UltraPower GM / Workhorse 8.1L Custom Tuning (ECM & TCM)

UltraPower GM / Workhorse 8.1L Custom Tuning (ECM & TCM)


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Most orders are shipped within 24 hours from the order date. Orders placed on the weekend or after cutoff on Friday, and orders placed on select holidays are processed on the next business day. Please see our shipping terms for more information.

We are now offering 5-speed Allison Transmission tuning for 2001-2005 model years. The main change you will notice is the transmission will shift into overdrive below 50 MPH when under light throttle. We also demand more load before it will downshift when pulling hills which means less downshifting. Increased line pressures also helps prolong the life of the transmission and optimizes the shift points.

If you have a non-Allison equipped vehicle or a 2006+ with 6 speed transmission, change the quantity of the UPTCM to zero (0)


  • 2001-2011 Workhorse Chassis with 8.1L
  • 2001-2007 GM Pickup Trucks and SUV’s with 8.1L (May require Passkey and Crankshaft Relearn Procedure
  • 2001-2010 Chevrolet Kodiak and GMC Topkick with 8.1L


The GM 8.1L UltraPower ECM has long been the ultimate performance modification you can make to your GM 8.1L powered RV or truck with the highest power gains on the market! Thousands of satisfied customers have reported fuel economy increases as well as less transmission downshifting because of the increased horsepower and torque. The UltraPower ECM performs very well on both stock engines and ones that have been upgraded with other modifications.

What sets us apart from the others? Banks even admits their handheld AutoMind only changes one parameter within the computer, whereas UltraPower changes approximately 400 parameters. That is the difference between cookie-cutter and custom!

While most tuners rely on “canned” tune files (not custom), our GM 8.1L Custom Tuned ECM is tailored specifically to YOUR vehicle. We require the VIN so that we can pull up your vehicle’s specific parameters and create a truly customized tune for your vehicle.

UltraPower 8.1L ECM Benefits:

  • Fuel mileage improvement of up to 1 MPG
  • Gains of 50-60 Horsepower and Torque Gains of 70-80 lb-ft
  • Maintains speed and higher gears when climbing hills
  • Improved throttle response coupled with more power makes driving more enjoyable
  • Includes a datalogger that you plug into the OBD2 for us to analyze and optimize engine efficiency and performance



ECM Removal Video (Workhorse Application): 

I have a Jayco 2007 Kodiak Greyhawk. My vin number shows that my chassis is a 2006 with a 8.1 and a 6 speed Allison transmission. Do I need both a ECU and TCU or just the ECU. Will this help with some gas mileage also? ( Joe Brantley, 05/11/2022 )
You would only need the ECM tuning, the 6 speed Allison TCM isn't one we tune, we have reported mileage improvements of up to 1 mpg.   ( Support )
Hello, I have a 2004 Winnebago Adventurer 33v and am looking at your TCM upgrade. I definitely have the Allison transmission but I'm not sure if it is a 5 speed. It's positions show 123D but it also has an overdrive switch. Is this considered a 5 speed? ( Edward Burris, 05/02/2022 )
Yes, you have the 5 speed Allison. If you have a W22 and the 8th digit of the VIN is a 1, 2, 3, 4 or 5 (year designation) then it will have the 5 speed Allison. ( Support )
i have a 2006 itasca sunrise 38j ,8.1,6sp allison banks powerpak stainless headers and exhaust with cold air intake, irridium plugs and taylor wires and 30k miles.how would this set up benefit me? is it a plug and play unit? ( jason burnham, 04/23/2022 )
Yes, the tuning will compliment the air flow modifications you made with the Banks Power system. It is a direct ECM replacement, completely plug and play. ( Support )
will this raise or allow me to adjust the speed limiter? ( joe, 01/10/2022 )

We raise the limiter by default in the programming to 90 mph. If you want something different, just request it in the order instructions.

( Support )
Hey, someone has stole the the ECM and TCM out of a unit we purchased at the auction. Can we use this a a direct replacement?

Thank you

( David Hall, 11/25/2021 )
Yes, you can do this. You just would not be eligible for the core refund as you won't have any to send in exchange. ( Support )
I have a 2006 Fleetwood Southwind. Do I need just the ECM? If so, what is the cost? ( Mark E Conant, 06/23/2021 )
Yes, just the ECM for your application. The cost is $595 and if you want to pay for a core exchange, that is an additional $150. ( Support )
Hi. I have a Fleetwood Pace Arrow Workhorse 2004 (vin shows 03 production) with 112,500 miles. I am considering upgrading with your custom tuned engine and transmission module. Would you recommend this? I bought this unit with about 80000 miles on it and have always wished it had little more power. It has bank’s system installed by previous original owner. Also like idea of overdrive under 50. Any input would be appreciated. Thanks ( Clarence Snapper, 01/23/2021 )
For what you are describing, it sounds like you would be quite happy with the upgrade. As long as the engine and transmission are in good health, the added power will not cause any reliability issues. We have tuned many 8.1L's with more miles than you do with no problems. ( Support )

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  • Views: 11985
  • Brand: UltraPower
  • Product Code: UP81-KIT
  • Availability: In Stock
  • $695.00

Available Options

Please fill in Qty of each part desired

Non-Allison or 6 Speed