rpm and speed question
Thread Starter
Safety Car
Joined: Dec 2004
Posts: 3,565
Likes: 5
From: stafford country, va. Avatar: Me on turn 3 @ Bristol (The World's Fastest Half-Mile)
rpm and speed question
can someone with a bit more knowledge than myself explain this for me.
in a recent comparo. the c6 z51 was reported to run 1500 @ 60 mph in top gear (6th ?).
http://motortrend.com/roadtests/coup...rs/index6.html
after I read this I thought I would see how mine compared. I've got the F55 MN6 coupe, well anyway, in sixth gear at 1500 I'm running 70 mph. I was under the impression that the z51 and the standard mn6 were pretty close in gearing so why is there such a large difference in speed at the same rpm ?
in a recent comparo. the c6 z51 was reported to run 1500 @ 60 mph in top gear (6th ?).
http://motortrend.com/roadtests/coup...rs/index6.html
after I read this I thought I would see how mine compared. I've got the F55 MN6 coupe, well anyway, in sixth gear at 1500 I'm running 70 mph. I was under the impression that the z51 and the standard mn6 were pretty close in gearing so why is there such a large difference in speed at the same rpm ?
Last edited by Zig; Jul 12, 2005 at 11:11 AM.
Thread Starter
Safety Car
Joined: Dec 2004
Posts: 3,565
Likes: 5
From: stafford country, va. Avatar: Me on turn 3 @ Bristol (The World's Fastest Half-Mile)
does this mean that the standard mn6 has the potential for a higher top speed ? aren't all of the c6's "limited" to 186 mph, so if the limiter was removed would the base mn6 be faster at the top end ?
Instructor
Joined: Apr 2005
Posts: 213
Likes: 0
From: Dover NH
Originally Posted by Zig
does this mean that the standard mn6 has the potential for a higher top speed ? aren't all of the c6's "limited" to 186 mph, so if the limiter was removed would the base mn6 be faster at the top end ?
You cannot pull the high speed in 6th gear.. I believe the 186 number was achieved in 5th at redline.
6th gear is for cruzing and getting gas mileage.
Why are you asking... 186 isn't fast enough? It has been said in another thread on the forum that if you tilt in the mirrors on the doors and tape the foglights you could hit 190.
Melting Slicks
Joined: Jul 2001
Posts: 3,284
Likes: 3
From: Southwest Florida
Originally Posted by iluvmyc6
It has been said in another thread on the forum that if you tilt in the mirrors on the doors and tape the foglights you could hit 190.
Mike
Team Owner
Joined: Jun 2001
Posts: 26,714
Likes: 344
From: Houston, TX
Originally Posted by rfopt
Does anyone know why GM made the 6th gear ratio in the Z51 .57 vs .50 in the Base and F55 cars?
On the other hand, I have now had two C6s- one of each. The Z51 is much more responsive in 6th gear than the F55 I have now. That little bit of gearing difference makes a big difference in responsiveness! And so far, I am not seeing a difference in highway mileage (the new car is a convertible, the first was a coupe. The drag coefficient could be offsetting the gearing, I suppose).
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Le Mans Master
Joined: Aug 2000
Posts: 5,529
Likes: 1,943
From: Austin Texas
Originally Posted by Zig
does this mean that the standard mn6 has the potential for a higher top speed ?
Originally Posted by rfopt
Does anyone know why GM made the 6th gear ratio in the Z51 .57 vs .50 in the Base and F55 cars?
Team Owner
Joined: Sep 2003
Posts: 43,084
Likes: 33
From: Raleigh / Rolesville NC
Most Corvette reach top speed in 5th gear not 6th. 6th gear is a highway cruzing gear for good gas milage.
C6
gear/ ratio
1 2.66
2 1.78
3 1.30
4 1.00
5 0.74
6 0.50
1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6300 6500
1st 9 13 18 22 26 31 35 39 44 48 53 55 57
2nd 13 20 26 33 39 46 52 59 65 72 79 82 85
3rd 18 27 36 45 54 63 72 81 90 99 108 113 116
4th 23 35 47 58 70 82 93 105 116 128 140 147 151
5th 31 47 63 79 94 110 126 142 157 173 189
6th 47 70 93 116 140 163 186
C6 z51
gear/ratio
1 2.97
2 2.07
3 1.43
4 1.00
5 0.71
6 0.57
1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6300 6500
1st 8 12 16 20 24 27 31 35 39 43 47 49 51
2nd 11 17 23 28 34 39 45 51 56 62 68 71 73
3rd 10 14 19 24 29 34 38 43 48 53 58 60 62
4th 23 35 47 58 70 82 93 105 116 128 140 147 151
5th 33 49 66 82 98 115 131 148 164 180 197
6th 41 61 82 102 123 143 163
Sorry did not come out as nice as I had hoped.
