i heard that if your car producing a lot of power(for an A4) you need a torque convertor...what is it actually do and why do you need them?? thanks for the info

 

Every automatic has a torque converter, it is like the clutch in a manual tranny. It transfers the power from the engine to the rest of the driveline using fluid instead of a mechanical connection. You can kind of think of it as a boat propeller, if it spins slow you don't really go anywhere like when you just let off the brake. But when you give it gas it turns faster thus turning the rest of the drivetrain. Now performance converters basically have a higher stall speed. The higher stall speed means you have to give it more gas before it starts moving good. It is like letting your clutch out at 3,000 rpms instead of 1,500 rpms. It basically gets your motor to its peak power faster and lets you use more power on the launch. You can cut down your 1/4 mile times dramatically with a higher stall speed. I hope I helped you understand a little better, I am sure someone will chime in with some finer points.

 

wow, thanks...i get it now...but installing a higher stall means worse gas mileage...am i right??

 

That depends on your driving habits. If you drive a lot around town, then you'll be higher in the rpm's when your accelerating resulting in a little lower gas mileage. If you spend most of your time on the freeway it won't really effect your gas mileage.