# Setting Trigger Angle (16V)?



## xr4tic (Dec 10, 2001)

I got my car all wired up, and was actually able to fire it up (after fixing a bad battery to starter cable)
16V dist using MSnS, VB921 firing the coil.
I followed these instructions for setting the trigger angle: (from http://megasquirt.sourceforge.....html)
Setup - Hall sensor 
First, in Megatune in the Codebase and outputs function, set LED18 to "irq trigger" and send to ECU. 
1) Set the crank at TDC 
2) Rotate the distributor (opposite direction) just until middle LED turns OFF (sets the crank angle) 
3) Make sure the rotor arm points towards the correct contact in the distributor cap 
4) Fix the distributor 
5) Turn engine backwards until middle LED turns ON (should be almost immediately) and continue turning until it turns OFF again 
6) Measure angle BTDC (+/- 10 degrees is good enough) at the crank 
7) Enter measured angle in "Trigger angle" 
8) Enter "Fixed angle" to 10 degrees 
9) Start the engine 
10) Adjust "Trigger angle" until the timing light is at 10 degrees 
11) Set "Fixed angle" to -10 
12) Start tuning 
By my calculation, the base trigger angle is ~82 degrees (+/- 2 degrees)
I set my trigger angle to 72, roughly 10 degrees BTDC 
However, I've been doing some searching, and I see all sorts of values being used, in the 60 - 65 range, some are using 0.
Am I way off, or is there a big difference in distributors, or are most people not actually measuring it, and just going by what everyone else was using?
If the base isn't set right, then I would think other people's timing maps could be way off if they just guessed.
I just want to make sure I'm not messing anything up


----------



## mjleamy (Mar 16, 2004)

*Re: Setting Trigger Angle (16V)? (xr4tic)*

You might be right about the 72 degree trigger angle. The people using 60, including me, are still using correct timing maps as long as they have moved their distributors enough to compensate for 12 degrees (72-60). In the end, it doesn't matter too much what you set the trigger angle to be, as long as the timing you put in for the fixed angle in Megasquirt (say 6) agrees with that measured with the timing light (6 BTDC).


----------



## need_a_VR6 (May 19, 1999)

*Re: Setting Trigger Angle (16V)? (xr4tic)*

John, here's how I do it:
Set distro up so it 'looks good' roughly 6-10deg btdc like you would any other 16v. That puts the rotor leading edge about 1/4" past the #1 post. 
I set the trigger angle to 60 to start, and the fixed to 6deg. 
Crank the car and turn the distro until it starts. This might take a few tries. 
Once it starts get out your timing light and turn the distro until you can see the 6deg mark on the flywheel. Lock it down there and you're done.
You can also play with the trigger angle to do this but I've had better luck leaving that set and physically moving the distro. 
This won't work as well if you have the hall sender triggering on the wrong edge of the window. It will take a good amount of distro adjustment to get it in the right spot but it will still work.


----------



## mjleamy (Mar 16, 2004)

*Re: Setting Trigger Angle (need_a_VR6)*

need_a_VR6's post is the same as what I said, but in actionable form


----------



## EuroVeeDub (Nov 16, 2001)

*Re: Setting Trigger Angle (mjleamy)*

Yep, that's how I did it...there are so many "how to set initial timing" guides it can be pretty daunting. If you don't have a adv. timing light, no worries! Use the 6deg mark on the flywheel (like they said^).
Good luck!


----------



## VWralley (Mar 30, 2002)

*Re: Setting Trigger Angle (EuroVeeDub)*

i have always set mine up per pats website. there is a discrepency in the setting vs. what you guys are recomending an im checking to see which is supposed to be the correct way








this is how i have done it as well, but when you say set it fixed back to 6 deg btdc in the settings, the way pats site (an the instructions listed above) say set it to -10. this is what im tryin to figure out 

_Quote, originally posted by *need_a_VR6* »_John, here's how I do it:
Set distro up so it 'looks good' roughly 6-10deg btdc like you would any other 16v. That puts the rotor leading edge about 1/4" past the #1 post. 
I set the trigger angle to 60 to start, and the fixed to 6deg. 
Crank the car and turn the distro until it starts. This might take a few tries. 
Once it starts get out your timing light and turn the distro until you can see the 6deg mark on the flywheel. Lock it down there and you're done.





