MR Turco

iTrader: (16)

I am no expert, by a long shot, but from what i understand option 1 seems to be better. If i understand it correctly VE will be calculated instead of having a set values? I assume this will avoid the complexity of trying to statically define VE which from what i understand is the most difficult part of tuning SD. I could be completely wrong though.

Slo_crx1

iTrader: (9)

This sounds like a very good idea and a lot less hassle. FWIW I used to tune a lot of stock ecu speed density setups (Honda mostly) and even with them I really don't think the VE math was 100% correct. Fuel and timing tables for them look exactly like our tables with the exception that load % would be pressure (or vacuum) and instead of a rough afr listed they use the actual injector pulse time in milliseconds. These values are then adjusted against the intake air temp depending on the intake charge temp. Most times though the entire tune had to be redone after a season change or major temp drop, which isn't too far off from what I have to do now lol.

I think that even if the VE values can be roughly figured, and as long as the IAT adjustment can be fine tuned, that the values that may be off could be adjusted to meet our tuning needs and stay there. If I understand VE correctly, every part we add to allow more flow through the engine can either increase or decrease the VE, so is it really possible to calculate VE to apply, or would it be easier to use a set VE and make the necessary adjustments to our maps? If it has to do with load calculation I would think that would be thrown out seeing that tuning would have to be done referencing pressure against rpm instead. Am I on the right track? It's been a long time since I put any thought into this stuff lol.

jcsbanks

I think you're on the right track. I was proposing to use the MAF Hz scaling map to correct the fuel pulse width, but let load = MAP.