If I get a stall converter, can I still drive on the road?
You Bet! When looking into stall converters many people have heard silly things from uninformed friends. One misconception is that if you install a converter with a 3400 stall speed, the car won’t move until 3400 RPMs. Consider that stock is close to 1600 RPM and you have no problem moving at idle with the stock unit. The same is true for the higher stall. It will take a little more throttle, but the car will still move at low throttle and RPMs. In fact, the vast majority of the time, even with very high stalls, the car will still move off of idle.
What do they mean by "loose?"
The looseness of a car or a converter refers to the amount of throttle it takes to move the car at a certain rate. As a general rule, as the stall increases, it will require a higher throttle position to move the car.
Example: Park your car so that it is parked facing up a surface with a slight incline such as a driveway. Put the transmission in a forward gear and take off the brake. Assuming the incline is not too great, the car will either slightly climb, or it will hold itself in place. If you were change to a higher stall converter, in the same situation, the car would likely roll back when the brake is released.
Do I need a transmission cooler?
Yes. We recommend that a transmission cooler is used with even stock converters. They are a great safety precaution and considering that high levels of heat are damaging to transmissions, they just make sense. With higher than stock stalls, more slipping is allowed by the converter creating additional heat. Without an aftermarket transmission cooler, the added heat can be disastrous to the transmission.
Do I need a shift kit?
No. Shift kits will not make your car run any faster. After a higher stall converter is added, shifts can feel softer. A shift kit will firm the shifts back up. Basically it is a preference modification. We recommend driving the car with the new stall for a while. If you still feel that you need firmer shifts, invest in a shift kit, or if you have the capability, shifts can also be firmed through tuning.
What does "STR" mean?
STR stands for Stall Torque Ratio. Basically, STR is torque multiplication. If a car has a higher STR, it will feel tighter on the street because the converter is multiplying the input torque by a higher number. It will also give a harder punch out of the hole. STR is created by two components inside the converter moving at different speeds. Shortly after launch, those components reach an equal speed eliminating STR completely.
For More info on STR, Click Here
What is flash stall?
When the car is in idle and the throttle is stabbed, the converter will jump to a certain RPM. This is flash stall. It is also the rated/advertised stall. Fuddle Racing torque converters are custom built to your set-up; they will flash stall as advertised. As power increases, so does the stall speed. If you are making less than the 400 hp, the converter will stall slightly lower than the advertised stall speed.
What is foot stall, foot-brake stall, or brake stall?
Foot stall is related to the flash stall. However, other factors come more directly into play with the foot stall. Brakes, tires, gear ratios and a cars weight, just to mention a few, can all play into the foot stall speed. To determine foot stall speed, hold one foot on the brake and slowly press down on the throttle. At the point when the drive wheels begin to brake loose, foot stall has been achieved. Foot stall is related to the flash stall. However, other factors come more directly into play with the foot stall. Brakes, tires, gear ratios and a cars weight, just to mention a few, can all play into the foot stall speed. With all of the outside factors playing on foot stall, it is conceivable that the foot stall could be as much as 2500 RPM less that the flash stall.
What is lock-up?
When a converter is locked, converter input and output become equal. A locked converter is as efficient even as a manual transmission. Higher stall torque converters are inherently less efficient than the stock converter. That is simply how they are designed; they slip. A converter can be "locked-up" to counter the slipping. The computer on most cars is programmed to lock the converter at certain speeds depending on engine load and throttle position. Locking the converter gives considerably better fuel economy. It is locked by a solenoid forcing a clutch to engage inside the torque converter. Converters can be locked at WOT, but most converters use clutches that cannot handle that kind of abuse for very long. We offer a model that is built specifically to handle WOT lock-up repeatedly. The clutch it uses is massive compared to normal clutches. With the converter locked at WOT, the 1:1 input/output efficiency makes the car pull HARD at the top end.
What is Pulse Width Modulation?
There is no partial apply on the converter clutch. Lock up is either on or off. PWM is used to get the effect of a partial apply. Your transimssion uses a solenoid to very quickly "pulse" the clutch on and off. With a stock torque converter's clutch, it isn't usually even noticed. This is because the clutch is made of a material that is allowed to slip. The aggressive non-slip clutch material used by Fuddle Racing, this pulsing occasionally is audible. By simply installing even some of the most basic shift kits, you can completely eliminate PWM.
Other Questions?
Please feel free to email or call if you have any questions you don't see listed here.
