The Dyno

Baseline

test-tune-civic-si-103-007

Since a few days had passed since we last turned the Dynojet rollers at MD Automotive with our T&T Civic Si, we had to establish a new baseline horsepower rating. This is essential as variations in weather conditions and the condition of the daily-driven vehicle will have an effect on the amount of power measured to the wheels on any given day. For this round of testing, our K20Z3 put down 205.0 whp and 143.5 lb-ft torque.

205.0 WHP @ 7,772 RPM
151.0 LB-FT TQ @ 6,143 RPM
Dynojet


Test 1 Vibrant Performance Header

With baseline power measured at 205.0 whp, the addition of the Vibrant Performance catless header brought the peak power output to 217.6 whp. The straight-through piping allows exhaust gasses to flow unrestricted.

217.6 WHP @ 7,855 RPM
153.9 LB-FT TQ @ 6,050 RPM


Test 2 Vibrant Performance Header w/Cat

Following the cat-less header with the catalytic-including header was intentional; street-applications may need a functioning cat. This header managed a 213.9 whp peak number.

213.9 WHP @ 8,056 RPM
150.7 LB-FT TQ @ 5,981 RPM


Test 3 Drag Cartel Drop-in Cams & Flashpro ECU Re-flash

The DIC cams were drop-in as advertised, but we opted to maximize airflow by including new fuel and ignition tables through Hondata’s FlashPro. This combinations was good for 222.8 whp peak.

222.8 WHP @ 8,080 RPM
164.0 LB-FT TQ @ 5,805 RPM


Since a few days had passed since we last turned the Dynojet rollers at MD Automotive with our T&T Civic Si, we had to establish a new baseline horsepower rating. This is essential as variations in weather conditions and the condition of the daily-driven vehicle will have an effect on the amount of power measured to the wheels on any given day. For this round of testing, our K20Z3 put down 205.0 whp and 143.5 lb-ft torque.

test-tune-civic-si-103-003The first test involved installation of the Vibrant Performance 4-2-1 Stainless Steel race header with the cat-delete option. Although the unit is constructed in one piece, installation was easy as access to the factory header was simplified with the use of a lift. Back on the dyno, Jeren fired up the Civic and spun the rollers again. At the extreme low end of the RPM spectrum, the larger header runners allowed power to dip slightly below the stock numbers, but those were recovered to negligible levels by 3,500 RPM. In the area just after iVTEC actuation, the header gained a consistent 8-to-10 increase in horsepower to the upper region of the powerband, where increases as large as 15 whp were seen. Additionally, the header reduced the power drop-off just before redline, maintaining the upward power curve for a longer period of time. With the cat-less header option, peak power output rose to 217.6 whp with 153.9 lb-ft of torque.

test-tune-civic-si-103-005We tested the second header, the Vibrant Performance 4-2-1 Stainless header with hi-flow catalytic converter, after the cat-delete-option header primarily because the particular combination of parts that we’re testing are better suited for street vehicles instead of full-race cars. The target customer for these mods would be more inclined to purchase and use a header that utilized some type of catalyst for street driving; with this in mind, simple switching of the order of testing would allow us to continue the testing straight through without having to re-install a header to continue testing. The Vibrant 4-2-1 header with the catalytic converter installed as easily as the cat-less option header, and the Civic hit the rollers again. With the large runner header in place, there was a slight loss in power from the new baseline in the lower end of the powerband. From 4,800 RPM to 6,000 RPM, the header saw 3-to-4 horsepower gains. After a zero-sum power gain from about 6,000 RPM to 6,700 RPM, the header picked up steadily until redline, showing gains as high as 12 whp. Final peak numbers from the catalytic-equipped race header came in at 213.9 whp and 150.7 lb-ft torque.

test-tune-civic-si-103-001The final parts installation involved both the Drag Cartel Drop In Cams and the Hondata FlashPro ECU reflash. As the name suggests, the DICs are intended to be drop-in replacment iVTEC cams that don’t require additional valvetrain changes or upgrades; our installation experience verified this. However, because of the adaptive factory ECU found in the Civic, new fuel and ignition maps were required to take advantage of the increased intake air flowing into the cylinder head. So, we also reflashed the ECU with predesigned map tables from Hondata’s website using Hondata’s FlashPro unit. The new maps are tuned for a greater volume of air and will allow maximum horsepower extraction from the parts currently installed at this stage of the testing. With both camshafts and new map tables in place, we strapped the Civic to the dyno one last time and spun the rollers to the tune of 222.8 whp peak and 164.02 lb-ft torque. The entire powerband shifted upwards on the order of 10-to-12 whp starting at 2,500 RPM and continuing consistently all the way to the iVTEC actuation point. Here, we saw the return of the crossover power dip at approximately 4,800 RPM, with full recovery to positive 12 whp power gains around 5,300 RPM and slowly tapering off until redline. We believe that the updated maps were not tuned for this particular camshaft profile and, with fine-tuning at that iVTEC actuation point, the dip could be eliminated. Still, there was a respectable amount of power extracted with the camshaft and reflash combination.

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