[C2] How fast could I go?
11-26-2016, 01:07 PM
#21
Le Mans Master
I have had my car up to top speed once and i i will never try that again with a original C2
At high speed the car behaved like the wing of a airplane and the front end got so "light" that the only thing i could do was to put the cluctch pedal to the floor since the most stupid thing i could have done was to brake at that speed
If i have had a front spoiler on the car i am sure that would have helped a lot
I can for sure say that even with a front spoiler i would not try to get up to high speed with any C2 again
Cant say it was any fun either...
At high speed the car behaved like the wing of a airplane and the front end got so "light" that the only thing i could do was to put the cluctch pedal to the floor since the most stupid thing i could have done was to brake at that speed
If i have had a front spoiler on the car i am sure that would have helped a lot
I can for sure say that even with a front spoiler i would not try to get up to high speed with any C2 again
Cant say it was any fun either...
Last edited by TheSaint; 11-26-2016 at 01:08 PM.
11-26-2016, 01:07 PM
#22
Melting Slicks
After 120 mph, it's more about aerodynamics and suspension/tires than anything else, geared properly. My early GTO's hit a wall at 130 mph: steering is light, car is about to take off the road, wiper arms are blown straight up, scary. 145 in my friend's lowered spoilered '74 Firebird is as solid as a rock. There's a gent from Finland who hit about 200 in a mildly modded '65 coupe....spoilers and small aero mods. The C2 is far better than most mid '60's platforms to try to go fast with.....the mid size musclecars are like a brick. Another thing to consider is the gassers back in the '60's....they changed over to funny cars around '67 or so when the speeds were getting high enough for the cars to take off and get fully airborne at 3/4 track (about 170mph)! Aerodynamics is critical at speed!
Last edited by biggd; 11-26-2016 at 01:09 PM.
11-26-2016, 01:14 PM
#23
Safety Car
except
I frequently take mine past 150 with 3.70 gears.
Very stable.
Alzo weiter................sehr interressant....aber dumm..........
Last edited by 65tripleblack; 11-26-2016 at 01:28 PM.
11-26-2016, 01:42 PM
#24
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I am still waiting for someone in this thread that has a car like the OP's to show up and report his car will run 135 mph.
All sorts of reports from those with hot rod engines, spoilers, tires, gears, race cars, etc. that are nowhere near the same configuration of the OP's car.
I am also in amazement that we have a report that a BB with a factory hydraulic camshaft will easily run 6200 rpm in high gear and get to the target speed.
Back when these cars were new, I had three BB's with hydraulic lifters and I don't recall any of them revving that high and if they would have, it would have likely been for a short period of time before a valve hit a piston. But maybe there was something wrong with the ones I had?
Now, it you want to change the gear to a 3.08, or change the valve train where the engine could rev higher and make more power, I believe the OP's car could make 130.
All sorts of reports from those with hot rod engines, spoilers, tires, gears, race cars, etc. that are nowhere near the same configuration of the OP's car.
I am also in amazement that we have a report that a BB with a factory hydraulic camshaft will easily run 6200 rpm in high gear and get to the target speed.
Back when these cars were new, I had three BB's with hydraulic lifters and I don't recall any of them revving that high and if they would have, it would have likely been for a short period of time before a valve hit a piston. But maybe there was something wrong with the ones I had?
Now, it you want to change the gear to a 3.08, or change the valve train where the engine could rev higher and make more power, I believe the OP's car could make 130.
Last edited by MikeM; 11-26-2016 at 01:44 PM.
11-26-2016, 01:58 PM
#25
Le Mans Master
I am still waiting for someone in this thread that has a car like the OP's to show up and report his car will run 135 mph.
All sorts of reports from those with hot rod engines, spoilers, tires, gears, race cars, etc. that are nowhere near the same configuration of the OP's car.
I am also in amazement that we have a report that a BB with a factory hydraulic camshaft will easily run 6200 rpm in high gear and get to the target speed.
Back when these cars were new, I had three BB's with hydraulic lifters and I don't recall any of them revving that high and if they would have, it would have likely been for a short period of time before a valve hit a piston. But maybe there was something wrong with the ones I had?
Now, it you want to change the gear to a 3.08, or change the valve train where the engine could rev higher and make more power, I believe the OP's car could make 130.
All sorts of reports from those with hot rod engines, spoilers, tires, gears, race cars, etc. that are nowhere near the same configuration of the OP's car.
I am also in amazement that we have a report that a BB with a factory hydraulic camshaft will easily run 6200 rpm in high gear and get to the target speed.
Back when these cars were new, I had three BB's with hydraulic lifters and I don't recall any of them revving that high and if they would have, it would have likely been for a short period of time before a valve hit a piston. But maybe there was something wrong with the ones I had?
