So how fast
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Some of the old Road and Track articles claim 150 in the coupes with a big block. My 68 427/390 coupe has a factory 3:08 rear and it gets into triple digits very easily. Haven't had it any where near what I think it's capable of but it's far from running out of breath at 120.
Team Owner
Joined: Jan 2006
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From: Crossville TN
It's pretty simple to "do the math" to determine maximum possible vehicle speed. You need to know tire diameter (or rolling radius), rear axle ratio, and engine 'red line' [assuming it has enough horsepower to get to redline at max speed].
Base SB will probably do around 120 or so. BB should do 130 or more. Big BB in a coupe could reach 150.
Base SB will probably do around 120 or so. BB should do 130 or more. Big BB in a coupe could reach 150.
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69 L88 http://www.corvetteactioncenter.com/...8/l88perf.html
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Melting Slicks
Joined: Aug 2005
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From: Lincoln CA
My speedo says 160. I'll let you know when I get back......
Just kidding. I know mine will slice through 100 mph without much fuss. It's too old and too valuable to risk something stupid like a high speed pass. Besides, the CHP takes a dim view of these things. Mine has 3.36 gears and an M21 4 speed.
I just checked out that Car Life matrix in the post above. I think I would have to call B.S. on that 13.41 e.t. for a 427 with 3.55 gears unless it was the 435 hp version. My L36 has 3.36 gears and I know it's nowhere near as fast as my LS1 Z28. That car turned a best of 13.44 @ 107.43 mph with 35K miles on the clock and a set of 2.73 gears.
Just kidding. I know mine will slice through 100 mph without much fuss. It's too old and too valuable to risk something stupid like a high speed pass. Besides, the CHP takes a dim view of these things. Mine has 3.36 gears and an M21 4 speed.
I just checked out that Car Life matrix in the post above. I think I would have to call B.S. on that 13.41 e.t. for a 427 with 3.55 gears unless it was the 435 hp version. My L36 has 3.36 gears and I know it's nowhere near as fast as my LS1 Z28. That car turned a best of 13.44 @ 107.43 mph with 35K miles on the clock and a set of 2.73 gears.
Last edited by RagTop69; Apr 21, 2011 at 12:05 PM.
Safety Car
Joined: Sep 2007
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From: Indy Indiana
a 3.08 does about 2200 rpm at 60 mph = about 37 RPM per 1 mph.
divide a redline of 5600 rpm by 37 = about 151 MPH..
presuming of course you have the horsepower and torque to pull to the redline at high speed. it takes alot of horsepower/torque to run a car at 151 MPH
I think you will run out of torque and be past your horsepower peak to a fair degree below your redline.. limiting your top speed.
the 435 may get you there since it has higher torque and horsepower peaks at higher rpm.
hitting redline going thru the gears is entirely different than running at redline for a couple of minutes trying to top end a car.. I am not that brave and my engine is too valuable..
Don't forget clutch or torque converter slippage also..
also doing this on improperly rated or old tires may win you a darwin award.
divide a redline of 5600 rpm by 37 = about 151 MPH..
presuming of course you have the horsepower and torque to pull to the redline at high speed. it takes alot of horsepower/torque to run a car at 151 MPH
I think you will run out of torque and be past your horsepower peak to a fair degree below your redline.. limiting your top speed.
the 435 may get you there since it has higher torque and horsepower peaks at higher rpm.
hitting redline going thru the gears is entirely different than running at redline for a couple of minutes trying to top end a car.. I am not that brave and my engine is too valuable..
Don't forget clutch or torque converter slippage also..
also doing this on improperly rated or old tires may win you a darwin award.
Last edited by joewill; Apr 21, 2011 at 12:11 PM.
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From: Forked River NJ
Can I play. My motor will turn 7000 rpm. With my gearing and T56 trans I can do 258 mph. 
Seriously a lot depends on which motor you are talking about, what gearing is in the car. To vague a question. Like how high is high.
Way up there. 
Seriously a lot depends on which motor you are talking about, what gearing is in the car. To vague a question. Like how high is high.
Way up there.
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I chickened out @ 120 mph 
with what felt / appeared to be a lot more room to go ........ BB 427 / 4spd / trips / 3:08's
with what felt / appeared to be a lot more room to go ........ BB 427 / 4spd / trips / 3:08's
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From: Wexford PA
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From: Huntersville NC
You guys forgot wind resistance. Even turning redline, "doing the math" won't give you the real top speed; your car will "hit the wall" much lower. Not to mention I have heard these cars get very "light" at speeds far below theoretical maximum.
