2017 Question on Sport Mode and 4A Mode

[troverman]

4A can be used 100% every day in all conditions, if you so desire. Dry hot pavement, wet pavement, snow, ice, mud...whatever.

The single biggest thing that happens when you switch to 4A mode is that vacuum is removed from your front IWE hubs, causing them to engage. At this point, your whole front drivetrain will be turning (CV joints, axle half-shafts, front differential, and front driveshaft) but no power will be sent forward from the transfer case. When slip occurs (from powering away from a stop hard in wet conditions, or slippery conditions, the transfer case clutch will send some power to the front wheels until the slip is gone. When you turn the front wheels, the clutch will allow enough slip to occur so that no binding happens like would if you were in 4H or 4L. A computer controls the clutch in the transfer case and monitors a variety of vehicle inputs when you are in 4A...such as how much throttle you are giving the engine, steering angle, individual wheel speeds, etc. It can infinitely vary how much the clutch engages to send power forward and it can engage and disengage almost instantaneously.

So while 4A is very useful and nice in bad weather, most of the time you are just operating in rear drive mode. Keep in mind 4A is not full-time AWD like what you would get in an Audi quattro or Subaru. Unless slip happens, power is not being sent to the front. So if you power into a wet corner, don't expect the front wheels to pull you through the curve like those other cars would. Slip has to occur first.

The only downside to using 4A at all times is you will get slightly less fuel economy (front drivetrain is turning), the steering effort will be slightly more, and your front drivetrain will receive slightly more wear and tear.

 

[jaz13]

4A can be used 100% every day in all conditions, if you so desire. Dry hot pavement, wet pavement, snow, ice, mud...whatever.

The single biggest thing that happens when you switch to 4A mode is that vacuum is removed from your front IWE hubs, causing them to engage. At this point, your whole front drivetrain will be turning (CV joints, axle half-shafts, front differential, and front driveshaft) but no power will be sent forward from the transfer case. When slip occurs (from powering away from a stop hard in wet conditions, or slippery conditions, the transfer case clutch will send some power to the front wheels until the slip is gone. When you turn the front wheels, the clutch will allow enough slip to occur so that no binding happens like would if you were in 4H or 4L. A computer controls the clutch in the transfer case and monitors a variety of vehicle inputs when you are in 4A...such as how much throttle you are giving the engine, steering angle, individual wheel speeds, etc. It can infinitely vary how much the clutch engages to send power forward and it can engage and disengage almost instantaneously.

So while 4A is very useful and nice in bad weather, most of the time you are just operating in rear drive mode. Keep in mind 4A is not full-time AWD like what you would get in an Audi quattro or Subaru. Unless slip happens, power is not being sent to the front. So if you power into a wet corner, don't expect the front wheels to pull you through the curve like those other cars would. Slip has to occur first.

The only downside to using 4A at all times is you will get slightly less fuel economy (front drivetrain is turning), the steering effort will be slightly more, and your front drivetrain will receive slightly more wear and tear.

Not true, lots of torque steer in 4A because it puts power to front wheels much of the time. Check the power distribution screen and front tires get power every time you get on throttle even without rear slip.

 

[BajaFred]

Not true, lots of torque steer in 4A because it puts power to front wheels much of the time. Check the power distribution screen and front tires get power every time you get on throttle even without rear slip.

Correct - flip to the power disti screen, and you'll see the fronts get power alot

That said, I run sport + 4A all the time

 

[troverman]

Not true, lots of torque steer in 4A because it puts power to front wheels much of the time. Check the power distribution screen and front tires get power every time you get on throttle even without rear slip.

I'm not saying you can't have power sent to the front - but you should never feel "torque steer" in a vehicle with a longitudinal engine and a primary rear-drive bias. What you are feeling is slight binding as the clutch tries to balance how much power can be sent to the front versus causing binding. Obviously power does go to the front in this mode when slipping - that's the point - but I've run the power distribution screen plenty of times and unless I'm accelerating hard the front is always virtually blank. This is primarily a reactive system. The only time I'm aware it can be proactive is if you use hard throttle.

