The last time we posted about the 11th Gen Honda Civic 1.5T High Volume Intake System, we were still in the development phase of the design. Today we are here to post some updates on some of our functioning, first article prototype samples. Recently, the PRL team was able to strap our 11th Gen Civic Si to the dyno to see what kind of gains we could make with a totally stock ECU calibration.
Before we get into the nitty gritty regarding power gains, it’s worth mentioning some of the changes Honda made between the 11th and 10th Gen 1.5L Turbo cars. The factory intake system on the 11th Gen is a vast improvement over the 10th Gen, with it's functioning air duct that utilizes a significantly larger inlet that drapes over the core support and pulls cool air in from in front of the radiator.
How were we able to improve upon the factory intake's design? The main contributing factors to how our intake will improve in terms of performance all come down to increasing air volume and decreasing air temps. We were able to increase the inlet size to the maximum allowable without performing more extensive modifications. Examining the comparison pictures (pictured below), the PRL inlet (black) has a total opening size increase of approximately 23%. Furthermore, we did away with the factory ribbing blocking the air path on the factory design by using a high density thermoplastic blend, which provides enough structural rigidity to warrant eliminating the ribbing. The result of that is the air rushing into the box has a much smoother path, which promotes an increase of horsepower.
Beyond this, we significantly increased total volume housed by the air box. This means that a larger majority of the ambient air is separated from the hot engine bay, which improves the power produced during combustion due to higher air density.
We also briefly touched on a provision towards the base of the air box for a possible secondary air source. In the future, PRL is looking into designing a (Cobra-style) secondary air source that would draw in air from behind the driver’s side fog light, and velocity-stack into the air box.
Now onto the dyno results:
During our dyno session, we saw a maximum peak of 205 WHP with our standard High Volume Intake and a maximum peak of 196WHP with the factory intake. We make sure to do a baseline test to directly compare stock to modified per session to avoid artificially inflating our numbers. Baseline power numbers can vary depending on dyno, ambient temperature, elevation, fuel quality and ECU parameters such as knock control. For reference, this dyno test was performed at 81 degrees Fahrenheit with a humidity of 58.7% and an elevation of ~1100 feet. All dyno pulls were performed on the same dyno on the same day with identical ECU parameters to ensure fairness. The difference in power between the pulls is important to examine, rather than just the peak number. However, further analyzing the graph, we can see that the High Volume Intake made power consistently throughout the rev range. In the mid-range, we see as much as 11 HP at 4400 RPM, and a notable 12 ft/lb torque from about 3700 RPM on. All of this is achieved while keeping fuel trims within 3% of factory spec.
Our team has also confirmed fitment of our 11th Gen Civic 1.5T HVI with the 2023+ 5th Gen Acura Integra 1.5T. We plan to release pre-orders within the next month. Customers can click "Notify When Available" on our product listings to receive an alert when pre-orders are live!