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torque curve

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tom954x4
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torque curve

Post #1 by tom954x4 » Wed Nov 24, 2010 1:09 pm

Does anyone have the torque curve for a stock 300 (EFI years)? I would prefer graphical form if available. If not, the numbers between 1000 and 2500 rpm would be of interest. Thanks
1995 F-150 XL, 300-6, 4x4, ex-cab, sb, 3.08 5-speed, 2 1/2 in. exhaust w/flowmaster 50, MSDignition failed with no warning, now out, canopy, 179,000 + miles. Gone but not forgotten 1965 F-100 240 3spd lwb "the green hornet"; 1960 F-250 4x4, 223 six, 4sp with wrap-around rear window, two-tone paint, overhead camper.
Tow vehicle: 2012 F-250 4x4 6.7 diesel XLT s/c lwb

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StrangeRanger
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Re: torque curve

Post #2 by StrangeRanger » Wed Nov 24, 2010 1:23 pm

It's a well kept secret.
The points we know are
260 ft-lbs @ 2000
225 ft-lbs @ 3500
I would assume it's fairly linear between those two points.
I would also assume it's basically the same at 1800 as it is at 2000 since in some years the torque peak was listed at 1800
Below that ????? No data that I've seen :cry:
1996 F-150 (tow missile)
1993 Mustang 5.0 (hot rod and auto-x monster)
1982 Tiga Formula Ford (SCCA racecar)
2013 Hyundai Elantra Coupe (daily driver)

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tom954x4
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Re: torque curve

Post #3 by tom954x4 » Wed Nov 24, 2010 4:33 pm

That is a pity.
Is there a desktop dyno that could generate the torque curve using the known stock camshaft parameters (set forth in the stock cam sticky in this board), displacement, etc.? I am way out of my league here . . .
1995 F-150 XL, 300-6, 4x4, ex-cab, sb, 3.08 5-speed, 2 1/2 in. exhaust w/flowmaster 50, MSDignition failed with no warning, now out, canopy, 179,000 + miles. Gone but not forgotten 1965 F-100 240 3spd lwb "the green hornet"; 1960 F-250 4x4, 223 six, 4sp with wrap-around rear window, two-tone paint, overhead camper.
Tow vehicle: 2012 F-250 4x4 6.7 diesel XLT s/c lwb

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StrangeRanger
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Re: torque curve

Post #4 by StrangeRanger » Wed Nov 24, 2010 4:58 pm

Actually those 3 points may give you a pretty good approximation.
You know there are no discontinuities in the curve nor are there likely to be any sudden changes. If you were to sketch a curve through 0/0, 250/1800, 260/2000 and 225/3500 it would necessarily be close to accurate.
1996 F-150 (tow missile)
1993 Mustang 5.0 (hot rod and auto-x monster)
1982 Tiga Formula Ford (SCCA racecar)
2013 Hyundai Elantra Coupe (daily driver)

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THE FRENCHTOWN FLYER
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Re: torque curve

Post #5 by THE FRENCHTOWN FLYER » Wed Nov 24, 2010 6:28 pm

i'VE GOT A CURVE. iLL DIG IT OUT AFTER THE HOLIDAY.
FORD 300 INLINE SIX - THE BEST KEPT SECRET IN DRAG RACING

CJ455
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Re: torque curve

Post #6 by CJ455 » Wed Nov 24, 2010 6:30 pm

This is a stock 300 @ almost 200,000 miles
96 efi
http://i268.photobucket.com/albums/jj19 ... G_1014.jpg

twowheelstan
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Re: torque curve

Post #7 by twowheelstan » Thu Nov 25, 2010 12:02 am

A long time lurker is chiming in on this one. I'm going to have the truck referenced in my signature below dyno'ed in the next week or two. If you're in no huge hurry, I'll post the results once I have them. (I'll likely have a few questions for the brain trust at that time as well as to making the truck a better tow vehicle). I'm curious about a couple things I've observed while hauling my Miata to race tracks here in the SE the past year. I'm hauling a 2200 lb Miata on a 900 lb Trailex trailer carrying two full sets of spare wheels / tires. It is just under the 3500 lb max trailer load for the drive train, actually a 3.55 rear as a 3.73 is not listed per Ford for 1996.

When running the Interstates at my preferred, for that weight, 72 - 74 mph / 2500 rpm, trying to maintain that speed while climbing a grade is difficult, if not impossible. It often requires a downshift to 4th, which is around 3200 rpm. I don't like spinning it that high, but I have to say, it runs quite well there. Not surprisingly I suppose, considering that's just under its max hp rpm.

