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View Full Version : IVT..........Let's talk.........



Redline Motorsports
May 18th, 2007, 07:01 AM
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

Redline Motorsports
May 19th, 2007, 08:53 AM
Looks like the IVT pid is used quite a bit in the Dynamic Compensation and Open Loop multipler tables.

Redline Motorsports
September 2nd, 2007, 10:19 AM
Bringing it back!

Seems like an important pid..........

MN C5
December 16th, 2007, 10:25 AM
TTT

I'd like to know as well... Searched it too...

Redline Motorsports
December 16th, 2007, 10:39 AM
I forgot about this thread :bawl:

Maybe it will re-awake some minds!

Howard

MN C5
December 16th, 2007, 11:52 AM
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...
:nixweiss:

Bruce Melton
December 17th, 2007, 04:05 AM
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.

GMPX
December 17th, 2007, 02:19 PM
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