In the last installment of our all-motor saga, we were able to make improvements with the help of Crower cams and Skunk2 adjustable cam gears. The two modifications pumped up Project 200's horsepower output by 13.6 peak hp, and pushing the Integra's output from 177.8 to 191.4 ponies. However, as we inch closer to our goal, we're finding it more difficult to gain ground. In this installment, we have plenty of products to test, with some working to our advantage-and some not.
We mentioned last month that we'd be testing a JG Edelbrock Victor X manifold on Project 200. Realizing the manifold would be a dead giveaway for the smog inspector, we went a different route for more airflow. The Skunk2 intake manifold was a perfect match for our project. It's designed with a larger plenum and runners to maximize flow while retaining a stock appearance. Testing by Skunk2 showed significant power gains in mid- to high-rpm bands. All the factory sensors are retained and the factory throttle body can still be used.
On initial installation and dyno testing, we actually lost power vs. the stock 2000 Civic Si manifold, but after some fuel tuning (Field SFC fuel computer and AEM fuel pressure regulator) we were able to bump the peak output by 1.3 hp. The largest gain was realized at 8900 rpm, where the Skunk2 manifold made more than 12.1 hp compared to the Civic Si manifold. The Skunk2 manifold would've made even more horsepower than the stock manifold at redline if we'd revved out the baseline run to 9500 rpm. Our guess is the manifold makes about 20 to 25 hp more than the stock at 9500 rpm.
Next, we installed a set of Sun Pro Systems Hyper Ground wires. Having had great luck with most of the vehicles we tested the ground wires on, we knew these were a sure bet for making power.
After locating the ideal grounding points, the Integra was back, tearing up the rollers. This time, peak power checked in at 193.9 hp, an improvement of 1.2 hp more than the previous run. At 4400 rpm, the ground wires increased the power output by 4.2 hp. Interestingly, the air/fuel ratio became slightly richer over the entire rpm band. Most likely, due to the additional grounding points, the injectors became more responsive and increased the fuel output of the squirters, thereby lowering our air/fuel ratio.
Just as a top-speed Bonneville Salt Flats racer has to struggle against the wind for that last couple of mph, we're forging ahead one pony at a time toward our 200-whp goal.
Currently, we're just 6.1 hp shy of "the double century" and still have a few tricks up our sleeves. We plan on tweaking cam timing with the adjustable cam gears a bit for more power on top to add UR pulleys and a few other secrets. The Integra, amazingly, looks completely stock, except for the 50-state legal AEM cold-air intake and DC Sports header. Until next month, know the rollers are still spinning.