I checked my archives and there's a table in the Oct/00 issue of Corvette Fever that provides the facts. For those of you who don't keep archives:

Year/ bhp needed at 130 mph/ Front Lift (lbs)/ Rear Lift (lbs)
'63/ 108/ 254/ 163
'79/ 143/ 220/ 183
'80/ 126/ 155/ 24
'84/ 97/ 148/ 55

Not a very graceful piece of machinery. Let's hear it for rear spoilers.

 

If you note that a chin spoiler such as a 78 pace car does nothing other than channel air to the underside of the radiator. In NASCAR the "ground effects" push the air around and out hense the reason they are right at the nose, not under, thus causing a low pressure area under the car increasing tire friction and stability at high speed.

 

I don't know about the 69, but i have an 81 and ive hit 145 with it, it handled really good i was stunned, i rode an a 93 saleen that was all beefed up and we hit 130 and it was all over and felt like it had NO contact with the ground, not sure about the 69 but my 81 is a dream.

 

Been there, done that to.
have fun

 

I had my '69 BB Vert up to 120 at the drag strip last year. Honestly, about 90MPH the car squatted down and became increasingly stable. I liked it more at 120MPH than at 50MPH.

At 125 a C5 feels like it does at 25!

 

CGGorman, I have a 68 427 (L36) roadster also - International Blue. Mine is #4473. My max has been 105 after 1/4 mile, so actual speed was probably 108ish. Car felt fine, but I would be very wary of exceeding even 120 mph for reasons cited above! SammyB, how did you get up to 120 mph??

 

I have had my stock 1968 427 convertable C3 up to 140mph. I didn't feel any lift. As stated before the car has a lot more Ganads then I do. Telephone poles going by like a picket fence! The feeling of Adventure is all I can say! It is as good as hanging on a cliff at 13,000 feet above sea level in my 1981 Scrambler Jeep....It isn't something you do everyday or even year...

In Colorado we have some open farm roads in the Eastern part of the state that are all good for speed!

 

I top out at 125mph and the car feels stable with the old TH350, and 3.08s. My dad took his '64 to 145mph and it was getting light he said. It had a M21, 3.08s, 327/350, and headers.

 

I'm 23 years old now. I'm still young. When I bought my car at 16 I drove it up to 133. There were no seatbelts in it at the time. I'm glad I did it then because I sure wouldn't now.

PS: Oh yeah and after I slowed down to the speed limit, I passes a highway patrolman coming the other way. Two rushes at once.

 

I bury my speedometer every time I take it out! How many of you can say that?

 

Does it count that I take my neon to 120+ often?
It feels quite stable... and does it with ease.. LOL
Id be scared ****less to do that in my 75.

 

Finally had a chance to hit triple digits, and had no problem with stability at all. If I wasn't on a hilly road, I feel like I could have gone much faster without too much problem. But then, what do I know?

 

I've had my '68 up to 165mph once and the car was still pulling hard.. My car has enough power and gear to get to 200 mph.. but the tires are only S-rated (112 mph) .... so I went off the gas at 165 mph.. I was surprised how stable the car was at that kind of speed.. Well - my suspension is not stock anymore.. I currenlty have the 460 lbs/inch front coils and 330 lbs/inch fiberglass rear spring...

 

Well I just got home, and this was the first post that court my eye. Left the car show early and decided to take a ride. I put a creat engine in last year. ZZ4 385hp. Last month a TKO-1, 5 speed. I'm here to tell you. Putting these two together w/ 308's in the rear. It scares the (*$@# out of me at 130 mph. And, I still have alot of RPM before I get to 5500. When I play like this I have to get up on the steering wheel. I can't be doing the Gangster lean at that speed

 

Had mine to 140 with no drama. That was at 6,200 rpm in 3rd.
Still had 4th to go and convert unlocked.

