Yesterday the Sileighty went on the dyno at Unigroup as planned. I was pleasantly surprised to find that Yavuz himself ran the car. His polish really comes through in the patient and calculated way he approaches the car and the feedback he gives. The fact that he starts the session by asking about the aim and where the car is heading makes so much sense.
Last time the car made 170 rwkw, started to heat soak and ping. I left with instructions not to push it. Since then I had changed to 2 inch muffler to 3.5 inch, all new intercooler and piping, base timing corrected (5 degrees of advancement), shortened intake pipe and dump pipe pin holes welded.
This time the car made 181 rwkw with less timing and more fuel key places (for safety). The boost was upped a tad bit to around 18 psi. I upped the aggression of the response in the boost controller n the way home which further improved the mid range. The net result is a safer level of tune with more power. The dip in the midrange is a misfire that developed on the last run. I haven’t changed the spark plugs yet, so when I do, I’ll gap them smaller and get a colder heat range to match the higher boost.
Discussions with Yavuz were probably the most interesting part. He played with settings in the ECU and performed runs to check and verify the changes. The most interesting one was moving the VTC cut off above the rev limiter. This should have the effect of killing power above 5750 rpm as the cam timing chokes the engine. It made no difference at all which Yavuz suggests the engine might have cams and a replacement adjustable cam timing gear. The solenoid still clicks so either this or something broken up top.
The car has a clean bill of health so now I can safely advance to the next step and start pulling bits off for upgrades.