At various times, two cars were undergoing carb mods while the third was preparing to go b
One trickled-down benefit from OE electronic fuel injection was the widespread use of wide-band oxygen sensors. Once the OEs began building these sensors in the millions, the price plummeted, and Innovate Motorsports was one of the first companies to build affordable air/fuel ratio meters. In the beginning, the original LM-1 control box was rather large and clunky, but it got the job done. Innovate just released the Digital MTX–series in-dash air/fuel (A/F) ratio gauge. While gauges themselves are nothing new, Innovate chose to offer this as a complete in-dash package for less than $200. We decided to put the new gauge to the test on three different cars during a full day of testing we called Carburetion Day.
Our willing test subjects were Eric Schmiege's '65 Bel Air with a 396 sportin' a pair of 0-1850 600-cfm Holleys, Doug Eisberg's 496ci roller-cammed Nova fitted with a 750-cfm Holley mechanical-secondary carb, and Eric Rosendahl's '77 small-block Corvette running a spread-bore, 650-cfm Holley. The guys had previously equipped their cars with 18mm oxygen sensor bungs, so the installation of the sensor was easy. While the Digital MTX gauge is designed for in-dash installation, we rigged it as a handheld meter to expedite swaps among three cars. The gauge also offers two 0- to 5-volt linear analog outputs so you can use this sensor with closed-loop engine management systems as well, plus it can be easily configured to data-log A/F to Innovate's free LogWorks program to run on your laptop computer. And if you really want to go high tech, you can purchase the Innovate OT-2 that will convert the A/F data from the Digital MTX and transmit the information wirelessly to your iPhone using a LogWorks app.
This is about as simple as it gets. The Digital MTX system comes with a wide-band sensor,
While the eight-barrel Bel Air appeared to be the most challenging, it turned out to be the easiest to tune. With some slight changes to idle mixture and a secondary metering change, we quickly had the Rat package tuned, eventually pulling high 13:1 A/F at light-throttle cruise. The Corvette was more of a challenge since the idle mixture screws were incredibly sensitive. Eric also told us he had changed the power valve from a 6.5 to an 8.5, which was evident when the A/F would transition very quickly at medium throttle to a very rich mixture, so we returned it to a 6.5 and improved the part-throttle mixture.
Doug's Nova proved to be the most difficult of the three. At light cruise, his A/F indicated high 11:1 ratios and at highway speed the A/F was a still-fat 12.1:1. We returned to the shop and installed 0.015-inch wire restrictors in each idle feed jet to reduce the area and readjusted the idle mixture. We also changed the power valve from an 8.5 to a 6.5. The final results were significant since this put the highway cruise A/F at 13.5:1 and improved the Nova's highway mileage by more than 11 percent from 11 to almost 13 mpg.
We were going to also tune our new 455 Olds engine in our '64 F-85, but the smell of steaks on the barbecue became more enticing that sniffing exhaust, so we hung up our Innovate for the day.
How Much: $199.95 MSRP, PN 3844
We Say: You can't afford not to own a tool this good.
Learn More: Innovate Motorsports; Huntington Beach, CA; 714/372-5910; InnovateMotorsports.com
What It Is: Schott Wheels' line of three-piece wheels
Why You Care: Having a three-piece wheel design means you can choose the exact offset that will allow you to fit the widest tires under your car. Schott Performance Wheels recently expanded its lineup to include new three-piece wheels. Three different center designs are available, with more on the way.
How Much: Not cheap.
We Say: No custom wheels are cheap.
Learn More: Schott Performance Wheels; Los Alamitos; CA; 562/598-4411; SchottWheels.com
Some Museum for Your Garage
What It Is: Custom tool chests
Why You Care: This Guy's Garage is a very popular section of the magazine. We all love reading about and seeing the cool stuff guys (and gals) have squirreled away in their workspaces. Wrenchers Tool Chest is a company started by a carpenter and contractor in Northern California selling several configurations of tool chests on his website, but the company can also custom-make tool chests to your specs. No crappy plywood and composite laminates are involved, either. He uses high-quality hardwoods that are finished with a durable acrylic urethane.
How Much: Pricing ranges from $1,400 to $2,700. That's on par with a lot of metal cabinets.
We Say: Check out the rocker arm drawer pulls.
Learn More: Wrenchers Tool Chest; San Jose, CA; WrenchersToolChest.com
New Pontiac Parts
What It Is: Edelbrock Performer heads for Pontiacs
Why You Care: We see fewer new parts for Pontiacs, and that's too bad. The brand may no longer exist at your local dealership, but the legacy lives on. We were happy to see Edelbrock has spent some dough developing a bolt-on head that works with factory manifolds or off-the-shelf headers. Edelbrock's previous heads used the Ram Air IV exhaust port design that required custom exhaust. The Performer heads work with the factory parts and are machined to fit factory accessories. You can buy them bare or fully assembled with CNC-ported chambers in either 72 or 87 cubic centimeters. An as-cast 65cc chamber version is available, too. The intake runners measure 195 cc, the exhausts are 145 cc, and the valves measure 2.11 and 1.66 inch.
How Much: Buy the assembled 72cc versions for $1,143.99 each from Summit Racing.
We Say: Looks like we need to build a Pontiac soon.
Learn More: Edelbrock; Torrance, CA; 310/781-2222; Edelbrock.com
Rear Suspension for Early Impalas
What It Is: Global West's rear suspension kit for '58 to '64 Impalas.
Why You Care: Don't let them all get turned into lowriders. Grab up one of these sweet cars and show that it can turn a corner. Global West's kit includes a brace to strengthen the attachment points, trailing arms with performance bushings, and your choice of single- or double-adjustable coilover shocks.
How Much: Prices start at $1,399.
We Say: Cornering is more fun that hopping.
Learn More: Global West Suspension; San Bernardino, CA; 877/873-2975; GlobalWest.com