We have completed our initial testing of the PRL Motorsports High Volume downpipe on the FL5. The PRL HVDP was an easy choice here because we knew that if a check engine light was presented due to an emissions error, there would be no way for us to override the error due to current tuning limitations. This is not a concern with the HVDP. This is the same unit that was produced and sold for the FK8. This downpipe is currently NOT in production but there are still a few new units available here and there. Whether or not PRL will be producing more of these and/or another downpipe later down the road I am not sure of. The HVDP was paired with a beautiful form fitting blanket from PTP.
The test vehicle had less than 200 miles on the odometer so we wanted to take it somewhat easy. Pulls were completed in 3rd gear with a minimal load being applied from our Dynojet 224xLC. No ECU tuning was performed because there are no available options to do so at this point. Under these test conditions, we found peak gains of approximately 12whp and 8 ft lbs of torque. More notably, we found gains of approximately 15-20whp throughout the powerband from about 4600RPM until redline.
We believe the car was fueled with 93 octane but haven't not put any fuel in ourselves since it was driven off the showroom floor, so I have no way to guarantee the fuel quality.
Our dyno has a history of not being as "generous" with it's measured output in comparison to others so we are not surprised by these numbers being a bit lower than the baselines that are being reported by Hondata and such. As always, dynos are a tool and the best comparisons are always done when using the same car, on the same dyno, under controlled conditions. (as we have done here.)
Below I have included a photo of the stock downpipe (partially disassembled) where it transitions to the front pipe. 😫 Definitely glad to have that off the car now.
Last but not least, we did some informal sound output testing using a basic decibel meter. We found that exhaust noise (at the back of the car, a few feet away from the side of the car) with the factory downpipe peaked at 105.4dB during a wide open throttle pull and this was increased to 108.9dB after installing the HVDP.