Now, it you want to change the gear to a 3.08, or change the valve train where the engine could rev higher and make more power, I believe the OP's car could make 130.
11-26-2016, 02:52 PM
#28
Enjoy while you can.
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11-26-2016, 02:54 PM
#29
Safety Car
11-26-2016, 03:05 PM
#30
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I remember a buddy of mine had a '57 Chevy Power Pack. He installed his brand new Sun Tachometer. Wasn't long, he came running over to the gas station talking about how his power pack 283 would rev 10K. He was impressed and thought everyone else would be as well.
A quick file and regap on the points and his engine would only do about half that.
A quick file and regap on the points and his engine would only do about half that.
11-26-2016, 05:01 PM
#32
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So, once again, guys who won't do it are telling guys who have done it that it cannot be done............
I gotta ice cream headache now.
I gotta ice cream headache now.
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11-26-2016, 07:27 PM
#33
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130 is no problem in a StingRay and is easily obtainable if you have:
A) the gear
b) the rpm
c) the horsepower
In this case, I think the horsepower is there but not the gear.
Even the wimpy 4.6L Crown Victoria police cars would bust 130.
11-26-2016, 08:13 PM
#35
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I don't think anyone has mentiioned a speedometer yet until now. A tachometer/rpm has been mentioned a number of times.
11-26-2016, 08:27 PM
#36
Burning Brakes
My Porsche owners manual has a section that gives you the speed in gears based on the rear end ratio and the gears that came with the original car. Mathematicly it could do about 130 with 130 hp. I think you'd need to be going downhill. Once I put in the twin plug 3.0L with 245 hp it would do 140 pretty easy but still on a long road.
If I remember after you pass 100 the aerodynamic drag increases by the square root. It takes horsepower, a well designed car and a long road to get up to those speeds.
If I remember after you pass 100 the aerodynamic drag increases by the square root. It takes horsepower, a well designed car and a long road to get up to those speeds.
11-26-2016, 08:52 PM
#37
Le Mans Master
My Porsche owners manual has a section that gives you the speed in gears based on the rear end ratio and the gears that came with the original car. Mathematicly it could do about 130 with 130 hp. I think you'd need to be going downhill. Once I put in the twin plug 3.0L with 245 hp it would do 140 pretty easy but still on a long road.
If I remember after you pass 100 the aerodynamic drag increases by the square root. It takes horsepower, a well designed car and a long road to get up to those speeds.
If I remember after you pass 100 the aerodynamic drag increases by the square root. It takes horsepower, a well designed car and a long road to get up to those speeds.
Here is the video of 65 running 195mph.........
Last edited by 63Corvette; 11-26-2016 at 09:22 PM.
11-26-2016, 09:12 PM
#38
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I'd be very surprised if that engine would have gone much over 5500 RPM without valve float when it was new and the stock rods are probably the limiting factor now...
11-26-2016, 10:36 PM
#40
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So if it had 27" tires...it would take 5650 RPM to get 135 mph.
A 205/75 R15 is about 27.1" tall and a 205/70R15 is about 26.3" tall. Both are in the realm of replacements for 7.75x15's. I ran 205/75's on the front of mine until recently...now have 205/70's (to at least get a V-speed rating) so they clear easily.
Not sure the front spoiler made a big difference...but it could have since I hadn't tried to push it past 160-165 in the past. Things change quickly at speed so it could have been a big difference. Otherwise it handled similar to before. I did have hood cracked to relieve air pressure. Always did it that way at the track to clear a cab spacer..so for this run it just seemed logical.
I've run a lot of stock 427's over the years. First...the 3/8" rods are NOT an issue. My old 427 still has 3/8" rods in it (with upgraded bolts-somewhere over the years) and it has routinely spun 7500 RPM plus. Stock cast pistons don't like prolonged 6500+ RPM use...but will live to 6000 usually just fine for some time. I've sprayed 150 shots of N20 on cast pistons and never hurt one yet.
The cam in a 427/390 is so mild it takes very little spring pressure to control in...so they start with little...and over the years they can certainly get weaker. That would cause one to run out of steam...but I wouldn't expect "the end of the world" to occur at under 6000 RPM.
I think the 3.36 gears would help it achieve the speed by making it a little easier to get there.
Ok...not a 'Vette...but a true story. Many years ago I used to take my '68 SS/RS Camaro to Duquoin, IL for the annual Street Machine Nationals. There was always a lot of street playing over the weekend. We were die hard and we'd install 3.31's for the drive from TX to IL and then swap the gears in the KOA campground when we got there. I had the needed shims figured out so it wasn't hard. Then we'd swap back for the drive home. Some years we had 4.10's and others we used 4.56's.
