Some Gear Calculations of Possible Interest
12-26-2005, 10:16 AM
#1
Staging Lane
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Some Gear Calculations of Possible Interest I see discussion about gears and the M6, and thought I壇 share some information. The following data assume stock tires (275/40R-17) that have a diameter of 25.66 inches and a circumference of 80.61 inches. The calculations for tires are easy. If you want them for a different tire size, let me know.
Below, keep in mind that the F-Body is electronically limited to 161 mph. It is also drag-limited. If the electronic limiting weren稚 there, and if you had a stock LS1, I think there is enough power in 5th gear to get to 168 or 169 mph before the drag equals the horsepower. If you shift to 6th, you will slow down because the engine doesn稚 make enough power to go that fast in 6th gear.
My car is a 2002 Camaro SS with the T-56 M6. At least for the 2002 year, the internal gear ratios for the T-56 are as follows:
1) 1st: 2.66
2) 2nd: 1.78
3) 3rd: 1.30
4) 4th: 1.00
5) 5th: 0.74
6) 6th: 0.50
7) Rev: 2.90
If your car has a 3.42 rear gear, then you could go 268 mph in 6th gear at 6000 rpm assuming you could GET 6000 rpm. In 5th, you can theoretically get to 181 mph at 6000 rpm. 4th is 134 mph and 3rd if 103 mph, both at 6000 rpm. So, if you are on a dragstrip, you値l have to rev higher than 6000 to go faster or shift. At 65 mph, you値l turn 1456 rpm in 6th gear and 2155 rpm in 5th gear.
If you switch to a 3.73 rear gear, the theoretical speeds at 6000 rpm are 6th: 246 mph, 5th: 166 mph, 4th: 123 mph, 3rd: 94 mph. So, you値l have to shift into 4th on a dragstrip. At 65 mph, you値l turn 1588 rpm in 6th and 2350 rpm in 5th.
If you switch to a 3.91 rear gear, the theoretical speeds at 6000 rpm are 6th: 234 mph, 5th: 158 mph, 4th: 117 mph, 3rd: 90 mph. So, you値l have to shift into 4th on a dragstrip. At 65 mph, you値l turn 1665 rpm in 6th and 2464 rpm in 5th.
If you switch to a 4.11 rear gear, the theoretical speeds at 6000 rpm are 6th: 223 mph, 5th: 151 mph, 4th: 111 mph, 3rd: 86 mph. So, you値l have to shift into 4th or 5th on a dragstrip, depending on your power level. At 65 mph, you値l turn 1750 rpm in 6th and 2590 rpm in 5th.
If you switch to a 4.56 rear gear, the theoretical speeds at 6000 rpm are 6th: 201 mph, 5th: 136 mph, 4th: 100 mph, 3rd: 77 mph. So, you値l have to shift into 5th on a dragstrip. At 65 mph, you値l turn 1941 rpm in 6th and 2873 rpm in 5th.
Keep in mind that the stock rear gear has a certain size. If you cram in more teeth, there is less metal, so each step up in gearing above will yield a slightly weaker gear. By the time you get to a 4.56, one speed-shift will probably turn the rear gear into a hand grenade.
If anyone wants the Excel spreadsheet I am using for these calculations, let me know and I will send it to you.
Below, keep in mind that the F-Body is electronically limited to 161 mph. It is also drag-limited. If the electronic limiting weren稚 there, and if you had a stock LS1, I think there is enough power in 5th gear to get to 168 or 169 mph before the drag equals the horsepower. If you shift to 6th, you will slow down because the engine doesn稚 make enough power to go that fast in 6th gear.
