Main Jet

[Arttu]

Just guessing but your BOV is after the pitot port. So when you close the throttle air flow from the turbo to BOV goes past the pitot and keeps pushing pressure to the float bowls. And the same time pressure at carb venturis goes down as the throttle is closed. So there is plenty of pressure difference to push fuel from float bowls to the engine.

Like said, this is just guessing as I'm not an expert with pressurized carbs.   

[Goo'Roo]

8 hours ago, Arttu said:

Just guessing but your BOV is after the pitot port. So when you close the throttle air flow from the turbo to BOV goes past the pitot and keeps pushing pressure to the float bowls. And the same time pressure at carb venturis goes down as the throttle is closed. So there is plenty of pressure difference to push fuel from float bowls to the engine.

Like said, this is just guessing as I'm not an expert with pressurized carbs.   

I'll give a try.

I've changed the malpassi regulator, fittings the newer black one, just to be sure that there weren't issues with It.

It didn't solve the problem, but transition Is smoother and more stable.

I"ll move the bov.

[Goo'Roo]

I've sorted the bowls pressurization moving the port to the front of the plenum duct and the main jets now are 125 with a really nice transition and 12,2-6 afr at wot.

2 problems remained.

1. When I shut off the throttle under boost, from mid to high revs, the afr falled to sub 10:1 choking the engine of fuel.

If you kept slowing down, without touching the throttle the overly rich condition after few seconds returned normal with a 13,5-14,4 afr. 

2. At the very first opening I had a weird overly rich transition.

Both problems were caused by the blowoff valve in the plenum, disturbing in both cases the idle circuit.

I moved the bov just after the turbo and before the pilot pressure plug and magic has happend.

 

 

 

 

[Goo'Roo]