OK, I know I should not do this, but we all know that sometimes we do. When I get up to 120 MPH or better my C3 gets light in the front end and the car gets a floating kind of feeling to it. What improvements can be made to the car to make it more stable at high speeds? What are the more cost effective remedies? I could push the car way past 120, but it feels like it wants to go airborn and I don't have a pilots license yet. I figure my top end is somewhere around 170 with my 3:24 rear gear, but I'll never see it.

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My best guess is that your front suspension is a little weak. Ya may want to stiffin 'er up. Shocks are a major factor in my opinion. Maybe even coilovers.
How's the rear feel? You must achieve balance grasshopper.

 

Don't remember what year yours is but if pre-80, then a front pace car spoiler might help.

In the words of Zora when asked about the new 1963 body style, he said it has just enuf lift to be a bad airplane. []

 

It may be the aerodynamic difference since my '72is a convertable, but it does not feel light at all around 120. I just wish I had the pedal left over that you have.
Hope you find a way to plant all that power!

David

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The front air dam idea should make a difference. You could lower the front about 1" as well. You must redirect the air around instead of under. Side pipes or ground effects on the sides will also be beneficial for keeping it down. With the least drag underneath and the dihedral effect of the air flowing over the body, It will want to lift naturally. you have to lessen the air pressure underneath to a point less than the pressure of the air flowing over the top to keep it from lifting. Almost like a vacuum underneath. Most cars will do this but they weigh more so the effect may be less at those speeds. I had a '70Torino SCJ when I was a kid, that would lift at 155 and become almost un-steerable at 162. I put on a "cheezy" air dam Chin spoiler and 72" thrush side pipes(tire to tire)and it solved the problem to about 180. Further aerodynamic changes brought the car to a documented 208 in a straight line. That's as high as the NYST radar gun would go. Just look at any NASCAR. They keep nearly all the air out from underneath, but be prepared if the air finds it's way to the underside. with light weight of a Stock C3 vette it would literally fly at about 180. Cheers

 

I really didn't know that the C3 had the "front-end floating problem." My '81 is so damn low in the front that it's on the border-line of being impractical. I see that in '80, the front-end islower from earlier years. The front of the fenders flare out alittle in the front and it's lower below the grills with that bigger rubber piece. I can't say first-hand how my '81 feels at 120mph as I've only been slightly over the top (85) a handful of times andI wanted to up-shift two times prior to getting there. I've read that the new front design for the '80 and '81 was more aerodynamic than the earlier years, but have no idea whether this new front-end design made the front-end of the car stick to the road better.
Just over-all, the C3s are VERY different from one another. From '68 to '71 the engines were more than healthy compared to the later years (my '81 w/ 190 hp) and although the basic bodies were very similar, the front and rear of the 'Vette changed drastically. And in '77 the name "Stingray" was dropped due to Bill Mitchell's retirement. Now I look closely at the front-ends of the C3s from '68 to '82 and can see how open the bottom of the earlier ones are. Would replacing an earlier C3 withan '80-'82 front-end fix the floating problem?Anyone???

 

Here's the front of my'79 now




It is really high in the front here because there is no motor or tranny in the car!



And here it is with the aftermarket chin spoiler. I took the aftermarket spoiler off for 2 reasons. First, it is cracked and needs repair - you can see it in this picture, it looks a little ragged, second - I was fighting a losing battle with cooling issues and thought that the aftermarket chin spoiler might have had a negative effect for some reason, so I installed a stock chin spoiler. It made no difference in cooling, but I had to try, it was just one more ingredient in the recipe that had to be eliminated as a possible problem.




I guess I will be reinstalling the aftermarket chin spoiler. I love the way it looks with the ground effects, I just hate the way it acts like a cow catcher and gets broken so easy. I am also in the market for new Bilstein shocks on all four corners, unless I hit the lottery, then I'll buy QA1's instead.

C3 Starship - you asked about what suspension work? I have a new VB&P 400# composite monospring in back, stock coils in the front and some crummy old Monroe shocks. The more I stiffen the rear suspension, the better the front end feels!


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That's one good lookin VETTE!!

 

DeeVee, Looking at the '63 and knowing that it had "front end floating problems" and looking at the front end of most of the C3s, I think it's plain to see that theboth of themwould act the same at high speed. With the rounded nose and all the room underneath, just forward of the front suspension, plainly looks like trouble in the discussed area.
Have you compared the floating with and without the chin spoiler?The front being , like I said, almost impractacle as far as dragging on everything and anything unless you hit every uneven spot on an angle makes it a pain in the *** for ordinary daily driving.But in the case of your car, with all the performance stuff you have, I'm sure thecareful drivingwith the low front would be well worth it if the spoiler really works well enough to make the car stable at speed.
To me, a 'Vette should run like a 'Vette (and I hate to say, unlike mine) and your car is the way it should be. I hope the spoiler works for you I think your 'Vette is "super sharp."

Also, I see that you're in Jersey. (my Grandmother and Great Aunts lived in Hoboken forever back when it was all German) To you also, "hats-off" for having a "vintage performance ride" in a climate where there's more "inside wrench-turning weather" than "cruising time."

 

DeeVeeEight, black is beautiful car looks great!.
From lookingata C-3, one would think thatlong front would hold it down, don't it? PG.

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