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Posi traction question

J

JavierN

Guest
Hi guys,

I'm looking to upgrade the gears in my '88 and I would like to install an 3.73 Eaton Positraction Differential to get full usage of the power, is an auto and running 310 HP.

My concern is about drivability since I drive it every day to work, How will it corner on the street? on the freeway? I also like to drive it in long trips on the highway.

Will it loose drivability?
 

Ken

Gone but not forgotten
Joined
Jan 30, 2001
Messages
8,236
Location
Hermosa Beach, CA
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1987 Z51 Silver Coupe
Do I understand you to mean that you are going to swap the independent rear with a live axle rear end?

The "driveability" issues, as far as road-handling is concerned, would be you major drawback, but if you're only interested in straight-line acceleration, then a live axle is the way to go for dependability amongst other things like gears and axle selections, etc.. ;)

_ken :w
 
Joined
Oct 30, 2001
Messages
2,273
Location
Glen Burnie, MD, USA
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1986 Bright Red Coupe
I'm confused, Ken - don't we already HAVE posi rear ends? Positraction is just a brand name of a particular limited-slip differential (like TorSen) - there should be zero driveability issues because the differential never locks. It will just allow some power (varies by application) to get to the non-slipping wheel.

Anyway, I thought an LSD rear was standard equipment since the 70's.
[RICHR]
 

Ken

Gone but not forgotten
Joined
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Messages
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Location
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1987 Z51 Silver Coupe
The only thing I could find on the Eaton posi unit was in regards the Nova and Z28 rear ends. :confused

_ken :w
 

Hib Halverson

Technical Writer for Internet & Print Media
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Your 88 already has a limited-slip (or "Positraction") differential.

If you are autocrossing and sense that the limited-slip is not working, then you need to overhaul the rear axle assembly.
 
J

JavierN

Guest
Ken,

I'm not intended to use it for off road or drag racing only, but I'd like to upgrade it and will get a 3.73 for sure, but I noticed that when burning tires only one does the trick.

Thanks guys for the replies.
 
Joined
Oct 30, 2001
Messages
2,273
Location
Glen Burnie, MD, USA
Corvette
1986 Bright Red Coupe
Ken, this is on their product info page for the posi rear:
"The key here is that a limited-slip differential's power transfer is primarily based on input torque. So, with normal or light throttle applications on dry pavement, only the drive wheel receives torque, or power - just like an open differential."

Eaton sells some cool electronic full lockers (offroading and dirt track). Neat to take one of those to the strip because with the push of a button BOTH rear wheels aer locked together...

A simple test for your posi rear: jack up the back of the car and, with the transmission in neutral, turn one of the rear wheels. If the opposite side turns the OPPOSITE way, your differential is open (or broken). If it turns the SAME way, then it's posi/LSD (and still working).

[RICHR]
 
J

JavierN

Guest
rrubel,

I haven't try the test you mentioned but in the case of an open differential, is it easy to upgrade it with those electronic lockers?

I was thinking the other day on how to utilize an electronic device to lock and unlock the differential and make some money of it, well, I don't have to worry any more.

Also was thinking how to make an electronic supercharger but some body had that idea before me, the problem is that it works like a regular mini fan mounted directly to the air intake and should be used only while in WOP. But if anybody can sincronize it electronicaly to the RPMs it should be a lot of $$$$ in reward. Just think on all the aplications.

Anyway, just a thought.
 
Joined
Oct 30, 2001
Messages
2,273
Location
Glen Burnie, MD, USA
Corvette
1986 Bright Red Coupe
I only know people who off-road that upgraded to electronic lockers. It's essentially a matter of replacing the rear diff (or front in their case), running power to it and running a control line to the cabin.

Regarding an electric supercharger, I would expect that any reasonably high-pressure one would be such a drain on the battery/alternator that you'd wind up losing power. I *think* Eaton has an electro-mechanical one but it's been in development for years and still isn't out.
[RICHR]
 

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