Pilot Dan
High Speed Steering Instability
Thread Starter
Burning Brakes
Joined: Oct 2008
Posts: 884
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From: Blacksburg Virginia
High Speed Steering Instability
I have recently fiinished a body off restoration of my 64 convertible 327 300hp. It has manual steering and brakes. I replaced every steering and supension component with new Moog parts with the exception of the steering steering shock and original stabilizer bar. I left the shock since it looked like new and seemed to be working well. When I get to high speeds of over 60 and go around curves the car feels like it is on the ragged edge. I doesn't shake or vibrate it just feels like the slightest movement of the steering wheel could upset the car. I also replaced the front shocks, coil springs, steering box, rag joint, rebuilt steering column, new tires and wheels. Had wheel computer balanced and front and rear alignment by a person familiar with corvettes. It this just the way the old cars handled or do you have any ideas? My new car and truck drive like they are on rails going around curves.
Race Director
Joined: Feb 2007
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From: northern california
C2 of Year Finalist (track prepared) 2019
Negative caster and/or a toe-out condition can cause the unsettling sensation of unstable steering. What were the actual caster and toe settings to which the front suspension of your car was adjusted?
Jim
Jim
Le Mans Master
Joined: Aug 2009
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From: Houston Texas
St. Jude Donor '10-'12-'13
I have recently fiinished a body off restoration of my 64 convertible 327 300hp. It has manual steering and brakes. I replaced every steering and supension component with new Moog parts with the exception of the steering steering shock and original stabilizer bar. I left the shock since it looked like new and seemed to be working well. When I get to high speeds of over 60 and go around curves the car feels like it is on the ragged edge. I doesn't shake or vibrate it just feels like the slightest movement of the steering wheel could upset the car. I also replaced the front shocks, coil springs, steering box, rag joint, rebuilt steering column, new tires and wheels. Had wheel computer balanced and front and rear alignment by a person familiar with corvettes. It this just the way the old cars handled or do you have any ideas? My new car and truck drive like they are on rails going around curves.
C2s and C3s have an edgy feel. High performance tires can give a more modern feel. So can power steering and a smaller steering wheel. Some which compromise your restored look.
On my restored 63 vert. I use Edelbrock Performer shocks and the meatiest poly bushing sway bars I could get. They updated the feel quite a bit. I also added stock non power discs all around. I don't feel it needs power brakes.
I am adding a jeep power steering box and a set of 17 inch wheels with proper tires for everyday driving and will save the classic wheels and tires for show. I did all of the above on a 65 vert in the past and it makes the C2 a whole different beast.
Last edited by MiguelsC2; Nov 16, 2009 at 06:47 PM.
Le Mans Master
Joined: Aug 2009
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From: Houston Texas
St. Jude Donor '10-'12-'13
Team Owner
Joined: Feb 2009
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From: Nearby Mayberry in NC
Crowd Plow For Now
hokie04, let me know what trues up the car. Personally I'd try the alignment first to the specs John Z and other drive by... then?
BTW - hokie04's way to get home is 13 miles of twisting, turning roads where the speed limit is ~55M from the highway exit... Is he doesn't feel safe at 60, then it's bad! He's been driving those roads for a few decades and I'm sure knows every crack in them.......
BTW - hokie04's way to get home is 13 miles of twisting, turning roads where the speed limit is ~55M from the highway exit... Is he doesn't feel safe at 60, then it's bad! He's been driving those roads for a few decades and I'm sure knows every crack in them.......
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Thread Starter
Burning Brakes
Joined: Oct 2008
Posts: 884
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From: Blacksburg Virginia
I will have to check with the guy who aligned my car to see what specs he used.
My 64 has drum brakes and only a front sway bar 3/4 inch I think. Recently adjusted wheel bearings.
The tires are Uniroyal Tiger Paw AS-6000P205/75R15
Wheels are Corvette America bolt on Knock Offs
My 64 has drum brakes and only a front sway bar 3/4 inch I think. Recently adjusted wheel bearings.
The tires are Uniroyal Tiger Paw AS-6000P205/75R15
Wheels are Corvette America bolt on Knock Offs
Cartoon Character
Joined: Jun 2006
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From: Can't be more than 114... Arizona
Alignment:
http://www.vbandp.com/instructions/h...ruct/align.htm
I also have a 64 and they are pretty twitchy cars indeed. If you are cornering at speed and you want to make an abrupt change of direction or line it is not a pleasant feeling at all. As said above these are not modern cars and on the stock suspension (which I have as well) they are not super stable and can be a bit tricky. This is a car that you turn into a corner , have it settle and then do not upset it or it will give you an acid stomach for sure. Tintin has over 50,000 miles of professional FIA endurance racing in his past and does not push this car very hard.. Track cars are different and do not really relate to the street version - not in the least of which is safety as there is a lot of run off room at tracks..
You should maybe do an autocross or something with the car to get a feel for its true limits..
http://www.vbandp.com/instructions/h...ruct/align.htm
I also have a 64 and they are pretty twitchy cars indeed. If you are cornering at speed and you want to make an abrupt change of direction or line it is not a pleasant feeling at all. As said above these are not modern cars and on the stock suspension (which I have as well) they are not super stable and can be a bit tricky. This is a car that you turn into a corner , have it settle and then do not upset it or it will give you an acid stomach for sure. Tintin has over 50,000 miles of professional FIA endurance racing in his past and does not push this car very hard.. Track cars are different and do not really relate to the street version - not in the least of which is safety as there is a lot of run off room at tracks..
You should maybe do an autocross or something with the car to get a feel for its true limits..
Team Owner
Joined: Aug 2007
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Army
I drove a LOT of '60s cars off my father's used car lot back 'in the day'. Raced a lot of 'em too when I thought he wouldn't catch me at it. These 'straight line', 1/4 mile cars, even with everything 'tweaked and peaked' are skittish when cornering at speed in my experience....that was on bias ply tires back then and radials will help but you can't compare these vintage cars to modern sports cars.
Le Mans Master
Joined: Apr 2001
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From: Granbury Texas
Please disregard the other responses, as I believe that (although they are sincere) they are incorrect. I drove at "high speeds" (155+) and cornered "HARD" this weekend, finishing 11th of 31 cars at TWS, and found NO problems with my stock 1963 suspension hardware. I DO suspect that your suspension ALIGNMENT is incorrect, and should be realigned by a professional. According to your post, you have already replaced everything that is a wear item, therefore, the only remaining issues should be alignment. Please note that bias ply tires handle and tramline differently than radial tires. I personally run Hoosier Street TD (bias ply) tires, but (as mentioned) radial tires on correct slignment will quicken your steering and add to your sense of stability at speed. OTHER than high speed front end lift, there is no reason to suspect that any midyear Corvette with good tires and suspension alignment will be other that stable in all handling modes.(For contrast, my street car is a 2004 Z06)
Last edited by 63Corvette; Nov 16, 2009 at 08:58 PM.
Le Mans Master
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From: Southeast Missouri
JohnZ's recommendations are as follow:Rear: Zero to 1/2 degree negative camber, and 1/16" total toe-in, split equally across the thrust centerline (1/32" per side, exactly).
Recommend slot shims, not hole shims for ease of alignment.
Front: Zero camber, 2.5 degrees positive caster, and zero to 1/16" total toe-in.
Note: On the caster, 2.5 is perfect for good tracking and wheel return, but increases static steering effort. 1.5 - 1.75 is a better setting with manual steering.
Race Director
Joined: Feb 2007
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From: northern california
C2 of Year Finalist (track prepared) 2019
On my vintage racer, a car on which I treasure high speed stability, I run 5 degrees of positive caster (and manual steering).
In general, you want as much positive caster as you can stand.
Jim
Racer
Joined: Apr 2000
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From: eureka, ca
More positive caster increases rolling steering effort too, but the flip side of that is that it contributes greatly to high speed stability.
On my vintage racer, a car on which I treasure high speed stability, I run 5 degrees of positive caster (and manual steering).
In general, you want as much positive caster as you can stand.
Jim
On my vintage racer, a car on which I treasure high speed stability, I run 5 degrees of positive caster (and manual steering).
In general, you want as much positive caster as you can stand.
Jim
6.2 degrees on mine.
Race Director
Joined: Oct 2005
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From: Camp Verde AZ
C1 of Year Finalist (performance mods) 2019
2017 C1 of Year Finalist
Add an air dam, get the air out from under the car. Works on a C1, anyway.
And align as per Lockwood, et al suggest.
Doug
And align as per Lockwood, et al suggest.
Doug
Thread Starter
Burning Brakes
Joined: Oct 2008
Posts: 884
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From: Blacksburg Virginia
Thanks for the great infomation! I going by the alignment shop today and see what he did and give him JohnZ's specs. Hopefully this will settle the car down a little. I generally just drive the car around town and it is not an issue. But recently I went on a road trip and found the car made me pretty nervous on some of the curves at high speeds. I didn't remember this problem back in the sixties when I had a C2 but I wanted to check and be sure my memory wasn't playing tricks on me.
Le Mans Master
Joined: Jun 2004
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From: Southeast Missouri
With manual steering and normal daily driving (read as around town and normal highway speed when out of town), I think you'll be better satisfied overall by keeping your caster to around 2.5 - 3.0 degrees. Although higher caster amounts than this do add to stability, I don't think you'll like the steering effort increase it'll also add . . . you can always try it both ways and decide for yourself though!
Just my thoughts . . .
Just my thoughts . . .
Last edited by Ron Miller; Nov 17, 2009 at 08:50 AM.
Le Mans Master
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From: Going too fast over the hill. Iowa
IMO when a Sting Ray or Stingray is squirrely cornering, and the front alignment is correct, the ususal suspects are rear alignment and bushings
Le Mans Master
Joined: Jun 2004
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From: Southeast Missouri
IMO an air dam also improves high speed handling and stability on Sting Rays. My car feels more stable at speeds above 75mph than below.
IMO when a Sting Ray or Stingray is squirrely cornering, and the front alignment is correct, the ususal suspects are rear alignment and bushings
IMO when a Sting Ray or Stingray is squirrely cornering, and the front alignment is correct, the ususal suspects are rear alignment and bushings
After all is said and done, I think you'll find that these are more likely to be suspect in your case than the amount of camber you're running . . . .