TwinSpark MegaSquirt conversion - Page 5 - Alfa Romeo Bulletin Board & Forums

Reply
 
LinkBack Thread Tools Display Modes
post #61 of 99 (permalink) Old 08-20-2012, 04:48 AM
Registered User
 
Join Date: Feb 2010
Posts: 52
If VVT is based on TPS instead of MAP, then you can't tune accurately.
The engine will work on same tuning boxes with VVT on and off, depending on the circumstances.
I think the ideal would be to have 2 set of maps, one for VVT on and one for VVT off.
Table switching could be triggered more efficiently in MS3 than in MS2 I suppose.
madk4speed is offline  
Sponsored Links
Advertisement
 
post #62 of 99 (permalink) Old 08-20-2012, 06:11 AM Thread Starter
enablieri
Platinum Subscriber
 
aikendrum105's Avatar
 
Join Date: May 2006
Location: Melbourne, AU
Posts: 562
Send a message via Skype™ to aikendrum105
It's interesting, VVT is switched based on ITB load and RPM - same as the VE and advance tables. I think setting up the secondary VE and advance and switching with VVT will give better granularity when moving between - but it doesn't seem to be much of an issue at the moment.

Scott Murray
'04 156 JTS Sportwagon -- brilliant car for the daily, kids taxi and parts hauling

in officina -
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

'66 Giulia Super 105.28.720988 -- TwinSpark+MS3+ITB+COP
'65 Giulia Sprint GT 105.04.753710

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


che figata -

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
aikendrum105 is offline  
post #63 of 99 (permalink) Old 08-20-2012, 06:18 AM
Registered User
 
Join Date: Feb 2010
Posts: 52
Being at the limit of VVT function and turning on/off rapidly could cause poor engine performance and driveability.

Take into account the fact that VVT alters the Volumetric Efficiency, and it is obvious that you need to have specific VVT state for specific combinations of load and rpm. At least if you are aiming at superb engine response and performance.

Also you might need to turn off the VVT in higher rpms, depending on the valve timing.
Can you set VVT state on more than 2 parameters with MS3? (turn on rpm, turn off rpm, load)

Last edited by madk4speed; 08-20-2012 at 06:22 AM.
madk4speed is offline  
 
post #64 of 99 (permalink) Old 08-20-2012, 08:58 PM Thread Starter
enablieri
Platinum Subscriber
 
aikendrum105's Avatar
 
Join Date: May 2006
Location: Melbourne, AU
Posts: 562
Send a message via Skype™ to aikendrum105
There's a hysteresis window for both RPM and Fuelload switchpoints that stops it chattering - but that hysteresis window is the grey area where a single VE table lacks the fine control that the extra table gives. It says 'Nitrous' below but it's just the default name for that output pin. There is an output for VVT - but I mixed up the wiring for the VVT relay and the Radiator FAN relay - will sort that later when I setup the individual injector outputs for sequential injection. (that also needs the camshaft sensor - so a bit of a bling/nice to have thing for later)

I think we talked about the VVT upper RPM limit earlier in the thread - if you needed to limit it at high RPM then you could tie two outputs together or feed an output back through an input to get the final logic output level you needed. The MS3X board certainly has plenty of spare i/o.

I know we found the motronic cuts the VVT at high RPM - I had a feeling that was more used as a soft rev-limit function than anything else like valve-piston collision at high RPM, or emissions? I wasn't planning on using it that way - by default the MS3 has spark retard, spark cut and fuel cut as a 3 step rev limiting system which is a really gentle (at least initially) reminder to get off the loud pedal

I think in a few weeks I'll do as you suggest and setup the extra tables - at the moment I'm still a long way off an ideal tune - basically just my drive to/from work providing the opportunity for the auto-tune to do it's magic.

I'm going to use a couple of the spare inputs and outputs to wire up a couple of discreet warning LEDs for 'Lean under load' 'high temp/low oil pressure etc' idiot lights and maybe a shift light for sprint days. Lots of fun !




Great fun though !
Attached Images
  

Scott Murray
'04 156 JTS Sportwagon -- brilliant car for the daily, kids taxi and parts hauling

in officina -
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

'66 Giulia Super 105.28.720988 -- TwinSpark+MS3+ITB+COP
'65 Giulia Sprint GT 105.04.753710

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


che figata -

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Last edited by aikendrum105; 08-20-2012 at 09:01 PM.
aikendrum105 is offline  
post #65 of 99 (permalink) Old 08-20-2012, 09:10 PM
Registered User
 
festy's Avatar
 
Join Date: Jul 2007
Location: Sydney, Australia
Posts: 520
Quote:
Originally Posted by aikendrum105 View Post

I know we found the motronic cuts the VVT at high RPM - I had a feeling that was more used as a soft rev-limit function than anything else like valve-piston collision at high RPM, or emissions?
No, it disables at high RPM and WOT for extra performance.

