Go In-Depth Inside MSD's High-Tech Power Grid Ignition System

Author: Wayne Scraba | 04/01/2021 < Back to Motor Life Home

The age of EFI has forever changed the way engines are tuned. High quality modern aftermarket electronic fuel injection systems such as Holley’s Dominator and HP platforms allow you to minutely tune almost every facet of engine fuel, ignition and boost. The Dominator EFI even adds more, including the control of specific automatic transmission functions. Many systems integrate comprehensive data logging. And in a number of cases they ultimately allow for traction control. Technology such as this is why one regularly sees racers stroking keys on a laptop perched on a car roof or fender. Something like a Dominator EFI setup can prove to be a colossal advantage for racers. No secret to most we’re sure.

But what if you have a car that’s bound by rules mandating a carburetor or two? Good examples on the class legal side include NHRA Stock, Super Stock and many Competition Eliminator cars. Ditto with many fast street competitors. On the other side of the equation, there’s a sea of bracket race cars out there that are also carb-equipped. Here there are no rules mandating the type of induction, but for many enthusiasts carburetors are really in the comfort zone. Now what? Are you then stuck with the basics?

Fortunately not. Enter MSD’s Power Grid. This system allows you to set up the complete ignition package by way of your laptop. In essence this parallels a modern EFI package, but without the fuel system controls.

The short end of it is, the Power Grid is an extremely flexible ignition controller allowing for the addition of a wide range of timing controls and data logging. What this means is, the racer now has an easy means to tune the ignition without being bound by the various add on control parameters. In fact, the Power Grid controller is engineered so that you can use it with almost any type of ignition system (for example, a good old fashioned 7AL “legacy box”). It can also be coupled with MSD’s dedicated Power Grid ignition box, and we’ll address that in a bit.

Making A Solid First Impression

Power Grid cylinder tuning

The ability to tune the Power Grid system is only limited by your skill set. Want to tune each individual cylinder? Yes, you can, and you will see instant results with each change.

Right out of the box, the Power Grid “System Controller” offers the following features (this doesn't take into account MSD’s available add-on options): USB connection for ease of programming, timing based on engine rpm, gear and time, individual cylinder timing based on gear and time, five retard stages for nitrous, four rpm limits for Max Rev, Launch, burnout and turbo spool, output switch configured by rpm, time or both, shift light settings for each gear, high speed data acquisition that records 19 ignition channels (Sample rate 100/per second or 10 ms. and 1000/per sec on Launch wire) along with a Racepak V-Net connection.

The USB connection is a pretty obvious advantage – that’s the basic interface to your laptop. But once you dig into it, you’ll discover the Power Grid is capable of performing intricate tasks such as individual cylinder timing. This is particularly useful in high boost settings but it can also prove beneficial in normally aspirated applications. This can become a wee bit complicated though, because in order to make full use of individual cylinder timing, you really should have a good grasp of what is happening within the combustion chamber (for example, obtaining sample air-fuel ratios) of each cylinder at a specific time. To get here quickly, you’ll need some sophisticated sampling hardware, and that may well be beyond the average little guy racer pocketbook. But resourceful racers might find a path to figure it out by way of individual cylinder EGT sensors (exhaust gas temperatures react to ignition timing). This may take some testing, but the bottom line is the Power Grid has the capability to equalize the performance of each cylinder.

Something less complex is the Power Grid’s capability of establishing an overall ignition-timing curve for each gear. Eons ago drag racers discovered that retarded timing in high gear could actually improve performance in some applications. MSD’s Power Grid offers this feature, but it’s a little more sophisticated than a toggle switch that cuts out one set of ignition points. With the Grid system, you can fashion an ignition-timing curve for each gear based upon the engine speed along with the amount of time a car spends in each gear.

That’s not the end of it either. It’s not uncommon for a stick car to “like” a short shift with a lower RPM limit on the lower gear changes, but in high gear, more RPM can prove advantageous. The Power Grid allows for it. And if the application is turbo charged, the Grid includes a spooling RPM limit. The Power Grid can be set up to control the engine speed during a burnout, and simultaneously provide RPM limits for the launch along with RPM limits for each gear noted above.

Nitrous users know there is regularly a need to retard the timing while introducing a stage of N2O. With MSD’s Power Grid it’s possible to program up to five stages of retard to accommodate multiple nitrous kits. MSD notes that you can program a specific timing action at any point in the gear or rev range to control a specific condition. Like what? Let’s say your home track has a bump in the right lane. That bump just so happens to coincide with the 2 – 3 shift in your car. That clearly unsettles the hot rod, just as it’s ready to make a charge in high gear. With the Power Grid, it’s possible to compensate by changing the rev limit threshold for the 2 - 3 shift or by pulling out timing. Problem solved.

