AutoVE Questions

[Gelf VXR]

When logging AutoVE, you are logging the efficiency of the engine to pump air in varrying conditions, in which case

It does not matter which gear you are in? or does it?

What about the effects for example if you had a proven ram air CAI.

When doing 140 mph in 5th as opposed to say 35 mph in 2nd at the same rpm, there would be a difference in the MAP sensor readings, 1 or 2 psi for example. How is this dealt with?


Could VE maps be set up for differnet gears?

All totally hyperthetical, but I'm interested to know the answers

[macca_779]

VE is RPM and MAP axis's mate. Selected gear doesn't apply. The efficiency of the engine will not change with different gears. Even with ram air added to the equation it shouldn't matter as the MAP pressure will respond to it and just build up to ambient more easily, the faster you go and thus select and different cell to account for it. When it comes down to it AutoVE is all about making commanded AFR's match actual AFR's by reverse engineering the VE table. That's it really. Theoretically it is possible to go above baro with ram air. But we are talking some serious speed here and a very efficient intake for it to be noticeable.

[Gelf VXR]

Thanks, I've got it now, i been chasing my tail with this one lol. Obviously if you logged higher map reading in higher gears, it would just log data in the cells for that map pressure at that rpm. DOH

[stigmundfreud]

fun isnt it gelf

I had the same thought for maf scaling as I never get it above 9500 frequency so my scaling stops there - I wondered if doing 170 leptons would mean it read higher but its the same air flow at 6000 rpm in 2nd as in 5th as the air box can only acomodate so much

going otrcai could prove fun but I'll get a new throttle body if I go that route = start the sodding process again :D

How is it going? It has taken me till this weekedn to get it all scaled and +/- 0.01 on my bens with the maf scaled in.

Also take a look at dfe1's updated dfco settings = much nicer than stock but then you are on an e38 pcm so not sure how it will differ on there.

[joecar]

Also keep this in mind...

the VE Table is a cylinder airmass table normalized ("generalized") for temperature/pressure and has units g*K/kPa;

The name "VE Table" is partly a misnomer.

:)

[stigmundfreud]

luckily the temp has been very constant here lately so every run was done with an outside temp of circa 17c

[Gelf VXR]

fun isnt it gelf

I had the same thought for maf scaling as I never get it above 9500 frequency so my scaling stops there - I wondered if doing 170 leptons would mean it read higher but its the same air flow at 6000 rpm in 2nd as in 5th as the air box can only acomodate so much

going otrcai could prove fun but I'll get a new throttle body if I go that route = start the sodding process again :D

How is it going? It has taken me till this weekedn to get it all scaled and +/- 0.01 on my bens with the maf scaled in.

Also take a look at dfe1's updated dfco settings = much nicer than stock but then you are on an e38 pcm so not sure how it will differ on there.

I am back in India now, so i'm just doing my home work before i return to start the next process. I have an E40 btw.

Progress so far

2 LC-1 installed, done some logging and saved calibration file of stock tune, varified the wide bands are functioning. Programming harness shipped from US

When i return

Disable DTC's for the two front NB O2 circuits, i think i must be in speed denisty at the moment. Verify the simulated NB output. Check for off set voltages between the LC-1 and V2 reading, and start AutoVE logging

[stigmundfreud]

be interested to see/know where you located your contoller boxes!

I dropped mine under the center console and routed the sensor through the bung to the exhaust. I'm thinking of getting one for the other bank too as the switching is more accurate for nb simulation and if I get 2 lc-1s I may revert back to running fuel trims too.

I need to tidy my wiring up so will start on that this week, Might bridge out to a perm guage so I can keep an eye on things whilst not logging...

[Gelf VXR]

be interested to see/know where you located your contoller boxes!

I dropped mine under the center console and routed the sensor through the bung to the exhaust. I'm thinking of getting one for the other bank too as the switching is more accurate for nb simulation and if I get 2 lc-1s I may revert back to running fuel trims too.

I need to tidy my wiring up so will start on that this week, Might bridge out to a perm guage so I can keep an eye on things whilst not logging...

I kept them under the bonnet, cable tied to the wiring loom at the rear of the engine bay, once i'm happy all is well, i'll tuck them up out off sight along the bulk head.

[stigmundfreud]

ah right, be nice to take a peek at some point!