160 MPH in 4th gear!!!
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From: PA
160 MPH in 4th gear!!!
I had to run to the store today and decided to take the long way there. There's a nice long stretch of road that runs right along side of a steep rock mountain on one side and the Susquehanna river on the other. (So no chance of animals running out in front of me :D) There was absolutely no traffic so I came to almost a dead stop and nailed the gas. I shifted out of 3rd at about 122 MPH and help the gas to 5,800 RPM in 4th gear. The speedometer just kept climbing at a rate that astonished me. To my surprise I looked down and saw the needle hit the 160 mark on the speedo so I let off and shifted to 5th. I knew this car was fast but that absolutely blew my mind. I remember taking my '94 Z28 to 150 one time but that seemed to take forever. It sure would be fun to hit the Bonneville Salt Flats in the Vette sometime and try for the magical 200 MPH mark. I'm sure she's got it in her! By the way, the new Kirban shifter worked flawlessly! The shifts are nice and firm now. :cheers:
Burning Brakes
Joined: Oct 2000
Posts: 1,094
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From: Seattle suburb wa
Re: 160 MPH in 4th gear!!! (QuickSilver97)
just out of curiousity, how are you able to rev to 7200 rpm, which is what 4th gear would be at 160 mph with stock rear 3.42 and stock sized rear tires..
maybe you were in metric mode on your gauges..
maybe you were in metric mode on your gauges..
Thread Starter
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From: PA
Re: 160 MPH in 4th gear!!! (no cure)
So by what you're saying, the only way to increase the top speed of a car is by changing the gear ratio or tire height? Horsepower and torque have nothing to do with it? You could take a C5 and drop in a 4 cylinder Celica engine and as long as those gears and tire heights stay the same, the car will still be capable 175 MPH?
I don't like being called a liar. Which is exactly what you're calling me. I guess the next time, I'll take a camera with me so I can take a picture of the speedometer and shifter. :rolleyes:
I don't like being called a liar. Which is exactly what you're calling me. I guess the next time, I'll take a camera with me so I can take a picture of the speedometer and shifter. :rolleyes:
Thread Starter
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From: PA
Re: 160 MPH in 4th gear!!! (QuickSilver97)
For that matter, how is it possible then for a stock '01 Viper GTS to have a top speed of 190 MPH while the new Viper with the same size tires and same gear ratio have a top speed of 220MPH? You're also telling me the No Mercy's car with 700+ horsepower is still only capable of 175 MPH because he still retains the stock gears and tire height? :confused:
I need you to explain to me how horsepower has nothing to do with top speed.
I need you to explain to me how horsepower has nothing to do with top speed.
Burning Brakes
Joined: Oct 2000
Posts: 1,094
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From: Seattle suburb wa
Re: 160 MPH in 4th gear!!! (QuickSilver97)
So by what you're saying, the only way to increase the top speed of a car is by changing the gear ratio or tire height? Horsepower and torque have nothing to do with it? You could take a C5 and drop in a 4 cylinder Celica engine and as long as those gears and tire heights stay the same, the car will still be capable 175 MPH?
if you leave the transmission gear ratios alone, and the rear gear ratio alone, and keep the same rear tire height (inches), and don't change your rev limiter, than speed in gears is exactly unchanged, no matter what you do to hp/tq, except for where the top speed in a gear was drag limited (ie, one could not achieve revlimit in a given gear) and in that case more power will allow you to get more revs in the previously drag limited circumstance, but that is not the case with what you said. 4th gear is not drag limited. on a stock m6 c5, 5th is drag limited at about 175 mph..
as to calling you a "liar", that's your interpretation. what you stated, if the parameters I mentioned are stock, is an obvious falsehood/error/misstatement/whathaveyou. I didn't say "liar, liar, your pants are on fire" but you can call it what you want.
ask anyone who knows anything about cars :)
a still camera won't prove squat. take a video showing you shifting thru the gears, and then you speedo doing "160 in 4th". if all the other parameters are stock, as you claim, I'll bet you $10,000 on the outcome.
Melting Slicks
Joined: Jul 2001
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From: not speeding just flying low
Re: 160 MPH in 4th gear!!! (QuickSilver97)
I don't think anyone is calling you a liar, but the numbers don't seem to add up. I don't dare ever go into third gear above 100 mph, and I am not exactly sure what speed redlines third gear, but that seemed awful high to me. What is your rev limiter set at?
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Thread Starter
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Joined: Mar 2001
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From: PA
Re: 160 MPH in 4th gear!!! (rbeckham)
Quicksilver - No disputing the car is capable of these speeds, but you have either strange gearing or a weird speedometer.
By even mentioning that my car was revving at 7,200 RPM when I distinctly said 5,800 RPM is calling me a liar.
