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Well after getting my motor to run decent on a map sensor, it would buck under a low load. I was told that I would need to switch to alpha n since the cams are creating a low vacuum. My question is how would you tune alpha-n since it is running off the tps?
Hey Cespo, The tuning procedure is pretty much exactly the same as Speed Density just instead of the load axis being Map values (kpa, psi etc) they are Throttle percentage. It is the preferred method for multiple throttle body applications and cars with big cams can benefit also. As long as its not Turbo as then you need to do a mix of altha N and Speed density...
One thing a little different with speed density is you would want more load columns (or rows depending what software you are using) around low tps openings...
for example on a speed density setup using map sensor you may have rows at 20kpa, 30kpa, 40kpa, 50kpa, 60kpa, 75kpa, 90kpa, 100kpa
Using Alpha-N you would set it up like 0%, 2%, 4%, 6%, 8%, 10%, 15%, 20%, 30%, 50%, 70%, 90%, 100% TPS
But then you just go and tune each cell exactly as you would Speed density. P.S. those above figures are not gospel adjust to suit each motor... Different size throttle bodies may not need as closely bunched groups while others will... as long as you can get nice smooth response.
Oh and obviously you need a Pot type TPS and not just a switch
Gotcha, thank you for the info.
@Cespo500 there is a worked example in the dyno tuning course where we configure and tune a BMW engine on alpha-n.
Thanks Andre, The dyno course is next on my list.
Does this worked example still exist? I can't seem to find it..
EDIT: Found it. For those also wondering, it's inside the Practical Standalone Tuning Course. Link G4 worked example on an E30.