Ignition Coil Dwell Time
Thread Starter
Joined: Dec 2008
Posts: 575
Likes: 1
From: Colorado Springs
Ignition Coil Dwell Time
Disclaimer: I am not responsible for anything you may do to your car
Thanks to UT EvoX for defining this table before. Today I went out and did some testing with this table. I previously had to set my plug gap to .018" so I could run 25 psi on my EFR 8374 without any plug blow out. Any higher plug gap and it would blow out and make the car stutter. To thoroughly test this table out, I set my plug gap .025" (stock is .022"), my boost at 35 psi and AFR at mid to low 11's on E85.
I did a couple pulls with the stock settings in this map, and of course the spark blew out like crazy. I then highlighted the whole map from 4k rpm and above and multiplied it by 10%. The spark still blew out, so I multiplied everything from 4k rpm and above by 20%. No blow out until after 5k rpm. So I left 4000-4500 rpm at 20% above stock, and selected everything from 5k rpm and above in the map and multiplied the stock values by 30%. No more blowout at all!!
I did pulls in 2nd gear, 3rd, 4th, and 5th gears and no blowout at all with the settings like this. Of course this map will have to be tailored for each car and engine/turbo setup. There will be a point in which increasing the table only helps so much and if you increase it to much you can overheat the coils and they can fail.
My car is at 600 whp and I did around 20 pulls in a row with the settings like this and they didnt show any sign of overheating. Now if you are going for 1000 whp, they may not be able to keep spark from blowing out even if you max the table out. Only way to find out is to test.
Hope this helps.
Thanks to UT EvoX for defining this table before. Today I went out and did some testing with this table. I previously had to set my plug gap to .018" so I could run 25 psi on my EFR 8374 without any plug blow out. Any higher plug gap and it would blow out and make the car stutter. To thoroughly test this table out, I set my plug gap .025" (stock is .022"), my boost at 35 psi and AFR at mid to low 11's on E85.
I did a couple pulls with the stock settings in this map, and of course the spark blew out like crazy. I then highlighted the whole map from 4k rpm and above and multiplied it by 10%. The spark still blew out, so I multiplied everything from 4k rpm and above by 20%. No blow out until after 5k rpm. So I left 4000-4500 rpm at 20% above stock, and selected everything from 5k rpm and above in the map and multiplied the stock values by 30%. No more blowout at all!!
I did pulls in 2nd gear, 3rd, 4th, and 5th gears and no blowout at all with the settings like this. Of course this map will have to be tailored for each car and engine/turbo setup. There will be a point in which increasing the table only helps so much and if you increase it to much you can overheat the coils and they can fail.
My car is at 600 whp and I did around 20 pulls in a row with the settings like this and they didnt show any sign of overheating. Now if you are going for 1000 whp, they may not be able to keep spark from blowing out even if you max the table out. Only way to find out is to test.
Hope this helps.
Code:
52680015-56290021 <scaling name="DwellTime" units="mSec" toexpr="x*0.064" frexpr="x/0.064" format="%.2f" min="0" max="16.3" inc="0.064" storagetype="uint8" endian="big"/> <table name="Ignition Coil Dwell Time" category="Timing" address="58555" type="3D" swapxy="true" scaling="DwellTime"> <table name="Battery Voltage" address="61a2a" type="X Axis" elements="9" scaling="BatteryVoltage"/> <table name="RPM" address="61a06" type="Y Axis" elements="15" scaling="RPM"/> </table>
Code:
55570006-55580006 <scaling name="DwellTime" units="mSec" toexpr="x*0.064" frexpr="x/0.064" format="%.2f" min="0" max="16.3" inc="0.064" storagetype="uint8" endian="big"/> <table name="Ignition Coil Dwell Time" category="Timing" address="585f9" type="3D" swapxy="true" scaling="DwellTime"> <table name="Battery Voltage" address="61096" type="X Axis" elements="9" scaling="BatteryVoltage"/> <table name="RPM" address="60f50" type="Y Axis" elements="15" scaling="RPM"/> </table>
Code:
56890009 <scaling name="DwellTime" units="mSec" toexpr="x*0.064" frexpr="x/0.064" format="%.2f" min="0" max="16.3" inc="0.064" storagetype="uint8" endian="big"/> <table name="Ignition Coil Dwell Time" category="Timing" address="58605" type="3D" swapxy="true" scaling="DwellTime"> <table name="Battery Voltage" address="6174e" type="X Axis" elements="9" scaling="BatteryVoltage"/> <table name="RPM" address="61608" type="Y Axis" elements="15" scaling="RPM"/> </table>
Code:
58010005 <scaling name="DwellTime" units="mSec" toexpr="x*0.064" frexpr="x/0.064" format="%.2f" min="0" max="16.3" inc="0.064" storagetype="uint8" endian="big"/> <table name="Ignition Coil Dwell Time" category="Timing" address="5861d" type="3D" swapxy="true" scaling="DwellTime"> <table name="Battery Voltage" address="61792" type="X Axis" elements="9" scaling="BatteryVoltage"/> <table name="RPM" address="6164c" type="Y Axis" elements="15" scaling="RPM"/> </table>
Code:
59540005 <scaling name="DwellTime" units="mSec" toexpr="x*0.064" frexpr="x/0.064" format="%.2f" min="0" max="16.3" inc="0.064" storagetype="uint8" endian="big"/> <table name="Ignition Coil Dwell Time" category="Timing" address="585b1" type="3D" swapxy="true" scaling="DwellTime"> <table name="Battery Voltage" address="61726" type="X Axis" elements="9" scaling="BatteryVoltage"/> <table name="RPM" address="615e0" type="Y Axis" elements="15" scaling="RPM"/> </table>
Last edited by chetrickerman; Oct 15, 2014 at 07:31 AM.
Thanks for sharing these Chet. 
Here's 56890013:
Here's 56890013:
Code:
<scaling name="DwellTime" units="mSec" toexpr="x*0.064" frexpr="x/0.064" format="%.2f" min="0" max="16.3" inc="0.064" storagetype="uint8" endian="big"/> <table name="Ignition Coil Dwell Time" category="Timing" address="58605" type="3D" swapxy="true" scaling="DwellTime"> <table name="Battery Voltage" address="6176a" type="X Axis" elements="9" scaling="BatteryVoltage"/> <table name="RPM" address="61624" type="Y Axis" elements="15" scaling="RPM"/> </table>
Last edited by itzwolf; Oct 15, 2014 at 07:46 AM.
Thanks for sharing these Chet.
Here's 56890013:
Here's 56890013:
Code:
<table name="Ignition Coil Dwell Time" category="Timing" address="58605" type="3D" swapxy="true" scaling="InjectorLatency"> <table name="Battery Voltage" address="6176a" type="X Axis" elements="9" scaling="BatteryVoltage"/> <table name="RPM" address="61624" type="Y Axis" elements="15" scaling="RPM"/> </table>
Trending Topics
Evolving Member
Joined: May 2013
Posts: 191
Likes: 20
From: St.Louis
Just curious, if this was set to a value of 0, would that effectively cut spark completely? I ask this because I'm curious if it would be possible to use this value as a rev limiter? Such that instead of running the current rev limiter setup with fuel cut, change the assembly to set dwell to a value of 0 cutting spark, creating a spark cut, or possibly a soft cut with a mixture of both
Thread
Thread Starter
Forum
Replies
Last Post
tunermt
General Engine Management / Tuning Forum
0
Jun 16, 2015 10:30 PM