4 EAT , options nobody uses or knows ?

[Hendrik]

Impreza , 1993 , 1.8L , awd .

 

My house on the beach is only acessible via at least the last 2000 m sand.

Sand as you only can imagine on dunes in a tropical ambient.

So far I tried the manual button and 2 gear , does not work....

 

Just first gear and lower tire pression , brings me everywhere.

An even more important : brings me back !

 

Now the "manual" button seems to bring a more agressive way for the first gear , that what I read somewhere.

 

Who knows more about it , if it is critical , ativating the switch to manual in 1 gear brings what ? Lower gear ratio ?

[Legacy777]

All the manual button does is keep the transmission from shifting into 1st gear when the gear selector lever is in the 3 or 2 position.

 

When the gear selector is in D or the 1 position, the manual button doesn't do anything.

 

Here's another post from the sticky

http://www.ultimatesubaru.org/forum/showthread.php?p=410273#post410273

[Hendrik]

All the manual button does is keep the transmission from shifting into 1st gear when the gear selector lever is in the 3 or 2 position.

 

 

Ok , I have seen and read the 1001 times story before , and I agree.

I only was misunderstanding the following txt :

 

 

"In 1st range manual the transmission stays in 1st gear and

also will upshift to second at 6500 RPM to prevent damage to the engine.

Additionally, on AWD vehicles, the TCU applies a more aggressive AWD map

when the selector is in the 1st position, manual switch “ON” or “OFF.”

 

These changes result in improved driveability on low friction road surfaces"

 

(from Endwrench)

 

My real question is : What means "more agressive AWD map" ?

An extra reduction compared to "1" selected in D ?

 

There are more issues not known (to me...) with 4EAT :

There is at about 90Km/h an upshift (In case of no or low acceleration) to what ? Overdrive ?

I first thougt that it does this only in the "economy" position , but that is not true , happens always...

[wtdash]

My real question is : What means "more agressive AWD map" ?

 

An extra reduction compared to "1" selected in D ?

 

I believe this means it is closer to a 50/50 split front and rear. No extra reduction, as there is no 'dual-range' (low and high) 4WD option - unless you have one in your country - you'd know this as you'd have an extra lever. Like this:

 

There are more issues not known (to me...) with 4EAT :

There is at about 90Km/h an upshift (In case of no or low acceleration) to what ? Overdrive ?

I first thougt that it does this only in the "economy" position , but that is not true , happens always...

 

4 speed automatics in most cars I've driven have an extra 1/2 a gear before the overdrive....If I have a slight hill, my 4EAT will down shift slightly and the RPMs will rise a few hundred. If it gets steeper, it'll then shift to 3rd and RPMs will rise a thousand or more. If I step on the accelerator enough, it'll skip the 1/2 gear and go straight from overdrive to 3rd. Does that sound accurate?

[nipper]

 

 

 

4 speed automatics in most cars I've driven have an extra 1/2 a gear before the overdrive....If I have a slight hill, my 4EAT will down shift slightly and the RPMs will rise a few hundred. If it gets steeper, it'll then shift to 3rd and RPMs will rise a thousand or more. If I step on the accelerator enough, it'll skip the 1/2 gear and go straight from overdrive to 3rd. Does that sound accurate?

 

Counting gears can drive you batty on computer controled trannies

 

Between lockup being available in every gear, and the fact that they now engage two gears at once to smooth shifting, you can loose count. It still sometimes gives me a knot in my stomach on the 2-3 shift as sometimes it feels like a slip, but its actually 2nd and 3rd engaged, the TC unlocking, and the ignition shutting off for a split second to make for a smooth shift.

 

http://www.endwrench.com/archive/sysdrive.html will tell you someplace in there exactly how your transmission operates.

[Hendrik]

 

I believe this means it is closer to a 50/50 split front and rear. No extra reduction, as there is no 'dual-range' (low and high) 4WD option - unless you have one in your country - you'd know this as you'd have an extra lever. Like this:

 

 

No extra lever , but in 1 it brings me everywhere.

Only doubt I have from time to time , is that the sandcrossing need , it needs more power , and the 1.8L engine is fine but not very powerfull.

But , sofar always got away without help.

 

4 speed automatics in most cars I've driven have an extra 1/2 a gear before the overdrive....If I have a slight hill, my 4EAT will down shift slightly and the RPMs will rise a few hundred. If it gets steeper, it'll then shift to 3rd and RPMs will rise a thousand or more. If I step on the accelerator enough, it'll skip the 1/2 gear and go straight from overdrive to 3rd. Does that sound accurate?

 

Yes , it sounds familiar , but to reproduce it is another story.

But is it more of theoretical value , the internals off the technique and how it works , is very interesting.

[Legacy777]

My real question is : What means "more agressive AWD map" ?

An extra reduction compared to "1" selected in D ?

 

 

Yeah, means the torque split will probably be more towards 50/50 then it would if the manual button wasn't depressed.

[Legacy777]

 

4 speed automatics in most cars I've driven have an extra 1/2 a gear before the overdrive....If I have a slight hill, my 4EAT will down shift slightly and the RPMs will rise a few hundred. If it gets steeper, it'll then shift to 3rd and RPMs will rise a thousand or more. If I step on the accelerator enough, it'll skip the 1/2 gear and go straight from overdrive to 3rd. Does that sound accurate?

 

That's most likely the torque converter unlocking or locking.