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Drop in power on each dyno run

Posted: Wed Mar 22, 2017 8:33 pm
by ITR1102
Car - 2015 Civic Si with forged 10.5:1 pistons and CT supercharger. Not sure on the pulley size, but was seeing a max of 10.3psi (stock map sensor). Stock I/H/E.
Calibration - US Acura ILX, MAP Based, CT Super Charger, 1000cc. The injector dead times have been changed for the injectors being used. Fuel tables copied from a prior map that the owner claims drove the car well.

Issue - The AFR on the first pull appeared to be decent. On the second pull before making any changes, there was a roughly 5hp drop in power. Third pull, no changes made to calibration and lost another 3-5hp. We didn't hear any pinging, but the knock count kept climbing. We do not know what the engine clearances are or who assembled it. The knock count increased prior to full throttle and at different areas of the map. I've mainly experienced false knock in one particular area of a map but not everywhere. Are sensitivity settings too high or is this most likely piston slap or some other issue? When I last saw this car with the original motor and supercharged, FlashPro was not detecting knock.
We let it sit for a couple of minutes before doing another pull and the power was back up; however, lost about 3-5hp with the next 2 pulls.

To do: Consider replacing the stock intake arm. Replace the map sensor with RDX or Hondata as the reading may be maxed out and boosting beyond what the sensor can read. Recommend a full exhaust.

What else are we missing? Calibration and Datalogged attached.

Re: Drop in power on each dyno run

Posted: Tue Apr 04, 2017 9:43 pm
by keto06
Knock level is 0 but knock retard and high counts? Cylinder 2 is your troublemaker.

Re: Drop in power on each dyno run

Posted: Wed Apr 05, 2017 12:29 pm
by ITR1102
Do you believe there is an assembly or other mechanical issue with cylinder 2, or that it needs timing retard on that one cylinder? I have yet to use individual cylinder timing retard on an engine.

Re: Drop in power on each dyno run

Posted: Sun Apr 09, 2017 5:30 pm
by Zperformance
Compression test. Add more fuel into cylinder 2 and see.