Top speed in 4th with 3.55's and 3.73's?
- Thread starter J DAWG
- Start date
onerareviper
Enthusiast
Re: Top speed in 4th with 3.55\'s and 3.73\'s?
Rear Gear ********* 1st ********** 2nd ********* 3rd ********** 4th *********** 5th ********* 6th
3.07 stock ********* 58 ********** 76 ********** 114 ********** 151 ********** 204 ********* 302 mph
3.31 ************** 54 ********** 70 ********** 105 ********** 140 ********** 189 ********* 280 mph
3.55 ************** 50 ********** 66 ********** 99 *********** 131 ********** 177 ********* 262 mph
3.73 ************** 48 ********** 63 ********** 94 *********** 124 ********** 168 ********* 249 mph
4.10 ************** 44 ********** 57 ********** 85 *********** 113 ********** 153 ********* 226 mph
*** 6th gear is theoretical (ie - have enough HP to reach redline)
Rear Gear ********* 1st ********** 2nd ********* 3rd ********** 4th *********** 5th ********* 6th
3.07 stock ********* 58 ********** 76 ********** 114 ********** 151 ********** 204 ********* 302 mph
3.31 ************** 54 ********** 70 ********** 105 ********** 140 ********** 189 ********* 280 mph
3.55 ************** 50 ********** 66 ********** 99 *********** 131 ********** 177 ********* 262 mph
3.73 ************** 48 ********** 63 ********** 94 *********** 124 ********** 168 ********* 249 mph
4.10 ************** 44 ********** 57 ********** 85 *********** 113 ********** 153 ********* 226 mph
*** 6th gear is theoretical (ie - have enough HP to reach redline)
BlueGTS
Viper Owner
Re: Top speed in 4th with 3.55\'s and 3.73\'s?
onerareviper,
Great post, thanks!
onerareviper,
Great post, thanks!
Re: Top speed in 4th with 3.55\'s and 3.73\'s?
http://chuckware.net/viper/gears.asp
viper gear speed calculator
http://chuckware.net/viper/gears.asp
viper gear speed calculator
Fast Freddy
Enthusiast
Re: Top speed in 4th with 3.55\'s and 3.73\'s?
so like i have gone 180 mph in 5th gear. i was pulling 5,500 rpms. according 2 that viper gear speed calculator if i stay in it 4 another 500 rpm's i will be going 200 mph. if i would have known that i would have never slowed down. thanx 4 the info marv.
so like i have gone 180 mph in 5th gear. i was pulling 5,500 rpms. according 2 that viper gear speed calculator if i stay in it 4 another 500 rpm's i will be going 200 mph. if i would have known that i would have never slowed down. thanx 4 the info marv.
Re: Top speed in 4th with 3.55\'s and 3.73\'s?
CAUTION:
The Chuckware viperspeed calculator is in conflict with the speed calculator on the the Unitrax website. A couple of interesting points;
1. The chuckware calculator math seems to checkout, however, the calculated speed does not seem to correlate to actual.
2. The Unitrax calculator does not publish its math, however, it seems to correlate better to actual.
I am worried about fourth gear and max speed/rpm thru the traps. I do not want to hit the window switch (5800) before the traps. The Unitrax shows me being safe and the chuckware shows me hitting the window switch. With 3.33's they show a difference of 10 mph at 5800.
I have emailed or talked to both, they are cordial and helpful, but, someone is wrong.
CAUTION:
The Chuckware viperspeed calculator is in conflict with the speed calculator on the the Unitrax website. A couple of interesting points;
1. The chuckware calculator math seems to checkout, however, the calculated speed does not seem to correlate to actual.
2. The Unitrax calculator does not publish its math, however, it seems to correlate better to actual.
I am worried about fourth gear and max speed/rpm thru the traps. I do not want to hit the window switch (5800) before the traps. The Unitrax shows me being safe and the chuckware shows me hitting the window switch. With 3.33's they show a difference of 10 mph at 5800.
