Sorry its long, read if you'd like 
I am working with a 2008 Duramax, so it is equipped with a DPF system. When I bought this truck I had 2 things in mind, leave it stock, and be able to tow. Well that did not last long. I thought to myself, what the heck, lets throw a tuner on it. Not thinking about warranty, I went with a canned tuner that will change the ECM parameters and will be logged where GM can see it. I thought oh well. With general knowledge, I knew the transmission could only handle a small tune, but I went with a big tuner anyway for those days when I really didn’t care. First choice, a PPE Hot +2 for a DPF equipped truck. Man this tuner was great. Lots of fun. Then one night, I was called out for a race. Truck did well, but the ol’ DPF system was clogged tremendously. It took hours to get it to stay out of “reduced power mode”. At that point I was ordering a 5” turboback exhaust and having PPE switch me to a DPF delete tuner. Now with no DPF, the difference is night and day. Feels more peppy, picked up a little mileage too. I played a lot and at that point realized I could benefit and possibly gain some more power with a lift pump. Chad at Alligator Performance, who did the exhaust, pulled me in the shop and on went a PPE lift pump. Again a noticeable difference, including a bit of electric pump noise. But I didn’t care, the truck seemed a lot better on the big tune. Also at that time a set of Cognito braces were added and a set of Pac-Brake tie rod sleeves. Knowing that the transmission was starting to hurt with only 5k on it, I figured I had better visit Mike L. at Inglewood Transmission. I told Mike, Daily driving with heavy foot, planning on hitting the strip quite often and pulling a 10k-15k trailer once a month. His first words were a 1058 converter and a Stage 4 from Suncoast. He went to work and I was done in less than 8 hours. You want to talk about a noticeable gain? Its incredible how much power was lost thru a stock Allison. At that point I felt I was good. The night before my first real race at a track we decided a S&B filter/intake might make a difference. So I put it in that night. I don’t know if I picked up any power, but looking at a friends dyno numbers I felt it was needed at 500ish horsepower. Next it was time for some tuning specific to my truck. I wanted as much power from tuning alone. EFI Live was the ticket. I placed an order thru Nick at Duramaxtuner, and he was ready to help get this truck moving. 13.1’s in the quarter mile felt great. But like anyone I wanted more. I knew the heavy tires I was running was probably hurting my times, but I wanted my truck to run the way I drive it everyday. Nick played with the tuning in the ECM and TCM but my truck was stuck at 13.0’s no matter what. Even a set of Bilstien 5100s, which make a ride feel oh so much better, I was still stuck with 13’s. It was at that point I decided to go with a turbo kit from PPE. GT4094R. Awesome turbo, little laggy on the street but fun at the track and on the highway. Alligator Performance installed this turbo along with a set of Cognito Traction bars. Then it was to the track I went. With rough tuning and lots of logging that day I laid down consistent 12.7’s. Now, I am having fun and its all down hill now. I was happy with 12’s and now it was time to work on getting low 12’s. With only appearance mods between running a few tracks and still running 12.7s, I headed out one night for another race. 12.7 run and then a scary noise after the run. Turns out, a main bearing spun and oil pump gave up. Time for a build with only 16k miles. I started gathering parts for a build and then decided with all the time and money needed to do a real built motor, I needed my truck drivable until the build was complete. I just picked up a new stock motor to run. With this new motor I am running everything above, only now a stock turbo and a PPE Dual Fueler kit installed by Alligator Performance. We tried 40% honed injectors but could not tune them to get the truck to run great at all. After taking it easy for a few weeks, it was time to try a turbo I wanted for awhile, a Cheetah. I picked one up second hand and PPE had it on in less than 2 days for me. We dyno’d with it only to find out the seal/bearing was bad, and would have to be rebuilt. I am back to a stock turbo now, but again will be trying this turbo again.
Hope all this will shed some light on this hobby to all. And answer a few questions you may have on your mind about modding your truck.
