LSx coil thread
#141
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Raw data straight from a 5.3 truck ECM (6.0 data is extremely similar):
I punched that all into Excel and produced the same data as a percentage of dwell at 14v, then distilled that a little further to give me two 2D curves to punch into the MS3.
Dwell vs. RPM:
Dwell vs. Battery voltage:
Without a 3D table like the GM ECU has, you're stuck with two linear 2D curves. The battery curves are correct for everything above ~5000rpm and a little low below that, but since these coils discharge with excessive dwell at high RPM, I felt it was better to stay on the conservative side everywhere. The tables above will never produce a dwell figure that's higher than the OEM table, which is what I wanted.
I have cranking dwell set at 4.5ms and the car cold-started in my 68*F shop, but YMMV.
#142
4.5ms might be too much depending on what your battery correction table looks like.
Raw data straight from a 5.3 truck ECM (6.0 data is extremely similar):
I punched that all into Excel and produced the same data as a percentage of dwell at 14v, then distilled that a little further to give me two 2D curves to punch into the MS3.
Dwell vs. RPM:
Dwell vs. Battery voltage:
Without a 3D table like the GM ECU has, you're stuck with two linear 2D curves. The battery curves are correct for everything above ~5000rpm and a little low below that, but since these coils discharge with excessive dwell at high RPM, I felt it was better to stay on the conservative side everywhere. The tables above will never produce a dwell figure that's higher than the OEM table, which is what I wanted.
I have cranking dwell set at 4.5ms and the car cold-started in my 68*F shop, but YMMV.
Raw data straight from a 5.3 truck ECM (6.0 data is extremely similar):
I punched that all into Excel and produced the same data as a percentage of dwell at 14v, then distilled that a little further to give me two 2D curves to punch into the MS3.
Dwell vs. RPM:
Dwell vs. Battery voltage:
Without a 3D table like the GM ECU has, you're stuck with two linear 2D curves. The battery curves are correct for everything above ~5000rpm and a little low below that, but since these coils discharge with excessive dwell at high RPM, I felt it was better to stay on the conservative side everywhere. The tables above will never produce a dwell figure that's higher than the OEM table, which is what I wanted.
I have cranking dwell set at 4.5ms and the car cold-started in my 68*F shop, but YMMV.
#145
"A dwell figure of 3.5ms is advised for LS2 coils. (was 4.5)"
"A dwell figure of 3.5ms is advised for truck coils."
#149
If you made them by hand I tip my hat to you - I did mine by hand and they took ages.
Yours look too perfect and complex to make by hand though.
Are you grounding the coils on the top rear bracket bolt?
Would be better/tidier to use an out-of-sight bolt at the rear that connects to the engine block - there's plenty to choose from.
Tip: You might want to number your harness plugs and their corresponding CNP so you don't mis-connect them in future, based on your ignition leads between the plugs and CNPs, the CNPs aren't mounted in sequential order.
#152
@Vincentmiata, I didn't think the IL Motorsport reroute worked on 1.8L
I need to check the CAD drawings if i can shave a few mm of. Ive already seen the new 1.8 prototype. So i can use the new 1.8 piece if shaving doesnt work
I only designed the original piece and i tought it should fit the 1.8 also. But somehow something went wrong.
#153
It does fit but the reroute piece in het back is touching the coolant hose that goes from the back to the oil cooler. So we decided to bring it out for the 1.6 only.
I need to check the CAD drawings if i can shave a few mm of. Ive already seen the new 1.8 prototype. So i can use the new 1.8 piece if shaving doesnt work
I only designed the original piece and i tought it should fit the 1.8 also. But somehow something went wrong.
I need to check the CAD drawings if i can shave a few mm of. Ive already seen the new 1.8 prototype. So i can use the new 1.8 piece if shaving doesnt work
I only designed the original piece and i tought it should fit the 1.8 also. But somehow something went wrong.
#154
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Since the inception of this thread there have been a couple of who have come out with some products to help successfully integrate these LSx coils onto the miata chassis.
Sean over at SadFab's kit: http://sadfab.com/coilmounts.html
My Hawley Performance kit: https://squareup.com/store/hawleyper...il-bracket-kit
Thanks for all those that have helped contribute information to this thread.
Sean over at SadFab's kit: http://sadfab.com/coilmounts.html
My Hawley Performance kit: https://squareup.com/store/hawleyper...il-bracket-kit
Thanks for all those that have helped contribute information to this thread.
#155
Since the inception of this thread there have been a couple of who have come out with some products to help successfully integrate these LSx coils onto the miata chassis.
Sean over at SadFab's kit: http://sadfab.com/coilmounts.html
My Hawley Performance kit: https://squareup.com/store/hawleyper...il-bracket-kit
Thanks for all those that have helped contribute information to this thread.
Sean over at SadFab's kit: http://sadfab.com/coilmounts.html
My Hawley Performance kit: https://squareup.com/store/hawleyper...il-bracket-kit
Thanks for all those that have helped contribute information to this thread.
#157
Hey guys, the tuner that has my car has hit a wall with spark blowout. I'm using the information @Savington posted and he's narrowed it down to spark.
He's reduced the boost a smidgen and it works fine, then he reduced the dwell by 0.1 and its on the cusp of blowout. He's unsure if he wants to push the final row in the dwell table up because he's also read on other forums that self ignition can occur as low as 4ms. He stating that because the coils have been superceded and now it's in the hands of other manufacturers (mine are Napa coils) that he can't confirm that these will autoignite at 5ms as reported with stock GM.
Is there still headroomto increase dwell at the upper rpm by 0.1-0.2? Would the battery dwell correction then need to be decreased at lower voltage? I've always seemed to run smaller gap even with Toyota COPS than what everyone reports but right now the plugs are taken down to. 020
More dwell? New coils? Blow motor?
He's reduced the boost a smidgen and it works fine, then he reduced the dwell by 0.1 and its on the cusp of blowout. He's unsure if he wants to push the final row in the dwell table up because he's also read on other forums that self ignition can occur as low as 4ms. He stating that because the coils have been superceded and now it's in the hands of other manufacturers (mine are Napa coils) that he can't confirm that these will autoignite at 5ms as reported with stock GM.
Is there still headroomto increase dwell at the upper rpm by 0.1-0.2? Would the battery dwell correction then need to be decreased at lower voltage? I've always seemed to run smaller gap even with Toyota COPS than what everyone reports but right now the plugs are taken down to. 020
More dwell? New coils? Blow motor?
Last edited by psyber_0ptix; 05-16-2017 at 05:09 PM.