Adjust Ignition Timing - Ahead Of The Curve

One of the easiest ways to tune your engine’s power is by adjusting the ignition timing. Usually, most normally aspirated engines can stand to use a little more advance in the timing curve, while supercharger applications require a bit of retard. This is all fairly basic motorhead stuff that guys have been doing since the Dodge Brothers first started turning wrenches. However, with the advent of onboard computers and electronic engine management, most of the standard tune-in-your-driveway techniques are no longer just a reach for a distributor wrench. For anybody who has a ’96-or-newer OBDII- (On Board Diagnostics II) equipped Magnum truck, the options have been limited. At least OBDI (On Board Diagnostics I) has been around long enough that the aftermarket has learned how to tune it with new computer chips and piggyback modules. But with OBDII, there is no real way to change the timing—or anything else for that matter—short of going with the OE manufacturer’s hot replacement computer.

The problem with the hotter computer is that it’s set up to work within a fixed set of parameters, then is locked in to those parameters. You buy it, bolt it in, hook it up, and go. Step out of what the manufacturer felt was the ideal package when it was programmed, and you’re in no-man’s-land.

Problems frequently incurred with the OE hi-po electronic control modules include the addition of nitrous or a blower. The hot programs take into account new cams, maybe higher compression, headers, and so on, but they don’t think about setting up the computer for the boosted atmosphere that blowers and nitrous present. As we’ve stated, some advance usually is desirable to make more power. As a result, the hotter computer has a more aggressive advance curve built into it. But with a blower or nitrous, you want the timing to be retarded. We know more than a few people who have lifted head gaskets by running the hotter computer with a blower, due to detonation. With the potential for damage with detonation on a blower application, they’re lucky all they did was blow head gaskets. Throw nitrous anywhere into the equation, and things can get real ugly. That’s why if you are going to run a blower with OBDII, it’s generally recommended that you stick with the stock computer to avoid most of the detonation problems, though you should still be wary of it in all cases.

Pat Stajdel at Superchips called us one day and asked if we knew anyone who owned an OBDII vehicle with a blower on it, because they were working with Vortech Superchargers on a timing control module for ignition retard to eliminate those detonation problems. We didn’t know anybody, but got to thinking that if they can retard the timing for a blower, could they advance the timing for nonblower applications? Pat liked the idea a lot, so we drove our Dakota over to their shop in Longwood, Florida, to do a little R&D on their chassis dyno.

Their module is called the Icon Race, and it works by intercepting the signals between the computer and the coil, then resending it to the coil at a programmed rate. Because the Icon picks up the signal after the vehicle’s computer does, the computer doesn’t even know it’s there. Not only is Icon infinitely adjustable, but you can also set retard and advance throughout the entire RPM band in ½-degree increments. The added advance is in addition to the advance already set in the stock computer. Because it is completely programmable with a laptop, you can do cool things, such as ramp the curve up to 8 degrees through 4,500 rpm, then pump it up another 2 degrees through 6,000. You can also back it down a couple of degrees at the shift points. The great thing about this is that you can play with the timing on the computer graph and get rid of any spikes and valleys in the powerband. Because the vehicle is tuned on their chassis dyno, you can dial it in from idle to redline. We found that our relatively stock (only headers and exhaust modifications) Dakota liked 9 degrees more advance than what the vehicle’s computer has, which turned out to be good for almost 20 lb-ft of torque at the rear wheels!

The module installs quite easily, with the only leads being a keyed 12V power source, a ground, and a pair of wires that intercept the signal at the coil. The Icon also can be quickly disconnected, should the need arise. Right now, the module is in the “For Off-Highway Use” category, because it hasn’t proceeded through the Executive Order process, required by the California Air Resources Board. This procedure is tantamount in the automotive aftermarket, as well as emissions-legal in all U.S. jurisdictions. Also, we don’t know how Chrysler feels about the module, as far as the factory warranty is concerned.