C6
gear/ ratio
1 2.66
2 1.78
3 1.30
4 1.00
5 0.74
6 0.50
1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6300 6500
1st 9 13 18 22 26 31 35 39 44 48 53 55 57
2nd 13 20 26 33 39 46 52 59 65 72 79 82 85
3rd 18 27 36 45 54 63 72 81 90 99 108 113 116
4th 23 35 47 58 70 82 93 105 116 128 140 147 151
5th 31 47 63 79 94 110 126 142 157 173 189
6th 47 70 93 116 140 163 186
C6 z51
gear/ratio
1 2.97
2 2.07
3 1.43
4 1.00
5 0.71
6 0.57
1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6300 6500
1st 8 12 16 20 24 27 31 35 39 43 47 49 51
2nd 11 17 23 28 34 39 45 51 56 62 68 71 73
3rd 10 14 19 24 29 34 38 43 48 53 58 60 62
4th 23 35 47 58 70 82 93 105 116 128 140 147 151
5th 33 49 66 82 98 115 131 148 164 180 197
6th 41 61 82 102 123 143 163
Sorry did not come out as nice as I had hoped.
Last edited by AU N EGL; Jul 13, 2005 at 12:06 PM.
Thread Starter
Safety Car
Joined: Dec 2004
Posts: 3,565
Likes: 5
From: stafford country, va. Avatar: Me on turn 3 @ Bristol (The World's Fastest Half-Mile)
Originally Posted by AU N EGL
Most Corvette reach top speed in 5th gear not 6th. 6th gear is a highway cruzing gear for good gas milage.
C6
gear/ ratio
1 2.66
2 1.78
3 1.30
4 1.00
5 0.74
6 0.50
1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6300 6500
1st 9 13 18 22 26 31 35 39 44 48 53 55 57
2nd 13 20 26 33 39 46 52 59 65 72 79 82 85
3rd 18 27 36 45 54 63 72 81 90 99 108 113 116
4th 23 35 47 58 70 82 93 105 116 128 140 147 151
5th 31 47 63 79 94 110 126 142 157 173 189
6th 47 70 93 116 140 163 186
C6 z51
gear/ratio
1 2.97
2 2.07
3 1.43
4 1.00
5 0.71
6 0.57
1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6300 6500
1st 8 12 16 20 24 27 31 35 39 43 47 49 51
2nd 11 17 23 28 34 39 45 51 56 62 68 71 73
3rd 10 14 19 24 29 34 38 43 48 53 58 60 62
4th 23 35 47 58 70 82 93 105 116 128 140 147 151
5th 33 49 66 82 98 115 131 148 164 180 197
6th 41 61 82 102 123 143 163
Sorry did not come out as nice as I had hoped.
C6
gear/ ratio
1 2.66
2 1.78
3 1.30
4 1.00
5 0.74
6 0.50
1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6300 6500
1st 9 13 18 22 26 31 35 39 44 48 53 55 57
2nd 13 20 26 33 39 46 52 59 65 72 79 82 85
3rd 18 27 36 45 54 63 72 81 90 99 108 113 116
4th 23 35 47 58 70 82 93 105 116 128 140 147 151
5th 31 47 63 79 94 110 126 142 157 173 189
6th 47 70 93 116 140 163 186
C6 z51
gear/ratio
1 2.97
2 2.07
3 1.43
4 1.00
5 0.71
6 0.57
1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6300 6500
1st 8 12 16 20 24 27 31 35 39 43 47 49 51
2nd 11 17 23 28 34 39 45 51 56 62 68 71 73
3rd 10 14 19 24 29 34 38 43 48 53 58 60 62
4th 23 35 47 58 70 82 93 105 116 128 140 147 151
5th 33 49 66 82 98 115 131 148 164 180 197
6th 41 61 82 102 123 143 163
Sorry did not come out as nice as I had hoped.
Team Owner
Joined: Sep 2003
Posts: 43,084
Likes: 33
From: Raleigh / Rolesville NC
Originally Posted by Zig
very nice info.. i don't know the formula to est. the speed at specific rpms, etc. ok, i understand the top speed issue and fifth gear, sixth is overdrive, etc. but.... if the road was long enough what would be the speed of each if taken to redline in sixth just as is done in fifth.
if you would like the excel spreed sheets that I use to caclulate this info shoot me your email addy and I will be happy to send it to you.
these spread sheets also take into account while size, gear ratios, rear ends. Many different things.
Safety Car
Joined: Jun 2005
Posts: 3,989
Likes: 5
From: DFW This user does not support or recommend the product or service displayed in the ad to the right
Here is a great tool for for calculating different gear ratio changes. It appears that if someone with a base equipped 6sp wanted z51 performance you could just swap the rear gear for a 3.73 or 3.90 and it would be very close to the same ..check it out...
http://www.reverendsgarage.net/index...calculator.php
http://www.reverendsgarage.net/index...calculator.php