Trad mentioned in this thread that with VVT disabled there are mid-range losses, but top end gains:
Quote:
Regarding the VVT, i had wired up a relay off the shift light output from the ecu as mentioned. I set it to 2,500rpm (for no special reason other than a guess). On the last dyno run, we ran a back to back with the VVT unplugged. There was a noticable effect. The engine wasn't as smooth around 2,650 - 3,600 and with slightly lower HP and torque. It eventually caught up and produced slightly more at 5,900.
festy is offline  
post #66 of 99 (permalink) Old 08-20-2012, 10:33 PM Thread Starter
enablieri
Platinum Subscriber
 
aikendrum105's Avatar
 
Join Date: May 2006
Location: Melbourne, AU
Posts: 562
Send a message via Skype™ to aikendrum105
So picked up some Denso pencil coils on the weekend from the local motorbike wrecker. The info on the web was a little sketchy about which of these coils best suit use in a car.

the Denso 127900-4150 is one of the shortest coils - and has a resistance of 1.2Ohms - however without buying them all brand new (at $60 each) I struggled to find them at the local wreckers.

What I could get a few of were the 127900-3400 and -4400 coils. The 4400 are about 0.8 Ohms and the 3400 about 0.2 - the 0.2 might be a bit low to run in parallel - less dwell but much higher current. Happy to be corrected on that btw

The 3400 and 4400 coils are about 5mm longer than the 4150 - just sitting proud of the top of the TS cam cover.

I wanted to run these coils in serial or parallel pairs to simplify the output system of the MS - and continue to use just the one Bosch 211 module. Serial is better for lower spec current drivers on your output stage - like the older VB921 units - but you can run them in parallel with less dwell with the BIP373 or Bosch 211 style drivers.

Anyway - I have the loom neatly wired up with a connector for the output of the Bosch 211 - means I can swap back to the wasted spark coilpacks quickly if I have to. Just waiting on one more 4400 from fleabay to test it out. The pencil coils are designed to fit on the threaded post on the top of the sparkplug - and as luck would have it the NGK Platinums (BKR6EIX) I bought recently for the engine have the blunt ends (not the screw off variety) so I have to source some new plugs too. Grrr

Scott Murray
'04 156 JTS Sportwagon -- brilliant car for the daily, kids taxi and parts hauling

in officina -
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

'66 Giulia Super 105.28.720988 -- TwinSpark+MS3+ITB+COP
'65 Giulia Sprint GT 105.04.753710

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


che figata -

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
aikendrum105 is offline  
post #67 of 99 (permalink) Old 08-20-2012, 10:45 PM Thread Starter
enablieri
Platinum Subscriber
 
aikendrum105's Avatar
 
Join Date: May 2006
Location: Melbourne, AU
Posts: 562
Send a message via Skype™ to aikendrum105
Quote:
Originally Posted by festy View Post
Trad mentioned in this thread that with VVT disabled there are mid-range losses, but top end gains:
that's funny - I completely misread that part of his thread twice .. what a duffer - Cheers Festy.

I actually read back through the earlier parts this thread (from February 2012) and saw we'd already gone over it in heaps of detail and I'd forgotten. I'm getting old...

I'm really looking forward to getting that accelerometer wired up to the MS (for logging) and running a few different setups on the MS to compare things... mainly to help dial in the ideal AFR target table.... but would definitely revisit the VVT off at high rpms test...

I'll wire up the VVT output back through an input to put the upper RPM limit on as Mad4kSpeed suggested way back in the thread - easy to enable/disable that aspect on the laptop then.

Great fun tinkering with all the options now that the system is in !

Scott Murray
'04 156 JTS Sportwagon -- brilliant car for the daily, kids taxi and parts hauling

in officina -
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

'66 Giulia Super 105.28.720988 -- TwinSpark+MS3+ITB+COP
'65 Giulia Sprint GT 105.04.753710

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


che figata -

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Last edited by aikendrum105; 08-20-2012 at 10:56 PM. Reason: spelling.
aikendrum105 is offline  
post #68 of 99 (permalink) Old 08-20-2012, 11:09 PM Thread Starter
enablieri
Platinum Subscriber
 
aikendrum105's Avatar
 
Join Date: May 2006
Location: Melbourne, AU
Posts: 562
Send a message via Skype™ to aikendrum105
Found a little extra info for VVT activation / deactivation areas - including some reasons to disable at high RPM... on MSEFI forums here..

which also refers to this thread on the miata forums which has dyno graphs I assume are similar to what Tony was seeing. The Miata's (MX5) can vary a few advance steps in between on/off compared to the TS - but the premise is the same

This lines up with what Grant was talking about earlier in the thread too...