My car is a 2002 Camaro SS with the T-56 M6. At least for the 2002 year, the internal gear ratios for the T-56 are as follows:
1) 1st: 2.66
2) 2nd: 1.78
3) 3rd: 1.30
4) 4th: 1.00
5) 5th: 0.74
6) 6th: 0.50
7) Rev: 2.90
If your car has a 3.42 rear gear, then you could go 268 mph in 6th gear at 6000 rpm assuming you could GET 6000 rpm. In 5th, you can theoretically get to 181 mph at 6000 rpm. 4th is 134 mph and 3rd if 103 mph, both at 6000 rpm. So, if you are on a dragstrip, you値l have to rev higher than 6000 to go faster or shift. At 65 mph, you値l turn 1456 rpm in 6th gear and 2155 rpm in 5th gear.
If you switch to a 3.73 rear gear, the theoretical speeds at 6000 rpm are 6th: 246 mph, 5th: 166 mph, 4th: 123 mph, 3rd: 94 mph. So, you値l have to shift into 4th on a dragstrip. At 65 mph, you値l turn 1588 rpm in 6th and 2350 rpm in 5th.
If you switch to a 3.91 rear gear, the theoretical speeds at 6000 rpm are 6th: 234 mph, 5th: 158 mph, 4th: 117 mph, 3rd: 90 mph. So, you値l have to shift into 4th on a dragstrip. At 65 mph, you値l turn 1665 rpm in 6th and 2464 rpm in 5th.
If you switch to a 4.11 rear gear, the theoretical speeds at 6000 rpm are 6th: 223 mph, 5th: 151 mph, 4th: 111 mph, 3rd: 86 mph. So, you値l have to shift into 4th or 5th on a dragstrip, depending on your power level. At 65 mph, you値l turn 1750 rpm in 6th and 2590 rpm in 5th.
If you switch to a 4.56 rear gear, the theoretical speeds at 6000 rpm are 6th: 201 mph, 5th: 136 mph, 4th: 100 mph, 3rd: 77 mph. So, you値l have to shift into 5th on a dragstrip. At 65 mph, you値l turn 1941 rpm in 6th and 2873 rpm in 5th.
Keep in mind that the stock rear gear has a certain size. If you cram in more teeth, there is less metal, so each step up in gearing above will yield a slightly weaker gear. By the time you get to a 4.56, one speed-shift will probably turn the rear gear into a hand grenade.
If anyone wants the Excel spreadsheet I am using for these calculations, let me know and I will send it to you.
12-26-2005, 02:53 PM
#2
This info is in the first post of the first sticky at the top of the forum.
https://ls1tech.com/forums/gears-axles/376207-want-know-effect-changing-gear-ratios-look-here-first.html
http://www.f-body.org/gears/ It's good info your just a little late on it.
https://ls1tech.com/forums/gears-axles/376207-want-know-effect-changing-gear-ratios-look-here-first.html
http://www.f-body.org/gears/ It's good info your just a little late on it.
12-26-2005, 11:11 PM
#3
Staging Lane
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Just wanted to contribute, and I didn't read everything ... so, OK, I reposted some already-known data ... ah well, could be worse .... I could have been wrong.
12-27-2005, 04:21 AM
#5
I wrote this a while back, it's much more universal as far as gearing/tires/shifting, try it:
http://redhardsupra.blogspot.com/200...ft-points.html
and then
http://redhardsupra.blogspot.com/200...iftpoints.html
right now my site is down, so the pics aren't up, but that should be taken care of by tommorow.
http://redhardsupra.blogspot.com/200...ft-points.html
and then
http://redhardsupra.blogspot.com/200...iftpoints.html
right now my site is down, so the pics aren't up, but that should be taken care of by tommorow.
05-16-2013, 10:45 AM
#7
Still interesting even if stickied.....you know that gets me thinkin, so with 4.10s you would be shifting into 6th in the mid 150mph range. Now I know my mostly stock WS6 cant redline 6th gear and go 240 mph, but will it keep pulling at all in 6th if I redline 5th? Or is the overall gear ratio just too small for it to keep accelerating at that power level? I doubt I will ever be in a situation where i could find out for myself, but it would still be nice to know.
