Diesel Tuner's Blog

6 Things To Know Before Upgrading Your Duramax Turbo!

Posted by Paul Wilson on Sep 9, 2016 10:00:00 AM

Stock Duramax Turbo Upgrades!

Duramax owners are generally proud of how their stock turbos perform.  They spool quickly, run hard and are capable of over 500 RWHP (once you tune it and make a few supporting modifications to handle the power).  However, after driving your truck around 520 RWHP for a while, the addiction will creep in and you may find yourself shopping for more power.  We all do it!  For some, it may not even be about more power, it may be about EGT control under load, or it may just be the factory turbo had an issue and needs to be replaced.  If you are anything like me, you will not want to replace it with the factory components if there is an upgraded, after market, charger available. 


LML 64 Cutout

What to know before you upgrade your factory Duramax turbo!

Everyone is new to diesel performance at some point.  We all need to start learning somewhere.  When it comes to deciding which turbo to chose for your Duramax there are a lot of confilcting opinions and hype to sift through.  Let us help you hone your decision making process.  

#1 Be clear in how you use the truck

This is the most important factor on matching you with the best turbo.  We all have different opinions on what looks good or sounds good, but if you know how you USE the truck then you find a turbo that plays to the features you need.  For example, if you have a daily driver LB7 and you are never going to take it over 600 RWHP (factory fuel injectors and Cp3 Pump), and you mostly daily drive the truck mixed between city and highway with just occasional towing, then you would want something that spools quick and is responsive down low.  On the other hand, if you just sled pull your built motor LBZ and it has big fuel and all the supporting mods, you need a charger that not only meets class specs but something that is specifically designed for peak power.  Tow only vehicles which tow at max GVW on a regular generally fit best into a twin turbo kit designed for towing.  The point here is when shopping for your turbo, be clear with how you intend to use the truck so you get a turbo that you will be happy with. 


Download Duramax Turbo Specifications


LML with trailer


#2 Understand how turbo's impact drive-ability

Once you know how you are going to use the truck it is time to start learning the basics of how turbo's work.  This is the best explaination I have found for people who are brand new to turbo's: VIDEO.  For those that have a good understanding of the basics, consider what modifying the turbo does to how the the truck drives. For most people strictly chasing a dyno number or quarter mile time is not the most important thing.  As previously stated though, more power is a common goal we all have!  Also keep in mind that just because someone says "it tows fine" does not mean it is the best towing turbo available. Same goes for peoples opinion on lag, which is how long it takes for a turbo to make boost in comparison to when you mash the throttle.  Here are some of the bare-bone basics on how different features of a modified turbo impact drive-ability (keep in mind these are in general terms and there may be exceptions).

  • Larger wheels take more enegery to spool and have more lag
  • Tigher exhaust housings increase spool up but can give up top end power
  • Looser vane packs/exhaust housings mean less effective turbine braking


#3 Write down your specific goals for the truck

It is hard to start on a build if you don't know what you want.  Understand that most people only build a few trucks in their life and generally each build takes years.  So if you are going to do it, do it right the first time!  Set out a realistic budget, timeline, and resource list, write it all down and look it over.  Find what gaps you have and come up with a loose plan for them.  Once you have this together it becomes much easier to decide on your first turbo, and making sure that it will fit into your long term plan for the truck.  No one wants to buy a turbo they wont want a year later so having a plan can really help.  Of course, plans and goals change sometimes and that is fine, at least an outline of your goal will help make that first decision.   You can always write a 'stage 2' into your goals to make sure you don't have to swap a bunch of parts on step two. 





#4 Know what is required for installation

The last thing you want is for a turbo to show up and go to install it only to find out you need some random fitting or gasket that is on a 2 week back order.  Also, there are many turbochargers appear very cheap that require installation kits  costing  twice the price of the turbo.  Know what you need before you purchase so you can figure the entire cost of the project as opposed to just the cost difference in turbo's. 


Turbo STR, Mach 2, Mach 2 Images-03

#5 Research the turbo

If you are reading this article then you're capable of doing a Google search.  And with today's easy access to customer reviews you can get a good idea of what ever turbo you are considering.  Check places like DuramaxForum.com, DieselPlace.com or even some Facebook groups like LML Brethren, Chi-Town Diesel or other local diesel groups.  Unless you are considering a brand new turbo to market like the LML Stealth 64, then chances are someone in one of these internet gathering places has already bought, installed and reviewed the turbo you are considering.  See if you can go for a ride in a truck similarly equipped, nothing beats experience and most enthusiasts are surprisingly accomodating.  




#6 Beware

-Buying a used turbo comes with a lot of risk. Most used turbos are being sold because the owner has some type of issue with it. If you are thinking about picking up a second hand turbo make sure there is a money back guarantee or a period of time that you can make a return. 

- Turbos that run great at sea level do not always run great at altitude.  Do not make decisions based on a reveiw from someone running the charger at lower altitude than you.

-EGT's are a tradeoff.  A turbo that cuts 400 degrees off of your full throttle EGT will likely add 300 to your towing egts (exception: twins)




If you are looking for a Drop-In, Upgraded, Stock Appearing turbo check out the Stealth 64 

If you have questions about your truck, I would like to speak with you.  Below you have access to book a meeting with me so we can go over your truck and what you would like to do with it. 



Topics: Duramax Performance, LLY, duramaxtuner, LML, LBZ, Turbo, Stock Turbo, Stealth 64, Turbo Wheel, LB7, Stealth