The 3 Best Basic Duramax LB7 Performance Upgrades
When it comes to LB7 performance upgrades the best place to start is with tuning, and exhaust system, and a cold air intake. These are the best first three modifications to make to the LB7. These three upgrades can add over 200hp and 400tq.
If you're just looking for a bit more horsepower than these upgrades will be all you need and will also help increase gas mileage, lower EGTs, and improve overall engine health. If you're planning a high horsepower build then these act as an important base to build off of.
Tuning is where the big power gains come from and an intake and exhaust serve as supporting upgrades to help maximize the benefit of tuning while keeping your turbo and engine healthy with more airflow and lower engine temps (and EGTs). Let's jump into the best basic Duramax LB7 upgrades and which brands we recommend.
3 Best Basic Duramax LB7 Performance Upgrades
- Exhaust System
- Cold Air Intake
You can push up to about 500whp before you need to upgrade the transmission and the lift pump - this is where things start to get pretty expensive. Without sinking more than a few thousand bucks into upgrades you are going to be capped around 500whp. The good news is: these 3 upgrades can get you to these power levels. An upgraded lift pump and intercooler wouldn't hurt at those levels and a downpipe would be recommended too, but these are really the only things you need to get there.
Tuning: LB7 PPE Standard Xcelerator
Tuning is the base for all modifications. It provides the biggest power gains for the price and helps optimize all other modifications. Without a tuner (also called a programmer) you won't see as much performance improvement from other upgrades like an intake or exhaust.
A tuner increases power by increasing boost levels. This puts more stress on the turbo and requires more air which then creates more exhaust gas. This is why we always recommend adding an intake and exhaust alongside a tuner: to bring more air in and help it leave faster.
For those looking for plug-and-play options we recommend the PPE Standard Xcelerator. It is the best handheld programmer that comes with pre-loaded tunes making it super user friendly and cost efficient at only $449. If you are just looking for some decent power gains, better gas mileage, improved towing, etc. then this is your best bet.
If you plan on pushing things further and upgrading the turbo, injectors, and doing other more advanced upgrades then we recommend EFI Live with custom tuning. This setup is going to end up running over $1,000 so it's really only ideal for people who need more than that PPE Xcelerator offers.
2. LB7 Exhaust Upgrade: 4" MBRP Downpipe-Back
Second on our list is an upgraded exhaust system. The factory LB7 has a very restrictive exhaust which causes a lot of turbo backpressure. This increases stress on the turbo which produces more exhaust heat causing high EGT and engine temps. Going bigger on the exhaust will help improve exhaust flow, decreasing backpressure and providing a ton of reliability benefits in the form of lower EGTs.
I recommend the 4" MBRP downpipe-back exhaust without a muffler. Unless you have an upgraded turbo and are running aggressive tuning then you won't see any performance gains from using a larger 5" exhaust. Mufflers cause backpressure and therefore aren't as good from a performance standpoint so I always recommend sticking without one, plus they are cheaper without one. Furthermore, the 5" tends to cause more drone which is why we prefer the 4". Stainless steel exhausts also cause more drone so while they are more durable I still prefer an aluminum one since it sounds better and is a couple hundred bucks cheaper.
The 4" aluminum exhaust is only $399 and is going to be the best sounding with the least drone and offers the same performance benefits at the lowest cost - it's an easy choice.
The downpipe is actually the main reason the factory LB7 exhaust is so bad. It is small and crushed which limits exhaust flow. Upgrading it is definitely the best exhaust modification you can do. The caveat is that installing it is very difficult unless you drop the transmission which is also difficult.
I definitely recommend upgrading the downpipe with the exhaust - the PPE 3" downpipe is only $170 - just keep in mind it is a bit harder to install but is very worth it.
3. Cold Air Intake: Banks LB7 Ram-Air
Cold air intake probably isn't the proper term as an intake on a diesel is really about bringing in more air, not just cold air. Higher turbo boost pressures (and producing more horsepower in general) requires more air. The factory air box becomes restrictive once tuning is added making it important to upgrade the intake and increase airflow.
I put an intake ahead of an exhaust since the exhaust on the LB7 is that bad from the factory - but an intake is just as important. If you're just running a modest tune the factory intake can hold its own, but even at these modest power levels the >40% increase in airflow you get from an upgraded intake is worth it.
I prefer the Banks Power Ram-Air Intake. It outflows the S&B with a 57% increase in flow compared to 44% from S&B.