I have emailed or talked to both, they are cordial and helpful, but, someone is wrong.
1TONY1
Enthusiast
Re: Top speed in 4th with 3.55\'s and 3.73\'s?
With 3.55's and 26" et streets I have seen 137 in the 1/4. It was close to the rev limiter.
With 3.55's and 26" et streets I have seen 137 in the 1/4. It was close to the rev limiter.
Paolo Castellano
Enthusiast
Re: Top speed in 4th with 3.55\'s and 3.73\'s?
Viper Gear Calculator
Tires size (nominal dia inches) 25.9
Differential gear 3.55
1st gear 2.66
2nd gear 1.78
3rd gear 1.30
4th gear 1.00
5th gear .740
6th gear .500
--------------------------------------------------------------------------------
Max RPM/Max Velocity (MPH)
Chart: Gear/RPM -- Velocity (MPH)
RPM 1st 2nd3rd4th5th6th
2000 16 24 33 43 59 87
2250 18 27 38 49 66 98
2500 20 30 42 54 73 109
2750 22 34 46 60 81 119
3000 24 37 50 65 88 130
3250 27 40 54 71 95 141
3500 29 43 58 76 103 152
3750 31 46 63 81 110 163
4000 33 49 67 87 117 174
4250 35 52 71 92 125 184
4500 37 55 75 98 132 195
4750 39 58 79 103 139 206
5000 41 61 83 109 147 217
5250 43 64 88 114 154 228
5500 45 67 92 119 161 239
5750 47 70 96 125 169 250
6000 49 73 100 130 176 260
6250 51 76 104 136 183 271
Viper Gear Calculator
Tires size (nominal dia inches) 25.9
Differential gear 3.73
1st gear 2.66
2nd gear 1.78
3rd gear 1.30
4th gear 1.00
5th gear 0.74
6th gear 0.50
--------------------------------------------------------------------------------
Max RPM/Max Velocity (MPH)
Chart: Gear/RPM -- Velocity (MPH)
RPM 1st2nd3rd4th5th6th
2000 16 23 32 41 56 83
2250 17 26 36 46 63 93
2500 19 29 40 52 70 103
2750 21 32 44 57 77 114
3000 23 35 48 62 84 124
3250 25 38 52 67 91 134
3500 27 41 56 72 98 145
3750 29 44 60 77 105 155
4000 31 46 64 83 112 165
4250 33 49 68 88 119 176
4500 35 52 72 93 126 186
4750 37 55 75 98 133 196
5000 39 58 79 103 140 207
5250 41 61 83 108 147 217
5500 43 64 87 114 154 227
5750 45 67 91 119 161 238
6000 47 70 95 124 167 248
6250 49 73 99 129 174 258
John, it all depends on how much power you will be having to spin or not to spin the tires; THat is the eternal question...
