Skip navigation

Customer:  Stacey D.

Vehicle:  2013 GMC Sierra Extra Cab 4X4 5.3L Vortec V8

Story:  Having brought other vehicles to us in the past, as soon as Stacey got his new truck he brought it over to do some dyno runs & map out a plan for future upgrades.

Truck pic

First order of business was to see what the truck would do bone stock.  We then threw a K&N drop in filter in to see what it would do.

Stock vs K&N


Although peak power didn’t change at all, the truck did pick up 5 ft/lbs of torque across most of the rpm range, so as usual, the K&N is a worthwhile upgrade.

While we were mapping out a plan, we decided to put our backpressure tester in the rear o2 sensor bung to get an idea of what sort of untapped power might be lurking in the catback portion of the exhaust.   After a few wide open blasts, we got consistent readings of approx 4 psi.  While that would indicate there is power to be had, 4 psi would lead us to believe there is probably less than 10 hp in there.  Given the $500+ price tag on typical catback exhaust systems, we decided that was a pretty poor return on investment.

Reviewing the data from our dyno runs though, we’re pretty certain there is a SIGNIFICANT amount of power left in the tune of this truck, so that will be the first thing that gets some attention.


Nov.11, 2014

So Stacey’s truck finally got tuned!

After driving the truck for a few minutes, it became apparent that the shifting had to be fixed in this truck.  Unbelievable how bad the 6L80E is set up to shift!!  Not only does the transmission calibration make the truck feel sluggish, but the slow shifts also kill all the trucks momentum during shifts making it feel like the truck has to work harder.  Fortunately this was a pretty straightforward issue to resolve & the truck is shifting nicely now!

We then set about unleashing whatever power we could from Stacey’s truck.  First thing we did was do a baseline pull to see what the truck was putting down on that given day & got a result of 266 whp/300 ft/lbs. (a little down from the last runs we did with the truck, but the results are what they are!)  After spending a couple hours tuning on the truck with 91 octane in the tank, we saw some pretty solid gains in hp up top.  Where the truck would nose over above 4500 rpm before, it continues to pull all the way to redline now, posting a peak gain of 24 whp!!  Stacey’s truck is now one strong running 5.3 posting final results of 290 whp/304 ft/lbs!

Stock vs tuned


Update Mar. 1, 2015

Stacey came by today to do some runs with our new software we’ve been experimenting with, Track Addict by RaceRender & HPTuners.

The software worked flawlessly as we have come to expect, & also generated results consistent with what we would expect from Stacey’s truck.

Results were pretty decent for a 5400 lb truck!

1/8 mile:  10.53 seconds

1/4 mile:  15.89 seconds



%d bloggers like this: