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Start Tuning and Stop Guessing
When you first fire up the motor with the Innovate wideband meter connected you'll immediately see where our excitement stems from. It is truly a revelation when you see the air-fuel ratio dance around on the LCD screen of the LM1 and realize it correlates to the slightest adjustment of the carburetor. The concepts of carburetor tuning don't change with this tool. You still want to start with adjusting idle speed, then idle mixture, followed by part-throttle tuning and ending with wide-open throttle optimization. The difference is that you'll use the Innovate system and software to make exact decisions, resulting in immediate results in a fraction of the time.

With the wideband oxygen sensor in place and RPM Converter set up, we are ready to fire up the motor and switch on the LM1. When you turn the LM1 on it will spend about 30 seconds heating up the oxygen sensor and will indicate so on the LCD display. Once warmed up it will display the current air-fuel ratio.
If you have a laptop you can use the supplied LogWorks software to view real-time data as you are tuning. This isn't a requirement, you can always view the logged data afterwards on your desktop. You'll need the supplied serial cable (or a DB9 serial to DB9 serial to USB converter cable if your laptop doesn't have a serial port...most do not.)

Here is a screen shot from our laptop while viewing real-time air-fuel ratio and RPM data of our Montego at idle. The LogWorks software allows you to customize the gauge view as analog or digital LCD style. This sort of output is real useful when you have a second person in the car helping you tune. If you are tuning by yourself don't worry, you can replay the stored sessions in LogWorks.

In the preceding photo our air-fuel mixture at idle looks a bit lean at 15.0 parts air to 1 parts fuel (represented at 15.0:1, we turned out the idle mixture screws on our Edelbrock carburetor to give it a bit more fuel. We ideally want idle air-fuel ratio to be 14:1 to 14.5:1 at idle. The wideband sensor and LM1 will detect the change instantaneously, and at the slightest turn of the screws. On any carburetor be sure to rap the throttle after adjusting idle mixture or speed to ensure the carburetor is metering properly.

Tuning for Part-Throttle and Driveability
Once the idle is set it is time to set out on the road and tune out all the gremlins that plague a new carburetor. The process is no different, find a road which allows you to drive the car under the load condition you are interested in tuning. Tune under high-load conditions, such as up a moderate hill, and under cruise conditions such as a long open stretch of highway. The rule of thumb here is that you want to aim for air-fuel ratios in the 13.0-13.7:1 range. Shoot for the high end of this range (leaner) of under less load, and richer when under high load. A vacuum gauge mounted in the car can help in understanding engine load. Your engines vacuum at idle represents no load, while vacuum numbers approaching zero show a high load condition.

We set out on the straight and desolate roads of Western Nevada for our part throttle, "cruise" tuning. Our Montego use to "surge" under these conditions. Let's find out why.
We hit the red "Record" button to start the data logging. The LM1 can log up to 44 minutes of data, and an infinite number of "sessions" or runs representing the driving condition you want to analyze. Hit record again to stop logging.

We pulled over to analyze the cruise data. Our air-fuel ratio was a bit lean, running in the 14:1 range during cruise mode.

We brought along our Edelbrock tuning chart, a metering rod and jet kit, and some tools to make quick roadside changes based on the data analysis.

We made a rod change to go one step richer in the cruise mode per the Edelbrock calibration chart. We also changed the step-up spring to a lighter one to address a momentary lean condition we observed upon tip-in of the throttle during cruise. The step-up springs in an Edelbrock function similar to power-valves in a Holley carburetor.
After our changes we headed back on the road to re-measure the cruise driving conditions. Without even looking at the screen we could feel the car was smoother at part-throttle and snappier upon goosing the throttle. Sure enough the air-fuel ratio was right where we expected it at 13.5:1. It only took one adjustment of the carburetor, made in full confidence without guessing.

Tuning for Wide Open Throttle

The last segment of carburetor tuning, but clearly the most important for power junkies, is wide open throttle performance. This is where wide-band tuning really shines because one can measure the effects of their tuning against standards such as time and horsepower. Head to your local track test and tune session or mark off a quarter-mile (be sure it is safe and clear!) and make some runs. You'll want to shoot for an air-fuel ratio in the mid to high 12's, but realize that you'll have to find the "sweet-spot" where your engine makes the most power and runs the quickest time. This could generally be anywhere from an air-fuel ratio of 12.5:1 to 13.5:1 for a naturally aspirated engine.

When tuning for wide-open throttle, our recommendation is to use your local track test and tune session. If you can't, then find yourself a straight section of road, with clear sight and no traffic. Safety is number one here, so use the record button and don't try to watch the LCD or laptop screen!
After you make a run pull over and fire up LogWorks on your laptop or head back to the house and download the LM-1 logfiles to your desktop. Jon's letting the Montego cool between rounds while analyzing the run data.

We're just logging on two of the LM-1's six available channels. Shown are air-fuel ratio (pink trace) and rpm (black trace). The horizontal axis is time in seconds. You can see at time-zero we put the pedal to the floor. Air-fuel ratio drops down to 11:1 as a result of the accelerator pump shot dumping in fuel. On this first run our air-fuel was overall way too rich. The callout box shows 11.8:1 at 4510 rpm before the shift into 2nd gear. This run took 15.07 seconds (expand image to view full time scale.)
LogWorks is an extremely powerful data analysis tool offering numerous ways to view the data. This cool 3D plotting feature helps us visualize what the predominant air-fuel ratio is in a given rpm range. We see here that between 3000 and 4000 rpm our engine is running in the 11:1 range.

Based on the data analysis we suspected we could improve on power by leaning the carburetor one or two jet sizes. Jet changes on an Edelbrock or Carter require pulling the top of the carb - a drawback to Edelbrock carbs, but not unfeasible out on the road. Just don't drop any of the tiny clips.
Now this is a familiar site for carburetor lover of any kind. These are Edelbrock jets, but nonetheless similar in principle to Holley jets. The stamped numbers indicate orifice size. However, look at the gibberish stamped on the first jet. This threw us for a loop when we pulled it our of our model 1405 Performer carburetor. Turns out this is Edelbrocks way of telling you it is the stock jet for the carb model. Another reason why you don't find Edelbrock carbs in the performance scene.

We jetted down one size smaller than what comes in the 600cfm model 1405 carburetor. Ideally we would have preferred to go two sizes smaller, however this is all we had out on the road. Nevertheless the next two runs confirmed what our data was showing us. By leaning the average air-fuel ratio from 11.8:1 to 12.6:1 we knocked off the same distance is 14.62 seconds, about a half-second faster than before.
We are wideband tuning converts. Here you have a great example of how modern technology can be applied to something as old-school as our 1972 Mercury Montego Brougham. It's a great example how you can easily tune any vehicle for more power with Innovate's digital wideband technology.


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Innovate Users Create a Huge Technical Support Network

This little Radio Shack item, called a 50k-ohm potentiometer saved us serious headaches in measuring accurate RPM. Often times aftermarket ignition systems, such as an MSD box, put out a "dirty" signal which the Innovate RPM converter picks up. This results in very erratic rpm readings, which can be frustrating to tune around. We solved the problem after spending just five minutes on the Innovate Forums.

The potentiometer works like a volume control on a radio. Simply ground one of the outer pins. The other outer pin goes to tach output, and the center pin to the Innovate RPM converter. We turned the knob until we got a clean and steady rpm reading.

Innovate! Technology, Inc.
5 Jenner
Suite 100
Irvine, CA 92618



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