common oem or upgrade ignition coils
| Coil Brand/Model | Dwell 8V (ms) | Dwell 10V (ms) | Dwell 12V (ms) | Dwell 14V (ms) | Type | Ext Igniter/CDI | Max HP per Cylinder |
|---|---|---|---|---|---|---|---|
| Audi R8 COP (Denso 673-9302) | 4.0 | 3.0 | 2.5 | 1.8 | COP | No, built-in igniter | 200–250 HP |
| Honda CBR COP (Denso) | 4.0 | 3.5 | 3.0 | 2.5 | COP | No | 75–125 HP |
| IGN-1A Smart Coil | 4.5 | 3.7 | 3.5 | 3.0 | COP | No, built-in driver | 250–350 HP |
| Ignition Projects Quad Spark | 4.0 | 3.5 | 3.0 | 2.5 | COP | No | 150–250 HP |
| Kawasaki ZX COP (Denso) | 4.0 | 3.5 | 3.0 | 2.5 | COP | No | 100–150 HP |
| MSD Street Fire/Blaster | 5.5 | 4.5 | 3.5 | 3.0 | COP/Dist | CDI compatible | 100–150 HP |
| Nissan R35 GT-R COP (Hitachi/Denso) | 3.4 | 3.2 | 3.0 | 2.9 | COP | No, built-in igniter | 200–250 HP |
| Precision Raceworks (PR) | 4.5 | 3.7 | 3.0 | 2.5 | COP | No | 200–250 HP |
| Splitfire Super Direct | 4.5 | 3.5 | 3.0 | 2.5 | COP | No | 100–150 HP |
| Suzuki GSXR COP (129700-4100) | 4.5 | 3.5 | 3.0 | 2.5 | COP | External Igniter | 100–175 HP |
| Toyota Yaris COP (Denso 90919-02240/02229/02265) | 5.5 | 4.5 | 3.8 | 3.3 | COP | No, built-in igniter | 150–225 HP |
| Yamaha R1 COP (Denso 129700-4400) | 4.0 | 3.5 | 3.0 | 2.5 | COP | External Igniter optional | 100–150 HP |
Do you really need massive ignition coils?
The adjacent picture shows the IGN-1A coils. Unless your goal is bragging rights, or a 2000hp drag car, these coils are very much overkill. On the other hand, they are cheaper than less powerful coils (unless you purchase a good set of used OEM Yaris coils off ebay). There's no point in purchasing them unless for some reason you can't mount any other ignition coil, or maybe you got them second-hand for very cheap and you want to use these. In my opinion, these coils belong on a high HP drag car. My recommendation is to run the spark dwell lower than their max so you prolong the life of your spark plugs. If you start to have issues under boost then raise your coil dwell, just don't go over the max settings listed above.
configure coil dwell to rise with boost
Coil Dwell With Boost: If you notice in the adjacent screenshot of my Haltech NSP tuning software, I've built out my coil dwell table to where my coil dwell time increases under higher boost. Boost is on the y-axis (left), and coil dwell is on the x-axis (top). This allows me to run the minimum spark I need at idle and driving under low boost.
Why? When the cylinder pressures increase with boost, the molecules for the spark to traverse are more tightly packed together, so it essentially needs to work harder for the same spark energy. When I increase my coil dwell the spark event will have more energy at higher boost levels. This has mistakenly been referred to as "spark blowout" in the past, which is not entirely accurate.
Do not increase your coil dwell past the numbers shown in the tables above. This will burn out the coil.
R35 vs Yaris ignition coils
Which is better? I'm running R35 ignition coils in my car that I purchased from Z1 Motorsports, and yes they are a bit overkill since my engine block is built to handle approximately 1000hp, these are compact, fit beneath my coil cover very well on my 2JZ, though they were a little more expensive per coil than the IGN-1A above, but they're more compact. My other option was the Yaris ignition coil, which supports approximately 1200hp on my 6 cylinder, and they're about the same price for a new OEM ignition coil. If I would have gone this route I would have purchased them used on eBay and buying two sets of 4 for a 6 cylinder will leave you with two extra if one fails. Haltech has a nice write-up on the Yaris ignition coils here. PRP has a nice writeup on looking out for fakes of these coils here. I personally like the R35 coils, I feel they'll last longer when pushed to work harder, but I'll let you determine that based off the two articles I've linked in the
