E85 4150 tunnel ram tuning

[HarrysTaxi2]

[FC-Pilot]

What I have seen in my experience (which is not as an expert by any means) is that an engine that will accelerate through the rpm band faster often will like to be a little bit leaner than one that would have more of a street gear and tight converter and therefore accelerate at a slower rate. Now what I do is choose a sweep rate on the dyno that will closely mimic what the engine will be like in the vehicle. It also helps as we can get a little closer on ignition timing for performance as well. Loading an engine lower and at a slower sweep rate tends to like a slower advance rate, but that is nothing new as most of you know.

Paul

[JETFAST]

[JETFAST]

[HarrysTaxi2]

[Woodruff]

I don’t think a .180 booster will signal the best with your combo.

[JETFAST]

Also the .176 angles with all the well emulsification, is definitely not helping the .180 booster, signal for efficient flame propagation. Big slugs of fuel are no good for seeding the flame front. Force the timing on a burn like that and atomic detonations start to occupy the cylinders.

[2x4b4fun]

[Right hand drive]

Isn’t emulsion of .028” X .028” X X and mab of 31 more like a gas calibration?

What about mab of ~.025” - .026” and smaller emulsion in the region of .020”? Number and height found through trial. MJ can be reduced then.

I’m wondering if the lean drop is in part because of the large MJ and .028” bleeds. Change gears, engine airflow drops draw on mab, the empty emulsion well refills taking some main well fuel leaning things. Fuel level in the main well being higher with larger MJ it refills emulsion well easier. Revs and air demand goes up things start working normal again as pressure differential becomes greater again. Smaller orifices may stabilize this scenario and smaller jet would have the level lower down the main well less likely to back flow into the emulsion well until pressure differential pushes it back out.

[HarrysTaxi2]