IMPROVE YOUR QUARTER-MILE
TIMES WITH THESE SURE-FIRE
(taken from the Mustang 5.0 shootout handout at Race City)
In the everlasting quest for performance, owners are constantly on the lookout for new ways to make horsepower and lower elapsed times. (given the base performance of the 5-liter engine, you can easily fine-tune your Mustang and unleash some hidden horsepower. To get you started on the performance trail, we've compiled a list of our latest top 10 go fast suggestions.
1. Air filter/silencer
The first thing any 5-liter owner should do to increase horsepower is remove the intake silencer (if so equipped) and replace the air filter with a free-flowing K&N unit. On '86-93 cars, the silencer is located inside the fender; removing it increases airflow and gives it a throaty sound. On '94-95 Mustangs, the silencer has been deleted, but the filter box incorporates a conical filter that seems to be very restrictive. Switching to a free-flow filter here is very effective.
2. Ignition timing
Provided you're running at least 92-octane gasoline, you can safely advance the timing on your 5.0 engine and feel substantial gains. By advancing the base timing from the stock setting of 10° to 13-14°, your Mustang should pick up one- to two-tenths in the
quarter-mile. Because each engine is different, you'll need to experiment to find the best setting for your application. A '95 picked up close to a tenth when advanced from 14° to 16°
3. Driving style
The way you drive your 5-liter plays a major role in performance. no matter how many performance parts you bolt on. But how do you know if you're driving correctly! Well, a stock Mustang LX with 3.08 gears and a T-5 should run in the 14.30-13.99 range. To obtain these numbers, there are a few techniques you'll need to master. First and most obvious is launch. With street tires, practice until you can consistently run the first 60 feet of the track in 2.10 to 2.20 seconds. Remember, a 2.40 60-foot compared to a 2.10 is the difference between a 14.25 and a 13.95 at the finish line.
Another driving tip is to shift your Stang at the proper rpm. Stock ('86-93) 5.0 engines should be shifted at 5300-5500, no higher; '94-95 GTs should be shifted a little lower (5000-5300). For all 2.73 equipped 5-liter cars and '94-95 GTs with 3.08s, you'll get your best numbers by only shifting into third gear. Since all factory tachometers are different, vary your shift points until you get your best ET.
Shifting your Stang with the gas pedal planted to the firewall
will give you a solid .15-.20 advantage over shifting while lifting off the throttle. Because of the wide gear ratios in the T-5 transmission, the engine tends to fall out of the power band on every upshift. By shifting with the throttle open, the rpms stay higher and the car can accelerate faster. During a properly executed power shift, the engine rpm should increase by only 400-500 rpm. If your engine revs by more than 500 rpm, you'll need to practice kicking the clutch and shifting quicker. To be as efficient as possible, sit in a position that will give you good leverage on the clutch and on the shift lever.
5. Weather conditions
The location of your track and the time of year you race have a lot to do with the performance potential of your car. Cool, dry air at close to sea level is considered optimum for performance. And humid (hot and sticky) air at high elevation is the worst. A resident '87 5.0 LX ran recently at Raceway Park (Englishtown, N.J.) on two separate days with varying conditions to prove this point.
On the first day the air was humid and the temperature was in
the low 90s. Fresh after a tune-up, our best run was 13.85 at 98
mph. We returned to the track for a test session in November, the air was very dry and the temp was down in the low 6Os. In the improved air, our 3.55 gear, short-belt and radial-tire-equipped LX ran 13.54 at 101.7 mph with no other modifications, it was our
best run ever (the 60-foot time was also a best-ever 2.03). It came after icing the intake for almost a full hour.
What this proves is that our engine made almost 20 additional horsepower on the second test day, enabling us to run more than
3 mph faster in the quarter. It's likely you'll run your best numbers in the beginning and the end of the racing season. Don't be discouraged if your performance falls off in the heat because it will return once the leaves begin to turn.
6. Tune it
A good basic tuneup can go a long way at the drag strip. To make maximum power, your engine needs a good spark and the correct supply of air and fuel. A clean fuel filter and some 93- or 94-
octane pump gas seem to work for us. We recently installed a new cap and rotor along with a set of Motorsport wires and Motorcraft plugs to freshen the ignition on our '87 LX. The plugs we chose are part No. ASF-32C and are one range colder than stock. We also run a K&N filter though it was removed on the 13.54 run.
Yes, it's true; weight equals horsepower You can basically count on .10 second reduction in ET for every 100 lbs. you remove. Run your car as light as possible, paying attention to how much fuel you have in the tank. Gasoline weights 6.2 lbs. per gallon, so carry only what you need to race. An extra 10 gallons weighs 62 lbs. Get the point! Weight also affects your gas mileage. The heavier the load you have going down the road, the worse your mileage will be.
8. Short belt
This is still the most cost-effective performance part you can buy
for your 5.0. For around $25 you can buy a shorter than stock length serpentine belt that will allow you to bypass the power steering and air pump. This will free up some horsepower for use at the rear wheels, which will quicken your quarter-mile times. For A/C-equipped '86-93 engines, use a 70 1/2-inch belt. We're still trying to find a suitable short belt for the later models.
9. Rear gears
By installing a lower (numerically higher) rear gear ratio, you can increase torque multiplication and make your car accelerate harder. By switching from 2.73s or 3.08s to a set of 3.55s, you can expect to drop .25-.35 off your elapsed time. For a stick car with a stock engine and radial tires, 3.55 gears are your best bet. Modified engines and cars with slicks might want to try running 3.73s. Cars equipped with the AOD transmission might consider 3.73s mandatory, though we know people running 4.l0s who pick up even more.
No matter how much horsepower your engine can develop, traction is your limiting factor. On a stock or fairly stock Stang, a set of racing slicks can reduce your ET up to four-tenths. With the sticky tires you'll be able to leave the line between 3000 and 6000 rpm, improving 6O foot times in the process. You'll also eliminate any tire spin on the 1-2 shift, which is often overlooked but will also slow you down.
Because some of the tips (weight, driving style) do not pertain to bolt-on items, you'll need to test and practice to get them to work. As we have learned, there is no substitute for experience. Get to the nearest drag strip and lay down some rubber. With repetition comes familiarity, which breeds lower ETs. --Evan J. Smith