Again, while ignition wires seem more than simple, there are actually many complicated factors to take into account when designing them. Since modern ignition systems don’t use wires that are nearly as long as their progenitors, there is less resistance for the spark energy to fight through to reach the spark plug — which again, leads to high spark energy transference and thus better fuel economy, more precise ignition events and more power. http://cdn.speednik.com/files/2016/0...40-640x427.jpg
However, with less resistance comes higher electromagnetic interference (EMI); which is sometime referred to as radio-frequency interference (RFI) when speaking in terms of radio frequency. The less restricted a circuit is, the better it is at creating a magnetic field (which, as we previously mentioned, is one of the main reasons the primary winding in a coil has low resistance).
These two variables create a juxtaposition with one another. You want as much spark energy as possible reaching the spark plug — which would mean less resistance. But the lower you allow the resistance to go, the more it interferes with key electrical components such as the fuel injectors, computerized systems and even the radio. Most manufacturers have settled for a happy medium which keeps EMI to a minimum while transferring as much spark energy as possible.
While compromise is great for selling to the masses and keeping the majority of people happy, it frequently doesn’t help you go faster. Granatelli refused to compromise on performance or drivability with their Malevolent coil pack sets for LT-series engines and found ingenious ways to get the best of both worlds, which is why we turned to them for the punch we needed to put C700 over the top.
Granatelli’s Malevolent Ignition Coils
“On a factory LS or LT engine, the factory coils are rated at about 42,000 volts,” said Joe Granatelli, owner of Granatelli Motor Sports. “Our coils are 85,000 volts, meaning they are double the voltage of the stock coil— what’s special about that is, no one else can do it.”
Granatelli attributes the fact that his company’s coils can produce more spark energy than any other competitor to the fact that the coils are produced domestically and investment in new techniques that allow a more compact design. This ensures that quality control on the units can be monitored directly, and allows the company to produce a coil with more windings packed into their compact shells.
He continued, “A lot of other manufacturers aren’t willing to put in the money or effort to figure out how to develop processes to get tighter winding to fit in the compact casings. We wanted to produce the highest voltage coil possible, and we didn’t take any shortcuts to get there.”
But that leads to another question. Do you really need that much more voltage?
“In a forced-induction application, like a supercharged C7, the boost increases the cylinder pressure and starts to cause spark blow out,” Granatelli said. “With our coils, spark blow out is all but eliminated — the stronger the spark the less likely people are to have problems with it.”
He continued, “We have customers that are running 2,500+ horsepower pro-mods that aren’t running a magneto. They are still running our coils, and having no problems with them.”
Not only does the additional power keep things cooking, especially under boosted conditions, it helps to ensure that the coils are producing adequate spark energy at higher rpms, where stock coils have a tendency to become saturated, according to Granatelli.
Higher rpm situations can see a coil’s energy production levels reduced to as low as 22,000 volts in the upper levels of the power band. Not so with the Granatelli coils.
“Our coil on first hit, and in most conditions, is 85,000 volts,” Grantelli explained. “In testing, under high load and high rpm conditions, we’ve never seen them go under 78,000.”
This ensures that C700 will be igniting the entire air-fuel mixture throughout the rev range, regardless of boost pressure, leading to, you guessed it, more power.
Once all that power is produced and the energy is discharged from the coil it heads to our set of Granatelli spark plug wires.
We selected a black set with the additional high temp sleeves to ensure that our freshly installed set of headers wouldn’t cook them to a crisp. They are also available in blue, red or yellow — no judgements here. You can get them with or without the protective selves that we selected. However, we would highly recommend them, since they will be seeing a lot of heat from the headers.
Granatelli’s spark plug wires feature an 8 mm jacket with fiberglass reinforced braid resistant to temperatures of up to 500 degrees fahrenheit. They are constructed with a solid stainless steel core that produces exactly 0 ohms of resistance, meaning every ounce of spark energy makes it from the coil to the spark plug.
“Our wires basically have no resistance,” Granatelli said. “If you ohmed the wire, you would maybe see .0001 ohm — since its impossible for a wire to have absolutely no resistance — but these are as close to no resistance as you will ever see.”
However, as we previously discussed, if there is no resistance, that means there is an increased possibility for electromagnetic interference (EMI and RFI). So how does Granatelli make sure that they don’t interfere with your cars electronics? Through a process they have patented that ensures none of the electromagnetic energy is making its way outside of the spark plug wire.
“We are the only ones that can get you a 0-ohm wire without EMI or RFI,” Granatelli explained. “That’s where our patent comes in; we have a ring that goes on the outside of the wires, that we call the magic donut, that suppresses all electromagnetic interference.”
We are the only ones that can get you a 0-ohm wire without EMI or RFI. That’s where our patent comes in; we have a ring that goes on the outside of the wires, that we call the magic donut, that suppresses all electromagnetic interference.– Joe Granatelli
Combined with a coil capable of producing up to 85,000 volts, our spark plug wires ensure that ample spark energy is making its way to C700’s spark plugs. After hearing of the coils’ and wires’ capabilites, we were eager to get them on C700 and see what they could do.
Before we were ready to bolt on the new coils, we strapped C700 to our Dynojet to see what kind of power we were making with our stock coils. We were pleased to see that the ProCharged LT1 was churning out a very respectable 566.32 horsepower and 570.39 lb-ft of torque — which works out to around 675 at the crank using rough estimates. However, we were hoping to see just a little bit more to push us closer to our goal of 700 crank horsepower. So, without even moving the car off the rollers, we started the install of our Granatelli Malevolent 85,000-volt coils.
Installation of the coils was extremely straight forward; especially on a C7 Corvette, and just might be the quickest way to put some extra ponies on to your LT1 — especially if it is running a power adder like we are.