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No Red line on tach


Mike92STX

Well-Known Member
Joined
Jan 14, 2012
Messages
214
City
Zion,Illinois
Vehicle Year
2004
Engine
4.0 V6
Transmission
Manual
Tire Size
245-75-16
I have a 2004 Ranger FX4, it has a manual trans. Can someone tell me why they didn't put a red line on the tach? The exhaust is so quiet I can't hear the motor good enough sometimes to tell when it's time to shift. It's not a real problem, just curious if anyone knows the reason. A guy I work with said that the tach only goes to 7000 rpm, so it doesn't need a red line.
 
Redline is probably 5500rpm.

7k would probably grenade it.
 
I’m guessing they didn’t do a redline because different engines have different limits, but the computer for the engine has a governor built in 500 revs under redline
 
Standard shift RPM is just over 2,500 for everyday driving. Most modern engines have a rev limiter on them to keep people from blowing the engine up.

Other applications would have different shift points depending on if you looking for peak torque or peak horsepower. You'd have to look up the specs for your specific engine for those.
 
Not sure why they didn't, the 3 engines offered in 2004 have pretty much the same redline above 5,500

2.3l Duratec makes best torque at 3,750, best horsepower at 5,250
3.0l Vulcan makes best torque at 3,900, best HP at 5,200
4.0l SOHC has best torque at 3,000, best HP at 5,250

Best Torque decides when you shift if you want the fastest acceleration, so go 200rpm above best torque then shift to next gear, that should get next gear 200-300 below best torque RPM, so still in the power band of that engine

Generally speaking, in a 5-speed, gears 2, 3 and 4 will have a 500-600rpm difference
 
Standard shift RPM just over 2,500 for everyday driving. Most modern engines have a rev limiter on them to keep people from blowing the engine up.

Other applications would have different shift points depending on if you looking for peak torque or peak horsepower. You'd have to look up the specs for your specific engine for those.
See, the 3.0l is just starting to get wound up at 2,500, and they were good out to about 4,500, past that you started to fade out of the powerband and the computer would give you the finger at 5,500 and she’d buck and snort and tell you to shift. Redline was something like 6,000-6,500.

The 2.9 and 4.0 OHV were something like 6k, but the computer stops you at 5,500 anyway, but those motors are far out of their powerband by 5,500 since they make their power lower than the 3.0, so you would have benefited by not getting up to the limiter anyway.

I can’t really speak to the 4.0 SOHC or the 4-cylinders since I’ve not really owned any and never researched it.
 
See, the 3.0l is just starting to get wound up at 2,500, and they were good out to about 4,500, past that you started to fade out of the powerband and the computer would give you the finger at 5,500 and she’d buck and snort and tell you to shift. Redline was something like 6,000-6,500.

The 2.9 and 4.0 OHV were something like 6k, but the computer stops you at 5,500 anyway, but those motors are far out of their powerband by 5,500 since they make their power lower than the 3.0, so you would have benefited by not getting up to the limiter anyway.

I can’t really speak to the 4.0 SOHC or the 4-cylinders since I’ve not really owned any and never researched it.

I want to say the SOHC red lines somewhere around 6,800 but I can't say for sure since I don't have the info on hand and I haven't tested it. The 1998 didn't have a tach. So no idea on the 2.5 Lima. I doubt it's a high revving engine.

EDIT: The red line for the 4.0 SOHC is 6,000 RPM. 207 HP @ 5,250 RPM and 238 LB-FT @ 3,000 RPM
 
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All the Ranger fuel injected engines have rev limits, sometimes they're just random as it seems, they're at a safe place you "could" sit at for a long period and not hurt anything... Lima's are 6000rpm, the 4.0L in a '91 Explorer I had was I'm pretty sure 4600rpm, my 5L explorer is 5000rpm, couldn't tell you about the rest...

