With nearly 400 horsepower to the flywheel we were running the injectors at the ragged edge. The factory 540cc injectors were nearly at 100 percent duty cycle at the top end. To ensure the Evo's thirst is always quenched we went big. At almost two times the size of the factory 540cc squirters, the MSD 96lb (1008cc) injectors are massive. The MSD injectors did require some machining in order to fit them into the factory fuel rail. Any competent machine shop should be able to perform this job. We had ours done at XS Engineering for about $100.
With the injectors in place Greg recalibrated the AEM EMS system for the larger injectors. This time around the injectors were only running at 45 percent duty cycle at full load; much safer than before.
To our surprise the MSD injectors also generated a little more power over the stock injectors. Our guess is the MSD injectors have a better spray pattern than the stock injectors allowing for better atomization of the fuel. Whatever it was the MSD injectors posted a 4.1 horsepower increase over the stockers, pushing peak power to 317.5 horsepower at the wheels.
In our December 2005 issue we were the first to feature the Blitz i-Color boost controller and now we are the first to test it out on the dyno. Previously we had been using the factory boost controller to maintain boost pressure but with the solenoid maxed out on the EMS computer we were only able to generate 1.196 kPA (17.58 psi) of boost pressure.
The i-Color is not just about glitz and glamour, the controller utilizes an extremely effective twin solenoid design for boost control. After dialing in the i-Color for increased boost we generated 1.463 kPA (21.51 psi) of boost pressure. With the increased boost we were able to generate 345.2 horsepower to the wheels on 91-octane pump gas. Gains as high as 30 horsepower were vividly illustrated on the dyno graph.
Considering we only increased boost pressure by 4 psi the power increase was substantial. In addition to the previous installment we increased the output of the Evo by 42.3 horsepower to the wheels. Compared to a stock Evolution we nearly generated an extra 100 horsepower and we have yet to open up the engine.
What's next you ask. We are itching to try out a larger pair of camshafts as well as a larger bolt-on turbo or complete upgrade. However, before we even address more bolt-on performance adders we must address the factory fuel pump and ignition system. So until next time we will keep turning those wrenches.