Project Evo 4G63: Upgrading The Cold Side Of The Turbo System

The 4G63 was fluttering and shuddering like it was about to have a heart attack. The blow-off valve on our 2006 Mitsubishi Lancer Evolution Special Edition was doing increasingly poor job at handling light throttle situations, and easing off the gas resulted in unnerving compressor surge.

Earlier Evo VIIIs with all plastic blow-off valves are known for having a finicky nature, but after 10 years and 103,000 miles, our “improved” metal OE unit was ready for retirement. We saw an opportunity, here, especially since we were digging into the induction side of the turbo system conditions, and it was ripe for some performance mods … namely some short-route intake piping and a more efficient front-mount intercooler.

Baseline Testing – Establishing Ground Zero

Before undressing the Evo, we elected to run baseline numbers to have more of an apples-to-apples, same-day comparison of power improvements. As this process is beginning, the 4G63 is running a GReddy exhaust, Buschur Racing intake, Helix housing/downpipe, Hallman manual boost controller, and an English Racing flash tune. Boost is set to a max of 26 psi, and in typical Evo fashion, it tails off to 19 psi in the upper rev range.

The initial pass netted 314.6 whp on the Drift Office Dynojet. This seemed a little off-pace, a feeling that was backed up by a graph that was rich at peak boost. Drift Office’s Bill Lee suspected the MAF reading may be unreliable, so he popped the cone filter off and sure enough there was a misting of oily grime on the screen and metering element.

Factory Lancer Evolution VIIIs and IXs use Karman-type MAF sensors. These units measure both air flow and air temperature before the turbo for load calculation by the ECU. All engines create positive crankcase pressure. The spinning of the internal rotating assembly generates this positive crank pressure that reduces the efficiency of the engine. To mitigate the pressure, many engineers utilize the scavenge effect created by the impeller of the turbo in the intake system to vent the excessive pressure in the crankcase. Due to the location of the sensor, it is very common for the MAF sensor to be coated with oil and residue.

A quick spray down and we were ready for a follow-up run. The 4G63 responded in a positive manner, with a 323.5 whp readout. It should be noted that the torque numbers were very much in line with the first run producing 302.6 lb-ft, and the follow-up checking in at 301.0 lb-ft. The performance fall-off was at peak boost but the meter was functioning well enough at peak torque at about 3,700 rpm to not be a deterrent, hence the similar torque readings.

Wagner Tuning Staggered FMIC Install/Comparison

The installation starts with removing the bumper cover, which entails also taking off the underbelly aero trim pieces. Some of these fasteners can get grumpy over time as flexing cycles can cause them to bind. The bumper bar is removed to gain access to the front-mount intercooler attachment points.

The upper and lower pipe hose connectors are removed, the stock chiller is pulled off, and the Wagner Tuning intercooler is positioned into place. Lee and the Drift Office crew were impressed with the precision of the install as the Wagner unit easily tucked behind the bumper support.

Intercoolers are critical to success in any boosted engine. But contrary to some misinformation, they are not designed to make power — intercoolers are all about efficiency. By cooling, and thereby increasing the density of the charge air going into the engine, an upgraded intercooler extends the detonation threshold which gives the tuner the opportunity to add fuel enrichment, timing, more boost, and tuning to make more power. There is one exception, however: when an intercooler replacement improves flow through the system a power increase can be realized. The name of the game is efficiency and battling pressure drop.

This chart compares pressure drop across the intercooler of a stock Evo IX unit and the better performing Wagner Tuning staggered FMIC. Pressure drop is the difference in pressure measured between nozzle of the turbo and the far side of the intercooler. All intercoolers have a natural pressure drop but the inner layout, tube diameter, number of bends, severity of bends, a larger volume with in the core, etc. The more resistance in the unit the more pressure drop you’ll see.

The true catalyst for this turbo system attack article was the Wagner Tuning staggered intercooler. We marveled at the idea of increasing intercooler efficiency without really changing the FMIC’s footprint or cutting up bumper bars and the like. We also appreciate how Wagner Tuning staggered the design and extended the top of the unit to take advantage of the Evo’s upper grille.

Wagner Tuning’s Henry Bueno says, “The Mitsubishi kit uses a Wagner Competition core. It’s a tube and fin design that allows airflow to the adjacent components such as the radiator and oil cooler. This design does not cause any increase in demand on the OEM cooling systems, and it has ran in 24-hour endurance race cars without any issues. The unit’s end tanks are made ​​of cast aluminum, and we optimized its design under flow analysis in CAD. The inlet and outlet were enlarged to 80 mm, and the kit comes with matching silicone adapter hoses so it can be a plug-and-play install for those running the stock pipe diameter setup.”