Viper Gear Calculator
Tires size (nominal dia inches) 25.9
Differential gear 3.55
1st gear 2.66
2nd gear 1.78
3rd gear 1.30
4th gear 1.00
5th gear .740
6th gear .500
--------------------------------------------------------------------------------
Max RPM/Max Velocity (MPH)
Chart: Gear/RPM -- Velocity (MPH)
RPM 1st 2nd3rd4th5th6th
2000 16 24 33 43 59 87
2250 18 27 38 49 66 98
2500 20 30 42 54 73 109
2750 22 34 46 60 81 119
3000 24 37 50 65 88 130
3250 27 40 54 71 95 141
3500 29 43 58 76 103 152
3750 31 46 63 81 110 163
4000 33 49 67 87 117 174
4250 35 52 71 92 125 184
4500 37 55 75 98 132 195
4750 39 58 79 103 139 206
5000 41 61 83 109 147 217
5250 43 64 88 114 154 228
5500 45 67 92 119 161 239
5750 47 70 96 125 169 250
6000 49 73 100 130 176 260
6250 51 76 104 136 183 271
Viper Gear Calculator
Tires size (nominal dia inches) 25.9
Differential gear 3.73
1st gear 2.66
2nd gear 1.78
3rd gear 1.30
4th gear 1.00
5th gear 0.74
6th gear 0.50
--------------------------------------------------------------------------------
Max RPM/Max Velocity (MPH)
Chart: Gear/RPM -- Velocity (MPH)
RPM 1st2nd3rd4th5th6th
2000 16 23 32 41 56 83
2250 17 26 36 46 63 93
2500 19 29 40 52 70 103
2750 21 32 44 57 77 114
3000 23 35 48 62 84 124
3250 25 38 52 67 91 134
3500 27 41 56 72 98 145
3750 29 44 60 77 105 155
4000 31 46 64 83 112 165
4250 33 49 68 88 119 176
4500 35 52 72 93 126 186
4750 37 55 75 98 133 196
5000 39 58 79 103 140 207
5250 41 61 83 108 147 217
5500 43 64 87 114 154 227
5750 45 67 91 119 161 238
6000 47 70 95 124 167 248
6250 49 73 99 129 174 258
John, it all depends on how much power you will be having to spin or not to spin the tires; THat is the eternal question...
Paolo Castellano
Enthusiast
Re: Top speed in 4th with 3.55\'s and 3.73\'s?
Freddy, you will need 516 RWHP @ 5900 RPM to go 200 MPH.
Freddy, you will need 516 RWHP @ 5900 RPM to go 200 MPH.
Re: Top speed in 4th with 3.55\'s and 3.73\'s?
Thanks for the graphs. It looks like I need to stick with 3.55's.
What rpm is the rev limiter. I pull 6000 rpm's all the time, but guess I have not gone above that. Isn't the limiter around 6100 or 6200?
Thanks for the graphs. It looks like I need to stick with 3.55's.
What rpm is the rev limiter. I pull 6000 rpm's all the time, but guess I have not gone above that. Isn't the limiter around 6100 or 6200?
Paolo Castellano
Enthusiast
Re: Top speed in 4th with 3.55\'s and 3.73\'s?
John, 6200 RPM is the fuel cutoff.
John, 6200 RPM is the fuel cutoff.
Re: Top speed in 4th with 3.55\'s and 3.73\'s?
I Agree with the "caution" statement to let people know the unitrax gear/speed calculator does not agree with other gear calculators out there. As much as I like Unitrax, I cannot find any way to support the accuracy of their gear calculator. I addressed this before http://vca2.viperclub.org/forums/showflat.php?Cat=&Board=UBB14&Number=259060 but will further expand.
[*]So According to the
http://www.gounitrax.com/UNITRAX/pages/calculator/mph.html
6,000 rpm in 4th gear is <font color="red"> 156.98 </font> so we'll just call it <font color="red"> 157 mph </font> to keep it simple.
[*]According to the http://chuckware.net/viper/gears.asp 6,000 rpm in 4th gear is <font color="red"> 148 mph </font>
But which is correct? Well let's take a few different approaches:
First Approach- The "Magazine" approach listing the speed in 4th at 6,000 rpm supports Chuckware:
[*]148 mph Road/Track 3-1992
[*]147 mph Car & Driver 3-1992
[*]144 mph Road/Track 11-1995 (showed estimated in 5th & 6th)
[*]144 mph Road/Track Specials 1998
[*]146 mph Road/Track GT-2 9-1998
[*]146 mph Road/Track Specials 1999
[*]144 mph Road/Track Specials 2000
[*]146 mph Road/Track Specials ACR 2001
Aslo Then M/T tests show 1,200 rpm and 1,220rpm in 6th gear at 60 mph. That would math out to 148 & 150 Mph in 6th gear at 3,000 rpm. The ChuckWare gear Calculator calcs out to 148. That's pretty close.