Excellent stuff !

For those reading along with carbed TS engines - don't forget Festy has designed a neat driver board you can use to give you this type of VVT control

Scott Murray
'04 156 JTS Sportwagon -- brilliant car for the daily, kids taxi and parts hauling

in officina -
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

'66 Giulia Super 105.28.720988 -- TwinSpark+MS3+ITB+COP
'65 Giulia Sprint GT 105.04.753710

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


che figata -

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Last edited by aikendrum105; 08-20-2012 at 11:20 PM. Reason: extra linkage
aikendrum105 is offline  
post #69 of 99 (permalink) Old 08-20-2012, 11:59 PM Thread Starter
enablieri
Platinum Subscriber
 
aikendrum105's Avatar
 
Join Date: May 2006
Location: Melbourne, AU
Posts: 562
Send a message via Skype™ to aikendrum105
Did a little more reading on the MS3 - it has 8 Pulse Width Modulated outputs - one of which is earmarked for VVT operation. I didn't bother looking into this as our VVT is on/off and that was easily done with a standard output config as I posted earlier, however the PWM output *can* be easily set to be on/off - and then provides a 6x6 table you can populate to control VVT - allowing me to set an upper and lower RPM limit, and a minimum Fuel Load (or TPS) for VVT activation without modifying any wiring or wasting an input/output.

It's explained better here

I think setting it up like this will do the trick - running as an on/off output - above 60 turns on VVT solenoid, under 40 turns it off - this gives me a 'deadband' between the 40 and 60 triggers to prevent hysteresis.

I couldn't select Fuel Load as the Y axis for this output - TPS should work fine. the MS uses Alpha-N (TPS vs RPM) for the load areas the VVT would kick in anyway.
Attached Images
 

Scott Murray
'04 156 JTS Sportwagon -- brilliant car for the daily, kids taxi and parts hauling

in officina -
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

'66 Giulia Super 105.28.720988 -- TwinSpark+MS3+ITB+COP
'65 Giulia Sprint GT 105.04.753710

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


che figata -

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Last edited by aikendrum105; 08-21-2012 at 12:05 AM.
aikendrum105 is offline  
post #70 of 99 (permalink) Old 08-21-2012, 03:52 AM
Registered User
 
Join Date: Feb 2010
Posts: 52
I am thinking to upgrade to MS-3 from the MS-2 I have right now. Also I am thinking seriously to turbocharge my Twin Spark. Turbo and IC are in the storage room already. And VVT function would be nice to be mantained.
Of course VVT should be turned off while engine starts to get boost.
But all this depends on the actual valve timing with and without VVT, and I am not an expert at all concerning camshafts etc.

I forgot you are running ITB's with Alpha-N, so yes indeed TPSvsRPM controls VVT absolutely correct.

If MS-3 does not include serious upgrades on programmable outputs, then I see no reason why to spend any money on it.
madk4speed is offline  
post #71 of 99 (permalink) Old 08-21-2012, 06:45 PM Thread Starter
enablieri
Platinum Subscriber
 
aikendrum105's Avatar
 
Join Date: May 2006
Location: Melbourne, AU
Posts: 562
Send a message via Skype™ to aikendrum105
I know what you mean - for me the full ITB mode was the major MS3 drawcard for me - the SDCard logging makes life much easier. The built in USB port isn't really more convenient than the serial port + USB adapter route - but still a nice-to-have.

I was just going to use the extra i/o on the main MS2 board through the supplementary ports / relay board for my extra i/o - but the MS3x just made life a lot easier for not that much extra. Gives me a lot more options to control / monitor more aspects of the engine - even with those few extra modules - it's still a brilliant price for such a flexible system..

Scott Murray
'04 156 JTS Sportwagon -- brilliant car for the daily, kids taxi and parts hauling

in officina -
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

'66 Giulia Super 105.28.720988 -- TwinSpark+MS3+ITB+COP
'65 Giulia Sprint GT 105.04.753710

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


che figata -

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
aikendrum105 is offline  
post #72 of 99 (permalink) Old 08-22-2012, 06:10 PM Thread Starter
enablieri
Platinum Subscriber
 
aikendrum105's Avatar
 
Join Date: May 2006
Location: Melbourne, AU
Posts: 562
Send a message via Skype™ to aikendrum105
Quick update - I setup the PWM output table to control the VVT relay - works perfectly, however I need to clean up my ignition advance table as it's far too advanced when the VVT cuts out at 5800 rpm - massive pinging.

