Horsepower/Torque graph? October 29, 2017, 11:11:07 am Does anyone have an accurate Horsepower/Torque curve for the Ford 6.8L V10 2 valve engine? I would like to be able to hold the engine at the rpm that gives me the maximum torque but minimum rpm for long pulls in the mountains.HD 2 Likes
Re: Horsepower/Torque graph? Reply #1 – October 29, 2017, 12:11:03 pm Do a search for improved performance, e.g. with Banks systems. For instance:http://50.62.23.47/~tuning/wp-content/uploads/48-2.jpgSteve
Re: Horsepower/Torque graph? Reply #3 – October 29, 2017, 10:46:04 pm What is the value of going up a mountain at the same rpm as the full throttle torque peak?My "steep hill" climbing method is to push down on the gas pedal until the engine noise get intrusive. On my E350, that was about 3200 rpm; on my E450 (current vehicle), it's about 3700 rpm (better sound insulation, I think). In neither case was the pedal floored.
Re: Horsepower/Torque graph? Reply #4 – October 30, 2017, 09:45:08 am Torque CurveGo the the Gear Vendors website for a troque curve peak is around 2700 rpm. There link is to the wrong curve.Maybe a moterator can remove this curve.
Re: Horsepower/Torque graph? Reply #5 – October 30, 2017, 10:15:05 am I use to have the chart, but like many things I can't find it. I do know that maximum torque occurs around 3250 rpm. Horsepower is much higher. A mechanic once told me in pulling a hill you don't gain much by exceeding the rpms where torque and horse power cross. I believe this is somewhere around 3600-3700 RPMS. 2 Likes
Re: Horsepower/Torque graph? Reply #6 – October 30, 2017, 12:26:57 pm For my 2003 E450 the torque peak is 420 at 3250RPM.Terry Tanner has some graphs on his TechSnoz Yahoo! site that will allow you to calculate highway speeds for that RPM in each gear of various transmissions. I think there are also some calculators out there that will do that.I did that once, one way or the other, and the MPH I got for the torque peak in each gear of my 4R100 transmission (3-speed plus Overdrive) were: 1st-23mph, 2nd-40mph, 3rd-62mph and OD-83mph.My hill climbing strategy over the past 100K miles, at least for longer grades, has been to attempt to hold the max torque speed for the gear I'm in, say 62mph in 3rd, but when the engine can no longer do that let the speed decline to close to the max torque speed for the next lower gear, say 40mph in 2nd and then if the transmission has not already downshifted do so manually and attempt to hold that new speed, thus mostly climbing with the engine producing maximum torque. With this strategy I'd say 80% of my grade climbing has been in 2nd gear at about 40mph. My thinking was max torque, fewer shifts as the grade went up and down a bit. Just put it in 2nd and drive 40mph until the top. Just like my old VW campers.But my transmission failed anyway, at just over 100K miles, the result of always towing a 4000 lb. Jeep Wrangler along with all the stuff in the LD. I had the transmission rebuilt by John Wood, the end result being a much more robust unit due to his various upgrades. The transmission works a bit differently now, more crisp and authoritative shifts. And I have more confidence in John's build than Ford's (I think they each have different economic incentives, John building his business on being the strongest, Ford perhaps more interested in economies).So now I find myself letting the transmission do more of the thinking and accepting more up and down shifts as I climb a grade with changing gradients. I still turn off OD for climbing but am letting the transmission go back and forth between gears more than I have in the past, usually 2nd and 3rd.As part of the transmission episode I finally got a ScanGauge, which allows me to have an RPM readout on the dash. So I no longer need my little chart to convert max torque RMP to highway speed. I just look for 3250RPM. I recommend that approach.I still think climbing at a steady "max torque" speed makes sense. It's like having the strongest guy in the room do the heavy lifting. And fewer shifts seem inherently better for a transmission. I've just gotten a bit lazy with the new transmission in place and less worry about whether it can "take it." 2 Likes