Second approach - the long hand math supports Chuckware. I'll walk you through the math and use 25.4" as the tire size:
25.4" tire diameter * pi = 79.7964368" covered each time the tire rotates
79.7964368"/ 3.07 gears = 25.99232469" covered each rotation of the driveshaft
6,000(rpm) * 60(min) * 25.99232469" = 9,357,236 inches per hour
9,357,236 / 12 = 779,770 feet per hour
779,770 / 5280 = 148 miles per hour
Third Approach - another gear calculator site aligns& agrees with Chuckware:
There is another site with a very nice gear calculator you can work with a bit. It gets the same results as the one at chuckware.net. Check it out at: http://www.f-body.org/gears/
Fourth Approach - Personal observation lines up w/ Chuckware:
2 months ago I had several runs in 4th at 6000 rpm and I was not over 150 mph on the spedo, let alone the 157 mph the Unitrax calculator says I should have been going.
Summary: I can't find any evidence in the 4 approaches above that supports the Viper going anywhere near the 157 that the unitrax site calcs to but I can find lots to support that the chuckware calculator is pretty close.
I Agree with the "caution" statement to let people know the unitrax gear/speed calculator does not agree with other gear calculators out there. As much as I like Unitrax, I cannot find any way to support the accuracy of their gear calculator. I addressed this before http://vca2.viperclub.org/forums/showflat.php?Cat=&Board=UBB14&Number=259060 but will further expand.
The Assumptions: 6,000 rpm ; 25.4" diameter tire; 4th 1:1 gear, 3.07 rear gear.
[*]So According to the
http://www.gounitrax.com/UNITRAX/pages/calculator/mph.html
6,000 rpm in 4th gear is <font color="red"> 156.98 </font> so we'll just call it <font color="red"> 157 mph </font> to keep it simple.
[*]According to the http://chuckware.net/viper/gears.asp 6,000 rpm in 4th gear is <font color="red"> 148 mph </font>
But which is correct? Well let's take a few different approaches:
First Approach- The "Magazine" approach listing the speed in 4th at 6,000 rpm supports Chuckware:
[*]148 mph Road/Track 3-1992
[*]147 mph Car & Driver 3-1992
[*]144 mph Road/Track 11-1995 (showed estimated in 5th & 6th)
[*]144 mph Road/Track Specials 1998
[*]146 mph Road/Track GT-2 9-1998
[*]146 mph Road/Track Specials 1999
[*]144 mph Road/Track Specials 2000
[*]146 mph Road/Track Specials ACR 2001
Aslo Then M/T tests show 1,200 rpm and 1,220rpm in 6th gear at 60 mph. That would math out to 148 & 150 Mph in 6th gear at 3,000 rpm. The ChuckWare gear Calculator calcs out to 148. That's pretty close.
Second approach - the long hand math supports Chuckware. I'll walk you through the math and use 25.4" as the tire size:
25.4" tire diameter * pi = 79.7964368" covered each time the tire rotates
79.7964368"/ 3.07 gears = 25.99232469" covered each rotation of the driveshaft
6,000(rpm) * 60(min) * 25.99232469" = 9,357,236 inches per hour
9,357,236 / 12 = 779,770 feet per hour
779,770 / 5280 = 148 miles per hour
Third Approach - another gear calculator site aligns& agrees with Chuckware:
There is another site with a very nice gear calculator you can work with a bit. It gets the same results as the one at chuckware.net. Check it out at: http://www.f-body.org/gears/
Fourth Approach - Personal observation lines up w/ Chuckware:
2 months ago I had several runs in 4th at 6000 rpm and I was not over 150 mph on the spedo, let alone the 157 mph the Unitrax calculator says I should have been going.
Summary: I can't find any evidence in the 4 approaches above that supports the Viper going anywhere near the 157 that the unitrax site calcs to but I can find lots to support that the chuckware calculator is pretty close.
Paolo Castellano
Enthusiast
Re: Top speed in 4th with 3.55\'s and 3.73\'s?
