Which Granatelli Coil Pack Do I Need?
Short answer: pick your engine family first, then pick how much coil you actually need. Buying the highest-output coil for a stock engine is money that does nothing; buying an OEM-output coil for a boosted engine is a misfire waiting for you at full throttle.
Step one: which engine
Granatelli builds coils for three engine families, and a coil that does not fit is the only genuinely wrong answer here.
- GM — LS and LT engines across cars, trucks and SUVs, including LS2, LS3, LS7, LS9 and LSA.
- Ford — 2.0L, 2.3L, 3.5L, 3.7L and 5.0L Coyote, covering both 2-valve and 3-valve applications.
- Dodge — HEMI applications.
Get that right and everything after it is a question of how hard you are working the engine.
Step two: how much output
The series ladder is genuinely a ladder. Each step up is a bigger spark, and a bigger spark only earns its money when there is more air and fuel in the cylinder to light.
| Series | Output | Built for |
|---|---|---|
| OEM Series | 10% over factory | A direct replacement for a failed factory coil, with a little headroom. Stock engines. |
| Street Fighter | 25,000 volts | Designed to run with aftermarket ignition systems such as Accel and MSD. |
| MPG/PLUS | Economy focused | Granatelli quotes fuel economy gains of up to 15%. A daily-driver choice rather than a power one. |
| Hot Street | 45,000 volts | Roughly double stock output. Bolt-ons, mild cams, a car that is worked but not boosted. |
| Pro Series | 60,000 volts | High compression and nitrous applications. |
| Pro Series Xtreme | 65,000 V Ford 2v/3v 85,000 V GM, Dodge, Coyote |
Serious boost, serious compression. |
| Malevolent Series | 85,000 volts | The highest-output coil Granatelli builds. The end of the ladder, for engines asking the most of their ignition. |
If your engine is stock and running fine, the OEM Series is the honest answer — and we would rather tell you that than sell you a Malevolent you will never use. If you are pushing boost through it, the top of the ladder is where misfire under load stops.
Does a bigger coil add horsepower?
On its own, rarely. A coil's job is to light the mixture completely and reliably. On a healthy stock engine the factory coil already does that, so a bigger one changes very little.
Where it matters is when the spark is being asked to jump a gap under pressure. Boost, nitrous and high compression all make the mixture harder to ignite, and that is where a weak coil starts to break down — usually as a stumble at the top of third gear rather than a warning light. A higher-output coil is insurance against that, and on an engine already suffering it, recovering the misfire looks exactly like finding power.
The part most people forget
Coils push spark into wires, and the wires matter. Granatelli's 0-ohm wires use a near-zero-resistance design; the company states they deliver 400% more power to the plugs than OEM wires, with gains of up to 5 HP naturally aspirated and 12 to 15 HP on supercharged, turbocharged and nitrous applications.
Upgrading coils while leaving tired wires in place is a common way to spend money and feel nothing. If the wires have age and heat cycles on them, do both.
Worth checking too: coil-on-plug connectors perish with heat, and a cracked connector will give you an intermittent misfire that no new coil will fix.
Where to start
GM coil packs, Ford coil packs, or the full ignition range including wires and connectors.
If you are not certain what is in your engine bay, call 1-805-486-6644, Monday to Friday, 8am to 5pm Pacific. Fitment questions are the ones we get most and the ones we are quickest on.
