Muscle Mustangs & Fast FordsHow To Drivetrain
Off The Brake! - 4R70W Swap
We swap a 4R70W into our Three-Valve Fox with help from Performance Automatic and Summit Racing Equipment
Once everything was installed and working correctly, we put a few street miles on the new combo and headed to the track. Auto-Plus Raceway at Gainesville, Florida, prepped the dragstrip for us on a hot September day. Combined with the intermittent rain, the conditions weren’t favorable, and it showed in our times. Out of the gate, we laid down a couple of high 12.80 passes. With a little work, and trying a few different things when it came to launching the car and locking the converter, we whittled out e.t.’s down to the mid-12.60s.
Later that week, we took the trip to Bradenton Motorsports Park, where the cooler air, and great track conditions yielded three passes between 12.26 and 12.28, all at 110 mph. Our 60-foot times are consistently in the 1.70-second zone, with a best of 1.69.
The best part of our new combo is the consistency. We roll in, lower the tire pressure, run four or five mid-12.20 passes, air the tires up, and head home. Did we mention the car is also pulling daily driver duty? While the new low times are not as quick as our previous best, we can now crank out time close to our best run after run. That is worth its weight in gold!
A Look Inside the Converter
There are three main elements that combine to transfer the power from the engine to the transmission: the pump, the turbine and the stator.
The converter is completely filled with fluid, which comes from the transmission. The fluid starts off its flow from the inside of the pump and then it is centrifugally pumped to the outside of the pump. The pump is welded to the front cover, which is bolted to the flex plate.
The engine rotates the pump and the fluid is pushed towards the turbine where the input shaft of the transmission connects. The fluid then flows to the stator and is redirected and the combined momentum of the fluid helps to spin the pump. This is how a torque converter can multiply the output power which is known as STR or stall-to-torque ratio.
The fluid then continues this movement as the turbine speed increases. Eventually, the turbine is spinning about 90-95-percent as fast as the pump. This is called the coupling phase, and the converter is simply transferring the engine power to the input shaft.
Safety and Comfort
What is your safety worth—$599? If you race a car with five-point harnesses, there’s no reason you shouldn’t have a head and neck restraint.
The stigma has always been that they are expensive and uncomfortable, but NecksGen has put both to rest. The NecksGen head and neck restraint sells for $599 and can be used with many different seat configurations. On top of being inexpensive, it is also comfortable. It takes the pressure from the shoulder belts and distributes it more evenly, and its cushioned straps conform to fit you perfectly.
Whether you have a race seat or a stock seat, the NecksGen head and neck restrain is a necessity if you race! Visit necksgen.com for more info.