I would like to interject some personal observations on this matter:
I myself and everybody here have surely observed 2,000 RPM in 6th gear @ 100 MPH. Now 4th gear should have double the RPM of 6th at 100 MPH(4,000RPM).
The 25.4" default on the chuckware/orbital gears page gives both 6th @2,000 RPM and 4th @4,000RPM 98 MPH. Definitely low in my opinion. The tire manufacturers list the 335/35/17 and the 335/30/18 tires as having an overall diameter of 26.3". I have measured slightly less than 26 in. putting the inflated tire on the rim near the wall and measuring. If you put in 25.9" into the calculator, it makes both 100 MPH that we regularly see on the speedo. I have measured 30 second miles @ 120 MPH which is right on the money. This would make for 151 MPH in 4th gear at 6,000 RPM.
I would like to interject some personal observations on this matter:
I myself and everybody here have surely observed 2,000 RPM in 6th gear @ 100 MPH. Now 4th gear should have double the RPM of 6th at 100 MPH(4,000RPM).
The 25.4" default on the chuckware/orbital gears page gives both 6th @2,000 RPM and 4th @4,000RPM 98 MPH. Definitely low in my opinion. The tire manufacturers list the 335/35/17 and the 335/30/18 tires as having an overall diameter of 26.3". I have measured slightly less than 26 in. putting the inflated tire on the rim near the wall and measuring. If you put in 25.9" into the calculator, it makes both 100 MPH that we regularly see on the speedo. I have measured 30 second miles @ 120 MPH which is right on the money. This would make for 151 MPH in 4th gear at 6,000 RPM.
Re: Top speed in 4th with 3.55\'s and 3.73\'s?
Thanks Paolo,
I think you confirm the math of the orbit/chuckware calculator is correct, the variable being the true tire diameter. Same as you I measured the tire and could not verify it to be more than 26"
btw- Using 25.9" tire diameter yields 160 mph on the Unitrax Calculator. There's just no way.
Thanks Paolo,
I think you confirm the math of the orbit/chuckware calculator is correct, the variable being the true tire diameter. Same as you I measured the tire and could not verify it to be more than 26"
btw- Using 25.9" tire diameter yields 160 mph on the Unitrax Calculator. There's just no way.
Paolo Castellano
Enthusiast
Re: Top speed in 4th with 3.55\'s and 3.73\'s?
Marv, I have not tried the Unitrax calculator, but if you use 26.3" in the chuckware/orbital of f-body gear chart (like the tire manufacturers list), YOu also get the 157-158 MPH @ 6200 RPM in 1.0 4th w/3.07 rear end gears.
Marv, I have not tried the Unitrax calculator, but if you use 26.3" in the chuckware/orbital of f-body gear chart (like the tire manufacturers list), YOu also get the 157-158 MPH @ 6200 RPM in 1.0 4th w/3.07 rear end gears.
Re: Top speed in 4th with 3.55\'s and 3.73\'s?
The Unitrax calculator says 168 mph in 4th at 6200 rpm with 3.07 gears and a 26.3" tire.
The Unitrax calculator says 168 mph in 4th at 6200 rpm with 3.07 gears and a 26.3" tire.
Re: Top speed in 4th with 3.55\'s and 3.73\'s?
