I just purchased a 5th wheel camper and am about to start towing. What is the maximum safe RPMs to run on a 7.3 IDI going up steep grades? What RPM do most of you run up hills? I have a ZF-5 with 4.10 gears and an ATS turbo.
You wont hurt the engine as long as the EGT's stay in check(I see you put a turbo on it). Actually you can floor board that engine and it will run all day long no problem. The trans will suffer before the engine. To directly answer your question. Your engine has a govenor on it, the gov will kick in before RPM's get too high.
__________________
Just eating rainbows and butterflies
Like Kanman said, the engines are governed and you can run up against the governor all day long.
Just make sure that the turbo is spooled up good before hitting the grade, if you tend to lose a lot of speed you should downshift to 4th BEFORE you hit the grade.
__________________
1985 International rollback, 6.9L 5 speed "Li'l Big Truck"
Every truck that I've driven has had a slightly different sweet spot. You'll more than likely have to figure out your truck's sweet spot on your own with time behind the wheel.
__________________
2005 Arizona Beige F350 XLT FX4 6.0 CC shortbed, 3.73 ls rear, 18" wheels, Tow Command. Additions: Vent Visors, bug guard, Fumoto Valve, Timbrens. Traded for...
Current Truck -- 2008 Black F350 XLT 4x4, 6.8 V10, CC Long Bed, 4.10 rear, 18" wheels, IBC. Additions: Chrome Step Bars, Chrome door handles, Silver barbed-wire pin stripe, B&W Turnover GN ball
Even though my truck has the E4OD, the 7.3 will turn 3000 rpm all day and pull to redline. The coolant temps like it better also, as long as the fan clutch and rad are in good condition. As soon as I let it drop below 2600rpm the coolant temps rise FAST. Watch the pyro temps and shift as necessary to keep the rpm/pyro/coolant temps balanced. Listen for the fan clutch to come on, even at 3000rpm, you will be able to hear it. If not, point truck back down hill and get it replaced($149.00 [img]/ubbthreads/images/graemlins/eek.gif[/img])!!! [img]/ubbthreads/images/graemlins/smokin.gif[/img]OkieGringo
Like others have said, you can run the RPM's up as fast as they will turn because the engine is governed by the computer module. My experience is that, with my foot pressed hard against the firewall, I rarely get above 2900 RPM on any hill/mountain, because the shift points for my truck (4:10 rear end) are such that when the truck downshifts, the new RPM point is just under 3,000 RPM. Even in the very few times I've had to punch it hard to get on an expressway, the engine shifts just before 3,000 RPM.
The DANGER comes from using the transmission lever to downshift when coming down a hill/mountain and over-spinning the engine. You can get the RPM's way up above redline that way and damage the engine.... according to the manual. I've never known anyone that had damaged an engine that way, but I'm sure some have done so.
As an aside, I drove a new 2005 6.0Liter Ford and it spun up over 4,000 RPM getting on the expressway. But the RPM's on the 6.0 is still governed by the computer module.
Florida Ed
__________________
2001 7.3 F-350 Dually Lariat CC LWB 4X2 Dark Green 4.10 4R100 5'ver Hauler (32' Montana 2 slides 10,500# - 2,000# tongue weight), 106 gal aux tank, 112K miles, nephews arguing over who will inherit it 'cause I'm gonna' drive it 'til I die. Bone stock.
2001 5.4 Gasser F-250 XLT Crewcab SWB 4X2 3.73 4R100 67K miles headed to 150K (wife's vehicle on the "junk-iron" theory of vehicle safety....most junk iron wins in a crash) stock as the day it was made
Before these: '00 F-250 CC PSD, '97 F-250 CC PSD, '94 Ford F-150, '91 Ford E-250, '81 Ford E-150, '66 Ford F-100 (cars not included)
AutoForums.com is the premier network of enthusiast-owned
enthusiast-operated automotive communities.
We operate more than 100 automotive forums where our users consult peers for shopping information and advice, and share
experiences and opinions as a community.
Linear Mode
