Performance Changes
First let me set the stage. I rebuilt the top end about 2 or 3 years ago. This included rebuilt heads and all that goes along with it, new IP, and new injectors. And we live at 6000 feet, which is the biggest culprit.
Normally aspirated the engine was overfueled. I tried turning it down slightly, but power dropped off dramatically. So I lived with it. Smoked like a freight train most all the time. It took literally a couple of miles to get to 75 mph. EGT's were 1050 at 75 mph and went to 1100-1150 when pulling a grade, but never went higher. And you had to downshift for anything that resembled a hill. Unfortunately, it sees a lot of mountain driving.
Adding the turbo has made it drive, I feel, like it should have come from the factory. Accelerating to 75 mph is nearly effortless. Driving on the flat and level (still at 6000') EGT's stay at around 650-700 degrees and boost at around 2.5-3 psi with very little to no smoke. I actually buried the speedometer for the first time without going downhill and the EGT only went to 800.
The hill I use for testing is a fairly long grade that climbs about 1000 feet. Boost maxed out at 7 psi while pulling that hill.
Since my EGT's were where I wanted them, but my boost was not, I decided to adjust the wastegate first. Shortened the rod by 5 turns today. I immediately noticed the turbo spooled faster...going to 5-6 psi quickly. When I pulled the hill today on my way to work, boost went to 8.5-9 psi, then fell flat and started to drop off. EGT went to 900 and stopped. Since I had virtually no smoke, I suspected this would happen, so tomorrow I'll turn the fuel up a bit and see what that gets me.
I have to make this foolproof. Even though the truck has the appropriate gauges, those are only for my benefit. My wife does not pay any attention to gauges, not even the speedometer. She just gets in and goes balls to the wall. So I have to get the most from it with out going over on EGT or boost...no matter what she throws at it.
As an added benefit, it appears that I'm getting about 50-60 more miles out of a tank of fuel in it's current state. Don't have the numbers yet, but that should be about 4-5 mpg. I'm sure that will change (less) by the time I'm done tweaking.
Tom