A few years ago, plenty of racers (particularly those in traction limited applications) quietly made good use of MSD’s Digital 7 box with Slew Rate Rev Control. With that ignition arrangement, you could essentially provide traction control to your racecar by way of the ignition system (slew rate is RPM acceleration). Some folks figured this was an unfair advantage. Race sanctioning bodies felt the pressure and before you knew it, ignition controllers with Slew Rate were deemed illegal in many classes of competition. What does that have to do with the Power Grid? Simple. It doesn’t have a built-in Slew Rate Control. Instead, MSD makes it available as an ad-on “ARC” (Advanced Rev Control) controller. With this arrangement, one Power Grid can be used for every application and only those with the ad-on are deemed illegal. Incidentally the ARC module is engineered so that you can pre-set the rpm limits based upon the slew rate or based upon time since launch. In essence, it’s designed to provide you with a means to limit wheel speed: If the engine and/or the driveshaft rpm increase(s) beyond a pre-programmed rate; the Advanced Rev Control will retard the ignition timing and/or the rev limits. What this means is a reduction (or a complete elimination) of excess wheel speed. The entire ARC package is easily setup (and tweaked) through a software package loaded into a laptop. There are also accessory modules available for boost retard and manual launch control. With this arrangement, you really don’t have to pay for features not required for your application.

Capability On Several Levels

Power Grid rev limiter

One rev limiter? Please. The "Safe Run" function offers up a way to set every last boundary your engine will need, and in race applications, this is second to none. Max revs for burnout, spool and launch are self-explanatory, but "Safety Run Time" means, in this case, that after nine seconds of full limiter, the system will drop down to 2,000 RPM and no more on this 8.50-second car.

You’ve probably heard of the term “CAN-Bus”. The “Can” in CAN-Bus stands for “Controller Area Network” – a technology found in most late model automobiles. CAN-Bus allows for a single (small) harness to transfer data to various different controls and sensors – all within that small harness. The MSD Grid System was engineered around a CAN-Bus network. According to MSD: “You can connect three different modules into our CAN-Bus hub, and although they will each provide different accessory controls with features to adjust, they don’t need to all be routed separately to the Power Grid module. They all attach through the same connector. This saves a lot of wiring and eliminates the need to duplicate a lot of sensors, saving racers time and money.”

Racepak is pretty much the standard of data acquisition systems, and plenty of racers use them. No surprise to many. Since Racepak is a sister company to MSD, several components can cleanly integrate with the Power Grid. For example, you can use an existing Racepak driveshaft sensor to work with a slew rate module. While the Power Grid is working with that driveshaft sensor, it’s not interfering with the data being acquired by the Racepak. The Power Grid records 19 channels of ignition data (stored on its own SD card or transferred to your laptop by way of a USB cable), most of which can be shared with a Racepak data acquisition device (a tip from MSD: “Remember to re-install the SD card after downloading data between rounds!”). Clearly, the benefits here are numerous – not the least of which is the capability to transfer data from the Power Grid directly to the Racepak data logger. As a result, there’s no need to physically compare two different readouts (one from the Power Grid and one from Racepak). They’re combined on the Racepak data. MSD’s Silver Gomez advises us the Power Grid uses a V-Net connector to transfer data into the Racepak, allowing it all to be viewed on one screen. What this really means is you can tune the ignition system to accommodate the down track data from the Racepak.

Recall those other “ad-on” modules we mentioned earlier? Several of them include a programmable three-stage timer, a manual launch control, the previously mentioned ARC rev control, as well as a boost controller along with a boost retard module. There’s even an exhaust pressure module for turbo applications. Each of these modules simply plug into the Grid. The CAN-Bus network is easily expanded too – you simply add CAN-Bus “hubs” (basically, a 4-port CAN-Bus terminal strip) as needed. What this means is you can add as many Power Grid accessories as you need for your application. And in this case, there is no real limit on what you can add.

We’ve just scratched the surface there. These are the bare basics of what the controller part of the Power Grid equation can do for your car. There’s more to the package and that’s the ignition system. While it’s possible to use an existing ignition system, MSD also offers a very powerful, yet compact ignition box engineered specifically for the Grid system. It measures 7.5-inches long by 5-inches wide by 2.25-inches tall. The box weighs 2.9 pounds and provides for 200-220mJ of spark energy (per spark). The primary voltage is 545-570 volts while the secondary voltage is 50,000 volts +. The Power Grid ignition can operate up to 15,000 RPM with 14.4 volts.