The tach is just a number, if you are going for something specific it's fine, I reference mine all the time on the '97 to make sure I'm cruising below 3000rpm to stay in closed loop fueling in a fuel mileage attempt or to remember what gear I'm in... I change my shift points based on how and where I'm driving, normal slow acceleration shift at 3k, harder shifting 4k, all out somewhere around 5500rpm...
 
Not sure why they didn't, the 3 engines offered in 2004 have pretty much the same redline above 5,500

2.3l Duratec makes best torque at 3,750, best horsepower at 5,250
3.0l Vulcan makes best torque at 3,900, best HP at 5,200
4.0l SOHC has best torque at 3,000, best HP at 5,250

Best Torque decides when you shift if you want the fastest acceleration, so go 200rpm above best torque then shift to next gear, that should get next gear 200-300 below best torque RPM, so still in the power band of that engine

Generally speaking, in a 5-speed, gears 2, 3 and 4 will have a 500-600rpm difference

the last time I hit peak power in my 2000 3.0 whatever it was that I needed the power for was long gone.
 
the last time I hit peak power in my 2000 3.0 whatever it was that I needed the power for was long gone.
I knew the 3.0L was slow, but I didn’t realize it was that slow.

You did mean it that way, right?
 
I knew the 3.0L was slow, but I didn’t realize it was that slow.

You did mean it that way, right?

yeah, this one is kind of slow. full throttle will wind it out to 5200, but anything over 4500 is slow progress.
it's an ex cab 4x4, auto. the 3.73 gears just aren't a good match, it struggles to maintain 70, down shifts for any kind of grade.
I once had some smaller tires on it, 225/70-15 and that made a big difference for only being 7% smaller.
4.10 gears are in the works, "soon" :icon_rofl:
 
The 3.0l Vulcan was designed in 1983/4 for use in the Brand New 1986 FWD Taurus/Sable models

The resulting engine was a clean-sheet, all metric design. The engine's 60° vee angle was chosen to help it fit into the Taurus' engine bay.
Displacement grew from an original 2.8 L to 3.0 L.
A variety of technologies were evaluated during development, including two different fuel injection systems, turbocharging, two sparkplugs per cylinder, variable displacement with cylinder deactivation, and Ford's experimental programmed combustion (PROCO) system

Power band/best torque varied thru out the years
165ft/lb @ 3600 RPM (1991 – 1995)
162 @ 3250 RPM (1996 – 1997)
178 @ 3750 RPM (1999)
190 @ 3650 RPM (2000 – 2001)
180 @ 3500 RPM (2002)
180 @ 3900 RPM (2003 – 2004)
180 @ 3950 RPM (2005 – 2007)

Most V6 and V8 engines do best torque at 2,500-3,000rpms
If driven that way the 3.0l becomes the 3.slow
It would be EXACTLY like driving around another V6 or V8 and keeping it under 2,000rpm, you would think its gutless as well :)

3.0l Vulcan was certainly no powerhouse, but it did what it was suppose to do in its comparison OHV engine sizes of the day
Had a 23 year run, 1986 thru 2008, very reliable for the most part
 
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I had an '87 Taurus wagon. the 3.0 was a good match and served me well for about 25 years.
 
It's literally just a red line on the tach, means almost nothing, just a visual guide that you are getting close to the rev limiter which is just the speed they decided that the engine should not exceed is which is the speed at which the engine should be able to run all day every day at... We build boat engines at work, I set the rev limits fairly low compared to automotive because in the jet boat world the prop load gets kinda dumb around 5000rpm so the highest rev limits we have are 5200rpm for the 6.2L LT4 supercharged engine, I set the EGT's and such to a point it can sit there at full load all day, sure it's probably not great on the rings, but it'll do it... well on that particular engine the intercooler won't keep up with it but whatever... The redline on the tach is just a visual thing. Before I climbed under my '97 to look at the diff tag I used the rev limit along with the speedo to help figure out what gears were in it by running the math, most people stress about rpm way too much...
 

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