When running around 78 mph / 2800 rpm, a ground speed which is too much like work for me, the engine is a monster. Anticipating the next uphill by gaining two or three mph, it will hold that speed up the grade in 5th gear, and I generally have to lift off the throttle a tad at some point up the hill. I just made a trip up to VIR in Danville, VA and back from home in Columbia, SC this past weekend. While running the higher speed I averaged a tad over 12 mpg. I made it home in record time, but would prefer running closer to 70 myself pulling that much weight.

Given that this engine is rated for 260 hp @ 2000 rpm and 145 hp @ 3400 rpm, according to Ford's literature for that year, I'm curious as to why it seems to be working so hard at 2500 yet flying at 2800.

As an aside, I suspect I made a mistake by going to a 3.73 from the original 2.73. I probably should have gone with the 3.55, but all of the local gear guys and racer dudes recommended the 3.73. I will admit, it does pull well now, but at what cost I'm wondering.

I'll post my data in a week or two.

Take care folks, and have a Happy Thanksgiving.
'96 F150, 4.9L I-6, M5R2, 3.73, 145,000 mi, owned from new, Tow vehicle
'97 Mazda Miata, Spec Miata chassis, Race Engineering 1.8L, mileage ?, Track car/Towed vehicle
'89 Volvo 240DL, 185,000 mi, owned from new, daily driver
Life is REALLY good!

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Re: torque curve

Post #8 by Harte3 » Thu Nov 25, 2010 1:56 pm

"Given that this engine is rated for 260 hp @ 2000 rpm..." You did mean 160 didn't you?
'83 F150 300, 0.030 over, Offy DP, Holley 4160/1848-1 465 cfm, Comp Cam 260H. P/P head, EFI exhaust manifolds, Walker Y Pipe, Super Cat, Turbo muffler, Recurved DSII, Mallory HyFire 6a, ACCEL Super Stock Coil, Taylor 8mm Wires, EFI plugs.

twowheelstan
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Re: torque curve

Post #9 by twowheelstan » Thu Nov 25, 2010 2:05 pm

Actually, I the value should be lb / ft of torque, not hp. That was typed past my normal bed time. Sorry.
'96 F150, 4.9L I-6, M5R2, 3.73, 145,000 mi, owned from new, Tow vehicle
'97 Mazda Miata, Spec Miata chassis, Race Engineering 1.8L, mileage ?, Track car/Towed vehicle
'89 Volvo 240DL, 185,000 mi, owned from new, daily driver
Life is REALLY good!

Lazy JW
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Re: torque curve

Post #10 by Lazy JW » Thu Nov 25, 2010 2:42 pm

twowheelstan wrote:.....

As an aside, I suspect I made a mistake by going to a 3.73 from the original 2.73. I probably should have gone with the 3.55, but all of the local gear guys and racer dudes recommended the 3.73. I will admit, it does pull well now, but at what cost I'm wondering.......


Howdy Stan and WELCOME! to the forums :thumbup:

Sounds to me like you made the right choice in your gearing; you are indeed working that engine tolerably hard with your described operating parameters, not abusively hard, but certainly making it earn its keep, and a 300 really isn't a very big engine so it needs a little help in the gearing. Taller gears would simply mean that you would get to downshift sooner.

It really boils down the question of what is the primary use to which the vehicle is put; if it is mostly a grocery getter and only rarely pulls a trailer then taller gears would perhaps have been better, but if it is mainly used for trailering then you are about spot-on for gear ratio in my opinion.
Joe
"The White OX" 1974 F-350 300-6, Stock single exhaust, Carter YF, T-18A, Dana70 w/4.11, Flatbed dually w/dump bed. "Where no oxen are, the crib is clean, but much increase is by the strength of the ox" (Proverbs 14:4)
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Re: torque curve

Post #11 by StrangeRanger » Thu Nov 25, 2010 2:53 pm

Stan:
I also put a set of 3.73s in my '96 which has an E4OD. It has a 0.7:1 OD vs. your 0.8:1 so I'm not pulling quite as much overall reduction as you are. I'm very happy with it although highway mileage when not towing took a pretty big hit from the original 3.08s. Even though the difference is rather small, I suspect that you would not have been as happy with 3.55s
1996 F-150 (tow missile)
1993 Mustang 5.0 (hot rod and auto-x monster)
1982 Tiga Formula Ford (SCCA racecar)
2013 Hyundai Elantra Coupe (daily driver)

twowheelstan
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Re: torque curve

Post #12 by twowheelstan » Tue Nov 30, 2010 10:39 pm

Thanks for the input on the gearing. It does pull much better empty with the 3.73.

