Quick EAE question...

[muythaibxr]

There are other things you can do to help stomps, like run more squirts per cycle for example.

If your MAP is that noisy, then you should probably mechanically filter it, but anything you do to filter it will slow down response.

Also, you need to run a pretty high lag-factor to get good response out of EAE.

I have some ideas that'll speed it up as well using TPS, but it might be a while before I implement those ideas.

Ken

[mops]

What kind of MAP thresholds are common for AE or I would guess EAE with lag comp? I'm afraid mine is particularly noisely as it seems I need over 200kpa/sec threashold to mask noise under boost. Should I look into mechanically filtering the line?

Base EAE settings work for casual driving, stomps are hopeless and I might as well have turned the ignition off.

funny that you mentioned that....

yes, i also need to use 200 kpa/sec as mapdot treshold... noise on map is particularity sensitive to electrical intereference (eg.large currents flowing through MS board)

+1 regarding eae. for mdeium/moderate movements i get near perfect response but quick movements (eg quick gear changes) are pretty bad...

[Black99rt]

Turns out that I also have rpm spikes under heavy loads. I have to mod the flyback circuit on my v3 as I am running lowZ injectors, hopefully that reduces map noise as well.

I haven't tried but don't think I can increase squirt further, I am at 4/alt with 65lb injectors on a 360ci v8, idle PW is around 1.6ms (I believe) with an opening time of .8ms. Do I have room to go to more squirts?

[muythaibxr]

You might have room for more squirts.

On a v8, the ideal # of squirts is 8. I've helped an NA v8 on 8 squirts with EAE, and it responded just fine; it was very responsive in fact.

Engines with large manifold volume compared to the engine displacement probably don't even need the changes I plan on making to help quick-tap response.

On the 20v 4age I was running an idle PW of 1.484 ms with 4 squirts alternating with no problem.

Ken

[Peter Florance]

There are other things you can do to help stomps, like run more squirts per cycle for example.

If your MAP is that noisy, then you should probably mechanically filter it, but anything you do to filter it will slow down response.

Also, you need to run a pretty high lag-factor to get good response out of EAE.

I have some ideas that'll speed it up as well using TPS, but it might be a while before I implement those ideas.

Ken

Hi Ken
Was just playing with EAE w/ lag comp.
right now quick stabs take my inject PW from 1.4 to 0. Which doesn't feel that great.
When you say lag-factor, you mean in General, Lags ?

What kind of #'s have you seen that seem to work?

With normal EAE stabs are pretty good, but I'm trying to learn about it. I can post msq and datalog tonight.

This is still on 2.0.1. Is there any EAE change to the later beta's?


Thanks!

[mops]

right now quick stabs take my inject PW from 1.4 to 0. Which doesn't feel that great.

after turning on/off compensation settings you need to power cycle MS.

[Peter Florance]

right now quick stabs take my inject PW from 1.4 to 0. Which doesn't feel that great.

after turning on/off compensation settings you need to power cycle MS.

The settings under General, Lags?

The EAE settings turned on and off without power, but maybe I missed something

Thanks!

[mops]

no sorry i mean lag compensation setting on or off.

lags, under, ganaral, lags can be adjusted on the fly.

[Peter Florance]

no sorry i mean lag compensation setting on or off.

lags, under, ganaral, lags can be adjusted on the fly.

Oh, that might explain it.
I'll try it again, cycling power after the change and datalog on the way home

I wonder what a good TPS threshold is? 9v/sec?



Thanks Mops!

[Peter Florance]

hmm... 2 things
One, somehow my EAE tuning isn't quite as good as it used to be or lag compensation is having the opposite effect.
two, feels better in some ways but I can't tell whether it's actually working (in the datalogs)

[mops]

as per earlier in this thread, you need to make sure your injector opening time is set correctly, otherwise lag compensation will not work as intended.

[Peter Florance]

as per earlier in this thread, you need to make sure your injector opening time is set correctly, otherwise lag compensation will not work as intended.

hmm I wonder if I could use this feature to figure it out?


If it's leaner with more squirts, I would say my opening times are longer than I think they are.

[mops]

it's a bit of a mystery for me.
you see i have timed it on the bench (but without osciloscope).

it's quite a complex subject... you see... with large injectors and very low PW's miniscule differences in opening and closing time result in several % differences between each injectors.

also, the fact that the injector coil has opened does not necessarily mean that fuel is not flowing at max rate. it takes time for the fuel to 'accelerate' out of the injector and it will effectively reach max flow.

anyways, enough of the BS. the idea is that if you are idling the engine... when it's idling change from 2 alternating squirts to 4, and then to simultaneous. if opening time is correct whatever you choose you should end up with same exact afr. in reality it will be always a bit different. set injector opening time so that when you are switching between injectioins per cycle, afr remains as constant as possible.

[Peter Florance]

I built the opening time thingy with the accelerometer (Bruce handed out blank boards at Megameeting 2007)
You strap it to an injector and it shows you when the injector actually fully opens. At 2008 I had it strapped to a low z injector and had the output displayed on USB scope. I think Mike Roberts and Andy Whittle saw it. I haven't really used it since.

