Ok so this may be in the wrong spot but here goes, I drive a tractor trailer for a living and my tractor will build full boost even at low rpms, my dually will not. if im pulling a hill and loaded down it will just lug along at about 14-17 psi until the rpms start to gain then it will run to max psi. even when floored with the tc locked unless i drop below 55 mph then it down shifts and builds max psi, is something wrong or is it just and auto tranny

 

I would like to know the the answer to this as well....

 

I'm not used to autos so i'm not sure. Can't really compare to a tractor though because they spool up almost instantly and they don't turn as many rpms. I would think though that if you were towing up a hill your boost should be higher than that.

 

Nope thats just how these trucks with auto's are. Yep wish there was a way to to push the boost up when in 4th even 5lbs would be enough.

 

Got an EGT gauge? Need to be watching that. Keeping the rpms up will keep the EGTs down when towing.

MikeyB

 

Not sure thats correct. My Auto will keep full boost the entire time. From the second I push the pedal to the floor, and whether it be a light 6k lbs or 20k lbs, it will stay between 32psi and 38psi. With Smarty and Booster Fooler off, it will still stay at full boost, 28psi to 32psi.

 

When you push your pedal to the floor does the converter unlock, or does the truck downshift? because he did state that when his downshifts he gets full boost. As does mine. When it stays lock he doesnt. As does mine.

 

My truck will not down shift below 65 mph with my 4.10's. So, if I'm above 65mph and hammer it, my boost still stays high. I have never seen it in the teens when going up a hill and in 4th with pedal down.

 

It takes fuel to build boost. The fuel curve is based on rpm's and if they won't rise fast enough the fuel curve does not rise. Either need to downshift to get the r's up over or use a fueling enhancement to overide the default behaviour.

 

So, is this why I still maintain a higher boost than what is previously posted... my 4.10's keep RPM's higher at a lower speed and I can still keep dumping fuel, even stock????

 

I normally see 25lb when i have the 5th wheeler hooked up and loaded down.

 

Your 06 has a different turbo then the 03-04s... it spools up quicker and provides more boost. Upgrading to the newer turbo is supposed to be a pretty good mod for the older trucks to help keep boost up and EGTs down. Bob P.

 

I have an 06 and mine does what the original posters 03 does. However if the fueling is the issue, then i would believe that. Maybe it is the smarty. When i had my juice, I didnt see a huge difference in boost (low rpm boost that is).

 

Esssentially yes. Fueling rate is determined by boost and rpm's. They both need to rise or the fueling rate does rises. With 4.10's its a lot easier to accelerate so the lag is less noticeable.

Loping along at 1800-1900 rpms with a load then pull into a grade is tough to get things to accelerating without a downshift. You don't get an rpm rise because there is not enough power to accelerate and keep the fueling rise going. Add a fueling enhancement that overrides that behaviour and it changes everything.

 

Yep 410 to 373 will make a diff. I'm running 373. I'm also running a Jr see your running a senior you have a bit more adjustments then I. Now I know if I have the Jr in sw2 tm4 tq2 it is better. But I normally run sw1 tm4 tq2 so just above stock hp. when truck hits 60 it will down shift and egts are around 1k and boost 28-32 and then I can maintain 60-65 mph up 6-7% grades.