I finally got to experiment more with my mods. Brief history: I have been taking my 10k trailer up into the mountains with Mach 1.6 and observed that I could not keep VA turned on or the water temperature would climb too much. Then I got boost and EGT gauges. EGTs would climb up to 1150 on extended uphills at 8,000 - 10,000 feet elevations. With stock injectors I had to shift into 3rd a lot. With M1.6, shifted into 3rd a lot less but still had to to keep the EGTs low. For example, Kenosha Pass on 285 in CO would be one place I had to get into 3rd to cool off. Boost was below 18, 19 at the most.
Now for the news. Everyone here been telling me to add a boost elbow, and I knew I needed to. Never got around to it. However, most people with moderate mods say they crank boost elbows all the way in, effectively closing it off. So I finally found a small hose clamp and pinched that hose off. WHAT A DIFFERENCE!
First off, on the empty truck it does not matter. I can not hit the higher boost than 18 or I start going too fast. With the trailer though the boost would easily reach 24 psi and that kept the truck as happy as it can be. The EGT would never go above 1000 on light uphills, and the most I ever saw was 1100 on Kenosha pass in 4th gear doing 55 mph. I never once had to shift into the 3rd gear the entire time. And that is, with VA on 100%. I could accelerate the truck almost at any time in 4th and most of the time in 5th.
However, I think that my fuel mileage was not as good as before; I hand calculated 12.6 in the past on the same run, and barely got 10.5 with VA on 100%. So on the return trip I turned VA off and still was able to get most hills in 4th (except when I got stuck behind a semi doing 10 mph up a hill), and I think that time I got close to 12.5 mpg. It is not a fair test; the westbound part of the trip is all uphill with elevation gain of 5,000 feet; the return of course is the opposite.
I am amazed how much difference for the EGT those extra 7-8 psi of boost pressure did. And, I have zero worries of over-pressure, I have never gotten it over 26 psi. I might be able to get it up to 30+ but with right foot control and common sense I think there is no risk of going over 35 psi, which seems to be the consensus of the safe limit for the stock turbo and head studs.
Hope this helps! Pinch the hose or plug it, all the folks with 1.6s and mild boxes, if you are like me and too lazy or busy or sclerotic to get the boost elbow (I think I test positive on all three of the above).
Cheers,
-P

 

with my set up I can hit 38 psi but then egts start to climb at 32-35 psi the truck will hold 1250 egts I pull a 17,000 lbs 5er and average 10-11 mpg.. you definitely needed more boost .glad to see it making you smile