by MMiller » Sun Apr 27, 2008 5:36 pm
I just returned from my weekend trip. I left my driveway on Friday night. I had my 93(7500#) hooked to my 32' gooseneck(7000#). On the trailer was my pulling truck(6500#) with about another 500# of extra weight in the bed. I also had a gutted cab and front clip on the trailer. Figure gross weight at around 21500#. When I pulled out of the driveway and headed west I was pulling into about a 20 mph headwind. I eased into it and started out. The first 15 miles was 4 lane road and the truck had no problems running 70 mph in OD into the head wind. It ran between 15-25 psi of boost and between 1000-1100* F on the pyro. Before the pyro would have been buried, and I'd be regulated to 58 mph in 4th gear. The next 120 miles were 2 lane roads and 55 mph speed limit. The first 50 miles of the 2 lane was long steep hills with slow vehicle passing lanes. Leaving Ottumwa Iowa there is a long grade(for Iowa) about 1 mile long. At the bottom of the hill I was rolling at 58 mph in 4th gear behind a mini van. I decided to let the old Dodge eat, so I flat footed it. At the top of the hill the pyro just touched 1300*, and we were running 70 mph, almost against the governor in 4th gear. Before, this hill I could top at 60, maybe 65, the pyro would be the regulating factor. Almost all the rest of the hills I pulled in OD at around 62 mph with the cruise on. It was about 145 miles into a 20 mph wind. Due to fuel pump problems at the truck stop, all I can say is the truck burned about 3/4 of a tank. Rough figures show 7 mpg. BUT, if the truck has the power to safely pull 21000# into a 20 mph headwind, in OD at 62 mph, its going to use some fuel. Hooked onto my big gooseneck, I figure that the truck is going to get 10 mpg, emtpy or loaded. I'll get some more numbers later next month.
Things I have noticed going from the stock turbo, stock down pipe, and stock manifold to the HTT manifold, Super 40 and 4" exhaust.
1: I have a much broader pulling rpm range. Before it was easy to get 1400# on the top of the RPM range, and surge the turbo down low. In 4th and 5th I would have to tach out the cummins to catch the next gear, and usually surge the turbo. When in OD before, I had to keep vehicle speed over 70 mph or the stock turbo would surge like crazy. I was either regulated to 58 mph in 4th, or 72 in OD to keep everything relatively happy. With the new setup, one hill I left it in OD to see what happened. The truck topped the hill at 50 mph, with about 1200* on the pyro and no surge. The getrag probably didn't like it, but the cummins was happy. On the top end the turbo can keep going up to the governor.
2: The truck has much smoother power, not the violence of the lag, the boost on. While it was fun before having the tires break loose halfway across the interstection when the charger lit, this new charger brings the power on smoother.
3: Like KTA said, EGT's went down, as did the engine temp. Only one time did the engine temp get any warmer then it does running around emtpy. Before on hills, the engine temp would follow EGTS, and be hot at the top of the hill.
4: The stock turbo was very easy to "bark", and surge. This HX40 has not barked at all yet, and has never surged. For my power level, and truck dutys, I'm not worried about the shaft breaking. Now if a SB Dual disk clutch went in, a 14mm rotor, and governor springs removed, and hooked to a sled, I'd count on it failing. In a street truck/tow pig/work truck, I think it will be hard to beat.
I've not decided yet, but I am relativly sure I picked up some power. It was not stagerinly different seat-of-the-pants feel, but it definatly has more usable power, and alot broader rpm range.
Thanks KTA for getting me looking for an HX40 over a year ago. So far, I'm happy with the investment.
Michael
1993 W250, 3.55, NV5600 , Con O, bosch 185's, 4" exhaust, Super 40, pump tweaks, ground pin, Smokehouse air intake, Hamilton Cam,
1985 D350, Crew Cab, 92 cummins and a 518. 47rh to be built and installed along with 3.55 LS Dana 80