Series V 3.89 differential

[DougCoad]

How much horsepower will this differential hold up to.

 

[alpine_64]

There are a few factors.

There is HP. And torque.. how much traction you have ( sticky tyres) and how you plan on using it.
If you often hard launch an alpine rear and have sticky tyres you will break it...
The stock axle keys are a weak point and can break and cause you to spin an axle.

The ring gear bolts have washer tabs under the nuts that crush and allow the bolts to vibrate and work loose.

If you add HP to the car but drive it normally it's probably fine... Some of the v6 conversions have done that. Once you add a lot of torque that will put pressure on the rear end.

I would say the stock rear with harder axle keys and the ring gear bolts snugged up are fine to 120-30hp for normal driving .... But if you hammer it ... It won't last

 

[DougCoad]

Thanks for the insight. I am doing the conversion. Estimate around 180 hp at the crank. I don't plan on running hard.

 

[DougCoad]

I am also adding limited slip. Don't know if that will make a difference.

 

[Shannon Boal]

Did not know that limited slip differential was an option, where didja get it?

 

[DougCoad]

 

[DougCoad]

From the UK.

 

[Aladin Sane]

Not this much. I replaced mine with a Dana 44 out of a postal jeep.

 

[DougCoad]

What engine is that

 

[Barry]

How much horsepower will this differential hold up to.

I am also adding limited slip. Don't know if that will make a difference.

Thanks for the insight. I am doing the conversion. Estimate around 180 hp at the crank. I don't plan on running hard.

I can't imagine putting a 180 HP Ford 2.8 V6 and a limited slip differential in a Series Alpine and then not stepping on the loud pedal. I'll take the under on the Alpine rear axle lasting 3 months.

 

[DougCoad]

You may be correct.

 

[Barry]

You may be correct.

Doug,

I suggest that you follow-up on post #8 in this thread by Aladin Sane. He is doing an Alpine V8 conversion with about double your estimated power.

Entering "postal jeep" and posted by "aladin sane" in the search function at the top right of any forum page will show a bunch of posts that are relevant to your project.

Welcome to the DARK SIDE.

 

[DougCoad]

Doug,

I suggest that you follow-up on post #8 in this thread by Aladin Sane. He is doing an Alpine V8 conversion with about double your estimated power.

Entering "postal jeep" and posted by "aladin sane" in the search function at the top right of any forum page will show a bunch of posts that are relevant to your project.

Welcome to the DARK SIDE.

Thanks will do

 

[jumpinjan]

I think its the "shock" of sudden torque that will break things. I would rebuild the 3.89 differential and get new bearings and so on. But, thats the problem, can't find new parts like bearings
Jan

 

[DougCoad]

Thanks. I don't plan on dropping the clutch of the line. I didn't k own parts are hard to come by.

 

[jumpinjan]

Hmm, well I check Rick's catalog and the pinion & carrier bearings are listed
Jan

 

[Aladin Sane]

What engine is that

Its a ford 302 from an 87 mustang gt. It's carbureted and should make about 250 hp.

I converted the Dana from drums to discs.

 

[DougCoad]

Looks awsome

 

[Aladin Sane]

I hope it works awsome.

 

[Bill Eisinger]

I’m just curious…I have seen a number of discussions here and in other threads about
”breaking” a rear end but does anyone actually have first hand experience with that and, if so, under what circumstance ?…for my SI V6 conversion project I completely rebuilt the stock rear end, new bearings all around, added the hardened axle keys, etc….I don’t plan to lose any sleep over something giving loose but, then again, I don’t anticipate going to the drag strip with it. Seems like there are quite a number of V6 conversions running around with stock rear ends that are performing just fine.