So one year there just didn't seem to be much racing happening. So late Sat night my buddy and I were riding around with the 3.31's (4 speed) and a full bottle of nitrous in the trunk. We decided to find a long stretch of road and hold my foot to the floor until the N20 ran out! Yes...we were young and dumb and it never even dawned on us this was our ride back to TX. It was always reliable and we never worried about minor details. I punched it in 3rd gear and let it wind out through 4th and just locked my arms on the steering wheel to hold on. Tried to forget about the N50x15 bias ply rear tires or the skinny VW tires on the front end. I had Moroso drag springs and worn out shocks so the front end bounced a lot. I had a big Autometer Monster tach on top of the dash so it was easy to read. Of course we were floating a good bit and the headers were bottoming on the pavement as we crested hills...but I distinctly remember seeing 7500 RPM before I let out! Now...if you took that as gospel...we'd be saying that old Camaro was hitting 188 MPH..which considering we ran a Looonnnng way...is possible. But even if it was 7000 RPM due to the tach and me bouncing around...it would still be 176 MPH!!
Point being....you can "HP" bad aero into high speeds....and a mild 427 can do well. Yes..this was a solid flat tappet cam....3/8" rods, GM/TRW 11/0 closed chamber pistons and oval port iron GM heads. The N20 was set on a 175 HP tune. So definitely feasible.
BTW- Donny is looking at about 6550 to get 113 MPH in his car...plus remember "trap speed" is an average...so at the line it's going faster than the trap speed shown on a time slip.
JIM
A 205/75 R15 is about 27.1" tall and a 205/70R15 is about 26.3" tall. Both are in the realm of replacements for 7.75x15's. I ran 205/75's on the front of mine until recently...now have 205/70's (to at least get a V-speed rating) so they clear easily.
Not sure the front spoiler made a big difference...but it could have since I hadn't tried to push it past 160-165 in the past. Things change quickly at speed so it could have been a big difference. Otherwise it handled similar to before. I did have hood cracked to relieve air pressure. Always did it that way at the track to clear a cab spacer..so for this run it just seemed logical.
I've run a lot of stock 427's over the years. First...the 3/8" rods are NOT an issue. My old 427 still has 3/8" rods in it (with upgraded bolts-somewhere over the years) and it has routinely spun 7500 RPM plus. Stock cast pistons don't like prolonged 6500+ RPM use...but will live to 6000 usually just fine for some time. I've sprayed 150 shots of N20 on cast pistons and never hurt one yet.
The cam in a 427/390 is so mild it takes very little spring pressure to control in...so they start with little...and over the years they can certainly get weaker. That would cause one to run out of steam...but I wouldn't expect "the end of the world" to occur at under 6000 RPM.
I think the 3.36 gears would help it achieve the speed by making it a little easier to get there.
Ok...not a 'Vette...but a true story. Many years ago I used to take my '68 SS/RS Camaro to Duquoin, IL for the annual Street Machine Nationals. There was always a lot of street playing over the weekend. We were die hard and we'd install 3.31's for the drive from TX to IL and then swap the gears in the KOA campground when we got there. I had the needed shims figured out so it wasn't hard. Then we'd swap back for the drive home. Some years we had 4.10's and others we used 4.56's.
So one year there just didn't seem to be much racing happening. So late Sat night my buddy and I were riding around with the 3.31's (4 speed) and a full bottle of nitrous in the trunk. We decided to find a long stretch of road and hold my foot to the floor until the N20 ran out! Yes...we were young and dumb and it never even dawned on us this was our ride back to TX. It was always reliable and we never worried about minor details. I punched it in 3rd gear and let it wind out through 4th and just locked my arms on the steering wheel to hold on. Tried to forget about the N50x15 bias ply rear tires or the skinny VW tires on the front end. I had Moroso drag springs and worn out shocks so the front end bounced a lot. I had a big Autometer Monster tach on top of the dash so it was easy to read. Of course we were floating a good bit and the headers were bottoming on the pavement as we crested hills...but I distinctly remember seeing 7500 RPM before I let out! Now...if you took that as gospel...we'd be saying that old Camaro was hitting 188 MPH..which considering we ran a Looonnnng way...is possible. But even if it was 7000 RPM due to the tach and me bouncing around...it would still be 176 MPH!!
Point being....you can "HP" bad aero into high speeds....and a mild 427 can do well. Yes..this was a solid flat tappet cam....3/8" rods, GM/TRW 11/0 closed chamber pistons and oval port iron GM heads. The N20 was set on a 175 HP tune. So definitely feasible.
BTW- Donny is looking at about 6550 to get 113 MPH in his car...plus remember "trap speed" is an average...so at the line it's going faster than the trap speed shown on a time slip.
JIM
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