T-56 1-6 Gear ratios?
07-09-2014, 12:50 PM
#1
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T-56 1-6 Gear ratios? Car is in my sig, just wondering what the real advantage is to change from the stock 1-4 gears to a closer ratio gear like below:
2.97-1st,
2.07-2nd,
1.43-3rd,
1-1-4th,
0.84-5th,
0.63-6th
Currently I have a 3.73 gear in the rear, I have been planning to change it back to 3.52~ or whatever the 12 bolt equivalent is. Seems like its a lot easier to change the rear end gear than the transmission gears but my trans is out right now and I'm more than likely doing a Magnum conversion which is all new gears anyway so now's the time if I want to change. I understand the benefit for overall drive shaft speed through the gears but to me at least it seems like I would never spool a single turbo 1-2 with gears this short? The car is mostly street driven so that's not a major issue but when I do bolt slicks on it I would like for it to go not do the Honda 10k rpm -> shift 10k rmp -> bog thing.
Opinions and knowledge greatly appreciated.
2.97-1st,
2.07-2nd,
1.43-3rd,
1-1-4th,
0.84-5th,
0.63-6th
Currently I have a 3.73 gear in the rear, I have been planning to change it back to 3.52~ or whatever the 12 bolt equivalent is. Seems like its a lot easier to change the rear end gear than the transmission gears but my trans is out right now and I'm more than likely doing a Magnum conversion which is all new gears anyway so now's the time if I want to change. I understand the benefit for overall drive shaft speed through the gears but to me at least it seems like I would never spool a single turbo 1-2 with gears this short? The car is mostly street driven so that's not a major issue but when I do bolt slicks on it I would like for it to go not do the Honda 10k rpm -> shift 10k rmp -> bog thing.
Opinions and knowledge greatly appreciated.
07-10-2014, 03:07 AM
#4
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1 and 2 are closer, but the rest are further apart.
Op, the point of a closer ratio trans is to keep the rpm drop between gear less. If you peak tq at 4600 and peak hp at 6100 (like my car) then you'd want to shift just after peak hp and drop right into peak tq at a minimum. Spacing the gearing out properly can accomplish this. Luckily my powerband and stock T56 gear ratio's actually work out nicely with this minus the 1-2 shift. Once the transmission gear ratios are matched to engine power band, then you can mess with the rear gear to optimize track performance.
If anything, I think a taller first (like a 2.36:1) gear would be better to bring 1 and 2 closer then adjust the final drive ratio (like 4.10) to maximize speed for what you want it to do (top out in 4th at 1/4 mile on 26" tires).
Op, the point of a closer ratio trans is to keep the rpm drop between gear less. If you peak tq at 4600 and peak hp at 6100 (like my car) then you'd want to shift just after peak hp and drop right into peak tq at a minimum. Spacing the gearing out properly can accomplish this. Luckily my powerband and stock T56 gear ratio's actually work out nicely with this minus the 1-2 shift. Once the transmission gear ratios are matched to engine power band, then you can mess with the rear gear to optimize track performance.
If anything, I think a taller first (like a 2.36:1) gear would be better to bring 1 and 2 closer then adjust the final drive ratio (like 4.10) to maximize speed for what you want it to do (top out in 4th at 1/4 mile on 26" tires).
07-10-2014, 12:07 PM
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Thanks hr, that makes since, I am on a relativity small turbo so it spools at any point after the shift, to be honest a little longer 3-4 might be a little better to stay in the power longer.