Auto VE correction amount

[1bar]

Hello Everyone,

I am curious how much the Auto Tune corrects per flash?

Thanks,
Glenn

[Stealth97]

Depends on the length of the logged data, and how much it was off.

There is no specific answer for this. The algorithms work the BEN factors out to be 1.0.

Search and read what a BEN is. Read the AutoVE tutorial, especially the one for Craig Moates RoadRunner.

Post some more detailed questions. Too vauge with these "how much does it fix per flash" questions.

[joecar]

Some people can get their VE corrected in one 20 minute drive.... ;)

[1bar]

LOL, I've gotten it down to one 19 minute drive.

Thanks for the replies. I ask because my buddy and I have begun tuning the new motor and we were just curious what percentage of correction it does,

I have worked with other softwares that you can adjust the percentage rate of change per flash.

I will check out the Moates article.

Thanks,
Glenn

[5.7ute]

Some people can get their VE corrected in one 20 minute drive.... ;)

I wish I could get it that quickly on the road. While there is a few small hills around here they are no where near big or consistant enough to get any reliable data from. That and a lack of available injector data has had me chasing my tail for ages with my last round of mods. (Anyone got any accurate voltage offset tables etc for 60lb siemens deka injectors?)

[1bar]

Sorry UTE I don't. What is your thought behind the voltage offset table?

[5.7ute]

There is just some strange anomolies in the BEN data collected, especially with small intake temperature variations. IFR has been set to fuel pressure(logged) so should be accurate.

[joecar]

Sorry UTE I don't. What is your thought behind the voltage offset table?Injectors don't open/close exactly when electrically commanded... with bigger injectors this gets worse... the voltage offset tables may be used to minimize this... it involves trial and error, and viewing the injector voltage and current on a scope helps (the waveforms have dips where the pintle physically moves... the attached scope capture is from my stock 28 lb/hr injectors).

[5.7ute]

Injectors don't open/close exactly when electrically commanded... with bigger injectors this gets worse... the voltage offset tables may be used to minimize this... it involves trial and error, and viewing the injector voltage and current on a scope helps (the waveforms have dips where the pintle physically moves... the attached scope capture is from my stock 28 lb/hr injectors).

Good post Joe.
A customer of mine(day job) was just in who happens to have an injector waveform analyser I can borrow. I will be able to sort out the offsets for normal operating voltages and try & work through some varying manifold pressures. I will post this info up when I have it.
How did the results from the scope measure up to the standard settings?

[1bar]

joe, nice info. I am with you on the offset table. I have used it to help bring AFR in line with my 60lbs mototrons and the two pumps in the tank I am running.

I need to work out a slight hesitation on tip in though. I thought about building a map to monitor Inj voltage between RPM and MAP. Than I thought I would use this info to adjust how much I have offset the voltage. I also thought about adding a point to the right of the decimal point in the offset table to adjust smaller amounts.

Am I going in the right direction?

Thanks,
glenn

[1bar]

Ute, I look forward to your findings as you are running the same injector as me I believe.

Are you running two pumps also?

[5.7ute]

Ute, I look forward to your findings as you are running the same injector as me I believe.

Are you running two pumps also?

Just a single 044 in a surge tank. The 60lbers are a bit big as N/A I am still under 400rwhp, but a bigger dry hit of nitrous is coming.

[joecar]

Good post Joe.
A customer of mine(day job) was just in who happens to have an injector waveform analyser I can borrow. I will be able to sort out the offsets for normal operating voltages and try & work through some varying manifold pressures. I will post this info up when I have it.
How did the results from the scope measure up to the standard settings?I'm still playing with this, I don't have enough data yet...

[joecar]

Something else to consider...

the scope waveform shows dips in the current (opening) and voltage (closing) waveforms...

the width of the dip represents the pintle moving from fully closed to fully open (or vice-versa)... during the this motion there is ramping flow which is proportional to the cross-sectional area of the open/closing "orifice"... i.e. the flow ramps up as the injector opens and then ramps down as it closes... from the waveform you can see that the dips have finite width... maybe about 0.2-0.4 ms.

[5.7ute]

I am sure on a proper bench the amount of fuel injected during the ramping could be measured accurately. Just comparing fuel injected from 3 different pulse widths would give you this amount. Then small pulse adjust etc will be able to be back calculated (I think) from this info. Any thoughts?

[joecar]

Yes, that sounds right... and with a proper injector bench you can measure the amount that flowed into the measuring vial.

[5.7ute]

Yes, that sounds right... and with a proper injector bench you can measure the amount that flowed into the measuring vial.

A mate up here with the proper flow gear has left, but he did onsell it. I will have to drop around to the new owner with a carton & see what he can do, or what his capabilities are.
Sorry about the hijack 1bar, I will start a thread on this as the info comes to light.
Cheers Mick