I'm going through Festy's awesome TunerPro xdf at the moment for the motronic trying to confabulate all of the various ignition tables / modifiers into one table to use as a starting point.. my head hurts already... but there seems to be some real hefty advance under WOT at lower rpms when the VVT kicks in, which should help performance quite a bit over the basic advance map I setup to start with - purely RPM based like a mech. advance (see below) (I know the ign load row headers are a bit mixed up at present - it's only using the lower 24 - 120 area atm.)

I also need to double check that 10 deg. in the ecu translates to 10 deg on the crank pulley - there's some conjecture about how many degrees btdc the motronic timing gear has it's gap. I counted it out and wound up with 84 deg, but almost all the motronic info I could find for similar vintage motronic engined cars were 90 deg. the MS has a simple test function to lock the advance as 10deg while you use a timing light to verify. I just need to mark my pulley at 10 deg. and test away. The motronic pulley has no timing marks from the factory so need to mark it up.
Attached Images
 

Scott Murray
'04 156 JTS Sportwagon -- brilliant car for the daily, kids taxi and parts hauling

in officina -
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

'66 Giulia Super 105.28.720988 -- TwinSpark+MS3+ITB+COP
'65 Giulia Sprint GT 105.04.753710

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


che figata -

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
aikendrum105 is offline  
post #73 of 99 (permalink) Old 08-22-2012, 06:53 PM
Richard Jemison
Platinum Subscriber
 
Alfar7's Avatar
 
Join Date: Apr 2005
Location: Pensacola, Fl. U.S.A.
Posts: 5,777
VVT and high RPM

Quote:
No, it disables at high RPM and WOT for extra performance.
You should not cut the VVT`s advance at high rpm. It is far too much retard for the cam and will always increase static and effective compression past detonation.

If you are determined to retard it above 4000 rpm it should ONLY be at closed throttle.

Richard Jemison
RJR Racing

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

"When you are dead you don`t know it.
Only those around you are distressed.
Same with stupid"
Alfar7 is offline  
post #74 of 99 (permalink) Old 09-19-2012, 12:00 AM Thread Starter
enablieri
Platinum Subscriber
 
aikendrum105's Avatar
 
Join Date: May 2006
Location: Melbourne, AU
Posts: 562
Send a message via Skype™ to aikendrum105
A quick update - started to run into issues with the VVT on/off points and the VE/Ign maps - primarily because the PWM output couldn't be set to use ITB load as the Y axis - so had to choose TPS or MAP for that output - made it impossible to sync with the VE/Ign tables accurately.

Fortunately - there's been two releases of the MS3 firmware in the interim - and the current release, 1.1.2 - includes a dedicated VVT configuration area (allowing up to 4 vvt actuators) and the Load axis of the config tables works directly off fuel load (the load used by the VE table)

So I'll update that firmware and I should be back on track there.

I'm still changing things all the time - but it's starting to coalesce into a stable tune. It's interesting seeing how much more fuel is required when the VVT cuts in to maintain a good AFR - quite substantial.

I have a knock sensor and an accellerometer to wire up to the MS - which should help me get the spark advance squared away and also start some baseline torque/HP curves to work against when making changes.

One thing I've noticed with the ITBs is they have a pronounced squeak / chirp / whistle that occurs at small throttle openings - I think this will be masked by the eventual airbox I fit - and may be also caused by the blanked off injector holes (I capped them at the top, but didn't block them flush where the air passes by) so might be getting whistles there as the air passes over the holes (a little like a flute or a bottle) I'll clean those up when I tidy everything up.

Cheers,

Scott Murray
'04 156 JTS Sportwagon -- brilliant car for the daily, kids taxi and parts hauling

in officina -
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

'66 Giulia Super 105.28.720988 -- TwinSpark+MS3+ITB+COP
'65 Giulia Sprint GT 105.04.753710

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


che figata -

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
aikendrum105 is offline  
post #75 of 99 (permalink) Old 09-19-2012, 07:33 AM
Registered User
 
Join Date: Oct 2005
Posts: 113
I have the exact same chirp/whistle at small throttle openings. My airbox is pretty minimal and doesn't really muffle it but im sure with a more substantial airbox and filter element it would keep the noise down...

-1986 Spider Veloce (Megasquirt & soon to be Turbo)
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

-1974 GTV (soon to be Twinspark)
AGeorgi is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Alfa Romeo Bulletin Board & Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome