How much HP and Torque?

[UK Explorer]

Hi,

Hopefully a simple question!..

How much BHP and Torque can the standard transmission in a AWD 4.0L OHC take before it is on the limit?

Thanks

 

[gijoecam]

IMHO, it's marginal for stock use. A couple simple mods that add a few ponies aren't going to hurt anything. Bolt a supercharger or turbocharger to the engine, and the tranny will be short for this world.

I've never seen any actual numbers though...

-Joe

 

[chriswells78]

Kabukie put a roots blower on his with 6# of boost and grenaded a spider gear in his rear going from 2nd to 3rd on the drag strip. I witnessed this, pushed that damn thing all the way back from the end of the strip to the pits. The next day when we replaced his rear, it wasn't pretty. He was probably only pushing in the neighborhood of 300hp in his SOHC.

 

[Spdrcer34]

That is weird....I have PERSONALLY seen the 8.8" rear-end take as much as 630 RWHP/690 ft/lbs, in a 3,600lb SN95 and still live at the track. Short times were 1..48-1.59

A 16 sec. Explorer should have NEVER had that issue.

The transmission should be the first thing to break....

Ryan

 

[chriswells78]

I too have seen 8.8's take that kind of abuse, but in 3500# Mustangs with 26" tires. Joe was running it in a 4000# explorer with 30" tires. I think that is where the problem was. Joe's was open too, not L/S or a locker. He's got a limited slip now

 

[IAmTodd]

I too have seen 8.8's take that kind of abuse, but in 3500# Mustangs with 26" tires. Joe was running it in a 4000# explorer with 30" tires. I think that is where the problem was. Joe's was open too, not L/S or a locker. He's got a limited slip now

The speed difference from side to side with an open diff causes the destruction of the spider gears. Its all too common with high horsepower Saabs with no L/S. Being that the diff and trans in those are together, it takes the trans case to its knees as well, viscious cycle!

 

[chriswells78]

Makes sense, I would immagine the 30" tires would compound the speed difference problem too.

 

[kabukie]

Kabukie put a roots blower on his with 6# of boost and grenaded a spider gear in his rear going from 2nd to 3rd on the drag strip. I witnessed this, pushed that damn thing all the way back from the end of the strip to the pits. The next day when we replaced his rear, it wasn't pretty. He was probably only pushing in the neighborhood of 300hp in his SOHC.

Hey I witnessed that... it was a PITA pushing that thing back...

That is weird....I have PERSONALLY seen the 8.8" rear-end take as much as 630 RWHP/690 ft/lbs, in a 3,600lb SN95 and still live at the track. Short times were 1..48-1.59

A 16 sec. Explorer should have NEVER had that issue.

The transmission should be the first thing to break....

Ryan

I ran a 17 blowing up the rear and coasting 1/3 - 1/2 the way... I would think a 15 would be a more reasonable guess

 

[justin146]

My axle has held up to some ~5 second 0-60 runs, but part of that power is going to my front axle...

James's truck is faster than mine and RWD, he uses slicks at the track. His tranny held up to about 400whp before it started slipping; then he did a tranny swap in favor of the V8's 5r55.

 

[jah81592]

IMHO, it's marginal for stock use. A couple simple mods that add a few ponies aren't going to hurt anything. Bolt a supercharger or turbocharger to the engine, and the tranny will be short for this world.

I've never seen any actual numbers though...

-Joe

I run 8.27 with 8# boost on mine at the track. Keep the bands tight and service regularly. Get the tranny a tune to up the line pressures and the 5R55E will live. This is one tough unit. Keep in mind heat is the killer of these trannies and I believe this is the sole reason for the negative publicity for the little 5R55E. Keep it cool, keep it adjusted and keep it serviced and you won't have any probs (or shouldn't). Neutral slams---> out of the question, quick way to kill it. LOL

I pulled mine out with 140K before I did the 5R55S swap and it was still pulling fine. But, there was wear in the input and output shaft bushings. The trans wouldn't hold anything above 8# boost and time was borrowed. Keep in mind that I put 500+ track passes and 200+ were on slicks with 2450rpm launches. So my analysis is the tranny is very tough. Although treat it wrong and it will repay the favor.

My axle has held up to some ~5 second 0-60 runs, but part of that power is going to my front axle...

James's truck is faster than mine and RWD, he uses slicks at the track. His tranny held up to about 400whp before it started slipping; then he did a tranny swap in favor of the V8's 5r55.

One thing to remember guys is the gen 2 Explorers have 31T axles. Not only that but they have 31T big bearing axles (roughly 1/4" diameter larger) than the 31T standard Mustang axles. I am making around 450 ft.lb torque and they have lived well. If you break or bend one then obviously you have tried!

 

[chriswells78]

My axle has held up to some ~5 second 0-60 runs, but part of that power is going to my front axle...

James's truck is faster than mine and RWD, he uses slicks at the track. His tranny held up to about 400whp before it started slipping; then he did a tranny swap in favor of the V8's 5r55.

Are you and James running open or L/S?

 

[justin146]

Are you and James running open or L/S?

Limited slip in my truck; I am pretty sure James has the same.

 

[UK Explorer]

thanks guys,

so in summary, I do have a LSD and 4x4 so as long as I treat it well I should be good for 400/450bhp and about 400/450Ib of torque?

 

[Spdrcer34]

That 8.8" in your heavy Explorer SHOULD be good for 400-500 hp...

Ryan

 

[UK Explorer]

Let the mods begin !!