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Customer:  Brandon G.

Vehicle:  1999 GMC Sierra 2500HD 4X4 6.0L V8


Modifications:  Dual exhaust.

Story:  When Brandon contacted us his complaint was that his 6.0 just didn’t have what he thought it should & wondered if a tune would help out, so a date was agreed upon & the truck was presented.

We barely got a few km’s of driving in before it became evident that something was clearly wrong with this 6.0.  After 5 mins of doing some simple tests, it was determined that the truck had a bad MAF… off to the local parts store we went!  After the new MAF was installed, the driveability of the truck immediately improved significantly……alright, time to start tuning!

Our first WOT pull in the truck with the new MAF & factory calibration turned out a dismal 167 whp & 218 ft/lbs of torque.  Looking at the data showed the truck running air/fuel ratios in the 15.6-15.8 range at WOT & mid teens for timing….that explains a lot!!

After a few adjustments to get the air/fuel ratios & timing where they needed to be the truck responded with 229 whp & 260 ft/lbs…….gains of 62 whp & 42 ft/lbs of torque!!!

So now not only is Brandon’s 6.0 driving the way it should, he reports that the truck is also turning in approx 3 mpg better fuel economy….an excellent bonus!

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