VVT ideas and testers

Testing and development of Megasquirt 3

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Peter Florance
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Re: VVT ideas and testers

Post by Peter Florance »

jsmcortina wrote:
Peter Florance wrote:What about option of using throttle position as vertical axis?
Done in 1.3

I've asked Ken to consider the exhaust cam query as he is best to explain.

James
Thanks James!
Peter Florance
PF Tuning
81 BMW Euro 528i ESP Car
60-2 Wheel LS2 Coils, Low Z Inj
Co-Driver 1999 BMW E46 DSP car.
muythaibxr
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VVT ideas and testers

Post by muythaibxr »

The main issue with that is just that I can't use the same exact code to control exhaust cams as I can with intake cams if the advance number operates in a different direction. It is not impossible to do, but it increases the amt of code a bit and makes it a bit more complicated.
Megasquirt is not for use on pollution controlled vehicles. Any advice I give is for off road use only.
Peter Florance
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Re: VVT ideas and testers

Post by Peter Florance »

muythaibxr wrote:The main issue with that is just that I can't use the same exact code to control exhaust cams as I can with intake cams if the advance number operates in a different direction. It is not impossible to do, but it increases the amt of code a bit and makes it a bit more complicated.
I understand.

It's still works well; just more difficult to understand at first.

The only problematic part for me is the inverted output and how much solenoid heating it can cause.
Peter Florance
PF Tuning
81 BMW Euro 528i ESP Car
60-2 Wheel LS2 Coils, Low Z Inj
Co-Driver 1999 BMW E46 DSP car.
jsmcortina
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Re: VVT ideas and testers

Post by jsmcortina »

Thinking about it, how about I ensure that the outputs default to an off condition whatever the polarity setting ?

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

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Peter Florance
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Re: VVT ideas and testers

Post by Peter Florance »

jsmcortina wrote:Thinking about it, how about I ensure that the outputs default to an off condition whatever the polarity setting ?

James
That would be great. I'm assuming the loop is not active when there is no sync; would that be the condition you would use?

I think the car has been a little harder to start with the solenoid connected; but that could be in my head. :)
Peter Florance
PF Tuning
81 BMW Euro 528i ESP Car
60-2 Wheel LS2 Coils, Low Z Inj
Co-Driver 1999 BMW E46 DSP car.
dfzuntor
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Re: VVT ideas and testers

Post by dfzuntor »

what about Subaru 36-2-2-2 crank signal and 4-1 cam signal with Dual VVT support??? that will be great for subaru"s owners.

David
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Re: VVT ideas and testers

Post by dfzuntor »

dfzuntor wrote:what about Subaru 36-2-2-2 crank signal and 4-1 cam signal with Dual VVT support??? that will be great for subaru"s owners.

David
Here is The Crank Cam log for this setup
Thanks
David
Josh
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Re: VVT ideas and testers

Post by Josh »

Hello,
Even problem as david, I shall like making worked the AVCS of one EJ207 ( STI8) with a MS3X,
if you need technical information on these, say to me which I shall stain to give them to you

Kindest regards
Josh
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Re: VVT ideas and testers

Post by Peter Florance »

Peter Florance wrote:What about option of using throttle position as vertical axis?

When we installed and tuned the World Challenge car (Motec M-800 and DBW-4) we were advised to use throttle position as the load axis for VVT to avoid a circular reference. They felt that cam position could change MAP, which then could point you to a different point on the target (Motec uses term "aim") table, possible making the system unstable.

So far the M54 I'm tuning is well behaved, but I'm wondering about a cam with more overlap.
This change in the latest alpha codes has been huge for our autocross car at part throttle. Very easy to get on throttle earlier in corner exits.

Thanks!
Peter Florance
PF Tuning
81 BMW Euro 528i ESP Car
60-2 Wheel LS2 Coils, Low Z Inj
Co-Driver 1999 BMW E46 DSP car.
Peter Florance
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Re: VVT ideas and testers

Post by Peter Florance »

We're running the alpha code with TPS as VVT load axis.
We ran the car a couple of weeks ago; runs pretty good.
http://www.youtube.com/watch?v=Ci4RGKTaIFY
Peter Florance
PF Tuning
81 BMW Euro 528i ESP Car
60-2 Wheel LS2 Coils, Low Z Inj
Co-Driver 1999 BMW E46 DSP car.
jasaircraft
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Re: VVT ideas and testers

Post by jasaircraft »

subaru avcs support please :)
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Re: VVT ideas and testers

Post by jsmcortina »

jasaircraft wrote:subaru avcs support please :)
Details please.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

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jasaircraft
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Re: VVT ideas and testers

Post by jasaircraft »

jsmcortina wrote:
jasaircraft wrote:subaru avcs support please :)
Details please.

James
Hi James,

The subaru AVCS system moves the two intake cams in the models 2001-2006 sti (if not mistaken on the last year)
and move the four cams on later models.

I set up a motec for this a long time ago, and I remember it had position sensors (VR) in the back of the heads, I dont remember the number of teeth i believe they were four on the cam .
This happens with the later four cam variable engine too in the exhaust sides of course so 4 sensors in total.

I remember there was a duty cycle vs position map.
Of course four outputs controlling the oil solenoids.
4 inputs for the cams positions.

I could help with some logs in some days when the car arrives for the ms3x installation.
280GE 1JZ
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Re: VVT ideas and testers

Post by 280GE 1JZ »

Hi James,

1 1Uz vvti engine arrive today. It have 4 sensors, 1 crank sensor with 36-2 teeth. 1 Cam sensor with 1 tooth. 2 vvti sensor on each intake cam with 3 teeth. 2 vvti solenoids. Now I have to make vr conditioner for the other 2 vvti sensors, right? And where to I Connect them? Digital frequency in 1 & 2? Or I can connect both vvti sensor without additional conditioner? Thanks.

Regards,
Doddy
busher06
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Re: VVT ideas and testers

Post by busher06 »

GM LY7 engine using #1 Intake cam as main cam on MS3X. Trying to set up 4 cam VVT min and max values. Inlet cam opens @ 7* BTDC and lobe center @ 137*. TS will not accept a negative value (-7* ). Having set 'skip pulses' to 2, can I use ( 720 -7 ) 713* as the min value? The diagram in the manual indicates the main cam as exhaust. Is that the correct way to go? Just trying to clarify how to determine the absolute crank degrees to insert in the table.
Would it be possible to use the lobe centerline values as the basis and if so , how would that affect tooth#1 designation? The motor will be running in about two weeks but until then, I am trying to get a better understanding of what does what to what.
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Re: VVT ideas and testers

Post by jsmcortina »

You need to use the test mode to determine the min/max angles as the manual describes.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

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busher06
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Re: VVT ideas and testers

Post by busher06 »

Thank you James. It is back to the books then.
280GE 1JZ
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Re: VVT ideas and testers

Post by 280GE 1JZ »

Hi James,

It took me a while to get a good clean signal from 1 uzvvti cam sensor. Thanks to Matt from DIYAutotune and this Forum. So here is how I wired the sensors.

Crank Sensor to CKP + and CKP-
Front cam Sensor with single tooth not used
Left BAnk vvti angle sensor goes to JBperf Dual VR board and goes to CMP+
Right bank vvti angle sensor goes to JBperf Dua VR board and goes to Digital Frequency In 2

All sensors are VR. Crank sensor is 36-2. Vvti angle sensor have 3 teeth.

Regards,
Doddy
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Re: VVT ideas and testers

Post by E30_Driv3r »

I don't know if this is the right thread/section, But I had a simple suggestion In regards to VVT settings. For the simple off/on mode I know there is a small load table where you can control the duty but another option I think would be cool is having a lockout setting like VSS so that while not moving there's no cam actuation. I run a bmw m50 24v 6cyl and the stock ECU doesn't do any cam actuation unless the car is moving. The actuation at idle causes rough running so using a VSS lockout setting would be a good way to go around it.


My apologies if I appear to be rambling!


D.V
remsperso
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Re: VVT ideas and testers

Post by remsperso »

Hi all,

I am building a new engine for my impreza V4 (gc8 / ej20).
Headers are taken from a STI8 eudm : so it has single AVCS. I will use stock crank and cam sensors (36-2-2-2).

I am running my car with a MS2-Extra for some years using bio-ethanol, 660cc/min injectors and VF24 turbo : it works very good ! Except GM IAT sensor, all the sensors are stock ones.

But now I want to make more sunday tracks and I need a big upgrade.
So if you want me to be a subaru tester, no problem !

AVCS is working in closed loop. I will use my oscilloscope to check signals on solenoid and sensor on a stock STI8.
My neighbor has a supra mkiv with a single turbo, managed by a AEM EMS. He explained me its VVT system, it seems very similar to subaru AVCS.

But! The main difference is that the subaru has a flat4 and the Toyota 2jz a inline6.
So, there are 2 headers in the subaru vs only one for the Toyota.
Of course, there is 2 intake cams for the subaru, so 2 solenoids and 2 sensors for closed loop.
The need is only one target angle table, but 2 VVT closed loop : is that possible with a MS3?

Thanks!

http://drive2.subaru.com/Win05_WhatsInside.htm
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