1st gear top speed
03-13-06, 04:46 PM
#1
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1st gear top speed
Anybody know the top speed at redline for a 1993? I am wondering if I put the 390 rear end from a auto along with my 20b if 60 is possible in 1st. Should make a nice 0 to 60 time w/o a gear change.
03-13-06, 07:06 PM
#5
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1st =3.48
axle ratio =4.1
final drive =3.48 x 4.1 =14.268
Road Speed
=[rpm]/[final drive]*3.14*[tire width]*[aspect ratio]/25.4+ [wheel diameter]*1.57828283*10^-5*60
=8,000/14.268 * 3.14*225*.5/25.4 + 16 * 1.57828283 * 10^-5 *60
=41MPH with a 4.1 and 44 with a 3.9.
. . . I think.
axle ratio =4.1
final drive =3.48 x 4.1 =14.268
Road Speed
=[rpm]/[final drive]*3.14*[tire width]*[aspect ratio]/25.4+ [wheel diameter]*1.57828283*10^-5*60
=8,000/14.268 * 3.14*225*.5/25.4 + 16 * 1.57828283 * 10^-5 *60
=41MPH with a 4.1 and 44 with a 3.9.
. . . I think.
03-13-06, 07:15 PM
#6
Originally Posted by CCarlisi
1st =[something foreign]
axle ratio =[something foreign]
final drive =[something foreign]
Road Speed
=[something foreign]
=[something foreign]
=41MPH [something foreign] and 44 [something foreign]
. . . I think.
axle ratio =[something foreign]
final drive =[something foreign]
Road Speed
=[something foreign]
=[something foreign]
=41MPH [something foreign] and 44 [something foreign]
. . . I think.
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03-14-06, 10:27 AM
#9
Rotary Enthusiast
theres a table at the bottom.
http://rx7.com/store/rx7/fddrivetrain_rearend.html
http://rx7.com/store/rx7/fddrivetrain_rearend.html
03-14-06, 01:42 PM
#14
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Originally Posted by SiKoPaThX
No way. If I'm going 7mph at 1,000 rpm, there's no way I'm going 52.5mph at 7500rpm. There's more to it than your formula.
Gears are linear. Lets do a quick example using 1st gear in the FD. If I'm cruising in 1st at 1000rpm, then my speed is approximately 5mph (slightly rounded for ease of discussion). If I double my RPM (2000rpm) then my speed doubles as well (10mph). If I quadruple my RPM (4000rpm) then the same happens to my speed (20mph). Ergo, if I increase the revs to 7.5k rpm, my speed will go up at the same ratio (37.5mph).
03-14-06, 04:06 PM
#16
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Originally Posted by SiKoPaThX
No way. If I'm going 7mph at 1,000 rpm, there's no way I'm going 52.5mph at 7500rpm. There's more to it than your formula.
sammyD just got pwnt....
03-14-06, 04:38 PM
#17
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Originally Posted by SayNoToPistons
sammyD just got pwnt....
03-14-06, 06:06 PM
#22
Originally Posted by jic
damn thats a lot of thinking
LOL where here are some facts
From this page here: http://www.jadesupra.net/gears/
Tire Size 225/50/16
Max rpm 9,000
Axel Ratio 4.10
1st gear ratio 3.48 Max speed at 9k = 47mph
2nd gear ratio 2.015 Max speed at 9k = 81mph
3rd gear ratio 1.391 Max speed at 9k = 117mph
4th gear ratio 1.000 Max speed at 9k = 162mph
5th gear ratio .719 Max speed at 9k = 226mph
Last edited by t-von; 03-14-06 at 06:13 PM.
03-14-06, 06:30 PM
#25
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Just prior to fuel cut I hit just a hair over 40 and 60 in 1st and 2nd respectfully. 3rd is about 105 and don't recall 4th. Before the major upgrades (stock) hit about 155 in 5th.
Don't give a damn what the calculations say that what the car has always done. Now the speedo could be off a little but every time I bounce it off one of those portable radar machines it varies from unit to unit by about 1-5mph at 50. Not really sure what to make of that...
Don't give a damn what the calculations say that what the car has always done. Now the speedo could be off a little but every time I bounce it off one of those portable radar machines it varies from unit to unit by about 1-5mph at 50. Not really sure what to make of that...