 

[BajaFred]

I'm not saying you can't have power sent to the front - but you should never feel "torque steer" in a vehicle with a longitudinal engine and a primary rear-drive bias. What you are feeling is slight binding as the clutch tries to balance how much power can be sent to the front versus causing binding. Obviously power does go to the front in this mode when slipping - that's the point - but I've run the power distribution screen plenty of times and unless I'm accelerating hard the front is always virtually blank. This is primarily a reactive system. The only time I'm aware it can be proactive is if you use hard throttle.

You're going to get defensive, but you shouldn't

I run 4A all the time, and there's power going to the front even under normal, non spirited acceleration from a stop sign evidenced by watching the power screen

Go check it out - if you don't see it, maybe your system isn't running correctly

We have 2 Raptors built at completely different times and both run the same under 4A - fronts get power a lot

 

[WhatExit?]

Per Ford:

4A (4X4 AUTO)
Provides electronic controlled four-wheel
drive with power delivered to the front and
rear wheels, as required, for increased
traction. The system continuously monitors
road conditions, driver's input as well as
other vehicle sensors and optimizes the
system's behavior based on terrain mode
selection.


Weather Mode - For less than
ideal road conditions, such as
snow or ice covered roads.
Weather mode inspires confidence without
taking away from driving pleasure. Weather
mode automatically engages 4x4 Auto,
lowers throttle response and optimizes
shifting for slippery surfaces.

Link to above:
http://www.fordservicecontent.com/F...pplement-version-1_su_EN-US-EN-US_10_2016.pdf


And here's a description of 4A / Weather Mode

The throttle is muted, meaning the truck won’t accelerate as hard when you put your foot down. The idea is that this will help you avoid spinning your wheels into oblivion while you’re stuck in snow. The transmission shifts short to keep engine speed as low as possible while keeping you moving forward. Traction control operates on a heightened aggressiveness. Basically the system is quicker to cut power if it detects slight slips or yaw.

The 4WD system is set to “Auto” here which allows the truck to behave like some AWD vehicles, sneakily sending power to front wheels when sensors decide that can help the traction situation.

This is the only driving mode where auto start/stop is active other than “Normal.”

 

[troverman]

You're going to get defensive, but you shouldn't

I run 4A all the time, and there's power going to the front even under normal, non spirited acceleration from a stop sign evidenced by watching the power screen

Go check it out - if you don't see it, maybe your system isn't running correctly

We have 2 Raptors built at completely different times and both run the same under 4A - fronts get power a lot

Nope...you're right. I experimented more and the screen claims it is sending power north even under relatively sedate driving. It does seem to cut it off during corners, which makes sense.

The system cannot vary how much power goes to the rear, contrary to what the text from Ford says. It simply does not have the capability to reduce power going to the rear.

 

[Miker397]

How about just using Sport Mode in manual? Isn't that what the paddles are for?

What a pain in the arse with so many gears! I have a f1 Ferrari and love it, but more than 6/7 gears gets tedious.

Op you describe exactly how my truck drives in sport and the wet. I have found sport better without the gear holding if you are more progressive and easier on initial throttle, otherwise it is too prone to hold gears for wayyyy to long.

Really love this truck overall though.

 

[Miker397]

Not true, lots of torque steer in 4A because it puts power to front wheels much of the time. Check the power distribution screen and front tires get power every time you get on throttle even without rear slip.

Was just going to say this. I hate 4A because the torque steer is absolutely aweful any time you touch throttle at all. I dislike the steering feel all together in the raptor (although I drove a new v8 Silverado recently and it's even worse for different reasons), but 4A and 4h make it awful to drive.

 

[Toadster]

So if one was to take the truck to the 1/4 mile - put in 4A ? Or just RWD?

would 4A give you a better launch and switch to RWD farther up the track?