Hey I have a question. Why is it that I see so many people pulling out their T5s and T56's to put in Th400's. Whats the point? Don't automatics lose alot more power and torque through the transmissions then the manuals? Thats what I was told. Something like 25% through an auto tranny. Also if that be the case, why do I see many high powered race cars using automatic transmissions? A friends dad used to race, he had a TH350 with a 475 Horse engine and was pushing mid and somewhat low 10's!!

How does this work? I'm lost as to how some many people say a 25% loss regardless of work done on the tranny, and then you have racers who use them on their high powered engines and still get low 1/4? Thanks alot!

 

You heard right, auto's do take alot of power away, but you also have to look at it this way, you can not shift a standered as quick as well as a good built auto, it just can't be done, You can launch them better because you can bring the engine to the proper point to put power to the ground. When you side step the clutch tryin to launch you put instant power to the ground and in most cars that equals wheel spin, with a stall converter you can almost adjust how much power you put to the ground with minimal wheel spin.

Just my .02

 

but with the amount of power lost, isn't that kind of a mute point?

 

Not really, you can put alot of ROLLER bearing stuff in a auto to help with the power loss, Most well built auto will shift in thousands of a second compaired to the tenths of a second it takes to shift a standard.

 

i prefer standards over automatics for street cars. standards a lot more fun around town. tru autos are better for all out drag racing but again for street cars, i can shift my t5 pretty damn quick, side stepping with the right tires leads to no wheel spin, duh, thats why u side step to limit the torque to the wheels to get the best traction. i think a quick arm and a good clutch cost a lot less then a built tranny and a stall verter, IMO.

 

Autos generally lose give or take about 20% through the drivetrain, where as a manual will lose about 15% through the drivetrain. "Roller stuff" in a tranny???? I dunno what you are talking about. Anyways, there are several reasons why autos are better for drag racing. They put less stress on the drivetrain, shift faster than humanly possible, can be "tuned" to any car to give the best possible launch with the right stall, and the most important, which is 90% of drag racing, They are way more consistant. I honestly don't know why people think manuals are better. If you think they are, take a trip your local track and decide. I think it might have to do with people's ignorance or the fact that some cars are faster stock with the right driver with a manual, but who leave their cars stock that races? Auto vs Manual?, For drag racing, auto is by far superior!