KJ Jones
January 1, 2014
Contributers: KJ Jones

Bushing Basher

I am wondering if there's any easy way to remove the bushings in an 8.8 rearend's upper-control-arm mounts. I want to install new arms and spherical bushings in my '01 GT, but getting the stock, rubber bushings out is turning into a messy nightmare.

Chris T.
Via email

We're familiar with your dilemma and really wish we had been aware of Maximum Motorsports' rear upper control arm bushing tool (PN MMT-1 $29.95) years ago, as we've fought the stock bushings in '79-'04 solid rear axles many times. Maximum's tool presses old bushings out, and also can be used to press new bushings in—to the correct depth—making a difficult job simpler, faster, and a lot cleaner.

Call of Duty

In a recent dyno session that I went to with my buddy and his Mustang, I heard my friend and the tuner talk about the duty cycle for the fuel injectors in his 'Stang's engine. They said the injectors had "reached their duty cycle," or something like that. I would really like to know what this is. I should have asked them right there, but I'm just getting into upgrades for more power. I have a stock '12 GT.

I know that you replace fuel injectors, but I don't recall you guys actually mentioning duty cycle in the articles you've done on blower installs or nitrous installs. I bet there's a tie somewhere, right?

Name Witheld
Via the Internet

Yes, there is a correlation between fuel-injector duty cycle and the need for larger injectors for some power-adder applications. Basically, fuel injectors open (fire) for a specific length of time for a specific amount of fuel, regardless of the engine's speed (rpm). However, increasing revs actually cut the amount of time that the injectors have to fire in half (with each revolution). The progressive decrease in time actually increases the number of times the injectors fire, which for the most part, results in injectors being open constantly. Also more airflow from free-flowing engine mods demands the injectors stay open longer.

The catch here is that most fuel-injected Mustangs' engine-management systems are based on sequential injector firing, which injects fuel when intake valves are closed. The injectors' duty cycle actually refers to the relationship between the time the injectors are closed versus the time they're open. When duty cycle goes above 90 percent (open for more than 90 percent of the time), this means the injectors' capacity is on the edge and larger injectors are in order. In most power-adder installations, most OEM fuel injectors are swapped with larger ones for this reason.

Power Max

I don't have an '11-'12 Shelby GT500, but I'm curious to know how much horsepower those cars can make with just the factory supercharger, a pulley, and other simple bolt-ons.

Name Witheld
Via the Internet

We've done extensive testing with the '11 and '12 GT500s, evaluating everything from the basic, entry-level bolt-ons (pulley/tune/cold-air-induction/PCM calibration) as well as exhaust, and so on. With the most-basic package (CAI, pulley, and tune), we've typically seen approximately 550-560 ponies at the feet. Add a bigger throttle body and exhaust, and 580 hp definitely can be achieved—with 91 to 93–octane pump gas.

No More Tension

I have a '90 coupe that I just had painted. The body shop removed the trunk-lid tension rods and tossed them, and now I have to use a piece of wood to prop the trunk open. I've been looking at it and I think I can rig something that will keep the lid up without blocking as much useable trunk space as the tension rods. But before I start fabricating, does somebody already make a part that will do the same thing?

Mike Goodhall
Pelham, NY

Several years ago, a Canadian company called 2KoolPerformance offered a strut-based, trunk-support system for Fox Mustangs. We featured the bolt-in setup in our June '06 issue, installing its gas-charged rods as a direct replacement for the OEM torsion rods in Project T-top Coupe. However, that system is no longer available.

Using hinges from a '79-'93 convertible 'Stang is your best option. The spring-style hinges from rag-top Ponies are available through most late-model-Mustang, parts-bartering channels, and they can be adapted to hard-top trunks in just a few hours.

Virgin Of The Month

When Columns Collide

I'd like to try and switch the fixed steering column in my '92 LX, with a tilt column from an SN-95/New Edge Mustang. I know the tilt column was available for early Foxes, but the catch is I still want to have a driver airbag. Can you tell me their differences? Is it even possible to do this? Any info is appreciated.

Name Witheld
Via the Internet

We asked Jack Hidley of Maximum Motorsports for insights on such a swap. According to Jack, it's not an easy procedure but it can be done.

"The first thing you must understand is, the SN-95 and Fox columns have mounting bracketry that is unique to each platform," Jack says. "You will not be able to simply bolt the later column right into the Fox.

"Also, the SN-95's column features three U-joints, which require positioning and installing the later-Mustang's column-bearing assembly (which is smaller) in the recipient-Fox's firewall. As you can imagine, properly locating the bearing in the new spot requires a fair amount of precision to ensure linkage-geometry is correct."