So far Project EVO has been an amazing project. For very little money we have gotten great results in performance gains into an already very good package. Our current goal is to max out the simple and relatively inexpensive mods while retaining the stock turbo, injectors, intercooler, and underhood piping before digging more extensively into Project EVO's systems to extract really big, yet streetable power gains.
As most of you know, California is plagued with really bad 91-octane gas. Our gas really hates turbocharged cars. Due to what is a suspected juggling of the Motor and Research octane ratings California gas is more prone to detonation than its 91 octane suggests. Before those of you in the rest of the country where gas of up to 94 octane is available smugly chuckle, don't laugh too hard. With shortages and rising prices there is a call to standardize the many different regional gas blends into just a few. There is a good chance that more of you will fall under the doom of 91 octane as well. In that case, our experimentations of how to get power in a poor fuel environment should pique your interest.
One of the issues we have had with Project EVO from the beginning is inconsistency in measured and felt power and torque levels. Once we installed Vishnu's XEDE/Flash system and tuned it the inconsistency decreased greatly on the dyno but when driving on the street Project EVO still has variability issues. Sometimes it feels as if torque varys from 20-30 lb-ft depending on the fuel of the day, air temperature, and if the car had been cruising on the freeway or heat soaking in traffic.
This was due to the EVO's very active ECU, which was constantly cutting ignition timing and boost levels to ward off detonation. We resigned ourselves that this was what we had to accept with our fuel and the engineering of the stock systems in the car. That resignation didn't last long after we got a call from Shiv Pathak of Vishnu Tuning. Shiv was excited about the results he was getting with his new S.M.A.R.T. (Self Monitoring Active Real-time Tuning) upgrade for the XEDE system. The S.M.A.R.T. system converts the XEDE into a fully adaptive engine control system that is more sensitive, faster, and has a wider range of control authority than the stock system. The S.M.A.R.T. system is capable of making real-time adjustments to fuel, ignition timing, and boost in response to changes in driving conditions.
The S.M.A.R.T. system works well because it's faster to affect changes to the engine's control parameters and more sensitive than the stock ECU. This means it can detect and react to the onset of detonation before the stock ECU. It can also return the engine to normal non-knock conditions before the cylinders substantially heat soak. The factory ECU's signal processing is hampered because it resides within the noisy electrical environment of the ECU in intimate proximity to components like the power transistors that drive the injectors and ground the coil triggers.
This electrical noise can mask the telltale signature of knock. To combat this poor signal-to-noise ratio, the engineers at Mitsubishi make the knock response of the ECU conservative. The ignition is retarded a lot, boost pressure is reduced, and the fuel mixture is richened for quite a while before the ECU releases the clamp. The power and torque dip and the driver gets bummed out.
The S.M.A.R.T. system puts the knock detection circuitry in a separate box mounted far away from the noisy ECU. This allows it to see a more pure, clean discernable signal so it can more accurately detect and react to the knock. The XEDE has a reduced operating set of instructions that its internal computer executes with each clock cycle when compared to the factory ECU which also greatly speeds its response. The S.M.A.R.T. system also uses a wideband O2 sensor that allows it to accurately monitor and control a wide range of air/fuel ratios, including the areas that are normally open loop such as full throttle. The S.M.A.R.T upgrade for XEDE includes Smart Software, Knock Box, Wideband O2 Controller w/ Bosch sensor, and OBD-II Diagnostic Tool.
After installing the S.M.A.R.T. system we did notice a substantial gain in driveability and fuel economy. The huge power variations we had grown accustomed to with Project EVO are now greatly reduced.
With S.M.A.R.T. we also took advantage of the XEDE's multi-map capability and had Shiv tune the car with separate maps optimized for 100-octane unleaded race gas; 91-octane pump gas; and the next step, methanol injection.