_Modified by VWralley at 9:53 AM 4-9-2007_


----------



## xr4tic (Dec 10, 2001)

*Re: Setting Trigger Angle (VWralley)*

Well, I guess as long as the end result is the same, it's ok.
You have to set the fixed angle back to -10 for it to use the ignition map, otherwise it will just use whatever value is in the Fixed Angle box.


----------



## need_a_VR6 (May 19, 1999)

*Re: Setting Trigger Angle (VWralley)*


_Quote, originally posted by *VWralley* »_ithis is how i have done it as well, but when you say set it fixed back to 6 deg btdc in the settings, the way pats site (an the instructions listed above) say set it to -10. this is what im tryin to figure out 

I don't use -10 as then you have to KNOW what the timing table is telling it at idle and it could be interpolating if you're idle is high. Say you have 5deg at 800rpm and 10deg at 1200 rpm, you're idling at 1000rpm for 7.5deg, PLUS any change in rpm is varying the timing. I set fixed to 6deg because I know it's locked there and there's already a mark on the flywheel for it. More or less doing the same thing, I just think that using the fixed is a little more robust and less likely to give people problems.


----------



## VWralley (Mar 30, 2002)

*Re: Setting Trigger Angle (xr4tic)*


_Quote, originally posted by *xr4tic* »_
You have to set the fixed angle back to -10 for it to use the ignition map, otherwise it will just use whatever value is in the Fixed Angle box.

this is the first i have heard of this(the fact that unless it is set back to -10 it will not use the ignition map), more details please


----------



## need_a_VR6 (May 19, 1999)

*Re: Setting Trigger Angle (VWralley)*

-10 should be what you have in fixed angle, if you plan to run ignition. I can't remember why other then there's no reason ever to put a fixed value as -10 so it was a good number to insure you weren't actually trying to use it. 
If you put 10 in fixed angle you basically electronically lock the timing there. On startup if I'm having some igniton issues I'll set it to 25 to sort out things and verify that it's triggering right and the timing is good. I used it once to sort an inversion problem as well. Nice feature.


----------



## VWralley (Mar 30, 2002)

*Re: Setting Trigger Angle (need_a_VR6)*

http://****************.com/smile/emthup.gif 
thank you sir








(still waiting on photos of those 13's you told me aboot







)


----------



## need_a_VR6 (May 19, 1999)

*Re: Setting Trigger Angle (VWralley)*

No problem. Sorry I've been busy trying to get MS2/Extra working


----------



## mjleamy (Mar 16, 2004)

*Re: Setting Trigger Angle (need_a_VR6)*

Hey - I am interested in the MS2/Extra work. It seems everyone, including Patatron, pooh-pooh it. I would like to go to it and then microsquirt. Are you using ISV control with it? Mike


----------



## VWralley (Mar 30, 2002)

*Re: Setting Trigger Angle (mjleamy)*

i am def interested as well! i need the mirosquirt for my snowmobile project if i ever get to it http://****************.com/smile/emthup.gif


----------



## need_a_VR6 (May 19, 1999)

*Re: Setting Trigger Angle (VWralley)*

Everything seems to work on the bench, throwing it in the car tonight. No idle stuff yet, the documentation just isnt' there for me to mess with it yet. It gets confusing because on this one I have to use the Fidle pin for spark so it can be swappable with the MS1/2.2 that's in the car now. I ended up leaving out D8 so I could run spark on D16 and just jumper the signal to the pin. I then have to backtrack from there for the idle valve.


----------



## vwjunkie42 (Jan 17, 2003)

*Re: Setting Trigger Angle (need_a_VR6)*

Iii


----------

