Series V 3.89 differential

[alpine_64]

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.

In my original post I said the axle keys need upgrades ( you have done) and that ring gear bolts etc replaced ( any alpine) and if driven normally would be ok.

If you have sticky tyres or go round launching the car it will fail... If you have a very torquey motor and don't feed the power but snap the throttle ...it will fail... This did happen to a few guys... Who all drove them hard.. they all went to the ford 8.8 rear... This also allowed them more ratio selection and easy LSD options.

A mild V6 not drive hard on a rebuilt rear would be ok

 

[Bill Blue]

Jose was adament that the Alpine rear could not live long in his cars, which was a world of side stepping the clutch while wearing slicks on the drag strip. DanR has seen a lot of 2.8 conversions and continues to say the Alpine rear is fine with the 2.8, street tires and "normal" street driving. No real need for anything larger than the Ford 8", even on the strip. I've read it is good in a car, any horsepower, up to 2500 pounds. As I type this, aside from Jose, I cannot recall any reports of the 2.8 killing any Alpine rear.

Bill

 

[DougCoad]

Bill, thanks for your input. I think I'm more in your camp. I won't be taking mine to a drag strip or attemp to tear up the asphalt with it. Just curious about your V6 conversion. Is it stock or modified. Mine has been modified

 

[Bill Eisinger]

Bill, thanks for your input. I think I'm more in your camp. I won't be taking mine to a drag strip or attemp to tear up the asphalt with it. Just curious about your V6 conversion. Is it stock or modified. Mine has been modified

Not sure what you mean by modified…at this point I think they are all modified…

My engine has had all the modifications suggested by DanR including a mild cam but I’m going with a stock 2 BB intake and a Holley Sniper EFI…we dynod the engine when it was built but the dyno had some issues and we weren’t able to get definitive results but the expectation was that the engine was good for around 170 hp. I’m also going with an A4LD trans so slamming the clutch won’t be an issue.

 

[DougCoad]

Thanks. I'm thinking my engine will be around the same as I followed Dan's recommendations. I did go with a stage 2 cam and and Offenhauser intake, wasn't cheap. I'm using a T5 out of a Mustang GT but no plans to drop the clutch so hopefully I'll be good. Sounds like you're pleased with your results.

 

[Aladin Sane]

Nice looking engine. The other plus for my v8 conversion is my Dana came with 3.07 gears and a Traclok. I am running wide sticky tires.

 

[DougCoad]

I would imagine it's a fun ride.

 

[Aladin Sane]

I can only imagine at this point too. I dont have the engine and trans back in the car yet. I had hoped to be driving it this summer, but things have been very busy so far and there has been little time to work on the car.

 

[DougCoad]

I can totally relate

 

[Bill Blue]

Bill, thanks for your input. I think I'm more in your camp. I won't be taking mine to a drag strip or attemp to tear up the asphalt with it. Just curious about your V6 conversion. Is it stock or modified. Mine has been modified

I do not have and never had a V6 A;pine. My first version of the car had a turbocharged Pinto 2000. I was expecting over 200 hp and still had lead foot, so it was built with a Ford 8" rear. The turbo got sick and the car became a naturally aspirated 2000. The new Ford four valve four banger was a very hot topic at the time, so I acquired one thinking I could show everyone how to install 150 hp into an Alpine. Instead, I showed everyone a beast of an installation project. But the project lived on, first with a Ranger 2.3 four valve, then as a Fusion 2.5 with Ranger 5 speed. The car is now being rebuilt as 2.5 Fusion engine with a 2.3 Ranger head and cams, homemade intake and exhaust, sending power through a '92 Explorer 4.0, A4LD automatic tranny. The entire car is similar mish mash of parts hiding inside a stock body.

Over the years I have kept an eye on the 2.8 as it was the inspiration for the turbo 2000. I have gained a repupation as a 2.8 hater, when I've only been interested in seeing improvements to the 2.8 and the installation, as the 2.8 has its own problems that need to be addressed. DanR has started to lead the 2.8 Parade by actively attending to these problems. I am proud to admit that I have helped Dan with the majority of his solutions.

Bill

 

[DougCoad]

Sounds like you have quite a history with the alpine. I think we've overcome most of the obstacles with the 2.8. The one thing we haven't worked around yet is hooking up an oil cooler. I did get an installation kit from Dan Including motor mounds, headers and the actual 2.8 block and heads.

 

[todd reid]

I've had an oil cooler on my 2.8 for 30 years! I didn't even know that was an "issue".

 

[DougCoad]

Todd, Would it be possible to take a picture or 2 of the installation if its not too much trouble ? We're having a problem hooking up the lines as there's not enough room to connect to the block.

 

[911tr8r]

I also am struggling with diff issues. The stock diff in my S5 causes my car to turn 4K rpm at 55mph. Took it to best shop in town and they said no parts available. Told me to install Dana housing and youj could put in any gear ratio. OTOH I see listed here that Capri or Bobcat gears would fit right into the stock Alpine housing. Or?

 

[DougCoad]

My seriesV has a 3.89. Not quite as bad. With the T5 it should help

 

[todd reid]

911tr8r
First thing to do is check the accuracy of your tach - it is 50+ years old and they are known to loose calibration. My tach was reading approx. 500rpm high. Next question: do you have a 4:22 or 3:89 rear? Easy test is to jack 1 rear wheel off the ground and put tape on both the drive shaft and the tire. turn the drive shaft 2 complete revolutions. Your tire should either slightly more (3.89) or slight less (4.22) than 1 revolution. If you have a 4:22 you can swap in a 3:89 (or 3:70 if you can find one). If you have bolt on wheels consider moving up to 14" wheels. Ford Mustang/Fairmont used the same bolt pattern. I originally had a 4:22 and 165/80-13 tires. Moving to a 3:89 and 165/80-14 tires made a big difference.

 

[todd reid]

Doug,
I will try to get you a couple pictures, but the gist was to use a remote oil filter set up - off the shelf parts from NAPA. Run the return line back thru the oil cooler.

 

[DougCoad]

Okay thanks

 

[DougCoad]

If it's not bother a picture may help. Did you use stock oil cooler or after market.

 

[DougCoad]

911tr8r
First thing to do is check the accuracy of your tach - it is 50+ years old and they are known to loose calibration. My tach was reading approx. 500rpm high. Next question: do you have a 4:22 or 3:89 rear? Easy test is to jack 1 rear wheel off the ground and put tape on both the drive shaft and the tire. turn the drive shaft 2 complete revolutions. Your tire should either slightly more (3.89) or slight less (4.22) than 1 revolution. If you have a 4:22 you can swap in a 3:89 (or 3:70 if you can find one). If you have bolt on wheels consider moving up to 14" wheels. Ford Mustang/Fairmont used the same bolt pattern. I originally had a 4:22 and 165/80-13 tires. Moving to a 3:89 and 165/80-14 tires made a big difference.