Re: Horsepower/Torque graph? Reply #7 – October 30, 2017, 12:47:16 pm Thank you Terry for your experienced and informative reply. Good ideas.As for John's transmission overhaul, I had him build one for my F350 7.3l diesel after destroying three 4R100 stock transmissions. This was likely due to hauling around a 4000lb. camper while pulling a 2500lb enclosed trailer, and towing a 10,000lb triple axle trailer . The first transmission self-destructed in 10,000 miles, the second in 28,000 miles. When my third 4R100 was installed, the tech told me to never tow in OD, always tow in 3d gear. That transmission lasted about 55,000 miles.When John installed his transmission, he said to tow in OD and let his transmission shift when it wants to. At nearly 40,000 miles, it hasn't even hiccupped. It is a robust transmission and nicely handles the torque of the chipped 7.3l diesel and the weight of the camper, trailers and the truck. I did take it back to John for a fluid replacement and torque converter flush at 20,000 miles and John commented that it could easily go 30,000 miles next time.Scan Gauge is next for the Lazy Daze. I hope that the 5R110 proves to be a better transmission than the 4R100 and I'll be tickled to get 100,000 miles out of it.HD
Re: Horsepower/Torque graph? Reply #8 – October 30, 2017, 01:04:08 pm The V10-2V torque curve has a small bump at 2500 RPM, and is then mostly flat to 4000 RPM, with the horsepower peaking at about 4200 RPM. The torque bump at 2500 is well situated for highway cruising. 2500 RPM is too low for climbing due to the lack of horsepower at the low engine speed. Hosepower = RPM X Torque / 5252http://www.hypertech.com/PerformanceGraphs/ford/42008_2005_2010_F250_550___6_8L_3V_V10.pdfOn long uphills, I usually cruise at around 3800 RPM, above which I find the noise unpleasant. The V10 does not have the sweet exhaust note or intake noise that V8s and V12s produce, both having better sounding harmonics.Ford designed the V10 as a truck engine, unlike a car engine, it is designed to be run at high RPMs for long periods, without damage or overheating . 4200 RPM is my acceptable upper limit, for long climbs. Torque starts dropping off above 4000 RPM, so there is no reason to run any higher an engine speed.Larry 3 Likes
Re: Horsepower/Torque graph? Reply #9 – October 30, 2017, 02:51:04 pm Quote from: Larry W - October 30, 2017, 01:04:08 pmOn long uphills, I usually cruise at around 3800 RPM, above which I find the noise unpleasant. The V10 does not have the sweet exhaust note or intake noise that V8s and V12s produce, both having better sounding harmonics.Ford designed the V10 as a truck engine, unlike a car engine, it is designed to be run at high RPMs for long periods, without damage or overheating . 4200 RPM is my acceptable upper limit, for long climbs. Torque starts dropping off above 4000 RPM, so there is no reason to run any higher an engine speed.LarryHmmm. I don’t think I’ve ever been that high (4 grand) except those brief moments when the tow-haul mode kicks in and suddenly downshifts on a descent, scaring the heck out of me. In fact, anything in the 3000s is unusual for us. Our ‘06 TK (5-speed tranny) seems to climb quite well in the mid to upper 2000s, with no sign of lugging. Of course, we don’t tow and are well under our CCC, and I’m in no hurry to get to the top, so I’m sure those are big factors. —Jon
Re: Horsepower/Torque graph? Reply #10 – October 30, 2017, 04:06:26 pm Quote from: Jon & Loni - October 30, 2017, 02:51:04 pmHmmm. I don’t think I’ve ever been that high (4 grand) except those brief moments when the tow-haul mode kicks in and suddenly downshifts on a descent, scaring the heck out of me. In fact, anything in the 3000s is unusual for us. Our ‘06 TK (5-speed tranny) seems to climb quite well in the mid to upper 2000s, with no sign of lugging. Of course, we don’t tow and are well under our CCC, and I’m in no hurry to get to the top, so I’m sure those are big factors. —JonIf you tow, especially a heavy vehicle, you will spend a lot of time in lower gears while climbing any sort of grade.The computer will allow the engine stay at 4000+ RPMs, while climbing.As stated before, it is well within the RPM range that Ford's engineers designed the engine to operate in.This is a result of the lightweight pistons and the overhead cam, features that allow higher RPM usage.Most owners do not spin the engine that fast due to the loud, unpleasant noises, many thinking that it is harmful to the engine. Don't worry, it isn't.Larry
Re: Horsepower/Torque graph? Reply #11 – October 30, 2017, 04:32:25 pm "I finally got a Scan Gauge, which allows me to have an RPM readout on the dash."I remember chatting with Ed Newton in 2004 when I was doing my homework. The conversation came around to the fact that Ford saw fit to include a tachometer on that model year. Ed says to me: "What in the hell do you need that for?"
Re: Horsepower/Torque graph? Reply #12 – October 30, 2017, 06:25:24 pm this is my torque app screen on my phone... along with my bluetooth scanner, i get trans temp, gear position and rpm. also has coolant and cylinder head temp... 3 Likes As an Amazon Associate Lazy Daze Owners' Group earns from qualifying purchases.
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