Easy To Install

When it comes to hookup and installation, there are some important considerations. We spoke with MSD’s Silver Gomez and he offered his insight into several key areas:

One factor is the voltage requirements along with use of an alternator. Silver notes: “The Power Grid system consists of two units, one is the controller, PN 7730 and the other is the ignition, PN 7720. The Power Grid Controller will operate between 7 – 18 volts continuous and can handle up to 20 momentary, and it draws .5 - .7 amps. The Power Grid Ignition will operate between 12 – 18 volts continuous and momentary 20 volts and will draw 1.3 amp per 1000 RPM”

As far as alternators are concerned, Gomez has a simple recommendation: “Alternators are a good idea.”

Silver then goes on to offer this advice: “Lightweight batteries need to be sized accordantly for ignition demand. Some might not have sufficient amp hours for the ignition demand. It is not uncommon to have two lightweight batteries, one for starting and supplemental products like gauges, pumps, fans, and data loggers and a second for ignition.”

With that, we also asked Silver if it is possible to use the MSD Power Grid system in a continuous duty application, such as a Drag Week car:

“Yes, the Power Grid system can be run for a long time, such as Drag Week -- just as long as the proper coil is used, such as PN 8261 HVC II Coil. (Larry Larson ran them in the Nova and S10 for several years on Drag Week)

“The Power Grid with a legacy ignition will work too with the correct coil. For example, on 7-series ignitions you can use the PN 8261 HVC II coil. (Pro Mags are not advised).”

Once you wrap your head around it, it’s clear the Power Grid system is not only potent, it offers tuning capabilities we once thought impossible for carbureted cars. Factor in ease of installation and the ability to data log and you have a quantum leap in ignition systems. For a closer look, check out the accompanying photos:

Power Grid components

MSD’s Power Grid is based upon two different components: The system controller on the left and the ignition box on the right.

MSD Power Grid controller

The system controller is essentially a high-speed RISC microcontroller that tells the ignition box what to do. The controller constantly analyzes the various systems such as launch, burnout, step systems, trigger signals and CAN-Bus data.

MSD Power Grid pointer

See the pointer? The little lamp is similar to those found on other modern MSD ignition systems. It’s a status display that can tell you if the ignition system is experiencing an issue.

Power Grid harness/CAN-bus plugs

Here’s where the main wiring harness for the ignition system and the CAN-Bus network plugs in. The harness assemblies will be covered down the page but suffice to say, MSD makes the entire wiring task plug and play.

Power Grid Micro USB port

Remove the cover from the right-hand port on the controller and you’ll find Micro USB computer connection along with the SD micro card.

Power Grid SD Card

The SD card is accessed like any other – push in and the card releases. This in turn allows you to slip it into a computer card reader. MSD also includes a USB to a Micro USB cable with the Power Grid system controller (allowing for direct hook up to a lap top). Either/or can be used for data downloads.

Power Grid output CD ignition

The spark part of the Power Grid equation is handled by this box -- a high output CD ignition system. You don’t necessarily need to use this ignition box. It’s possible to use the controller to operate “legacy” systems such as the 6AL, 7AL2, 8-Plus and even a Pro Mag.

Power Grid ignition box connections

Power Grid ignition box install is a simple plug and play operation. One plug goes directly into the Power Grid Controller harness. The other is wired into the coil.

Power Grid controller wiring harness

Here’s the controller wiring harness. The wires with connectors route to the ignition box, the V-Net cable (a Racepak connection), magnetic pickup (crank trigger or distributor) and to any CAN-Bus network accessories. Meanwhile the loose wires route to the ignition switch, tachometer, shift light, various step switches, etc.

Power Grid extension harness

An extension harness is included. This allows you to hook up the Power Grid controller to a legacy ignition box (for example, a 7AL-2).

Power Grid MSD crank trigger/mag pickup harness

Another harness MSD includes is this one. It’s engineered to plug directly into an MSD crank trigger setup or a magnetic pickup MSD distributor.

Power Grid stackable

The Power Grid system is designed so that it is stackable. The controller can be mounted directly on top of the ignition box or you can choose to mount the components separately.

Power Grid CAN-bus hub

A CAN-Bus hub allows you to add modules to a Power Grid. From here, you can plug in multiple modules (case-in-point, the ARC controller shown in the next photo). It’s also possible to multiple hubs together should it prove necessary (allowing for a completely expandable system).

Power Grid ARC controller

Here’s the “Advanced RPM Control” (ARC) controller mentioned in the text. Once the module is plugged into the CAN-Bus hub, it provides for slew rate-based traction control. The various parameters are selected and controlled through the included software.

Power Grid HVCII coil

MSD recommends this HVCII coil. It's a race coil based upon a u-core winding design. There’s more info in the text.

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