Hey, guys. So, yesterday I drove my truck up to grandma's house in N Dak for Christmas and I got great milage and the truck ran awesome. BUT when I got on the interstate and tried to run the cruise control at 75, the ride became unbarable. Now mind you, this is North Dakota, not exactly the hilliest state around. As soon as the grade would change in the slightest, my boost gauge would peg 25-30 lbs and with a stack, the drone of the exhaust was excruciating to listen to and the fact that it would push that much boost for extended periods of time worried me. So, after about few miles of this, I gave up and went back to 65-70mph and all was well- 10lbs of boost and 650*.
My question is, can I adjust anything to get my truck to run at interstate speed? There's nothing worse than perpetualy getting passed by old farm grannys in Buicks.

 

you can either throw a gearvendor on the back of there and cut your rpms down or you can change your rear end gears. either of those will help. the over underdrive units are sweet for cruising higher speeds

 

taller tires.....

 

that works too but youll most likely sacrifice gas mileage

 

what gearing u have? mine has 3.54 and seems to have no problem holdin the higher speeds.

 

x2 i can cruse at 80 if i want and not worry about anything, i got 3.54s

 

If his boost guage is hitting 20psi then hes not running into the governor.

 

Sorry for going MIA. Got kinda buisy. Thanks for the replies, fellas. My gears are 3:54 as well. As far as RPMs go, I think it's fine, I don't have a tach yet, but it does't seem to be screaming down the road. It just instantly builds boost as soon as the road starts to go up-hill, no matter how slight. As soon as the road levels out or starts heading down hill, the boost drops back down to normal. @ 75mph, It hits and holds about 27-28psi. Sketchy. But, like I said 65-70mph everything is fine, boost will go to maybe 17psi on an incline. Stillcummin, what do you mean "not running into the governer"? Ill hit 40 psi of boost if I want to.

 

ok... my girlfriend lives in mechanicsburg and i live in lebanon... i run the interstate to her place all the time, at 70 i'm only pushen 5psi if that, till i get on it, the most i have to do to clime hills is get on it a bit. i don't understand why your truck would start to build boost if you arn't adding more fuel.

 

Right. When the road is flat and level I'm about at 7PSI. But as soon as there is a slight hill, the boost builds and builds up to dang near 30 psi and stays there untill I crest the hill. This is just with the cruise control on. Driving with the cruise off, I can gradualy increase the fuel and keep the boost in check. It was just an incovenience, because I couldn't use the cruise control at 75 mph. Either way, I'm home now, so I'm going to do some tweaking and re-indexing on my pump this week. I'm sure I've got something bunged up. THANKS GUYS, for chiming in.