From the C3 forum......not sure if this has been posted here before. .. Here’s some interesting facts and figures of aero testing relative to different generations of Corvette.

Back in the old school days of ‘hands on’ road testing (70’s), I believe I had the ‘64 somewhere up around 115 to feel when/if the front end would start to feel light. With 4:11’s the engine was fairly wound out. The car felt stable at ‘V1’ so didn’t explore beyond that.

With 3:08’s in the car now, it would be easy to revisit
that time and place. At this stage of the game, maybe let sleeping dogs lie.

http://www.superchevy.com/how-to/cor...tunnel-testing

John

 

I could not get the videos to play?

 

I can tell you that a loose vent window regulator, where the window doesn't hold closed completely, will make the car pull to the open window side at 120. Push it closed by hand and the car will straighten out. It took going 140 to make the convertible top lift off the windshield. Car felt great, though, otherwise.

 

Yes, my first C2 was a 365hp coupe that I liked to run as fast as possible (I was 35 years younger then!)

As John says, above about 110mph the steering started feeling decidedly vague. I never took it much past 1200mph as it had a 3.70 rear and the engine was running out of revs at that speed.

So it's true, the C2's will lift at speed, for sure!.

 

You've got bigger ones than I do!

About 130 was the most I did. Deserted parkway about 11PM. What amazed me was how those nice, wide gentle 65mph curves tighten up when you got up about 110!

 

I had my SWC (340HP, 3.08 axle) up to about 150 a couple of times - the first over the I-5 ship canal bridge at about 0215 on the north bound express lanes (they were empty) north of downtown Seattle on my way back to the U-district the night I graduated from UW and got commissioned as 2LT, USAF. For those familiar with Seattle my exit was 42nd street which actually starts on the bridge. At the bridge apex I nailed the brakes and started downshifting. The J-65 brakes and fresh Pirelli CN-72 radials did a great job. The exit is downhill and curves fairly sharply to the right with a signal at the bottom that, fortunately,was green because I don't know if I could have stopped if it was red. The house I lived in on 8th Ave NE was only a couple of blocks away, and I drove straight into the garage.

The next day when I opened the garage to use the car I could smell the brakes. My passenger that night, also a freshly minted 2LT, lives a few miles from me and remembers that ride, vividly.

The front end does exhibit noticeable lift above 120-130, but the car is stable... just not real maneuverable because with so much weight off the front end it doesn't want to change direction, but it's okay in a straight line as long as there is not a significant cross wind component.

I recall, I think it was Corvette News, some aero performance graphs of a C2 and at 200 MPH the front end was literally off the ground, but even a L-88 didn't have enough power to push a C2 that high. The drag coefficient is about 0.50 and frontal area about 20 sq. ft. The power requirement increases with the CUBE of speed so it takes about EIGHT TIMES the power to achieve 200 MPH at it does to do 100.

Duke

 

This! In the late '70s I drove a rebuilt '64 coupe with a 350 LT1, factory FI, and 15" radial tires up to about 120+ on a straight section of highway and that's exactly what I experienced. Needless to say I took my foot off the gas and slowed down.

 

That's why fast cars need a front spoiler ......at high speeds and looks good as well

just .02 worth

max

 

I drove from South Dakota to Phoenix in 2009 (met SWCDuke there) and had the 3:36 rear end in. Did 155 (off the far in gps) but the Speedo was reading 160 / pegged. Did this on I-70 somewhere in Utah. Long straight open road, with two lanes and no traffic.

At about 130 I could tell it was getting light in the front. At 150 I was driving down the middle of the road and changed from lane to lane slowly and it responded but felt light on the steering wheel.

 

At Monterey in 2016 Peter Brock sat with us for an hour or so while we were working on my SWC racer. At one point we got into this discussion and he said he once was with Bill Mitchell looking at a completed mock up and told him the only thing remaining that was wrong with the car is the nose is too high and the rear too low. The aero was messed up. Mitchell looked over at him and said, "kid, make sure you understand one thing. There's only one guy here that designs the Corvette, me." Pete tried......

Steve

 

My experience with my 65 cpe was driving down to my sisters house in Bremerton, Wa. At 120 I had to keep my hands on the wheel. Some time later I had the car painted and added a front spoiler and a rear spoiler. Took the car down to show off to my sister and at 140 could take my hands momentarily off the wheel.