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Coil-on-plug options for stock TCI?

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Coil-on-plug options for stock TCI?

PostAuthor: spyder1219 » Thu May 21, 2020 7:43 pm

Like it says, I would like to explore options for COP. For no other reason than the Accel 140408 seems like a viable option, but is 150$. If that coil can work, why not a simple equation for more options? Money IS an option, so keeping the current TCI and such is preferred, but like any good project bike, it is done when it is done.

The service manuals state OHMs at 2.7 ±15% primary, and 8,700 ±15% secondary. After a bit of exploration, I saw a recent post of COP of an R1, but then made mention of the coil having 1k resistance? I have a light background in electronics, and obviously math, and 1k does not equal either of those service values. Could it really be as simple as finding a coil with similar resistance? Yes, a daunting task. What about simply placing a 1 OHM resistor in series with a coil/COP that is 1.7 OHMs (1+1.7=2.7)? Same with secondary and using a cap/plug resistance?

I would much prefer to delve deeper with the search function, and broaden my knowledge of previous questions, but I only achieve 5 results for "coil" and 5 results for "plug." Even trying -extremeodd-'s suggestion of site:BLAH BLAH yields me less information.

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Re: Coil-on-plug options for stock TCI?

PostAuthor: Crazy_Russian » Fri May 22, 2020 12:06 am

I'm actually in for info on this, as all of these are good questions.
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Re: Coil-on-plug options for stock TCI?

PostAuthor: nanno » Fri May 22, 2020 12:18 am

In short, welcome back to the groovy 70ies, because that's exactly what various manufacturers did. They put a throtteling resistor in series with the coils. Noteworthy though: it has to be quite a beefy ceramic resistor or you'll fry it.

I've run a stock box with COP-coils and it works just fine. Just make sure to measure the coils you buy, especially with second hand items, as there also coils out there with substantially less resistance, i.e. 0.1 to 0.3 Ohms. That being said, should you be running an aftermarket ignition like an Ignitech, these will either auto-adjust or you simply shorten the dwell time to suit.

Hope this helps
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http://viragotechforum.com/viewtopic.php?f=12&t=43227 - Nanno's accumulated findings (and blatant show-off) - infos on my TR1's, my performance and reliability mods and a bit of show-casing of the stainless steel exhausts I build

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Re: Coil-on-plug options for stock TCI?

PostAuthor: spyder1219 » Fri May 22, 2020 1:04 am

One thing I didn’t even consider was dwell time. I am certainly contemplating the ignitech. For all my reading, my gold TCI box and coils were supposed to be “less likely to go bad.” I fear that at 40 years, they have hit the “rarely” mark. The coil-on-plug I am browsing are from MSD or Accel, on the Holley performance website. I’m a form AND function guy, so the coil has to be of decently small size, and from what I can tell they look almost the part. I’m a tad worried I’m going to have to buy 1000$ worth of coils shipped to my local auto parts store, and check for sizing. I am still unaware of how I can test for current dwell time, and cross reference that with either coil manufacturers.

Greg, you made mention of the units (I am thinking the COP?) auto adjusting? How so? They way I understand the coil, it takes XX long to build the inductance, and then she fires. That does not seem self adjusting, but rather a glass of water that fills over and over again.

I’m not trying to reinvent the wheel, as it seems a large number of people said get the Accel 140408, and some good plugs. Seems easy enough, but I would like to know if the XV crew could open up more and slightly unique options.

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Re: Coil-on-plug options for stock TCI?

PostAuthor: nanno » Sat May 23, 2020 4:05 am

You can measure the current influx and saturation and that's what the Ignitech does. The exact means are hidden well under a layer of epoxy potting. The stock box most likely just has reached the point, where a few caps are the solution to your problem or if you're a bit lucky just a cold solder joint on the back. (There's 4-5 spots where that can happen.)
http://viragotechforum.com/viewtopic.php?f=12&t=43227 - Nanno's accumulated findings (and blatant show-off) - infos on my TR1's, my performance and reliability mods and a bit of show-casing of the stainless steel exhausts I build

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