Smarty starts at about 30 HP on SW1 all the way to 170 HP on SW9 for the 04.5+ trucks. You have a lot of choices of SW in between. SW3 or SW4, 60 and 90 HP, are good towing tunes. Adjust the timing so its not so retarded, bump the rail pressure to #2, set TM on #3 and you wonder how you ever drove the truck before.

TM (torque management) is the OE attempt to keep from destrying the trans with the TQ in lower rpms and keeping the emissions in check. It is also why you cannot power brake your truck and spin the tires. Under 12 lbs of boost fueling is drastically reduced, under 1800 rpms the fueling maps drop fast. Remove a bunch of that and add a little fuel and you can do a brake stand and roast the tires off the rim. It takes much less throttle to move the truck.

Add a good tight TC to the trans and you will be surprised how much less throttle it takes to do anything. On my truck, keeping the rpms under 2500 nets me a decent boost to drive pressure ratio. Over that at over 50% throttle and DP goes out of sight, 3rd event territory. Drive it like that, make it work in the lower rpms, and efficiency increases.

Use the TQ instead of spinning the HP and your efficiency and mpg increases.

 

Thanks - this is fascinating info. The logical question is: if you remove TQ management, will it tear up the trans if driven "normally"? If towing, will the 48re have to be modded to live? I had planned to put a tighter billet TC and reprogramming kit in it (after evaluation, had chosen Goerend a while ago) - would this be sufficient? It sounds like with a tighter TC and removing TQ management, mpg - especially around town - would go up substantially?

Would you say that of all the programmer choices, the Smarty would be the best choice for efficiency and tuning for towing (10,000-18,000 lbs)? Thanks!

 

Short answer, yes. While its entirely possible to add power, manipulate TM, and drive accordingly, and make the trans live it is wearing faster than normal and will eventually have issues. Stock trans is for stock power, period.

The TQ is the culprit, especially coupled with the way the trans is setup for NVH initiatives. It is simply not possible to make things smooth and nice, add power, drag around the huge loads these trucks can, AND have clutches and bands last indefinitely. The clutches and bands are already designed for NVH and with the trans setup so it feels like a gasser car its only a matter of time. Even stock power if you tow a lot and heavy there will eventually be some issues.

If you tow heavy, 12-16k a lot then yes you will need to mod the trans for preventative maintenance. It will last for a while but eventually it will cost you money at an inopportune time. I believe in proactive care to address this. There are some simple relatively inexpensive mods that will drastically increase the life and usefulness of a stock trans even with stock power.

A TC is NOT sufficient, its one piece of the puzzle. A deep pan is NOT sufficient either so don't chase that rainbow. There are certain things that need to addressed and fixed that will make the 48RE as reliable as any trans on the market. It may no work as good as a tweaked Ally or TQShift but it will be rock solid.

Yes, I and many others saw a definite improvement in mpg around town with tweaking TM and adding a good TC. Some improvement on the road but the biggest jump was slower speed driving.

For $$ to $$ comparisons and features, the Smarty is hands down the best value out there. There are other programmers that will work as well in certain cases and better in others but none will work as well in a multitude of situations nor have the features and adjustability.

No cheeleading just facts backed up by my experiences and many, many others. You can achieve the same results with other programmers\boxes but normally it will take 2 of them to do it, cost more, and you will still be short on adjustability.

 

Thanks again for your assistance. Beyond a TC, reprogramming kit (Transgo SK TFOD-diesel), deep pan, and a fan assisted aux. cooler; what are the "simple relatively inexpensive mods that will drastically increase the life and usefulness of a stock trans" - the certain things you have found need to be addressed and fixed for the 48re?

For around town driving, how did you end up "tweaking" TM, and what kind of TC did you use? What kind of mileage improvements did you see around town? Thanks!

 

I saw 1-2 mpg increase in the around town driving with a good TC. I increased TM to 2 or 3 on Smarty which fuels more in the lower rpms, couple that with a tighter TC to use the TQ and it makes a difference. The stock fueling maps start a sharp down ramp at 1800 rpms. If you can keep your rpms around 1600 and the TC will pull well mileage increase quite a bit.

A deep pan and aux cooler are nice to haves but definitely not a need. The factory pan is already deeper one can run 18 quarts in the trans without issues. Given you fix the heat generation sources and restrictions in the OE system, in 95% of the cases a deep pan and aux cooler provide zero benefit. The factory setup is hindered only by the factory screwups for NVH initiatives.

A good TC and shift kit is a must, in addition the following will address the major problem points in the 48RE transmission. There are more little things that can be done but its specific to builds and builders that these happen. These are generic and should be done on all transmissions.

Accumulator piston


Intermediate servo (couple choices)


Band strut and pieces


Governor solenoid



If you are going to do the TC then pull the pump and replace the reaction rings on the pump snout. While your at it rebuild your clutch packs with better seals and new steels\frictions. Also, put a new front band in like the following:





Once you have done these steps you have the basis for a $6k trans build just minus all the expensive billet pieces. Consider a billet input shaft if you are going to tow a lot and\or use a triple disk TC, just good insurance.