Superbird speed.

[Kjellemopar]

Hi.
What speed do you like to go with your Superbird? I Think 60-65 miles is acceptable then it start to be unpleasant. I have polyglass tire with 30 psi tire pressure.

[DAY CLONA]

If you get rid of the Polyglass tires you might enjoy some higher speeds, I'm limited to 140 ish MPH (225KM) with the 5spd .64 OD and 4:10 gears in my Daytona on modern radials, kinda wish I put the 6 spd in....I'd enjoy 160-170

[cudavic]

Get rid of the polyglass tires for driving, use them for show only.
Replace them with a good set of radials and check the front end alignment.

Polyglass tires - the road surface drives the car Vs. radials where you are in control.

[odcics2]

Almost 200 mph going into Turn 3 at Talladega on bias ply tires. 

Those guys had some stones!   

[DAY CLONA]

Almost 200 mph going into Turn 3 at Talladega on bias ply tires.  

Those guys had some stones!  

No "stones", just the only tire choice they had....  

[odcics2]

Hanging it out....

https://www.youtube.com/watch?v=4ScdQ0Pi2V4

Can't do that on radials.

[DAY CLONA]

Hanging it out....

https://www.youtube.com/watch?v=4ScdQ0Pi2V4

Can't do that on radials.

Street "radials" no, but modern race tires are radials in nature

[cudavic]

Almost 200 mph going into Turn 3 at Talladega on bias ply tires.  

Those guys had some stones!  

No "stones", just the only tire choice they had....  

Correct!

The 1969 Drivers' Strike Made Talladega Track Famous.

For one unsettling weekend in 1969, stock car racing behaved like other major-league sports. Unhappy with working conditions, its brightest stars went on strike.
Not surprisingly, Richard Petty was among them.

On Sept. 11, three days before its inaugural Winston Cup race, the Alabama International Motor Speedway opened at Talladega. Wide, high-banked and looming 2.66 miles, it was America's longest and fastest speedway.
But it's freshly-laid asphalt was uncommonly hard on tires. In some cases, good tires were coming apart after just 20 laps.
``It wasn't the companies' fault,'' Petty says. ``They just hadn't had enough time to develop a fast and safe tire for the track.''
Several drivers showed NASCAR president Bill France their shredded tires and implored him to delay the opening race until tire manufacturers could build better tires. When he refused, 37 drivers withdrew their entries.

The Firestone Tire and Rubber Co. withdrew its tires Saturday afternoon, leaving drivers no choice but to run Goodyear.
Unmoved, France ordered the race run as scheduled. It featured Bobby Isaac and Tiny Lund and several fringe Winston Cup drivers. In a race slowed every 25 laps for pit stops, Richard Brickhouse got his only NASCAR victory.

[cudavic]

An article from Hemming.

https://www.hemmings.com/hmw/bias-ply-or-radial-tires.html

"Bias ply tires are strong, but the rigidity offers some interesting handling characteristics if you're accustomed to driving on radial tires. The rigid construction means that bias ply tires do not conform to the road surface as efficiently as a radial tire. This creates a "wandering" sensation, as the tires tend to follow the ruts and breaks in the pavement. This wandering is not hazardous, but it definitely requires the driver to pay more attention, especially at highway speeds.

The major advantage to a bias ply tire that completely overrides the finicky handling is the authenticity. Bias ply tires were used on American automobiles until the '70s, so if you're building a car from that era, a bias ply tire is an appropriate choice. Coker Tire offers bias ply tires in many authentic brands, such as Firestone, BFGoodrich, U.S. Royal and more. Furthermore, Coker Tire refurbishes original molds and manufactures the tires using original methods with modern rubber and cord materials."

[Charger_Fan]

Hanging it out....

https://www.youtube.com/watch?v=4ScdQ0Pi2V4

Can't do that on radials.

Holy shit! Look at 8:22 in that video...until today, I had no idea that Marty Robbins raced NASCAR!  Looks like he didn't do all that great in his racing career, but it's still cool. 

[odcics2]

Hanging it out....

https://www.youtube.com/watch?v=4ScdQ0Pi2V4

Can't do that on radials.

Street "radials" no, but modern race tires are radials in nature

Yes, they use radials in Nascar, but you can't hang it out like a bias ply.   

[steve817]

Modern radial tires and install the most awesome 855 true bolt in 5 speed. Then go out and drive as fast as you want! For an 855 transmission, call 307-262-0125.

[odcics2]

Modern radial tires and install the most awesome 855 true bolt in 5 speed. Then go out and drive as fast as you want! For an 855 transmission, call 307-262-0125.

Not needed.  Bias plies and a MoPar 23 spline 4 speed got Isaac to 217 on the Salt Flats in 1971 !
Certainly, that's fast enough! 

[hemi68charger]

To the gist of the thread... The speed of it all depends on what tires you have, the wheels you have and how they are balanced. Those bias-ply are fine on the highway at cruising speed from my past experience. My experience with fancy reproduction goodyear bias-ply is they SUCK for a lot of cruising... I got rid of those things and bought 255/60R/15's and enjoy the car so much better.. At any speed on the street.....

[odcics2]

The repops you had were bias-belted tires.  (raised white letter??)

Old Goodyear race tires, like Isaac ran, were bias ply, not bias-belted.

As usual, the quality of repop anything is questionable here.   

In the 'old days' of the 70s, I ran Goodyear tires, bias and bias-belted, over the century mark with no issues.

[1969daytona]

Hi.
What speed do you like to go with your Superbird? I Think 60-65 miles is acceptable then it start to be unpleasant. I have polyglass tire with 30 psi tire pressure.

Are they old?

I have had my car floored on a racetrack many times. Have 3.55 in the rear so i am only get 120/130 (mph) on the straights and for a short time.
The tires was fine but my real big issue is that the brakes heated up very fast.

Mine is repro Poly GT run with 35psi. But they was only 1-2yrs old when i had track time.

K-E