I read a add in a dieselpower and the company claimed that their tranny added 47 HP. Is that true. I just thought tranny's could just handle more hp and torque. not actually add horse power.  

i wonderd that same question.  

I THINK THERE TALKING ABOUT THE POWER LOSS WHEN IT GOES THROUGH THE TRANS. IVE HEARD THAT TRANS WORK CAN(NOT ALWAYS) BUT CAN TAKE A SEC. OFF YOUR 1/4 MILE TIME.  

I've seen that it can improve times. So then the added horsepower is probably just the less amount of horsepower loss than that of the stock transmission  

there are two different ratings for horsepower... one: BHP... means Block horsepower... most manufacturers measure and rate their trucks as the amount of horsepower produced at the crankshaft without a drivetrain... two: RWHP... means Rear wheel horsepower as measured on a dynometer (dyno) that's the measure of the horsepower you're putting to the ground... and that's all that really matters... so yes a tranny can give you horsepower by improving the efficiency that your drivetrain puts the power to the ground... gear ratio's in the axles can do the same... to a point... you can't create something out of nothing... you cannot add to BHP with modifications to your tranny... someone will more then likely add more detail later  

A transmission doesn't "make" horsepower per se. It's simply a means of transferring the engine's output to the drive wheels. Now, having said that, if you have an especially efficient transmission, you could have a transmission that transmits MORE of the power generated by the engine to the wheels. But the transmission itself doesn't create the power, just transfers more of it through.  

so pretty much it lets more horsepower get to the ground from the motor than a stock tranny would. simple  

Yes, the last 3 posts are in the right neighborhood.  (FYI, BHP = brake horsepower, not block).  The basic issue here is drivetrain loss.  BHP is normally between 18% and 23% HIGHER than RWHP.  So, an earlier post that talks about shaving 1 sec off the quarter is unlikely with a 5% change.  But, you can see that if you have an inefficient trans, you might be losing 23% of your BHP, and by modifying your trans, you can get closer to the 18% loss level (thereby transmitting more power to the ground).  

Another issue that can make losses much higher than 23% relates to slip.  On most diesel trucks with automatics, there is a torque converter (TC) and then the trans.  The trans has clutch plates which if overpowered (too much power sent to them) will slip (there is an unmistakable smell that burnt clutch plates make).  If they slip, losses to the rear can eventually be 100%!  The TC is a liquid clutch, and also has slip until it is locked up.  Once locked, there are no real losses through the TC other than the power to spin it.  But though a lot of the power band, the TC is not locked, and slippage there results in power loss to the ground.  Therefore, a more robust TC can increase power transmission.

Ralph  

so would you recommend getting a tranny, or torque convertor? If money ws no issue. Plus I found a good tranny for 3500 and a torque convertor for 1200 even with paying more the aftermarket tranny would be more beneficial in the long run and would also aable to withstand alot more hp & torque  

both, reason being is because a good tranny is useless without an upgraded converter and the same is true the other way around. While you can run an upgraded converter in a stock trans, you wont see the full benefits without the rest of the package.

with that said look at suncost or nada, they seem to be the best on the market for automatics and converters.  stay clear of ATS, especially if you drive a dodge.  

if ats didnt install the parts stay clear of them. they are almost like banks their stuff works if you buy everything else to go with it.