It's no secret that Turbo magazine articles, be they tech or features, revolve around the dyno. It's also no secret we put the spin on more rollers than any other publication out there.
We've probably tested more than 100 exhaust systems over the years and we generally have a keen awareness of how much each exhaust system is going to make before it's even installed and tested.
On a naturally aspirated Honda or Acura, we generally see a gain of 5 to 7 hp at the wheels from simply bolting up an aftermarket exhaust system. The Honda engineers have done their homework when designing the powerplant and it's often fairly hard to squeeze a great deal more power from the already super-efficient engine.
However, the engineers at GReddy Performance Products in Irvine, Calif. have developed an exhaust system for the Honda Accord V6 that blew us away. The system we tested on the V6 Accord was from GReddy's Evolution line, which incorporates the popular larger-canister look without the overwhelming exhaust tone that can be associated with it.
From the rear of the car, the system features a small muffler look hiding most of the canister section within the bumper. This was made possible by an offset tip design giving extra road clearance for extremely lowered vehicles. The entire canister section is constructed from polished stainless steel, increasing the durability and reliability of the entire system while scoring big points on the aesthetics side.
All Evolution canisters feature a straight-through design for maximum airflow. On the Accord V6, the Evolution system is offered in single or dual option; for testing purposes, we went with the dual. The piping section for the Accord measured in at 60mm (2.36 inches) providing excellent flow without hindering low-end torque. The exhaust tips measure a massive 115mm (4.52-inches), and they protrude aggressively out each side of the rear bumper. The result? The Evolution system looks impressive and dominating. But what really matters is horsepower.
On XS Engineering's Dynojet chassis dyno, the stock V6 Accord equipped with 18-inch RH Evolution C2s registered 158.0 hp and 151.8 lb-ft of torque at the wheels. With the car still strapped to the dyno, we installed the GReddy system. The installation was straightforward with all the components fitting perfectly in place. Within 20 minutes the car was fired to life. We checked for any exhaust leaks, but the new gaskets that were provided did their job and the dyno rollers were spun.
The Accord laid down 169.9 hp and 164.3 lb-ft of torque, a jump of 11.9 peak hp and 12.5 lb-ft of peak torque. From 3,600 rpm to 6,200 rpm, the Evolution exhaust made 8 to 10 hp more than the stock system. In fact, the GReddy exhaust made significantly more power at any rpm range without any loss of torque all the way to redline.
On top of the impressive power gains, all of GReddy's exhaust systems are CARB-exempt for sound and emissions meaning they are 50-state legal. From our standpoint, we give two thumbs up to the GReddy R&D crew who designed the Evolution system. Looks, power and 50-state legality--what more can you ask for?