I have an appointment at the dyno Thursday afternoon. Anything you can think of that I should be asking the tuner while I'm there? Talking to him on the phone I get the impression he hasn't seen many, or perhaps even any, big sixes over the years. Right now I'm just interested in establishing a base line and use that to develop a game plan on improving the engine's towing performance. I'll post the results - once I figure out how.
'96 F150, 4.9L I-6, M5R2, 3.73, 145,000 mi, owned from new, Tow vehicle
'97 Mazda Miata, Spec Miata chassis, Race Engineering 1.8L, mileage ?, Track car/Towed vehicle
'89 Volvo 240DL, 185,000 mi, owned from new, daily driver
Life is REALLY good!

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tom954x4
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Re: torque curve

Post #13 by tom954x4 » Wed Dec 01, 2010 12:35 pm

My engine makes noticeably more power at 2000 rpm as compared to 1500 and below and I am wondering if this is just the effect of increased rpm with a flat Torque curve, hence my original post. With 3.08 gears, you are in the bottom of the power band with an early shift schedule and low rpms for economy. I would be interested if FTF found his curve or the dyno plot twowheelstan is going to get to see just what is going on between 1,000 and 2,000.

On a side note, in my inline six diesel (marine, Gardner 6LW) it has a nearly flat torgque curve from essentially off-idle with only a slight rise to the torque peak and then a gradual fall off to max rated rpm. (tq peak at 1100 rpm, max rated 1500 rpm).
I thought the 300 six engine curve would be rather similar in shape and not a straight line from 0 at 0 rpm to max torque at torque peak as indicated in SR's post above:
"If you were to sketch a curve through 0/0, 250/1800, 260/2000 and 225/3500 it would necessarily be close to accurate


Either I am misuderstanding SR or, more likely am wrong in thinking a 300 six and diesel are producing curves of roughly similar shape. Clarification anyone?
1995 F-150 XL, 300-6, 4x4, ex-cab, sb, 3.08 5-speed, 2 1/2 in. exhaust w/flowmaster 50, MSDignition failed with no warning, now out, canopy, 179,000 + miles. Gone but not forgotten 1965 F-100 240 3spd lwb "the green hornet"; 1960 F-250 4x4, 223 six, 4sp with wrap-around rear window, two-tone paint, overhead camper.
Tow vehicle: 2012 F-250 4x4 6.7 diesel XLT s/c lwb

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THE FRENCHTOWN FLYER
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Re: torque curve

Post #14 by THE FRENCHTOWN FLYER » Wed Dec 01, 2010 1:54 pm

I looked yesterday - I couldn't find any. I know I have some somewhere. I'll check again soon.
FORD 300 INLINE SIX - THE BEST KEPT SECRET IN DRAG RACING

twowheelstan
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Re: torque curve

Post #15 by twowheelstan » Fri Dec 10, 2010 11:57 pm

Well folks, as promised I have the dyno data for my truck. It is a bone stock, lovingly maintained 1996 4.9L I-6 with over 145,000 miles. I am the original owner, since October 1995. The data is an average of two pulls on a DynoJet rear wheel dynomometer. Please, let the discussion begin.

Torque
1800 rpm = 224 lb / ft
2000 rpm = 228 lb / ft
2200 rpm = 238 lb / ft
2500 rpm = 231 lb / ft
2700 rpm = 227 bl / ft
3000 rpm = 222 lb / ft
3400 rpm = 200 lb / ft
3500 rpm = 195 lb / ft

HP
1800 rpm = 83 hp
2000 rpm = 88 hp
2500 rpm = 113 hp
3000 rpm = 127 hp
3300 rpm = 132 hp
3500 rpm = 130 hp
4000 rpm = 111 hp (I assure you, I've never seen this figure on my tach!)

Bearing in mind that I'm interested in improving the trucks towing performance, my questions are:

1. Would I gain anything by modifying the exhaust? Any specific recommendations?
2. I understand the stock phenolic cam gears should be replaced eventually. Would there be a benefit to installing adjustable gears and degreeing the stock cam? If adding the adjustable gears, should the cam timing be tweaked?
3. If I'm changing the timing gears, (as I understand the cam has to come out anyway), for the extra money is it worth installing an aftermarket cam? If so, any recommendation?
4. For this engine, are there any suggestions for ignition improvements?
5. And finally, I understand the head is the limiting reagent in the reaction. What exactly would I want to have done to the head to improve performance, and any ballpark ideas on the cost? Again, for a tow vehicle.

