Hi all:

Trip to Central TX from AL, about 800 miles with a 6K gooseneck loaded with about 6K of lumber, so nothing too heavy but will see heavier.
The hills are pretty mild through MS, LA and TX but if I don't want to get into 1200 degrees going up, I have to back off the skinny pedal just a tad too much to the point where big rigs get closer and the empty ones think about passing.

I would like to see EGTs down by a 100 or so. I currently have a GDS 60mm and a 16cm housing and a 4" exhaust, KN air filter and stock intercooler and tubes. Where would you spend the money to try and lower EGTs for truck use under load, not toying, continuous highway driving towing a trailer?

Thanks!

 

i would start out by making sure that your existing system does not have any boost leaks. if not upgrade to 3" tubes. If that does not lower them enough go with a power stroke intercooler.

 

advance the timing and install a bigger intercooler would help,also water/meth will help just don't add a lot of meth and test it to see how big or how many nozzles you need to install or going to full twins setup.my son has a 91 with twins and never sees over 1000* and is putting 407HP/880tq to the ground

 

3" pipes and a bigger intercooler, and then water/meth injection if you still get hot.

 

hx-40, get a real turbo

 

Stock sticks still? If so, 12cm housing for sure.

 

stock sticks, yes.

so, if possible: hx40 with 12cm housing, mod the intake horn, 3" tubes would help right? HX40 with 12cm and 5 speed transmission is OK?

what do y'all think is cheaper: PS intercooler install or 2nd gen intercooler install or stock intercooler with 3" let-in and out welded?
Thanks!

 

I would start with a 12cm cause it's easy and cheap and see what that nets you. What elevation/terrain do you pull in?

 

Low, 500 in Birmingham to 1000-1500 into TN.
12cm with hx40, or 12 with GDS 60mm?

 

I disagree with the smaller exhaust housing lowering towing EGTs; same for advancing the timing.

My un-educated opinions, for what they're worth :

Advanced timing only fools the EGT readings by keeping the heat in the cylinder longer.

A smaller exhaust housing may spool the turbo quicker, but it will drive up the heat in a genuine heavy towing situation.


On a steep long grade, the fuel-pin will quickly become the enemy; you want the AFC cone turned to the slowest side; better yet, install a "valet" switch or remove the boost-tube and plug the holes.


Turn the fuel-screw back to factory setting.


I haul heavy, real heavy so far as 1-ton diesel trucks and goosenecks go.

It's best to avoid race-truck tuning when it comes to topping the grade.

 

Bear, I definitely won't argue that you know a thing or two about a thing or two when it comes to hauling heavy I would point out, however, that the original poster does not tow nearly as heavy as you. Also, at least looking at his sig, I see no race truck tuning going on, just some basic airflow mods. While I haven't towed extremely heavy, I have pulled in the neighborhood of 17k behind me, both with the '89 and the '96. I've also changed exhaust housings more times than most change their socks. The '89 had everything from a 21 down to a non-gated 12 and everything inbetween, as has the 96. In my humble experience, especially with stock or moderate fueling, the smaller housings win hands down--you're simply not throwing enough fuel at it to overwhelm it with exhaustflow to the point that it becomes a restriction. Heavier fueling and bigger sticks, etc, yeah, too small, I agree. The 12cm housings seem to 'resonate', if you will, closer to the sweet spot for the 5.9. Up on full boost and keeping things cool around 1650and still happy to flow without restriction to about 2500...right where a stock/lightly fueled 12v wants to work. My '89 with the 60mm comp wheel and a gated 12 would just flat stay cooler than the same setup with the original 18, again, with about 17k on the hook. When towing, I set the fuel so WOT with the load on a decent grade was about 30psi and she'd just tug at about 1000-1100. Not towing, I'd turn the fuel up, the gate would open at 35 or so. Lots of smoke and heat, but hey, that was just playtime Again, JMO. For as easy and cheap as they are to try, I think it's worth grabbing a 12 just to see. Ideally, the he351vgt I think is the cast bannanas---best of all worlds, including one bad-arese e-brake

 

I amended my statement a wee bit as it was meant to be aimed at anyone who might be following this thread, more so than at billut who clearly states that he is not interested in "toying" around.

 

Gotcha Again, not saying anything negative about your setups--they obviously work well and are reliable, and you work your rigs harder than anyone I know

 

With my current set up I see lower EGT's when pulling 75-80 than I do trying to hold 70. Its only about a 75-100 degree difference but it there. Also when approaching a good hill I will go ahead and start building speed prior to the hill. Not so much as I need the momentum to get to the top but the sooner I get my turbo up in boost the lower my EGT's. I think the difference in boost is also what makes the lower EGT's at 75-80 where with about 15,000 LBS i maintain about 15 lbs boost but if I back down to 70 its only making about 5-7 lbs boost.

A diesel shop I talked to not to long ago told me that the 12 valves dont make enough drive pressure for a big turbo, UNLESS you have heavy fueling mods and head work. The bigger the exhaust housing the more it takes it to spool and until it spools the EGT's will climb. This is what I used to experiment and figure out where my truck runs best. The higher RPM's create the drive pressure needed to keep the turbo moving and the EGT's in check.

 

I am just a'learnin' myself; and, I once heard a old man say that a wise man will oft change his mind; whereas, a fool never will.

So, you just might see me hiding behind the barn swapping exhaust housings.