:mike:
I am working with a 2008 Duramax, so it is equipped with a DPF system. When I bought this truck I had 2 things in mind, leave it stock, and be able to tow. Well that did not last long. I thought to myself, what the heck, lets throw a tuner on it. Not thinking about warranty, I went with a canned tuner that will change the ECM parameters and will be logged where GM can see it. I thought oh well. With general knowledge, I knew the transmission could only handle a small tune, but I went with a big tuner anyway for those days when I really didn’t care. First choice, a PPE Hot +2 for a DPF equipped truck. Man this tuner was great. Lots of fun. Then one night, I was called out for a race. Truck did well, but the ol’ DPF system was clogged tremendously. It took hours to get it to stay out of “reduced power mode”. At that point I was ordering a 5” turboback exhaust and having PPE switch me to a DPF delete tuner. Now with no DPF, the difference is night and day. Feels more peppy, picked up a little mileage too. I played a lot and at that point realized I could benefit and possibly gain some more power with a lift pump. Chad at Alligator Performance, who did the exhaust, pulled me in the shop and on went a PPE lift pump. Again a noticeable difference, including a bit of electric pump noise. But I didn’t care, the truck seemed a lot better on the big tune. Also at that time a set of Cognito braces were added and a set of Pac-Brake tie rod sleeves. Knowing that the transmission was starting to hurt with only 5k on it, I figured I had better visit Mike L. at Inglewood Transmission. I told Mike, Daily driving with heavy foot, planning on hitting the strip quite often and pulling a 10k-15k trailer once a month. His first words were a 1058 converter and a Stage 4 from Suncoast. He went to work and I was done in less than 8 hours. You want to talk about a noticeable gain? Its incredible how much power was lost thru a stock Allison. At that point I felt I was good. The night before my first real race at a track we decided a S&B filter/intake might make a difference. So I put it in that night. I don’t know if I picked up any power, but looking at a friends dyno numbers I felt it was needed at 500ish horsepower. Next it was time for some tuning specific to my truck. I wanted as much power from tuning alone. EFI Live was the ticket. I placed an order thru Nick at Duramaxtuner, and he was ready to help get this truck moving. 13.1’s in the quarter mile felt great. But like anyone I wanted more. I knew the heavy tires I was running was probably hurting my times, but I wanted my truck to run the way I drive it everyday. Nick played with the tuning in the ECM and TCM but my truck was stuck at 13.0’s no matter what. Even a set of Bilstien 5100s, which make a ride feel oh so much better, I was still stuck with 13’s. It was at that point I decided to go with a turbo kit from PPE. GT4094R. Awesome turbo, little laggy on the street but fun at the track and on the highway. Alligator Performance installed this turbo along with a set of Cognito Traction bars. Then it was to the track I went. With rough tuning and lots of logging that day I laid down consistent 12.7’s. Now, I am having fun and its all down hill now. I was happy with 12’s and now it was time to work on getting low 12’s. With only appearance mods between running a few tracks and still running 12.7s, I headed out one night for another race. 12.7 run and then a scary noise after the run. Turns out, a main bearing spun and oil pump gave up. Time for a build with only 16k miles. I started gathering parts for a build and then decided with all the time and money needed to do a real built motor, I needed my truck drivable until the build was complete. I just picked up a new stock motor to run. With this new motor I am running everything above, only now a stock turbo and a PPE Dual Fueler kit installed by Alligator Performance. We tried 40% honed injectors but could not tune them to get the truck to run great at all. After taking it easy for a few weeks, it was time to try a turbo I wanted for awhile, a Cheetah. I picked one up second hand and PPE had it on in less than 2 days for me. We dyno’d with it only to find out the seal/bearing was bad, and would have to be rebuilt. I am back to a stock turbo now, but again will be trying this turbo again.
Hope all this will shed some light on this hobby to all. And answer a few questions you may have on your mind about modding your truck.
:mike:
