Now that our project Duramax has the lift installed and some added goodies, it’s time to add some performance modifications! We tried a couple power adding modules, an exhaust system, along with a few other items.

      The first power module we tried was a TTS Power Systems tow/tune program. Steve Cole of TTS Power Systems has been in the fuel management industry for over 2 decades. He has worked closely with General Motors on various one-off projects as well as writing fuel management programs for the newer Harley Davidson motorcycles. Steve spends most of his time working to reliably increase the power of your diesel tow rig. 

      Since Chevy changed the Duramax motor in 2004 (from LB7 to LLY), it took Steve nearly a year to develop, dyno tune, and real world test his newest diesel fuel management program. Unlike other models where you would plug in one of his ‘Power Loader 2’s’ and reprogram your PCM (power control module), the new program for the LLY motor is a replacement PCM for the Duramax.  

      Steve’s Tow Tune claims to have 50 extra HP with 100 ft-pounds of torque. Steve tells us this number is actually higher than claimed, but since each truck is different he does not like to inflate his numbers simply to increase sales. During his real world testing, Steve heads out to the desert with his truck and finds the limits the Duramax is able to withstand, and then he backs off the settings to allow room for a safety margin.  He changes the amount of boost, timing, and amount of de-fuel between shifts for the maximum horse power without damaging other components. He also gets rid of the speed limiter and can reprogram to compensate for larger tires for accurate speedometer readings. 

      To be able to monitor the trucks exhaust gas temperatures and boost we installed a set of AutoMeter gauges. Installation took some time but just about anyone can do it. We mounted them on the A-pillar in the cab for easy viewing. 

      When we first tried the ‘tow tune’ we were very impressed! With the added lift and 35” tires we felt a huge loss in horse power. With Steve’s Tow Tune program, it felt as if we went from a big heavy truck to a sports car! The added power was incredibly smooth, had almost no excessive smoke out of the exhaust, and had very smooth firm shifts. We did notice a slight increase in gas mileage during our first week of testing but this quickly diminished due to our power hungry lead foot!

   The second power module we tried was the Edge Products Juice w/ Attitude monitor (version 1). The Edge Juice is a weatherproof module that installs under your hood in about an hour. The module itself is a small, black box that has cables that will plug in-line to your OEM wiring harness, a probe for monitoring exhaust gas temperatures (EGT’s) and a cable that runs into the cab of the truck for the Attitude monitor. 

      Another great feature of this product is the ability to monitor EGT’s and transmission slippage. If either of these gets out of hand, the Edge Juice system will automatically back down the power output. This prevents damage to the transmission, as well as, preventing the power train from generating fault codes and entering ‘limp mode’.  

      During transmission shifts (with the torque converter locked) the Edge Juice system limits the amount of power increase. This allows the torque converter to lock without slippage. Edge claims, in 5^th gear, the torque converter will hold about 680 foot pounds before slipping. Edge has tested up to 900 foot pounds in gears 2-4 with no slippage. 

      So how does it feel? Amazing! We use only setting 2, “Tow Mode”.  This setting adds an extra 60hp and makes a noticeable difference. While Edge claims no damage can be done to the transmission in any setting, we are overly paranoid and only use setting 2. Once we beef up our transmission, we will try setting 5 and hunt down some rice burners! 

      Between the TTS and Edge systems, we preferred the smooth power of the TTS system over the Edge. While the Edge’s power feels a tad stronger in setting 2 it’s doesn’t feel as smooth as the TTS system. The TTS system is custom designed for your truck (when ordering you need to provide precise tire measurements and a VIN) while the Edge system is designed for all trucks.

       With us liking the TTS power better, we still feel the Edge Juice system is the best bang for the buck. For about $800 you get a full set of gauges (analog gauges can cost upwards of $400 plus a lengthy install time) on the Attitude display, easily changeable power settings and a ton of other features. The Attitude monitoring system is much more accurate than analog gauges. As mentioned above, we also have a set of Autometer analog gauges (installed before the Edge Juice system) along with the OEM engine temperature gauge. As an example, the OEM temperature gauge always reads right around 210 degrees (unless towing up a steep hill). Since the Attitude Monitor takes readings directly from the head (as Edge Products claims) the engine temperature usually reads just below the 200 degree mark.
 

      We added a complete exhaust system and a new intake to compliment the added power.

      For exhaust we added a TTS Power Systems cat-back kit. It features a 4”mandrel bent pipe, a large (near stock size) muffler, and a polished 5” stainless tip. This cat-back kit was a direct bolt on kit and was very easy to install in about an hour. Since the muffler is large, compared to other aftermarket exhausts, the TTS system is as quiet as stock (which we really liked). No excessive droning noise in the cab! At the front end of the exhaust we added an MBRP cat-delete pipe. This 4” pipe replaces the stock pipe which has a catalytic converter. It allows the truck to breathe better thus reducing EGT’s by a couple hundred degrees. Some people have seen trouble codes coming from the trucks computer after installing this cat-delete pipe. From our understanding, as long as there is enough back pressure in the exhaust (i.e. muffler) no codes with show up. If you have a freer flowing muffler some other mods may be necessary to compensate for this.

      For an intake we added a Volant air box and their smooth intake tube. This kit is also an easy bolt on item. It comes with a new filter, outerware (pre-filter) and an optional cold air intake tube that is routed from the bottom of the air box to an opening in a stock bumper. In our case, with an aftermarket bumper, we bought some heavy duty RV sewer hose and made our own cold air intake. 

      The exhaust and intake modifications didn’t make as much of a difference as we expected. Our ‘seat of the pants dyno’ didn’t notice any increase. We did notice a slight improvement in gas mileage and with the addition of the MBRP cat-delete pipe and we definitely notice more turbo whistle!

      Topping off our added performance, we added a 45 gallon Transfer Flow gas tank. It’s a mid-ship replacement tank and bolts directly in. It increased our mileage from about 300 miles per tank up to about 420 miles per tank. The only downfall is the extra hurting it puts on your wallet when filling it up, especially at today’s fuel prices! 

      We also added a Mag-Hytec transmission pan and rear differential cover. The Mag-Hytec products are built from air craft aluminum with built in fins for maximum heat dissipation and use o-rings rather than gaskets. Each increases the amount of fluid for better cooling. Both have NPT temperature ports and the rear differential cover has a very handy dip-stick to check fluid levels.

      This has been a long winded article, but we hope it has sparked some ideas and answered a few questions about adding power to your Duramax. 

      In future articles we hope to ‘beef-up’ our transmission and try the Edge Products new V2 system which is a power adder/GPS system/rear view camera!

TTS Power Systems
http://www.ttspowersystems.com/

 Edge Products
http://www.edgeproducts.com

 MBRP Exhaust
http://www.mbrp.com/

 Volant Performance
http://www.volantperformance.com/

 Mag-Hytec
http://www.mag-hytec.com