When To Shift?

[MountainMike]

I have a '98 Ranger with the OHV 4.0L V6. I was just wondering at what RPM is a good point in the powerband. I usually shift at 3000 but it seems to me like although it is starting to yell a little it still has a lot of power left... any suggestion? And what is the redline of the motor, the tach doesn't have one! Last thing what is the trucks rev limiter set at?

Thanks

*edit* I found some curves for the OHV and the SOHC

 

[Hahnsb2]

Depends what shift it is and what you're trying to accomplish. Redline/rev limiter is supposedly at 4900 (at least on the earlier OHVs).

 

[MountainMike]

I'm talking just basic acceleration down the street, not escaping or anything.

 

[Fx4wannabe01]

uhhhhhhh........shift when you need to? lol. It's all about feel and knowing your vehicle dude.


My truck, I can regularly shift at 2000 rpm with ease, depending on grade and what I'm trying to accomplish.

 

[Jay FX4]

For max fuel economy, you can shift around 2000-ish, at least for 1st/2nd. 3500 seems a little higher than necessary, unless you're in a hurry or just like to move quick.

 

[Beanmachine7000]

I usually shift between 3000 and 3500, unless I'm just on a leisurely cruise and have nowhere to be, then i might shift around 2500... I wouldn't go too far past 4200, only because it doesn't make anymore power way up there... 3500 is nowhere near unnecessarily high... I consistently average ~18 mpg...

 

[MountainMike]

Thanks, normally I shift at around 3500 when moving quick and about 3000 when just crusing. Basically all I was trying to figure out when the motor is in its powerband. Thanks for the replies

 

[Fx4wannabe01]

alot of shift points are dependent on gear ratio and tire size... bigger tire, stock gear = higher shift.

 

[wahlstrom1]

When my truck was bone stock, I could hold it to the floor in first and not get 5k rpm out of it. Opening up the exhaust and installing a cold air style open filter and I can hit 5200rpm easy in first and 2nd, but it gets a little windy in 3rd. It makes peak horsepower around 42-4500 RPM, but you if your really gettin on it you need to go past that so when you grab another gear your rpm falls back into the higher hp range rather then below it.

 

[Will]

This is the torque curve for the pushrod 4.0, 1999 I think.

When you find the total torque in each gear it makes it pretty clear when not to shift. You don't want to give up available torque in the current gear. When you do shift it should be because your torque is falling away, as you can see at the top of third, for instance. If you keep accelerating past 4,600rpm your total torque will drop to 221ft# at 4,700 where if you upshift at 4,600 instead, you will find a 223ft# spot in 4th.

Keep in mind these are wide open throttle curves. If you aren't driving for maximum performance (racing or towing) then I would disregard the charts and drive by feel. I think using the least amount of torque necessary would be the best plan. That doesn't mean avoiding the best places in the curve, it means avoiding having to stick your foot into the throttle.

 

[AllanD]

LOVE the spread sheet

 

[MountainMike]

Thanks for all the info. That spreadsheet rules.

 

[AllanD]

I like this spread sheet so much that I'm making it a sticky

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[Will]

Thanks. I uploaded the actual sheet now. I did the SOHC 4.0 as well but I'll have to look for it.

 

[AllanD]

Now, if you had the chart for a 2.9... and a 3.0