How much power can a stock automatic handle?

[MyRedZx5]

I did a search in here but didn't find a "for sure" answer to I was wondering.
(Probably didn't look hard enough). I have heard that the stock ATX in the foci will only handle about 150 FWHP. How true is this?

Thanks

[blueovalbaboon]

it's not HP that kills them but torque

the torque convertor is the weak link and technically not rated for any more torque than the zetec is putt9ing out (135 ft lbs at the flywheel is what its rated for)

after that the clutches will go...they tend to hold abt 150 fwhp, like you said

Lentech and Performance automatic will either supply the parts for a rebu9ild yourself or they'll send you a whole transmission, lentech has one or two levels higher strength above the PA unit, although they both make one that hsould be more than adequate for mild FI and nitrous use (anything pump gas)

[Raysinda2001zx3]

something like a JRSC... would it still be a daily driver, shift-feel wise?

[blueovalbaboon]

the transmission will shift as soft as it always has with a JRSC

soft shifts kill transmissions though, because during a shift is a high friction moment, high friction = high heat = tranny death.

a JRSC will eventually kill your tranny. TooleBox had them go on him really really fast. JeffN has lasted longer than I thought he would.

[Majikal]

Now, with a JRSC and this soft shift problem, is it possible to have a chip programmed for hard shifting to be compatible with the JRSC?

[blueovalbaboon]

absolutely

i still feel like the hardware would be a weak link

the clutches would still eventually slip and the TC woudl still evnetually crap itself

[Z63R]

The 2nd and latest issue of Focus Fanatic has a Lentech article which says something like this:

The 4F27E has been beefed for the PZEV with more clutches in the forward clutch drum. The planetary gearsets are pretty strong; w/ other mods to the trans, they could handle up to 500 HP.
Stock, the torque capacity is 270 ft/lbs.

...but you know me... often wrong, but never in doubt.

[blueovalbaboon]

that's the torque convertor capacity, AFTER The torque converter multiplies the input torque by 2

thus torque converter capacity is 135 lb ft

if the ATX is rated for 270 lb ft, why do we use the AXOD-E and CD4E in v6 applications? CD4e is rated for 400 lb ft, yet it's behind a 190 olb ft motor, AXOD is rated for abt 500 lb ft, yet its behind a 245 lb ft motor.

point made?

don't believe me search in zetec tuning all abt it.

[Z63R]

thus torque converter capacity is 135 lb ft

point made?

don't believe me search in zetec tuning all abt it.

And it is VERY nice to meet you, sir!

The 2.3 PZEV develops what, 149 lb ft?

Go figure.

[hidrive]

And it is VERY nice to meet you, sir!

The 2.3 PZEV develops what, 149 lb ft?

Go figure.

I think he may mean at the wheels... I've always been curious what the ATX on the PZEV is capable of. I have a ZX3 with the 2.3 and an auto and am a little wary of modding because for all I know the atx could be hanging on a showstring right off the bat.

[blueovalbaboon]

we know they changed some of the weaker parts in the tranny including the clutch bands and the Torque convertor. I gave you guys the zetec figures, not being a duratecker. I haven't yet seen a firm number for what the new TC can handle

I was trying to let him know that he'll roast his TC if he thinks it can take 200+ lbft of torque. Evidently he dont' care

[Z63R]

Hey, Hidrive and Blue Oval Baboon!

No disrespect intended; you guys know your sh**.

We were talking about two diff'rent things. The Ford part # nomenclature:

4F27E
4) # of forward gears
F) front whl drive
27) add a zero for torque capacity
after the converter
E) electronically controlled

Whatever we were talking about after that, I forget.
Having said that,though, I do care about my equipment; but I will be modding suspension, tires and brakes way B4 I add any appreciable amount of power. My car's a driver and, having turned out a couple of knuckle draggin' machines in the past, I'm kinda likin' a bone stock driveline right now.
Besides, the 149 lb ft at the flywheel (stock) in the PZEV
is fine for a commuter. I get my ya-ya's out on Gran Turismo 3 (w/ the Logitec wheel and pedals), racing 1/10th scale touring cars and open tracking a friend"s 400 hp '65 Shelby at Willow.
You guys take it easy

[hidrive]

Hey, Hidrive and Blue Oval Baboon!

