Top Loader gearbox
11-19-2010, 01:46 AM
#1
Drifting
Thread Starter
Top Loader gearbox
Not sure if you boys and girls have seen this yet.
One of the Australian Landshark boys adapting a top loader to convert his auto to manual.
http://928.landsharkoz.com/Forums/ta...c/Default.aspx
One of the Australian Landshark boys adapting a top loader to convert his auto to manual.
http://928.landsharkoz.com/Forums/ta...c/Default.aspx
11-19-2010, 02:50 AM
#3
Nordschleife Master
The end result looks passable, but my gosh, why would you use a gearbox from the 60's ?
I was going to try the same thing with the Tremec T56 from a corvette. Same idea using adapter plated to mount to the factory rear diff in the automatic and I would create a new mainshaft to couple to both the TT and the pinion gear.
Really odd to move the clutch to the back ala 944 also.
I wish this guy would have just used something more modern then he could build a kit and help us all. But no way in hell would I put that transmission in any car.
I was going to try the same thing with the Tremec T56 from a corvette. Same idea using adapter plated to mount to the factory rear diff in the automatic and I would create a new mainshaft to couple to both the TT and the pinion gear.
Really odd to move the clutch to the back ala 944 also.
I wish this guy would have just used something more modern then he could build a kit and help us all. But no way in hell would I put that transmission in any car.
11-19-2010, 03:23 AM
#4
Administrator - "Tyson"
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11-19-2010, 03:30 AM
#5
Burning Brakes
hmmmm now this could be something to considder if i ever get around to putting the caddy 500 in one of the parts cars here awsome job sir and good luck with the rest of your build
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11-19-2010, 11:54 AM
#10
Rennlist Member
The end result looks passable, but my gosh, why would you use a gearbox from the 60's ?
I was going to try the same thing with the Tremec T56 from a corvette. Same idea using adapter plated to mount to the factory rear diff in the automatic and I would create a new mainshaft to couple to both the TT and the pinion gear.
Really odd to move the clutch to the back ala 944 also.
I wish this guy would have just used something more modern then he could build a kit and help us all. But no way in hell would I put that transmission in any car.
I was going to try the same thing with the Tremec T56 from a corvette. Same idea using adapter plated to mount to the factory rear diff in the automatic and I would create a new mainshaft to couple to both the TT and the pinion gear.
Really odd to move the clutch to the back ala 944 also.
I wish this guy would have just used something more modern then he could build a kit and help us all. But no way in hell would I put that transmission in any car.
07/07/2010 3:30 PM
Hello There
I tske it the top loader is a 4 speed option? woudnt it be better to choose a replacement 6 speed or at least a 5 speed unit .
In my opinion, and I do not denigrate your engineering ability , the 4 speed replacement is a retro step . I think you could find a market both here and overseas by sourcing a heavy duty replacement unit in 6 speed variety , as there are a few stroker units around with broken transmissions.
Anyway my 10 cents worth .
Best regards
John Gill
Hello There
I tske it the top loader is a 4 speed option? woudnt it be better to choose a replacement 6 speed or at least a 5 speed unit .
In my opinion, and I do not denigrate your engineering ability , the 4 speed replacement is a retro step . I think you could find a market both here and overseas by sourcing a heavy duty replacement unit in 6 speed variety , as there are a few stroker units around with broken transmissions.
Anyway my 10 cents worth .
Best regards
John Gill
07/07/2010 4:41 PM
John, for a highly strung high revving motor with a narrow powerband you are correct and I had a think about that too but you would have to appreciate for my car that I just don't need that many gears. Also for a 928 you don't really need or want a taller 5th gear and most all 5 and 6 speed boxes are overdrive 5th and 6th which would mean you would need a different diff and lose the direct coupled top gear which I think is a great feature of the 928 5 sp.
During my research I found a US drag racing forum for guys with supercharged big blocks and this is the only box they use, albeit a modified one.
One of them had the quote
"If you've got too much torque and want a manual then you need a toploader, If you think you need more than 4 gears then you don't have too much torque."
They all use the close ratio toploader which has a 2.32 : 1 1st gear.
The only reason I use first currently is because if I take off in second with boost and the wheels don't spin it will jump out gear.......with some perturbing bang noises.
The 2.78 first will be smack in between the G28-05 first and second so I can do a touch over 100km/hr in first. The ratio spread is quite nice and top is direct obviously which lets me use the auto diff setup which is really quite clever for mods with its hollow pinion. Also the 4 speed toploader is very similar length to the 928 3 sp auto.
John, for a highly strung high revving motor with a narrow powerband you are correct and I had a think about that too but you would have to appreciate for my car that I just don't need that many gears. Also for a 928 you don't really need or want a taller 5th gear and most all 5 and 6 speed boxes are overdrive 5th and 6th which would mean you would need a different diff and lose the direct coupled top gear which I think is a great feature of the 928 5 sp.
During my research I found a US drag racing forum for guys with supercharged big blocks and this is the only box they use, albeit a modified one.
One of them had the quote
"If you've got too much torque and want a manual then you need a toploader, If you think you need more than 4 gears then you don't have too much torque."
They all use the close ratio toploader which has a 2.32 : 1 1st gear.
The only reason I use first currently is because if I take off in second with boost and the wheels don't spin it will jump out gear.......with some perturbing bang noises.
The 2.78 first will be smack in between the G28-05 first and second so I can do a touch over 100km/hr in first. The ratio spread is quite nice and top is direct obviously which lets me use the auto diff setup which is really quite clever for mods with its hollow pinion. Also the 4 speed toploader is very similar length to the 928 3 sp auto.
11-19-2010, 12:09 PM
#11
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I think that is a cool option. If one had a lot of torque those tranny's can take it. Milage would suffer but I didn't buy a 928 to get good milage! I am with Hacker, being old school a rock cruscher tranny would be way cool. Hacker needs something like this for his beast!
I wonder how that would work if you had a 5 speed originally and not a auto?
I wonder how that would work if you had a 5 speed originally and not a auto?
11-19-2010, 12:30 PM
#12
Three Wheelin'
Looks like a great idea. Once the initial job is done,
parts are affordable & available. If you wanted to
take it to the next level for a track only car (no syncros) you could use one of these-
http://www.jericoperformance.com/wc4rev42.htm
parts are affordable & available. If you wanted to
take it to the next level for a track only car (no syncros) you could use one of these-
http://www.jericoperformance.com/wc4rev42.htm
11-19-2010, 06:58 PM
#15
Nordschleife Master
