Muscle Mustangs & Fast FordsHow To Tech Qa
Yo Ken! Tech Q&A - February 2015
Answering your technical questions
OK, so here it goes. I bought a Vortech V-3 supercharger for my stroked 347ci with TFS cylinder heads, TFS intake, 24-pound injectors, and billet fuel rails. Do I have to use Vortech’s FMU, or can I just keep what I have until I save up and switch to 40-pound injectors with a larger pump?
I don’t suggest using the 24-pound injectors without the FMU. You are only setting yourself up for potential engine damage caused by a lean condition without the proper fuel components. I know it is tough when you are on a budget, but it could cost you more in the long run if your engine burns a piston or valve.
I have a 1990 LX 5.0L and want to swap out the fuel injection for a carburetor setup. Would I need anything else but the intake, carb, and fuel pump? Also, what kind of distributor would I need to put in it? Finally, is this even possible with the automatic transmission in the car?
You will need to upgrade to an aftermarket distributor, or if you’re on a budget you can use a distributor out of a 1985 5.0L with a manual trans. But be warned: The Duraspark has been known to quit without notice. You will also need an ignition box. The factory Ford Duraspark can be used; however, you will need the wiring harness for the ignition system from a 1985 5.0L Mustang. The easiest way to go is with a MSD 6AL along with one of MSD’s distributors. The auto trans will work, but you will have install a new throttle cable. Lokar offers PN KD2AODHT for the cable and PN SRK4000 for the bracket. The cable needs to be hooked up, otherwise you will damage the transmission. To adjust the cable, just make sure there is neither slack nor tension when the cable is reinstalled onto the throttle-body lever, and this will get you fairly close. Worse case, you may have to go to a transmission shop if your transmission is shifting too softly or erratically.
F-150 Power Pulleys
I have a 2010 F-150 STX 4x2 with a 4.6L Two-Valve engine. I already have a cold air kit, a HyperTech tuner, and exhaust on the truck, but I would like a little bit more power and possibly more mileage. I want power pulleys but can’t find any for this truck. Will pulleys for a Mustang with the same basic engine fit my engine?
Via mustang-360.com The pulleys for a 4.6L Mustang would not work, and the power and mileage gains would be minimal at best. Currently you have done just about every thing you could do to improve power and mileage. I would suggest you get yourself a custom tune for your mods. Off-the-shelf tunes work well, but a custom tune will fit your needs much better. Several manufacturers offer this service, and it’s only a matter of selecting the one that best fits your need and availability.
The Ford Racing Cobra Jet intake for the 3V engine peaks very high at 7,200 to 7,500 rpm. Can the stock 3V handle that kind of rpm without damaging the internal parts? It seems like a lot of rpm for the 4.6L to handle, or did Ford design the 4.6L to handle upper rpm loads?
The stock 4.6L likes rpm and will handle it just fine. When we tested the Ford Racing Cobra Jet intake, it made very good power in the upper rpm range. While 7,500 rpm may seem like too much rpm for a stock engine, the 4.6L rotating assembly is not like a traditional 5.0L pushrod engine. The small pistons and rather light rods, along with no pushrods, make the 4.6L ideal for high-rpm use. Durability has not been an issue in naturally aspirated applications. These intakes are used in NHRA Stock Eliminator with great results and are seeing high rpm on a regular basis, using all stock rotating assemblies.
Wheel Size & Backspacing
I have a stock-suspension 1986 GT and want to install 15x10 rear wheels with 15x3.5 or 15x4 runners up front. What backspacing do you recommend?
On a Fox-Body chassis, the backspacing for a 15x10 should be 6 1/2 inches. It will be a tight fit, but 275x60 rubber will work well. Even then, the emergency brake cable will be in the way. To fix this, simply loosen up the brake cable bracket and move the cable for more clearance. For the front, the stock backing spacing on the 15x3.5 or 15x4 will work fine.