I pulled my boat down the interstate last weekend. It seemed the "sweet spot" was between 67 and 69 mph. At 67mph I'd get a continuous boost of about 6~7psi. At 69~70mph I'd get a continuous boost of closer to 9psi.

I rarely go down the interstate while pulling my boat. Usually I avoid interstate travel because I don't like running my truck that hard with the 4.10 gears. I typically prefer highway travel while pulling my boat, and at 60mph I get a continuous boost of around 3~4psi on flat grade.

My boat weighs in at about 4000lbs.

Do I need to turn down the turbo master?

I'd personally prefer to leave it where it is and continue to avoid interstate speeds while pulling the boat, but if these levels of continuous boost are detrimental to engine life, then I'd rather turn down the boost and save my engine.

EGT's?????

IIRC, EGT's on flat grade were around 600 ~ 700 (preturbo). While pulling hills I never let them get above 1100, and i do not let them stay above 1000 for any period of time exceeding a minute or two.

Surf on over to Heath Diesel - follow his recommendations for Turbomaster without charge-air cooling.

Wanna see what's really happening?

Install a 100-300deg oil temp gage with probe in the upper plenum - temp range is suitable for compressed Intake Air Temp.

Watch EGT vs Boost vs IAT, shut it back when IAT starts getting over 200deg.

I personally don't like IAT over 120deg on a 100deg day, but then, that's just me.......:cool:

Surf on over to Heath Diesel - follow his recommendations for Turbomaster without charge-air cooling.

Sorry gmctd, I can't find it over there. Can you post a link?

I didn't see it, but iirc it was 8-10psimax - maybe it's the instructions with the TM

Just give bill Heath a call over there and he will point you in the right direction. Nice Guy.

10 psi is close to 200*F IAT. In your situation I'd turn the boost up and go 60 mph.