No disrespect intended; you guys know your sh**.

We were talking about two diff'rent things. The Ford part # nomenclature:

4F27E
4) # of forward gears
F) front whl drive
27) add a zero for torque capacity
after the converter
E) electronically controlled

Whatever we were talking about after that, I forget.
Having said that,though, I do care about my equipment; but I will be modding suspension, tires and brakes way B4 I add any appreciable amount of power. My car's a driver and, having turned out a couple of knuckle draggin' machines in the past, I'm kinda likin' a bone stock driveline right now.
Besides, the 149 lb ft at the flywheel (stock) in the PZEV
is fine for a commuter.

I hear that, I'm going to take the same approach as soon as get enough expendable income. Suspension, get rid of these squeaky-ass brakes, maybe some weight reduction here and there via racing seats, etc.. I think my 2.3 kicks ass, even if it is an auto it gives me everthing I need.... for now.

Anyhoo, welcome aboard here, glad you like your car as much as I do.

[Z63R]

Abbo-frikkin-lootley!

[blueovalbaboon]

aright bud

I've been a bit touchy lately, sry.

you got the designation absolutely right. Torque after the convertor is twice what comes out BEFORE the converter...hence the 135 lb ft figure i gave you

miscommunication...ah...the thing that makes chatboards full of arguments for no reason.

Technically, the 4f27E is no longer the 4f27E because the new TC is stronger

I have my fun w/ drivetrain armchair engineering, so I'm going nuts on my auto PZEV as soon as I buy it.

[Z63R]

EXCELLENT, SIR!

May you be able to buy it tommorow, is my wish for you, so that you may enjoy Lincoln Town Car smoothness, and a level of refinement unprecedented in this class.

I was starting to make excuses for having the auto even tho I think it's a really good one... kinda like the " if I have to explain, you wouldn't understand" thing.

You, sir, may have forgotten more than I'll ever know...

[blueovalbaboon]

I learned most of it off of here

[BlackZX321]

4L60-E... Now were talking GM nomenclature

[Z63R]

4L60-E... Now were talking GM nomenclature

YES,sir! Is that not some serious hardware?

However, we are FORD people here, sir!

[P-51]

Ok, I'm gonna hang this one out here once and for all, since we have this cool new forum. I'll only say this once:

I used to be an engineer at Ford Automatic Transimission Operations.

As has been mentioned, the 4F27E was designed for 270 ft-lbs AFTER torque converter multiplication. The torque converter multiplies the torque by almost 2, so the transmission is at it's design limit with a Zetec.

The issue is the durability of the 3/4 clutches (not the TQ). They just can't take the energy dumped in by a higher torque motor. It's the actual energy they have to absorb on a shift, not the actual torque while in gear, that is a problem.

As has been mentioned, tightening up your shifts will help, because the shift is faster, and thus you dump in less energy on a shift.

Ford was fully aware of the potential problem with the clutches and the PZEV. So, in mid-2004 model year, they upgraded the clutches to go with the introduction of the PZEV. Internally, they referred to them as "high energy" clutches. In fact, ALL Foci got the stronger clutches in mid-2003 MY, I believe the build date switchover was December, or somewhere thereabouts.

That also may not be a hard date... since the plant has a propensity for losing parts, then finding them a few months later and putting them on the line. Particularly for running changes, which is what this was.

IIRC, there is a code on the tranny that tells you which one you got, but I can't remember off the top of my head. I was able to verify I got it on our 2003 Wagon, built in January 04.

Also, IIRC, the new clutches were designed for 30-40% more energy than the old clutches. Again, not torque, but energy. You can even get some custom made 1-sided clutches that can take twice the energy, but they didn't go this route, I can't remember if it's cost or shift quality.

I would think a high energy clutch tranny, with tightened up shifts, might live behind a turbo Zetec. The early transimissions were at their design limit in stock form. You might be able to live with them if you don't do full power 3-4 shifts, or at least not many 3-4 shifts in close succession. It's the repeated energy dumps that overheats them, and kills them.