" to a value much higher than stock. As a result, we are able to set and run boost levels up to and over 25 psi without the ECU intervening at all. What ever boost level we want to set through the wastegate, the ECU will allow it and boost is consistent and flat. The erraticness in the boost curve simply does not exist.

Dyno-Comp in Arizona has the ability to flash tune the HGC 2.0T ECU
//dyno-comp.com/blog/2012/03/2011-hyundai-genesis-coupe-2-0t-stage-3-performance-package/