 

GS, you and I have essentially the same springs, so similar ride height I presume, and with the Z rated tires at the time, AND the O/drive auto 700, THAT is why I would/could test that top speed , no concern on a 4 lane unoccupied bridge....

GENE

 

Guys,

The C3 is not as good aerodynamically as most newer cars; but it isn't all that bad either. Keeping air from passing under the car serves 2 things:

1) The bottom of the car is not as smooth as the shiny side and creates a great deal of wind resistance. My ZO6, and to even a greater extent new Ferrari's, have smooth bottoms for this reason.

2) Keeping air pressure from building up underneath the car helps keep the nose down. If air is block by a deep chin spoiler it is possible to even have a lower pressure under the car which can help suck the car down countering the lift generated by the arched fenders above.

A stiff set of springs greatly help rear end squat and front end lift. Most current C3's have a tendency to sit very high at the nose which exacerbates the problem. Get the car to sit like it was meant to!!!

Lowering the car makes them much more aerodynamic and stable. "Hydroplaning even at low speeds" as was earlier stated has absolutely nothing to do with aerodynamics and everything to do with tire selection. Loose, tired suspension components has been my most common experience with cars, any car, at higher speeds.

I would strongly dispute the published figures showing a 79 needing more hp to obtain 130mph than a 63 vette. I have seen numerous published figure elsewhere to counter this. Drag coefficients for the C3's are also all over the map, anywhere from .36 as stated earlier to nearly .50.

Bottom line for me is that from the article referenced by lostpatrolman regarding the Heinz Lemans vette running 212mph on the Mulsanne straight shows the car to be absolutely stock in shape except for the extra deep chin spoiler. Something anyone of us to copy pretty easily and simply bolt on. All you would still need is an honest 500hp at the rear wheels and gears/tires spec'd for such a speed.

Chuck

 

Guys,

The C3 is not as good aerodynamically as most newer cars; but it isn't all that bad either. Keeping air from passing under the car serves 2 things:

1) The bottom of the car is not as smooth as the shiny side and creates a great deal of wind resistance. My ZO6, and to even a greater extent new Ferrari's, have smooth bottoms for this reason.

2) Keeping air pressure from building up underneath the car helps keep the nose down. If air is blocked by a deep chin spoiler it is possible to have a lower pressure under the car which can help suck the car down countering the lift generated by the high arched fenders above.

A stiff set of springs greatly help rear end squat and front end lift. Most current C3's have a tendency to sit very high at the nose which exacerbates the problem. Get the car to sit like it was meant to!!!

Lowering the car makes them much more aerodynamic and stable. "Hydroplaning even at low speeds" as was earlier stated has absolutely nothing to do with aerodynamics and everything to do with tire selection. Loose, tired suspension components has been my most common experience with unstable cars, any car, at higher speeds.

I would strongly dispute the published figures showing a 79 needing more hp to obtain 130mph than a 63 vette. I have seen numerous published figure elsewhere to argue this. Drag coefficients for the C3's are also all over the map, anywhere from .36 as stated earlier to nearly .50.

Bottom line for me is that from the article referenced by lostpatrolman regarding the Heinz LeMans vette running 212mph on the Mulsanne straight shows the car to be absolutely stock in shape except for the extra deep chin spoiler. Something anyone of us can copy pretty easily and simply bolt on. All you would still need is an honest 500hp at the rear wheels and the right gears and tires.

Chuck

 

Chuck, or anyone else... where can and indy chin spoiler or that lemans spoiler be found for sale for a chrome bumber c3?

 

I've only had my car to 125 on a few occasions. It wasn't all over the place, but I was too busy death-gripping the wheel to really feel how it was handling. I have driven at 100 and 110 for many miles at a time, and it feels fine there. Not sure why the extra few mph feels so different?

I have new heads and headers now which must have greatly increased my top speed potential, but it needs some tuning before I try it out... I had my '92 Camry to 140 two or three times, not too bad, but overdrive sure makes it a hell of a lot easier getting there!

-Chris