90kPa is high, I agree, but I've had this car for years on it's original ECU and a boost gauge T'eed into the boost sensor port (it had a boost sensor and hotwire MAF) and it always saw almost 0 bar/1 atm at 120kmh cruising. It also saw consistent 0,7bar boost pressure which is stock gate pressure so I'm inclined to believe the sensor/gauge.PSIG wrote: ↑Mon Aug 03, 2020 8:07 pmYou may have to test for the most stable MAP location in your manifold, typically away from the inlet and runners, but dynamics can be weird.
90kPa is oddly high for cruise, but could be your MAP source point or the MAP mode. Generally, from best-torque fuel Lambda/AFR at stable cruise, lean to the point that you feel lean surge (slow push-pull feel), and enrich just out of it. Check MAP. Don't be surprised if it's higher, as lean is actually less efficient (assuming it was originally fueling for max torque).JoostXT wrote: ↑Mon Aug 03, 2020 3:06 pmThis brings up an interesting issue though; whilst cruising at 3000rpm I'm at 90kPa, so I want it to be quite lean to gain some mileage. …
Also, this engine seems to like a lot of timing, I'm up to almost 40 degrees high rpm cruising which seems a bit high to be honest.
In order to recover efficiency at the new Lambda; at stable cruise again, begin slowly testing timing advance until timing is at minimum value for MAP just at minimum value, indicating peak timing efficiency. Advance may be quite high relative to power Lambda timing, in order to compensate for the change in cylinder pressure rise rate. The table cell may change during this exercise. See where that gets you. Don't forget you are tuning for best target performance (and resulting Lambda) at any point, not a Lambda number, which is only a reference.
I think it's due to the small but very inefficient little 80s turbo that is on there. It starts to build boost as low as 1900rpm but doesn't actually attribute to any power gains until above 3000rpm. And after 5k it starts tapering off and heating up significantly. I guess it's mostly there for bragging rights (it has "TURBO" stickers all over the car )
Something new to consider; I noticed 10 PSI (!) fuel pressure difference between hot and cold engine, engine off. This seems like a lot! I think heating up the fuel would make it thinner, but the tank is full (60L) and the ride was only 20min so I don't think I could heat all that fuel in that amount of time? Maybe the regulator is bad?
edit; forgot to say, thanks for the sage tuning advice, I'll have to have someone else driving, but it's the best way forward!