Le Mans Master
Joined: Sep 1999
Posts: 7,393
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From: Los Angeles CA
Re: 160 MPH in 4th gear!!! (SAXN8R)
In my mostly stock C5 (as well as all others except Z06), the rev limiter cuts in below 110mph in 3rd gear. I don't think it's possible to go over 140 in 4th gear, probably even lower, before you get rev limited. End of story. This is not to say that you can't get to 160 or better in 5th gear. Now, does someone really dispute this?
Le Mans Master
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From: Fort Worth Texas
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Re: 160 MPH in 4th gear!!! (QuickSilver97)
quicksilver. Sounds like you had fun, and didnt die, and thats what counts :)
What no cure, meant, and he explained himself well allready, but if I could interject another analogy.
Lets say you have 200 HP and you are in 1st gear. You still are going to hit the rev limiter at the same speed in first, even if you increased your engines power to 1000 HP.
same for all gears.
The C5 is drag (wind) limited in 5th gear and cannot achieve redline. Thus the top speed is in the 170's in 5th. If you added say 200 HP, you could hit higher speeds, but only up to the rev limiter. You would have to increase the rev limiter to get more speed, no matter how much HP you added.
4th gear is not wind limited from a stock HP or greater HP perspective, so drag is not an issue with respect to top speed. Thus if you increased your power to 1000 HP without increasing your rev limiter, you will not go any faster. Granted you will get there quicker.
The engine is tied to the tranny which is tied to the rearend, which is tied to the tires. Its a law of phyisics and can easily be calculated beyond a shadow of a doubt.
[Modified by kewlbrz, 5:25 PM 4/4/2002]
What no cure, meant, and he explained himself well allready, but if I could interject another analogy.
Lets say you have 200 HP and you are in 1st gear. You still are going to hit the rev limiter at the same speed in first, even if you increased your engines power to 1000 HP.
same for all gears.
The C5 is drag (wind) limited in 5th gear and cannot achieve redline. Thus the top speed is in the 170's in 5th. If you added say 200 HP, you could hit higher speeds, but only up to the rev limiter. You would have to increase the rev limiter to get more speed, no matter how much HP you added.
4th gear is not wind limited from a stock HP or greater HP perspective, so drag is not an issue with respect to top speed. Thus if you increased your power to 1000 HP without increasing your rev limiter, you will not go any faster. Granted you will get there quicker.
The engine is tied to the tranny which is tied to the rearend, which is tied to the tires. Its a law of phyisics and can easily be calculated beyond a shadow of a doubt.
[Modified by kewlbrz, 5:25 PM 4/4/2002]
Burning Brakes
Joined: Oct 2000
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From: Seattle suburb wa
Re: 160 MPH in 4th gear!!! (QuickSilver97)
By even mentioning that my car was revving at 7,200 RPM when I distinctly said 5,800 RPM is calling me a liar.
stock 4th @ 6250 = 141 mph, stock 5th @ 5725 = 175.0, which is all you'll get at sea level on a level road in a coupe with the windows up. and less at higher elev and/or bad air. if one could hit 6250 in 5th, then one would be doing 191 mph, which requires at least 415 sae corr rwhp.
btw - my car can do 195 in fifth :) though I rarely go there.
no matter how you cut it, 5800 rpms, all else stock, is not 160 in 4th or 5th (or sixth for that matter)..
Le Mans Master
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From: Fort Worth Texas
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Re: 160 MPH in 4th gear!!! (no cure)
I ran the exact numbers and here is what I get: (no cure what tire diameter did you use?)
Tire Diameter: 275/40-18 = 26.6614173 inches
4th gear ratio = 1.00:1
rear gear ratio = 3.42:1
<BLOCKQUOTE>code:<HR><PRE>RPM SPEED
3500 81
3600 83
3700 86
3800 88
3900 90
4000 93
4100 95
4200 97
4300 100
4400 102
4500 104
4600 107
4700 109
4800 111
4900 114
5000 116
5100 118
5200 121
5300 123
5400 125
5500 128
5600 130
5700 132
5800 135
5900 137
6000 139
6100 141
6200 144
6300 146
6400 148
6500 151</PRE>[/QUOTE]
[Modified by kewlbrz, 5:32 PM 4/4/2002]
Tire Diameter: 275/40-18 = 26.6614173 inches
4th gear ratio = 1.00:1
rear gear ratio = 3.42:1
<BLOCKQUOTE>code:<HR><PRE>RPM SPEED
3500 81
3600 83
3700 86
3800 88
3900 90
4000 93
4100 95
4200 97
4300 100
4400 102
4500 104
4600 107
4700 109
4800 111
4900 114
5000 116
5100 118
5200 121
5300 123
5400 125
5500 128
5600 130
5700 132
5800 135
5900 137
6000 139
6100 141
6200 144
6300 146
6400 148
6500 151</PRE>[/QUOTE]
[Modified by kewlbrz, 5:32 PM 4/4/2002]
Burning Brakes
Joined: Oct 2000
Posts: 1,094
Likes: 2
From: Seattle suburb wa
Re: 160 MPH in 4th gear!!! (kewlbrz)
The engine is tied to the tranny which is tied to the rearend, which is tied to the tires. Its a law of phyisics and can easily be calculated beyond a shadow of a doubt.
