Well here we go folks.

https://www.miataturbo.net/attachmen...ine=1377758104

yes. ive posted it a few times for you lazies who cant take Jason's dwell curve findings, apply a little 3rd grade math and figure it out for yourself...

...this thread is 81 pages long, sorry i missed it. Dont make the mistake thinking i havent searched for it because i have for quite a while.

Alright now that i learned what that graph is called i can actually search for it (before google showed like 2-3 non specific results and then bunch of chinese symbols). It appears that at 7 volts you would be running these things for ~5ms. That said if one runs these things in series of pairs it should bring down the voltage per coil to ~7 volts. Am i crazy for trying it? (To eliminate the need for a dwell reducer while running on stock ecu).

Would the trigger mix things up?

lolwut?

I searched against my posts with the search term: dwell battery cops

this was the first result:

https://www.miataturbo.net/diy-turbo...22/#post749575

No? When you run the coil at lower voltage you need more time (dwell) to charge it up. The stock NB1 coils are charged for 5ms. The cops on the other hand are only for 2.3ms however at 7 volts they have to be charged for 5ms therefore running them in series should lower the voltage at the coils to 7 volts. Or am i thinking this completely wrong?

read my post.

I did. I saw that thread. I also saw another one with a graph that continued your numbers so ~7 ends up about 5ms.

well lets just hope your NB doesn't ever run at 7v.

Right however wouldnt connecting them in series lower the voltage per coil to 7ish volts?

We have 4 coils. You connect the + of the 1st coil to +, you connect the - of the 1st coil to the + of the 4th coil, then the - of the 4th coil to ground. Same for the 2nd and 3rd coils.

lolwut?!

Not sure if sarcasm of confused. I can bust out the MS paint if you need me to :P

why?

Figured I'd follow up in this thread with my results (even though it's in my build thread). Huge thanks to Lazzer/Brain and the rest of the forum for making this so damn easy.

https://www.miataturbo.net/attachmen...ine=1377869208
https://www.miataturbo.net/attachmen...ine=1377869208
https://www.miataturbo.net/attachmen...ine=1377869208
https://www.miataturbo.net/attachmen...ine=1377869208


With a little bit of filing the COPs fit great sideways. No excuse not to go this route since the wiring runs so much cleaner and you can use the cam cover bolts to secure the harness (important if you soldered the splices like me).

-Zach

I'm not an EE but I don't believe you cut the voltage in half by running coils in series. You would likely double the ohms by running them in series, but not halve the voltage..

But why wouldn't you run them in parallel?

each coil will have 1/4 the battery voltage, so ~3.5v.

good luck with your .0000001" spark gap.

also, you realize when one coil goes bad they all go bad? going to be interesting to see what happens when the first coil fires...as that would most likely momentarily cut power to the rest as it when send the power through the coil.

God dammit and you yell at me for not reading. :noob:

4 coils... 2 pairs of series.

1st paired with 4th, 2nd paired with 3rd.

The main reason i'm trying to work around this is to be able to run these coils on the stock ecu when i have to pass emissions.

i thought it was only the msm that had issues with them on the stock ecu?


anyways yeah i failed to read.

The stock nb1 ecu charges coils for 5ms which would probably burn them, no?