If you’re running a blower, the little Icon Race box is the least of your concerns in regards to the warranty. Our 3-year/36,000-mile warranty actually expired on the way to Longwood, Florida, so we’re on our own now, anyway. Superchips has franchises throughout the country, so this isn’t something that only magazine guys have access to. Most of the shops have a chassis dyno, but if you can’t find one near you, Superchips can supply you with a program for your laptop, and you can spend a day at the track dialing it in. Give them a call to find the dealer nearest you.

This is the Icon Race. Not...        read full caption This is the Icon Race. Not much to it, is there? Electronically, it mounts between the coil and the computer. Physically, you can put it anywhere you want.	The first step in any underhood...        read full caption The first step in any underhood installation on a new Dakota or Ram is to remove the whole air cleaner assembly.	We chose to mount the Icon...        read full caption We chose to mount the Icon on the inner fender, next to the truck's electronic control module. The wire we're holding is the ground.
Next, you'll need a multimeter...        read full caption Next, you'll need a multimeter to find a keyed 12V source. We figured we could find one near the main computer. The one we found here was hot when the key was in the "Run" position, but it was dead in the "Start" position. If it won't start, it won't run.	To find a switched hot lead...        read full caption To find a switched hot lead to run Icon, we had to run the lead over to the other side of the engine bay (driver side), near the underhood fuse block. The wire we tapped into ended up being the one labeled "Engine Coils" on the underdash fuse panel. We followed it through the firewall, and picked it up between where it goes through the firewall, into the underhood fuse block. It took us longer to find this wire than we care to tell--that's the downfall of doing R&D on a vehicle. To stretch across the engine bay, we had to splice a wire to the end of Icon's feed wire so it would reach. We ran the new, longer wire in a piece of plastic loom, which we shielded so it wouldn't be noticed. Then, we spliced into the 12V source, inside the factory wire channel that covers the bundle of wires from the firewall to the underhood fuse box. The instructions that come with the kit for Dakota/Ram applications will be more detailed.	After finding power and a...        read full caption After finding power and a ground, you'll need to trim the two extra wires off the Icon's coil pigtail. They're for marine applications. Just cut and toss the two as outlined in the instructions.
Next comes the coil interface....        read full caption Next comes the coil interface. Start by removing the power plug from the bottom of the coil.	Superchips attached a sophisticated...        read full caption Superchips attached a sophisticated piece of electronic diagnostic equipment to the two wires going into the coil, and determined the black one to be the one they needed to tap into. We read our shop manual when we returned to the office, and learned that the vehicle's computer opens and closes the coil's ground circuit (the black wire) for ignition coil operation. The manual stated: "By controlling the coil ground circuit, the PCM (computer) is able to set the base timing and adjust the ignition timing advance." We picked it up and adjusted it to our curve by intercepting the current between the computer and the coil.	Crimp the supplied male and...        read full caption Crimp the supplied male and female bullet connectors into the coil ground. Plug the bullet connectors together, and the truck runs on the factory settings. This is how the Icon is quickly disconnected.
The two remaining wires on...        read full caption The two remaining wires on Icon's pig tail plug into the bullet connectors we just installed into the coil ground. The current then goes from the OE computer, into the Icon and back out to the coil.	Next, a laptop is used to...        read full caption Next, a laptop is used to draw a new ignition curve graph. Here you can see the new graph, and the way it's stepped and tailored to our truck. The program is downloaded to the Icon via the printer port and cable on the laptop. Then, the fun begins with pulls made on the chassis dyno. After each run, the dyno chart is printed out, and the timing is adjusted accordingly. The new program is downloaded, another pull is made, and the next two hours are spent tweaking the ignition curve. When we were done, we picked up 8 peak horsepower, but we also got more than 18 lb-ft of peak torque, both at the rear wheels. Power was increased--fairly uniformly--over stock throughout the entire rpm band.	The Icon attaches to the vehicle...        read full caption The Icon attaches to the vehicle with a hook-and-loop fastener (such as VelcroTM) pads. This may seem like a cheesy way to do it in print, but this process actually is very clean, simple, and effective. Not only are you free from worrying about access for drilling mounting holes, but you aren't putting holes in your inner fender (which will rust the first time it rains). With our location on the inner fender, behind the air intake box, you can hardly see it. Drop your hood and start killing those tires!