lambda delay ?

[mads b (dk)]

Do vems have a feature like this ?

http://www.shoptalkforums.com/viewtopic.php?f=66&t=142706&p=1165015&hilit=veal#p1165015

Regards Mads

[Denmark]

What do you need it for?

[mads b (dk)]

Im not sure that i need it?

how do vems compensat for exhaust gasspeed 1000rpm vs 6000rpm ?

Regards Mads

[Denmark]

It dosent other then the delay engine cycles you tell it to,

I must say that its not something i would need to get a perfect running engine , but i also og the old School so i disable ego corection above 0.8bar and wot,
Above that i run openloop

[Mads Lund]

Hi Mads

I don't think it needs compensation, at 1000 rpm (500 ignitions/60 sek) = 8,3 ign/sec, pressure 0,4 kpa, expansion ~4x =1,6 * 0,5 l (cylinder volume = 6,7 liter exhaust /second

My primary tubes is 70cm ø40mm =0,9 l before the lambda = 0,135 sek from exhaust to lambda, with 0,120 sek between pulses

So not really an issue, your will anyway mean the feedback regulation over a number of engine cycles in order to have a stable reading. thus using a pid regulation loop.

Br Mads (from denmark) 

[mads b (dk)]

If you look at the megasquit lambda delay table you see that there is a big differense  30kpa vs 96kpa..... but what you all saying is that its not to worry about. :-)

Regards Mads

[fphil]

This is not easy to make a compensation when information is delayed. To compensate for a delay one can try to set a prediction filter (Kalman or whatever) on lambda measurement
But in this case, apart the fact that the timelag is not constant which makes the thing more complicated, the ego correction has to change the VE  table value in the case the engine does not run as it should, that is in an unpredicable case.
I guess that what is made is to put less weight on the ego correction when the delay increase.
Indeed this is a nice feature which can be added. Enough to have this weight as a function of RPM.
Is it not already the case but with only 2 values: 1 and 0?