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Intake Valve Temperature
It is a big factor in many of the tables in E40,E38 and E67. Does anyone really know how it is calculated? Apparently GM thinks its an important pid since its used in quite a few fuel and spark tables.
It obviously not measured directly so it has to be derived by GM's own calculated pids.
Any thoughts?:nixweiss:
Howard
Looks like the IVT pid is used quite a bit in the Dynamic Compensation and Open Loop multipler tables.
Bringing it back!
Seems like an important pid..........
TTT
I'd like to know as well... Searched it too...
I forgot about this thread :bawl:
Maybe it will re-awake some minds!
Howard
:nixweiss:Quote:
it's a mathematical model that uses ECT, MAP, RPM, spark, afr and also alcohol mix.
its a linear model with coefficients that are obtained by experiment I guess. not something you could easily "tune"
IVT = a.X + b.Y + c.Z + etc...
I wonder if it is an LS9 provision. In talking to a GM engineer at PRI he confirmed the big MAF valve table in the LS3 is in there for that reason.
I am guessing that the table is initially calcuated in a maths program at GM, probably verified on the dyno, but it's major contributors in the formula are ethanol percent, RPM, spark timing.
Cheers,
Ross