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 |
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8Pcs Crimping Tool Kit for Heat Shrink Terminals, Non-Insulated, Open Barrel, Solar Conncetors, Insulated and Non-Insulated Ferrules
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Buy on Amazon As an Amazon Associate I earn from qualifying purchasesDo 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.
• IGN-1A coils pictured are very powerful — overkill for most builds
• Only justified for extreme power levels (e.g., 2000 hp drag cars) or bragging rights
• Often cheaper than lower-output coils (compare to good used OEM Yaris coils on eBay)
• No need to buy unless: mounting constraints prevent other coils, or obtained very cheaply second-hand
• Best suited for high-horsepower drag applications
• Recommendation: Use lower-than-max dwell to extend spark plug life and if you're running high boost, follow my guide below to increase dwell time with boost
• If misfires/issues appear under boost → increase dwell gradually, but never exceed maximum recommended settings
For most street, track, or moderate-boost applications, OEM-style or less powerful aftermarket coils are more than sufficient and usually more practical.
configure coil dwell to rise 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.
Important warning: Do not increase your coil dwell past the numbers shown in the tables above. This will burn out the coil.
• Coil dwell time should increase with higher boost levels
• Y-axis (left): Boost pressure
• X-axis (top): Coil dwell time
• Minimizes dwell at idle/low boost for efficiency
• Higher dwell at high boost = more spark energy to overcome denser air/fuel mixture
• "Spark blowout" is a common misnomer – it's about maintaining spark quality under pressure
• Critical: Never exceed manufacturer/recommended maximum dwell values – will overheat and destroy ignition coils
Tune conservatively and monitor coil temperatures / performance when increasing dwell under boost.
R35 vs Yaris ignition coils
The following compares two popular high-output coil-on-plug options for built engines (e.g., 2JZ): Nissan R35 GT-R coils (often sold via Z1 Motorsports or similar) and Toyota Yaris (ZZ/Denso) coils. Both are widely used in high-horsepower swaps and aftermarket setups.
I'm currently running genuine R35 coils purchased from Z1 Motorsports on my built 2JZ (rated ~1000hp capability). They are compact, fit nicely under the factory-style coil cover, though slightly more expensive per coil than alternatives. The other strong option is the Yaris coils, which can support even higher outputs (e.g., ~1200hp on a 6-cylinder setup), often at a similar or lower price when buying new OEM units. Many users source them used via eBay (buying two sets of 4 leaves spares for a 6-cylinder if one fails).
Haltech has a detailed write-up on the Yaris/ZZ coils here. Platinum Racing Products (PRP) has guidance on spotting fake/counterfeit Yaris coils here (they refuse to sell copies due to reliability concerns).
Personally, I prefer the R35 coils—they feel more durable when pushed hard at high power levels—but check the linked articles to decide what's best for your setup. Always use genuine units to avoid performance/reliability issues from fakes.
• Popular high-output options for built 2JZ/1JZ and similar engines
• R35 (Nissan GT-R / Hitachi): Compact, fits under coil covers easily, often praised for durability at extreme power
• Yaris (Toyota ZZ/Denso): Potentially higher energy output in some tests, cheaper (especially used/OEM), buy extras as spares
• Price: R35 typically higher per coil; Yaris more budget-friendly but watch for counterfeits
• Fitment: R35 stalk is removable/flexible; Yaris fixed length
• Reliability: Genuine units recommended—fakes (especially Yaris) can lose significant output or fail early
• Sources: See Haltech write-up for Yaris specs; PRP for fake detection and R35/Yaris debate
Verify compatibility with your ECU/ignition setup (dwell, wiring, etc.) and always buy from reputable sources for best results.
