what is dot? and delta of t?

[mcobb]

Hi,
Sorry if this is a dumb question but I can't find a definition of dot as in mapdot and tpsdot?
and why it differs from map or tps graphs?
Also what is delta of T?
I'm trying to track down a surging issue & datalog is showing noise on delta of T at the surging.
any thoughts?
thanks
marc

[Matt Cramer]

Hi,
Sorry if this is a dumb question but I can't find a definition of dot as in mapdot and tpsdot? and why it differs from map or tps graphs?

It's from Newtonian calculus notation for the first derivative. In non-mathematician terms, it is the slope of the MAP and TPS graphs. 100%/sec TPSdot would be moving the throttle from 0 to 100% opening in 1 second, for example.

Also what is delta of T?
I'm trying to track down a surging issue & datalog is showing noise on delta of T at the surging.
any thoughts?
thanks
marc

That one I'm not sure of - it seems to be a track of the amount of time difference between ignition pulses, but in practice the way it's logged makes it not very useful for troubleshooting.

[DonTZ125]

'delta' is the notation for change - 'delta-T' is the change in variable T.

[mcobb]

T being time?
as in milliseconds?
Is this then change in vr pulse as engine accelerates, & decelerates?
thanks
marc

[DonTZ125]

'T' is typically either Time or Temperature; in the context of tpsDOT and rpmDOT it makes sense that we're discussing time.

Is this then change in vr pulse as engine accelerates, & decelerates?

Not sure where you're going with this. Could you post a screen-shot of what you're looking at?

[Bernard Fife]

Guys,

There are descriptions of all the datalog channels here: http://www.megamanual.com/mt29.htm#fl

Lance.