I learned two things from building the opening time jig:

1) 'Opening time' is not just opening time, but a more complicated sum of various parts of the total time and much longer than what I saw on the jig

2) I wasn't supposed to build the jig. In fact that's what Bruce yelled when he saw it at 2008 ("You weren't supposed to actually build it!") Didn't get the memo.

[KaPower]

Something interesting about injector opening time and characteristics that I read in a book called, Engine Management Advanced Tuning, by Greg Banish, is that when an injector first opens the amount of fuel that comes out is much more then the rate you would get at steady state flow (Static flow). The reason for this is the pressure differential is highest at first opening due to a higher initial rail pressure. Also at small pw's injectors tend to overshoot and supply more fuel then commanded, the net result is at small pulsewidths, injectors tend to have slightly higher fuel flow rates then the static flow rate. Some ECU's actually have two different flow rates in there injecor modeling, one for normal cruising and power delivery, and the other for starting and idling.

Only if your fuel injector's non linear fuel delivery is accurately modeled in the ecu, will switching between 2 & 4 squirts tell you if your opening time is correct.
Have you ever tried switching between 2 squirts alt then 4 squirts alt, and then 4 squirts simultaneous to dial in your opening time? I have and it produces very frustrating results!

[mops]

very interesting.
i was thinking it was another way around.
i'll have to get that book

[Peter Florance]

Something interesting about injector opening time and characteristics that I read in a book called, Engine Management Advanced Tuning, by Greg Banish, is that when an injector first opens the amount of fuel that comes out is much more then the rate you would get at steady state flow (Static flow). The reason for this is the pressure differential is highest at first opening due to a higher initial rail pressure. Also at small pw's injectors tend to overshoot and supply more fuel then commanded, the net result is at small pulsewidths, injectors tend to have slightly higher fuel flow rates then the static flow rate. Some ECU's actually have two different flow rates in there injecor modeling, one for normal cruising and power delivery, and the other for starting and idling.

Only if your fuel injector's non linear fuel delivery is accurately modeled in the ecu, will switching between 2 & 4 squirts tell you if your opening time is correct.
Have you ever tried switching between 2 squirts alt then 4 squirts alt, and then 4 squirts simultaneous to dial in your opening time? I have and it produces very frustrating results!

I did not get good results testing opening time at idle, but I run 6 alt. I think I need to try it under a load to get a decent flow rate. I was thinking 1 sim vs 3 sim for the test. my car runs funny on 2 sim.

But I thought the lag comp would be a way for me to rough the opening setting in, as I knew the non-lag compensated EAE ran ok (at least I recall it did). Just for laughs I'm going to add .1 msec and see how it runs this morning.

[Peter Florance]

very interesting.
i was thinking it was another way around.
i'll have to get that book

I'm afraid you just got a view of how non-linear my brain really is...

[Black99rt]

This thread made me do further reasearch on my injector set up, it seems MSIIx using 13.2v as base for the Vbatt compensation? And I have correction at .2ms/V as per manual.

I have bosch 65lb/hr lowZ resold through F.A.S.T. I email their technicians and he said that they use an opening time of .8ms on their system for this injector and that their battery correction curve is hardcoded and could be seen in their manual, we'll I installed their software and found the graph they were talking about. It's not great, but by counting pixels in paint, it seems that .2ms/V is VERY agressive compared to what F.A.S.T. uses and since my voltage regulator seeks 14.2 according to averages from long datalogs, my opening time is being used at 1ms for most of my base tuning, I am contemplating starting over, because I fear I will never have excellent AE as a result.

Should I figurure out to how transpose the opening time for a 14.2v base voltage and adjust the correction slope to better match the F.A.S.T. curve for my injectors, since I have what they would presumably recommend with their standalones?

http://i14.photobucket.com/albums/a319/ ... iginal.gif
http://i14.photobucket.com/albums/a319/ ... ection.gif

EDIT: What the annotated pictures should read is 9/28s of 5% y-axis increment rise over 14-13v and 11/28s of 5% y-axis increment rise over 15-14v (if the slope didnt change at 14.5v) I never "normally" see over 14.5v, so this is a convinent simplification for me. If I take the average of the change in opening time percentage, I get 10/28s of the 5% increment, which is 1.78% or 0.0178. Their graph crosses zero at 14v, which I assume is where they apply their recomended opening time to my particular injector, .8ms. So this results in an average correction in that voltage span of .0178*.8ms or .01428ms/V. If MS is correcting with 13.2 as zero point instead of 14, we need to move the input opening time for MS down .8v. Applying the correction we found and a .8V difference and adding it to a .8ms opening time yields .811428ms. So I figure this means I need to input .811ms at 13.2V into MS and a correction of .014ms/V. I am completely off base?

[KaPower]

^^^ Your numbers look good to me. It's interesting how non linear the voltage correction time is. It would be nice to accurately model an injector with MS.