Put a chalk mark on the sidewall of your back tire near the pavement, and on the pavement below it. Roll the car forward or backward until the sidewall chalk mark comes around to the pavement again, and measure the distance between the chalk marks. Divide that by 3.14159 and that's your diameter. From my own experience, and from what I've read here and there, Vipers that only have mild external mods like about 5500-5600rpm as an upper limit. They'll rev higher but power production drops off above that area. You might be seeing 6000 rpm in 1,2,or 3 gear, but it can be tougher in 4th. I've lowered my ET by changing to a gear ratio with lower numerical number more than once in the past on various machinery, including a CR500 Honda dirtbike that kept going quicker as I put smaller gears on the back, finally topping out at 12.35@107 when I had the smallest rear sprocket on it that would fit the hub. - That was fun, dusting off unsuspecting cars in the other lane on test and tune day. MPH equals RPM x TD divided by GR x 336 (GR means over all gear ratio; your trans ratio x axle ratio)
Put a chalk mark on the sidewall of your back tire near the pavement, and on the pavement below it. Roll the car forward or backward until the sidewall chalk mark comes around to the pavement again, and measure the distance between the chalk marks. Divide that by 3.14159 and that's your diameter. From my own experience, and from what I've read here and there, Vipers that only have mild external mods like about 5500-5600rpm as an upper limit. They'll rev higher but power production drops off above that area. You might be seeing 6000 rpm in 1,2,or 3 gear, but it can be tougher in 4th. I've lowered my ET by changing to a gear ratio with lower numerical number more than once in the past on various machinery, including a CR500 Honda dirtbike that kept going quicker as I put smaller gears on the back, finally topping out at 12.35@107 when I had the smallest rear sprocket on it that would fit the hub. - That was fun, dusting off unsuspecting cars in the other lane on test and tune day. MPH equals RPM x TD divided by GR x 336 (GR means over all gear ratio; your trans ratio x axle ratio)
Re: Top speed in 4th with 3.55\'s and 3.73\'s?
Ok, all this math is confusing me
All I know is that I hit 175mph @around 6k rpms in 5th with 3.55s with stock tires I wish I would have stayed in it till fuel cutoff or shifted to 6th
Ok, all this math is confusing me
All I know is that I hit 175mph @around 6k rpms in 5th with 3.55s with stock tires I wish I would have stayed in it till fuel cutoff or shifted to 6th Paolo Castellano
Enthusiast
Re: Top speed in 4th with 3.55\'s and 3.73\'s?
Mike, @ 6200 you would have been @ 182 MPH with your gearing. You would not have enough power with 6th gear to sustain the 180 MPH as 3.55/6th gear has only 78% the HP/TQ multiplication of a 3.07/5th gear==> You would slow down for sure going to 6th.
Chart: Gear/RPM -- Velocity (MPH)
RPM 1st2nd3rd4th5th 6th
2000 16 24 33 43 59 87
2250 18 27 38 49 66 98
2500 20 30 42 54 73 109
2750 22 34 46 60 81 119
3000 24 37 50 65 88 130
3250 27 40 54 71 95 141
3500 29 43 58 76 103 152
3750 31 46 63 81 110 163
4000 33 49 67 87 117 174
4250 35 52 71 92 125 184
4500 37 55 75 98 132 195
4750 39 58 79 103 139 206
5000 41 61 83 109 147 217
5250 43 64 88 114 154 228
5500 45 67 92 119 161 239
5750 47 70 96 125 169 250
6000 49 73 100 130 176
6250 51 76 104 136 183
Ok, all this math is confusing me
Mike, @ 6200 you would have been @ 182 MPH with your gearing. You would not have enough power with 6th gear to sustain the 180 MPH as 3.55/6th gear has only 78% the HP/TQ multiplication of a 3.07/5th gear==> You would slow down for sure going to 6th.
Chart: Gear/RPM -- Velocity (MPH)
RPM 1st2nd3rd4th5th 6th
2000 16 24 33 43 59 87
2250 18 27 38 49 66 98
2500 20 30 42 54 73 109
2750 22 34 46 60 81 119
3000 24 37 50 65 88 130
3250 27 40 54 71 95 141
3500 29 43 58 76 103 152
3750 31 46 63 81 110 163
4000 33 49 67 87 117 174
4250 35 52 71 92 125 184
4500 37 55 75 98 132 195
4750 39 58 79 103 139 206
5000 41 61 83 109 147 217
5250 43 64 88 114 154 228
5500 45 67 92 119 161 239
5750 47 70 96 125 169 250
6000 49 73 100 130 176
6250 51 76 104 136 183
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