To give Project EVO the ability to run aggressive levels of boost and timing like you can with race gas but without the expense of running race gas all the time we installed Vishnu's methanol injection system. This system uses an auxiliary pump, the stock intercooler sprayer tank, and a boost pressure-regulated electronic controller to inject methanol into the intake tract before the throttle body. The advantages here are twofold. Methanol has a high latent heat of evaporation and the phase change from a liquid to a vapor state substantially cools the intake charge. If you notice, this is the reason why many methanol burning turbo drag cars don't run an intercooler. Methanol also has a very high octane which suppresses detonation.
Vishnu uses the XEDE system to control the injection pump. When the system is activated, the XEDE switches to an engine control map with a more aggressive timing curve, higher boost, and a leaner mixture. It's like having a tank of race gas on demand without the expense.
If you remember in the last installment of Project EVO we added a test pipe and solved a problem with a leaky blow-off valve that was preventing boost above 19 psi. With our new tuning and parts we once again headed to XS Engineering's 4WD dyno. Our first pulls on 91-octane fuel netted 346.3 hp and 288.9 lb-ft of torque, a surprising gain for which we were quite pleased. This is an awesome amount of power for what amounts to simple bolt ons. Next we enabled the methanol. With a flick of a switch we jumped to 354.4 hp and 311.4 lb-ft of torque. This may be close to a pre-2005 model year bolt-on power record. (After `04, the EVO received a larger, less restrictive turbine housing which makes a bit more power.) Finally we topped off the nearly empty tank with 100-octane unleaded race fuel and pulled a peak output of 381.9 hp and 317.51 lb-ft of torque. We were quite impressed that the methanol injection made nearly as much power as race fuel.
XS Engineering's Power Pack Ignition Amplifier System
High reving, turbocharged engines with lots of boost pressure all require a great deal of spark energy from the ignition system to run properly. The higher the boost, the more spark energy is required to fire the spark plugs to complete combustion. Methanol, with a higher dielectric constant than gasoline, also requires a hot spark to fire properly under pressure. With the installation of these parts we decided it was time to upgrade the igntion of Project EVO.
In the past we have had many problems with aftermarket multi-spark and CD-type ignitions on late-model vehicles. These aftermarket igntions are often noisy which can wreak havoc with sensitive, OBD-II-type engine control systems. High output ignitions also have very intense but very short spark durations. This is often not the best way to ignite a stubborn, difficult-to-fire, highly-compressed mixture. Some iginition systems try to get around this by firing multiple sparks but this often compounds the problems with electrical noise and is usually only effective at lower rpm. We chose XS Engineering's Power Pack to get around these issues.
The XS Engineering Power Pack is an ideal upgrade for anyone who wants a compact and cost-effective way to maximize the performance of their OEM ignition system, boosting its performance without electrical noise and OEM system scrambling issues. The stock igntion system uses the collapsing magnetic field within the windings of the coil to produce spark energy. This sort of system is called an inductive system. Inductive systems don't have the super intense spark of the common capacitor-driven aftermarket systems but the spark has a comparitivly very long duration. The Power Pack unit capitalizes on this long duration and increases ignition output by boosting the secondary voltage to the coil, giving it more voltage to step up by saturating the coil to a much greater extent. The unit installs inline with the positive, secondary side of the coils and raises the input voltage to 20 volts up from the stock 13 or so. This translates into greatly increased spark energy. The Power Pack features internal power regulation, which keeps its output at or near 20 volts and up to 20 amps even when the input voltage dips below 12 volts as in the case of a marginal charing system due to a failing battery. Another one of the Power Pack's key advantages is its compact size, which is important as the EVO has very little space under the hood. Lastly, another impressive feature of the Power Pack is that all of its internal circuitry is epoxy-encapsulated to survive even in the toughest of racing environments.
We fabricated a bracket for the Power Pack and mounted it on the cowl in the engine compartment. We noticed an immediate improvement in idle quality and stabilty. Part throttle driveabilty is also greatly increased.
At this point we have come to the end of easy bolt-ons for Project EVO. In the coming installments we will be digging deeper to get some serious power out of the 4G63.