Frankly, I'm inclined at this point to leave the engine as it is and invest in a ZF transmission. The truck pulls my Miata just fine, and I've read enough about the Mazda transmission to be a tad rattled about it. I'm guessing that short of the head work, what I'd invest in the engine mods would equal a decent ZF, clutch pack and installation. Any observations on that would be appreciated as well.

Thanks folks.

Stan
'96 F150, 4.9L I-6, M5R2, 3.73, 145,000 mi, owned from new, Tow vehicle
'97 Mazda Miata, Spec Miata chassis, Race Engineering 1.8L, mileage ?, Track car/Towed vehicle
'89 Volvo 240DL, 185,000 mi, owned from new, daily driver
Life is REALLY good!

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THE FRENCHTOWN FLYER
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Re: torque curve

Post #16 by THE FRENCHTOWN FLYER » Sat Dec 11, 2010 9:51 am

1. Yes - a low restriction exhaust - a Flowmaster Series 50 stainless muffler. Keep the catalytic converters.
2. If you use the stock cam install it 4 degrees advanced.
3. An RV cam from a reputable manufacturer.
4. Leave the stock ignition alone. For your application there is nothing to be gained.
5. Clean up the area around the bowls and back-cut the intake valves. Remove the thermactor boss humps. Don't waste time on any other upstream porting / port matching. Costs to perform these mods vary greatly around the country. I wouldn't expect to pay more than $200 over the price of a normal cylinder head rebuild here in The Motor City.
FORD 300 INLINE SIX - THE BEST KEPT SECRET IN DRAG RACING

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tom954x4
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Re: torque curve

Post #17 by tom954x4 » Thu Dec 16, 2010 12:21 pm

Why are the max hp numbers significantly below specs in twowheelstan's dyno numbers, and in the graph posted by CJ455? Age/wear? Ford is too optimistic/lying?
1995 F-150 XL, 300-6, 4x4, ex-cab, sb, 3.08 5-speed, 2 1/2 in. exhaust w/flowmaster 50, MSDignition failed with no warning, now out, canopy, 179,000 + miles. Gone but not forgotten 1965 F-100 240 3spd lwb "the green hornet"; 1960 F-250 4x4, 223 six, 4sp with wrap-around rear window, two-tone paint, overhead camper.
Tow vehicle: 2012 F-250 4x4 6.7 diesel XLT s/c lwb

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tom954x4
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Re: torque curve

Post #18 by tom954x4 » Thu Dec 16, 2010 12:45 pm

what about powertrain losses - would that explain the low numbers?
1995 F-150 XL, 300-6, 4x4, ex-cab, sb, 3.08 5-speed, 2 1/2 in. exhaust w/flowmaster 50, MSDignition failed with no warning, now out, canopy, 179,000 + miles. Gone but not forgotten 1965 F-100 240 3spd lwb "the green hornet"; 1960 F-250 4x4, 223 six, 4sp with wrap-around rear window, two-tone paint, overhead camper.
Tow vehicle: 2012 F-250 4x4 6.7 diesel XLT s/c lwb

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StrangeRanger
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Re: torque curve

Post #19 by StrangeRanger » Thu Dec 16, 2010 12:45 pm

Those are chassis dyno numbers. Ford's published data are from an engine dyno. Typical powertrain losses are around 15-17%. if you multiply the chassis dyno numbers by 1.15 they are very close to Ford's numbers
1996 F-150 (tow missile)
1993 Mustang 5.0 (hot rod and auto-x monster)
1982 Tiga Formula Ford (SCCA racecar)
2013 Hyundai Elantra Coupe (daily driver)

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Re: torque curve

Post #20 by mutt » Fri Dec 17, 2010 10:36 am

After many years of incremental upgrades, in a '80 Econo, 4sp (OD) i ditched the 3.08 & have a 3.73.
Now im in the groove, at useful speeds. The gearing now much better matches the low rpm of the 6 & the fat part of the torque curve.
Never touched the ignition. Works a treat. As far as bang for buck- the Cloyes adjustable timing gear was an expensive >pip!<.....
Econos have bigger drag issues than cars or PU's. So mileage starts to drop off rapidly over 60 or so. The 3.70 actually helped here, and my vacuum is nicely higher 65-70 than it was before, givin me more mph for the same mpg. ill take it, on the long hauls.

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