Wagner Tuning Staggered FMIC Dyno Test

There is a little bit of the aforementioned restriction elimination going on here as we realized a 5.3 whp bump, as output jumped from 323.5 whp to 328.9. Torque checked in at 303.4 lb-ft, representing a 2.4 lb-ft increase. Lee is quick to point out another misconception in the intercooler game. “The common mistake for owners of forced induction vehicles is thinking bigger is better. That is only partially true. In the case of intercoolers and charge pipes, bigger is not always better. Remember, the intercooler is also a void space that must be filled by the charge air before the air is cooled and forwarded into the engine. The longer this takes, the more turbo lag will be felt by the driver.”

Wagner Tuning Staggered FMIC

  • Core Design: Tube and fin
  • Core size: 550 mm x 390 mm x 95 mm/50 mm
  • Frontal Area: ​​2145cm²
  • Charge Air Volume: 17.7 liters
  • End Tanks: Cast aluminum
  • Inlet/Outlet Size: 80 mm
  • Includes stepdown adapter for stock tubes
To test the effectiveness of the intercooler we decided to only install the intercooler and keep the tune as delivered. Looking at the chart you can see the performance of the engine increased after about 5,000 rpm due to the effectiveness of the bigger and more efficient intercooler. The boost curve also suggests the Wagner intercooler did not create more turbo lag and pressure drop normally caused by inefficient cores, which is quite impressive.

ETS Lower Charge Pipe Install/Comparison

Charge pipes are a critical, yet often overlooked, player in the turbo system. But, what’s in a pipe? Extreme Turbo Systems‘ sales manager Michael Roark explains that flow, just like a car, moves faster in a straight line. “We are able to increase performance and deliver power gains by eliminating all the excess bends in the factory Evo intercooler piping. Our testing shows throttle response is also increased by eliminating the large rubber hose that connects to the throttle body. The factory hose balloons under pressure; we solve this issue by replacing it with tubing and a straight silicone coupler.”

ETS Short-Route Pipe Kit

  • Mandrel-bent stainless-steel construction
  • Includes silicone coupler to turbo
  • Flows over 20 percent more than stock
  • 2x stainless-steel clamps
  • Weighs 3.5 pounds
We like how ETS has incorporated a funnel-shaped coupler at the turbo outlet nozzle to smoothly make the 1.8 to 2.5-inch transition to the pipe. Because there are no tight radius bends in the system, ETS can make the entire kit on its CNC mandrel bender without welding. This is a win-win because the pipes will install as advertised and cost less to manufacture, which eases the pain on enthusiasts’ wallets.

After testing the intercooler by itself we decided to see if there were any restrictions in the charge pipes by installing only the ETS lower charge pipe. Lee says the result was unexpected, but very insightful. “As you can see, the power graph would suggest an overall decrease in horsepower and torque suggesting the piping may be too big, causing a pressure drop, or worse — there could possibly be a boost leak. Upon closer examination of the dyno chart and the ECU logs, we noticed a slight increase in boost lag prior to 3,500 rpm, but the rest of boost curve stayed the same and the air/fuel ratio was running slightly leaner compared with the stock lower charge pipe.”

This suggests that the bigger lower charge pipe may be too big at lower RPM range causing the torque to decrease. However, the ETS pipe proved very efficient in the higher rpm range, resulting in a lean air/fuel ratio. Unfortunately, it is too lean for the engine causing a slight detonation above 6,500 rpm. Lee says, “This proves the lower pipe makes power and that, as indicated by the lean condition, ECU tuning is called for.” It seems a peak power drop from 328.9 to 324.7 whp is ultimately a good thing.

Wrenching To The Finish Line: Performance Distributors Dyna-Batt / ETS Mini Battery Kit

After our findings with the lower charge pipe, we installed the rest of the ETS short-route piping kit along with the Turbosmart blow-off valve, ETS mini battery mount kit, and Dyna-Batt battery to complete the installation phase.

One of the compromises of the short route kit is the need to run a mini battery. We elected to team an ETS Evo IX mini battery mount kit with a Dyna-Batt from Performance Distributors. The ETS battery mount is beefy, with a robust black powdercoat that makes it look like an OE piece, and is designed to bolt into the Evo engine bay using existing holes.

The Dyna-Batt taps into the weight reduction, and equals more performance axiom that is appealing to racers. “The Dyna-Batt only weighs 13 1/2 pounds,” says Performance Distributor owner Steve Davis. “Most car batteries weigh at least 40, and that weight savings means faster track times.”

Dyna-Batt Mini Battery

  • Three terminal designs to choose from
  • 13 1/2 pounds, great weight saver
  • 16 Amp hours reserve capacity
  • Low internal resistance, big cranking power
“Even on a performance street car, knocking off some weight reduces the load on the engine and increases the fun when you drop the hammer,” Davis said. “The Dyna-Batt has a fast current flow, and its low internal resistance allows the current to travel faster compared to conventional batteries. This leads to strong, quick starting.

