62 Biscayne Handling Problems

[fourspeed409]

Hi Guys.
I had my Biscayne to the drag strip last weekend. Things went good for the most part except the car was a handfull at the top end of the track.
The car has stock front suspension with new control arm bushings. The springs are stock 6 cyl and the shocks are cheap Summit adjustables.
Rear suspension has the stock mounting points on the frame (only has 1 lower hole at the front) . There are 2 tubular upper arms with heim joints. Lowers are rectangular tubing with urethane bushings that I made to the shape of the original ones. The panhard bar is origonal that was lengthened to center the tires in the wheel wells. There are air bags in the rear springs, 15psi on the rh and 0 on the left (hose was leaking)
The car works great through the first 3 gears. At the top of 4th and in 5th the car wants to change lanes.
Would the stock springs and cheap shocks make the car wander at the top end? The more speed the worse it seems to get. This was my best run of the weekend, it is the closest I came to a full run.
Any thoughts?

Thanks
Shane

 

[1958 delivery]

My guess is your alignment is way off with the front end lifted. I use to have an air bagged truck and if driving with too much or too little air the angle of the tires were way off and it would want to change lanes like you describe, was a handful to handle until I set the height at the correct level which in turn set the front wheels at basically straight up and down vertically.

 

[Don Jacks]

That,and what's your rear tire pressure?

 

[fourspeed409]

The rear tires are 28"x10.5"x15 with 13psi.
I initially was thinking the problem was me sawing on the wheel when shifting. On my last run when it got haywire in 4th I let off, got the car under control with 2 hands on the wheel and it made a left once i got back into it.
I will have to look into the alignment again. I do know the car has some bump steer that should be corrected, that is my first project.
It does feel like the car is steering from the back when it goes nuts.
Thanks
Shane.

 

[MRHP]

Seems a bit low on tire pressure. I run a 28 1050 15 et drag on my 62 at 16-18 psi and that seems about right. How much caster does it have? How much air in the front tires, and are the tires radial or bias front and rear?

 

[skipxt4]

I Don't drag race, anymore. I always thought, that centering the back tire's in the wheel wells, would cause a car to Dog Track? I Do know, the the PanHard bar, has Much to do with keeping a car going straight.

 

[Last 60]

With less than 14 lbs we get some walking at the big end.

Lonnie

 

[BSL409]

I never had a problem with either car at 11psi I would also say your alignment is off

 

[DonSSDD]

Is your steering stock and is it manual or power steering? My Pontiac had a half assed 605 setup that acted like that at 50 MPG.

Also, a question for the drag racers commenting, if the front springs were weak, would that have any effect? I assume Shane you mean those 6 cyl springs are stock and original? A 62 235 weighed more than your small block, especially if it had an ironglide and those original are likely toast if original.

 

[fourspeed409]

The tires are bfg radials on the front (35psi) and M/T et drag on the rear.
The steering is the original manual box and i would say the springs are 1962 vintage.
I am going to bring the car in the shop today and go over the front end alignment and see what i can do to eliminate the bump steer. I will report my findings.
Thanks for the suggestion.
Shane

 

[RCampbell]

Brian is right on tire pressue. We ran those tires years ago with 10#...they developed sidewall crawl at about 9#. Alignment may well be the issue. However the aligment issue is likely at the back of the car. First make sure the cross member you attach the upper contol arms to is secure. Any movement there will push the front of the car. Check the wheel base on both sides of the car. If there is a difference the rear axel is not square and that will certainly push the nose of the car. Rear axel push is the most noticeable at speed. A nice square car is safe and easy to drive.

 

[1958 delivery]

Simulate the front end height with a floor jack, the wheels should be 90deg to the floor. Use a 2-3ft level, place it against the tire and you should get a vertical ZERO bubble when the wheels are straight up. If the wheels are outward at top this would cause the handling issue.
Keeping in mind this is a drag strip alignment setting, would be out of alignment for the street.

 

[dm62409]

Please,,,,, never , ever mix radial tires with bias tires!!! You have radial fronts, and bias slicks on the back. This will cause all the handling problems your having. Get some lighter weight drag fronts on there to go with the drag slicks on back.

 

[MRHP]

That's why I asked about the tires Dave. I have seen it a bunch of times.

 

[models916]

Oh ya, bias slicks and radial on the front will go bad real quick. Add caster to the front for the strip. Put a large spacer in the rear upper control arm for the racing. Take it out or street use. Will cause the camber to be wrong but the straight line will go better with the added caster.

 

[fourspeed409]

I havent had much chance to work on the car yet. The caster camber gauge I use is on loan to someone else at the moment. A quick check did reveal that there is a ton of bump steer in the front of this car. The wheels go from being toed in 1/8" to toed out 3/8" when lifting the car only 2". When lifting the front to the point of the suspension being topped out it is toed out 3/4". The parts are on order to correct this.
If memory serves me correct there is 3deg positive caster and 0deg camber. What would be ideal for alignment specs? Keep in mind the more positive caster more spacers it will need between the tie rod and spindle to correct the bump steer. Is there a good balance to shoot for between the two?
Thanks for the help.
Shane

 

[Mark Steele]

Shan, I had the same problem as you explain, only I don't go as fast as you do. I'm running 14.5 now.
I told BSL 409 about my problem and he said have it lined up for drag racing, so I did.
When the local garage put it on the rack, I said before you start, lets raise the front end 3.5". Then he went on and lined the
'62 Biscayne up. It took care of the problem. Now I don't have any concern about handling at 95mph. Before I hung on for
dear life. Shan, thanks for all the help you have given me. Mark

 

[Iowa 409 Guy]

Do your slicks have the stiff sidewalls?

 

[models916]

Lifting the front adds caster. That's what you need.

 

[fourspeed409]

Hi guys. I was able to get the bump steer corrected on the Biscayne. Now throughout the entire front suspension travel the toe remains at 1/8" toe in.
The rear slicks are stiff sidewall.
Hopefully we can get to the track soon, just need to swap in a new set of gears.
Thanks for the replies.
Shane