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Message: [QUOTE="KCTurbos, post: 1111037, member: 13852"] In my experience it has shown that it as a fallacy that vgt turbos "always" run higher ebp... You just have the "ability" to adjust the vanes and use back pressure to drive the turbo harder. (kinda like being able to switch between .54 A/R to .90 A/R turbine housing by simply adjusting the vanes). I have about 20 different tunes and have been testing the truck a lot over the last few months. I was using a manual boost/ebp gauge because the Map and EBP gauge max out too early. But about 2 weeks ago my ebp gauge started acting up so I don't know exactly what EBP was doing. On average at WOT I ran a 1:1.2 boost/ebp ratio (30-40psi boost and 35-50psi EBP). The turbo runs very efficient at that range but only made around 630-650hp (unloaded dyno jet with 3000# roller which reads low on average).... BUT... I wanted to push the limits so I asked a couple of tuners to turn the boost up all the way and see what happens. I had one tune that pushed 50+ psi of boost... It was crazy. Truck pulled super hard and brought down. Anything below 50-60mph was useless and would just spin the tires in 2wd so I did most of my testing above 70mph. But my back pressure gauge was broken so I was not accurately able to monitor EBP. I wrote myself a tune that also built over 50+ psi of ebp but anything past 50psi and the turbo would stall out, lose power, and boost/ebp would skyrocket and max out my gauges so I don' know how high they ever got. That was last week and the truck seemed to be running fine afterwards. The dyno run in question when the problem started I was pushing around 45psi of boost and no idea what back pressure was... I would guess 50-60psi from previous runs on the street when my gauge was working. I was pushing around 670hp on what seemed like 7 cylinders (you could see the dead cylinder on the dyno graph). I could not really feel anything out of the ordinary until the truck came back to idle and had a miss... So I am still unsure of what exactly happened... Especially since the problem would come and go on the drive home. [/QUOTE]