Try Overdrive Re: <VV> 4Speed Powerglide?

[FrankCB at aol.com]

Keith,
    Reminds me that one of the reasons I bought my 1951  Hudson Hornet (in 
1955) was the Borg Warner overdrive that supplemented the "3  on the tree" 
(stock 3 speed manual transmission).  The BW unit was  added to the end of the 
stock trans and had a planetary gear set that gave,  in effect, 2 additional 
speeds to the stock 3 speed trans.  While most  people used the overdrive (about a  
0.7 ratio) as a simple 4th gear to  reduce the engine speed for cruising (it 
gave about 2.9 overall ratio), I also  used it when I was in 2nd gear 
especially when merging onto a major  highway.  The BW o'drive was semi-automatic, so 
while merging, if  necessary for a sudden major increase in acceleration, I 
would simply  "floor" the accelerator.  This instantly "kicked down"  the 
o'drive gearset from 0.7 to 1 moving the gearing combination from 2nd  gear PLUS  
o'drive to plain 2nd gear with a good increase in rpm  and pickup.
    The BW o'drive could be locked out  of operation (using a lever under the 
dash) thereby giving  just a straight 1:1 ratio useful in driving on steep 
hills.  In addition,  since it had an overrunning clutch inside, it also allowed 
clutchless shifting  (within certain limits).  Of course, as an inveterate 
"changer", I had  to add my own switch so I could "drop out" of o'drive without 
flooring the  accelerator pedal.
    All in all, it was a GREAT device and I'd love to  see somebody figure 
out how to install one on the end of a Corvair manual  OR PG transmission.  On 
the PG it would give, in effect, 4 forward  gears:  1.8, 1.3, 1.0 and 0.7.  
With the normal 3.55 rear,  it would drop the overall ratio in top gear to about 
2.5 and the rpm at 70 mph  from 3500 rpm to about 2500 rpm.
    Frank "stock is a good BEGINNING"  Burkhard      
 
 
In a message dated 2/14/2007 11:50:19 PM Eastern Standard Time,  
kwoodke at comcast.net writes:

the  narrator mentioned the PG had been engineered with a second planetary 
gear set  making for 4 forward speeds! Well that caught my ear. Now I have no 
idea how  this works. Maybe someone out there knows this set up? 
BTW this "guy " was  know for his hot 421SuperDuty Pontiacs. That is what was 
in the  Tempest  so this was one stout transaxle.
Alright figure out how this works and  report back I can't wait to have a 4 
speed auto  Vair.