i'm lost as to what good numbers for boost are. see mods in sig. i pulled a +11,000lbs load the other day and the heights boost i had was 13.5lbs egt 1100* using the Areoforce gauge. if you know US hwy 82 in Mississippi then you know there are not big hills. i have checked for boost leaks and have found a small one on the Plenum, boot i have just gotten the Plenum Reinforcing Inserts to day form Clay to fix them. i can see no soot on the up pipes, i dont push the truck that hard is that why i dont see 20lbs of boost.

i see people say they can get 25 on stock turbo i have never seen 15.

 

Have you adjusted your wastegate before? Try it with the wastegate disconnected red line pulled off, even empty I would think you should hit 20ish, I hit about 25 on stock tuning, empty hammered down.

 

i have not adjusted the wastegate. i dont wont to kill my turbo with to much boost. i may try the red line off and see what i get.

 

You wont kill it testing to see if you need to adjust the wastegate, Pull the line off, hammer it boost should jump up to at least 20psi IMO, if it does, might need to adjust your wastegate rod.

 

Doesn't sound too bad to me. Cruising at 65 mph on level road with a 16,000 lb 5th wheel I see about 7 lbs of boost. Small hills will see about 15lbs of boost in top gear. I only see 20 lbs on steep grades at around 2400-2700 rpms.

 

Cruising I get similar result, I was talking about MAX boost just so you know.

 

that makes me fill better i was only at 1900 rpms going 68mph. just running i was around 6-8lbs.
i dont hamper it on take off, but i just was thinking it must be a leak.

 

That is what I call sensible towing. These engines pull pretty hard even at 70% throttle so there is no reason to stand on it. For most people, the power band is around 2500-2600 rpm anyway so it doesn't really make sense to rev any higher while towing. So standing on the throttle is a bit of a wasted effort in most cases save for occasional WOT to merge onto a freeway etc.

 

i did not have to go to 2500rpms mine pulled it at 1800-1900 all the way just fine and never got less than 65mph. i pulled a 2 car trailer with a 2002 250 on it just for weight reference.

 

18psi max here. All stock besidesthe muffler delete and 6637. Pulling a 28ft toyhauler, loaded up Cajon Pass, 4th gear, cant get anymore. Un;loaded, seems like it defuels at 14psi. I'm thinking air temperature plays a role in how much the turbo produces?

With red line disconnected, i hit 21psi QUICK, let off after that, but think, it had plenty more to go.

 

Is it safe to leave the line unplugged ot jus stop it up

 

i think you can but it can kill your turbo if over boost it a lot.

 

Do you have gauges? I run with the wastegate completely disabled, but I have Boost and Back pressure gauges? Safe? It was not designed that way, but if kept in check and not abused at high boost levels I like the response in spooling personally, when I was running tuning, I would leave it hooked up and adjusted to keep from too high boost pressures, but with stock tuning, I don't hold PSI long enough to personally feel it is an issue.

I cannot back this up with any testing data for the longevity or effects with it disabled, and am considering installing an adjustable wastegate in the future, which will effectively bleed off at a set point.

 

I got a scangauge 2, I can see boost on it, I'm on factory tuning but I got a gpt38r to most I've ever seen was 17

 

That's probably accurate, even with the 38R you need more fuel to see more boost.