2.66 1st 1.78 2nd, why??
06-25-2008, 03:18 PM
#1
2.66 1st 1.78 2nd, why?? just wondering why the T56 in the later cars arent geared better. seems like a lot of guys run 4.10s with the 6 speed to make up for the longer 1st and 2nd. why arent these geared like most other sticks, 2.95 1st and 1.94 2nd?
06-25-2008, 04:06 PM
#4
Some has to do with the strength also. Heavier/powerful cars can shred gears if the ratio gets too numerically high. The tooth count gets too low and can't hold up. The Z06 got the M12 over the MM6 because it was lighter and could use it to accelerate quicker.
If you look back at the old T5 trans, they had 3.35 first gears and started shreding with small amounts of power. The Zbox strengthed them just by lowering the ratio down to 2.95..
mike
If you look back at the old T5 trans, they had 3.35 first gears and started shreding with small amounts of power. The Zbox strengthed them just by lowering the ratio down to 2.95..
mike
06-25-2008, 06:03 PM
#6
well i cant disprove the strength vs ratio theory. dont the 03-04 cobras have the 2.95 first gear t56? they make gobs of torque and arent to light. my girlfriend has an LS1 Z with an auto the car makes real good power but its a peaky motor, seems like the 2.95 gear would be better for drag racing.
06-26-2008, 12:21 PM
#8
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synchros have nothing to do with torque capacity of the gears. The GT0 has a 2.97 1st gear . The later T56s have wider gears and ,as such, can carry more torque. The T5 is a much smaller box( center distance of 77mm VS 85mm of the T56) and this limited the torque capacity more than anything else. Jeep T5s had 4.03 1st gear but no torque capacity.
06-26-2008, 01:20 PM
#9
Ummmm, ok.. Splitting hairs, but I didn't say they increase the capacity of the gears, but they do increase the TQ capacity of the Transmission.
???
Just installing a 2.95 gearset in place of a 3.35 gearset raises the TQ capacity of the T5 by 50lb-ft.. I'm not saying the T5 is not limited by its center distance, just a gearset change.
Are you saying the Jeep T5 has unlimited TQ capacity? Zero TQ capacity? If this is the same T5 that was in the S10/V6 T5, it definitely has a TQ capacity, and it's VERY low..
YMMV
mike
The GT0 has a 2.97 1st gear . The later T56s have wider gears and ,as such, can carry more torque.
The T5 is a much smaller box( center distance of 77mm VS 85mm of the T56) and this limited the torque capacity more than anything else.
Jeep T5s had 4.03 1st gear but no torque capacity.
YMMV
mike
06-27-2008, 06:40 AM
#10
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Mike , It seems you get a little testy when you're wrong. Let me restate:
The synchros affect shift capacity = as in available work to shift. More frictional surface area/ more work capacity/ higher shift RPM. This has nothing to do with the torque rating of the box- NOTHING. The totque capacity of the gearing is rooted in tooth design/ materials AND ratio.
As I stated the face width of the gearing in a T56 was changed( wider) and , as such, increased the torque capacity in the ratio sets by virtue of contact area.
When I said the 4.03 T5 had no torque capacity I did mean low( not zero)
The synchros affect shift capacity = as in available work to shift. More frictional surface area/ more work capacity/ higher shift RPM. This has nothing to do with the torque rating of the box- NOTHING. The totque capacity of the gearing is rooted in tooth design/ materials AND ratio.
As I stated the face width of the gearing in a T56 was changed( wider) and , as such, increased the torque capacity in the ratio sets by virtue of contact area.
When I said the 4.03 T5 had no torque capacity I did mean low( not zero)
06-27-2008, 04:58 PM
#13
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GTO uses an MN12 same as the C5 Z06. They in 05+ models produce more torque, and are heavier than their f-body counterparts. The MN12 has steeper gears, (2.97 1st, 2.07 2nd) and seems to have no problems holding the extra torque and weight of a GTO, into the 10s stock.
