what's the difference

[dieselpilot1969]

If you pump the engine up a 100 horses and don't pull a heavy trailer or don't pump the engine up and pull a heavy trailer, wont it be the same stress on the transmission?

 

[rashwor]

My theory has always been...

More power = less stress under all conditions. Seriously! Think about it. More power towing means it tows easier and is not lugging to do the same job... therefore, there is less overall stress. Understand, this is taking into account that you only use the power you need and avoid using all the power when you don't need it (read light on the go pedal except when otherwise required).



I will put my flame suit on now.

 

[dieselpilot1969]

only reason i ask is i hear about transmission failures from over powered trucks and that you need to bomb transmission 1st

 

[DLeno]

Originally posted by dieselpilot1969

If you pump the engine up a 100 horses and don't pull a heavy trailer or don't pump the engine up and pull a heavy trailer, wont it be the same stress on the transmission?

the answer depends on how you use the extra ponies. If you're foot is on the floor all the time, running empty, the pumped up engine will deliver higher peak torque to the transmission while you accelerate off the line. that means higher transmission stress.



assuming that you are within mfg towing limits (not overloaded), the transmission will be happier with the stock truck towing than if you hot rod around in a pumped up engine.

 

[DLeno]

Originally posted by dieselpilot1969

only reason i ask is i hear about transmission failures from over powered trucks and that you need to bomb transmission 1st

bingo. the stock automatics are barely capable of handling stock torque. Modified engines can generate high peak torque beyond the ability of the transmission to handle it. the new 48RE is pretty stout but its too early to tell if it will tolerate bombed engines.



In general, I dont' agree with "more power = less stress". first of all, "more power" without using it, is not more power at all. That aside, if you generate more torque from the engine, the internal parts are always stressed more becasue they have to endure additional forces. While this is always true, this is not to say that modified, higher HP engines are not "happier". Here's a couple of scenarios:



1. a timing box causes the engine to run more efficiently, burn more of the fuel, and generate more HP from the same volume of fuel. This is an advantage. For example, I'm told that tens of HP can be achieved in our trucks simply with timing changes -- no additional fuel.



2. generating higher torque at lower rpms allows the engine to run a tiny bit more efficient because you avoid the losses associated with high rpms (very fast piston acceleration, for example).