“Just like an ignition system performs best with low-resistance plug wires, a charging system works best when running a low-resistance battery,” he continued. “A pure lead battery like the Dyna-Batt resists that chemical reaction much better than a hybrid lead battery, which increases the life of the battery. In addition, the Dyna-Batt is a dry-cell battery, so if it were to be damaged/cracked in a collision, no acid would leak out.”

Turbosmart Dual Port Blow-Off Valve

We didn’t know what we were missing until we experienced a proper valve as the stock valve lulled us to sleep, slowly degrading over time and miles on the road … we’re awake now, and we were immediately impressed with the response improvement the Turbosmart Dual Port valve produced on the 4G63.

Turbosmart says the Dual Port delivers better boost handling, durability, and increased flow, which allows higher than stock boost pressure runs without any concern for surge, which is especially important if one’s plans include upgrading the turbo.

We had to supply our own hose to connect the valve. Measuring the length and approximate bend needed, we hit the local auto parts store, then relied on 'The Force' as we trimmed the hose to fit.

Turbosmart’s Marty Staggs is quick to point out that this is no universal blow-off valve. “Our Lancer Evolution valves have specific fittings to allow for easy replacement of the OEM valve without the need to modify the vehicle in any way,” Staggs said.

Turbosmart Dual Port BOV

  • Designed specifically for Evo 4G63 engine
  • Billet aluminum construction
  • Includes port blanking plug
  • 2x 6 mm hose clamps
  • Vacuum source hose
“The actuation spring inside the unit is specifically calibrated for the Evo,” says Staggs, “allowing the valves to be installed on perfectly stock vehicles without the need to be re-tuned, while also providing the flow and durability required when the vehicle is turned up.'”

Staggs was also quick to point to the valve’s tunability. “Out of the box, it is set up for 50/50 ‘hybrid’ operation. If the owner wishes to have it fully recirculating so that it is as quiet as stock, they can simply unscrew the VTA trumpet and install the included port plug,” he said. “All Turbosmart valves are also designed to work seamlessly with the vehicle’s ECU. The ports in the valves are designed to make sure that the factory sensors are provided with the necessary air to make sure that everything operates as designed. There are no compromises.”

With all of the performance gear installed, including the upper pipe sections, we verified our results. As you can see in the dyno chart, turbo lag was reduce prior to 3,500 rpm, and we experienced less drop in boost at red line. The results indicate it was crucial to have the entire piping kit to see the full benefit of the modification, however the engine is still leaning out a bit up top so some tuning was in order. Power output increased from 324.7 to 326.1 lb-ft, which was encouraging.

Tuning The Combination Via Open Source EcuFlash

Once we verified our installation, Lee and Drift Office wanted to address the lean condition and see how much more power they could extract by tweaking the tune in the ECU with EcuFlash software from openecu.org. 

The EcuFlash software, along with the tractrix cable, is a very powerful tuning tool for the Evo platform, and Lee was eager to spin the rollers. The tuning process began with increasing the target air/fuel ratio in the fuel map at higher RPM and load range to compensate for the additional air. He then made adjustments in the same RPM and load range for the ignition map to eliminate any detonation and adjusted the 4G63’s MIVEC variable valve system.

… the only thing that would cause the engine to run lean is the lack of fuel pump flow. – Bill Lee, Drift Office

“Once I was done with the cam adjustment, the only thing left to do was increase the boost,” Lee says. “I realized the engine was running leaner and leaner at high RPM regardless of the adjustment made in the fuel map. I know from experience the factory injectors are more than adequate at this power level and the only thing that would cause the engine to run lean is the lack of fuel pump flow.”

The chart shows the Evo still responded well to our mods by laying down 330.1 whp, a 15.5 whp improvement. Torque registered 315.3 lb-ft, a 12.7 lb-ft increase.

So, as Seinfeld‘s Soup Nazi would say, “it’s no soup for you!” Running out of fuel pump means we are increasing power. In fact, our biggest gains were realized at 5,600 rpm where the 4G63 improved by 21.1 whp and 19.3 lb-ft of torque. Beyond the numbers, the mods we’ve made produce a more snappy, more responsive drive. Our next installment of Project Evo 4G63 will involve installing a fuel pump, making fine adjustments to the blow-off valve, and tuning the 4G63 to realize the full potential of our mods at the top end as well. Stay tuned.

Article Sources

About the author

Evan Griffey

Evan Griffey was the editor of Turbo & High-Tech Performance magazine from 1992 to 2005. The magazine, a founding father of the import scene, gave a struggling, disrespected automotive subculture a voice, credibility, and ultimately its rightful place as a mainstream industry complete with its own movie franchise. Evan has freelanced for the likes of Sport Compact Car, Super Street, Import Tuner, Modified, urbanracer.com, and MSN Autos and we look forward to keeping his keyboard at full boost here at REVVED.
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