Burning Brakes
Joined: Oct 2000
Posts: 1,094
Likes: 2
From: Seattle suburb wa
Re: 160 MPH in 4th gear!!! (kewlbrz)
I ran the exact numbers and here is what I get: (no cure what tire diameter did you use?)
Tire Diameter: 275/40-18 = 26.6614173 inches
4th gear ratio = 1.00:1
rear gear ratio = 3.42:1
Tire Diameter: 275/40-18 = 26.6614173 inches
4th gear ratio = 1.00:1
rear gear ratio = 3.42:1
I used the REAL tire height, as measured (many times). your calculations are wrong, because you are using the theoretical tire height, not the real world tire height. there is side wall deflection. a 275/40-18 EMT at 30 psi is EXACTLY 26 inches tall. measure it yourself. redo your calcs..
:)
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From: PA
Re: 160 MPH in 4th gear!!! (kewlbrz)
kewlbrz- I understand that completely. That makes all the sense in the world. Like I said, the speedometer said what it said. I guess perhaps it's off. It must be. Irregardless, if I was doing 140 (actually) or 160 (what the speedo said) , it sure got there in a hurry. :)
Now, how then can I tell how "off" my speedometer is? It seems really accurate at around 60 MPH, but how can I find anyone stupid enough to drive next to me at 150 MPH to see how far off it is?
no cure- I sincerely apologize for jumping down your throat like that. I detected a bit of sarcasm in your original post and it hit me the wrong way.
On another note, the Vette has 295 35's on the back and if the speedometer wasn't calibrated to match, wouldn't that make the speed seem lower than it actually is? :confused:
Now, how then can I tell how "off" my speedometer is? It seems really accurate at around 60 MPH, but how can I find anyone stupid enough to drive next to me at 150 MPH to see how far off it is?
no cure- I sincerely apologize for jumping down your throat like that. I detected a bit of sarcasm in your original post and it hit me the wrong way.
On another note, the Vette has 295 35's on the back and if the speedometer wasn't calibrated to match, wouldn't that make the speed seem lower than it actually is? :confused:
Le Mans Master
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From: Fort Worth Texas
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Re: 160 MPH in 4th gear!!! (no cure)
Ok, per your 26 inch rear measurement :)
<BLOCKQUOTE>code:<HR><PRE>RPM SPEED
3500 79
3600 81
3700 84
3800 86
3900 88
4000 90
4100 93
4200 95
4300 97
4400 100
4500 102
4600 104
4700 106
4800 109
4900 111
5000 113
5100 115
5200 118
5300 120
5400 122
5500 124
5600 127
5700 129
5800 131
5900 133
6000 136
6100 138
6200 140
6300 142
6400 145
6500 147</PRE>[/QUOTE]
<BLOCKQUOTE>code:<HR><PRE>RPM SPEED
3500 79
3600 81
3700 84
3800 86
3900 88
4000 90
4100 93
4200 95
4300 97
4400 100
4500 102
4600 104
4700 106
4800 109
4900 111
5000 113
5100 115
5200 118
5300 120
5400 122
5500 124
5600 127
5700 129
5800 131
5900 133
6000 136
6100 138
6200 140
6300 142
6400 145
6500 147</PRE>[/QUOTE]
Racer
Joined: Aug 2000
Posts: 456
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From: Brentwood CA
Re: 160 MPH in 4th gear!!! (kewlbrz)
Kewlbrz is 100% right. With stock gears that speed is just not possible.
I can back this up in practice as well, just yesterday I was watching my speedo as I reached redline in 4th, and it was in the 130s when I shifted to fifth. It reachs that speed very quick with the nitrous on, so maybe it's worth the effort to get out the digital video cam and tape it next time.
The only way it could happen, would be with a very innaccurate speedometer.
I can back this up in practice as well, just yesterday I was watching my speedo as I reached redline in 4th, and it was in the 130s when I shifted to fifth. It reachs that speed very quick with the nitrous on, so maybe it's worth the effort to get out the digital video cam and tape it next time.
The only way it could happen, would be with a very innaccurate speedometer.
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From: PA
Re: 160 MPH in 4th gear!!! (QuickSilver97)
Okay, now you guys have me thinking. Does my car in fact have 3.42's in it? I guess I just assumed it does. Perhaps the original owner put a lower gear in it. God knows why anyone would, but why then is my speedometer off by 20 freaken miles per hour at high speeds??? :confused:
Pro
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From: Upper Marlboro MD
Re: 160 MPH in 4th gear!!! (QuickSilver97)
It would appear that you were in fifth and probably didn't realize it with the new Kirban. :yesnod: Traveling at that speed requires concentration on the road not the gears. Good speed and I'm sure your car will reach 200. :cheers:
[Modified by Sir Sel, 6:52 PM 4/4/2002]
[Modified by Sir Sel, 6:52 PM 4/4/2002]