I'm glad you measured them. 1/4" is great!
Just an FYI, I used screws to secure my ET Streets to the rims, went tubeless and used Dawn dish detergent to eliminate leakdown. I will confess that on a couple screws, I had to seal them up with YamaBond 4 case sealer.
If you really want to stiffen the sidewalls for better handling, go beadlocks.
Dave, from the old neighborhood in Jersey!
After sitting almost 2 weeks the one still had the same pressure and the other lost a little. I was going to question screws causing leaks. I've seen beadlocks but don't know how they install/work. Do you still have to drill the wheels? My wheels match my fronts and I guess I'm worried about quiting the racing and needing another rear wheel due to some mishap. They are the same as my rear street wheels, and they are discontinued and hard to find. When I got them for the slicks I got the last one at Summit and found a "blemished" one from Jegs on ebay. The only "blem" I found is that it was obvious it was mounted on a car, didn't really show signs of a tire being on it.
On a side note, a few days ago I went for a little ride in the morning when it was cool out. WOT on the interstate on ramp which is concrete, for the first time I'm pretty sure it chirped 3rd! (street tires) And before someone scolds me for doing that, the speed limit is 70 and everyone is going 80, so after letting off the throttle, I was at the right speed to merge.
Tony
1955 Bel Air Sport Coupe
I've seen beadlocks but don't know how they install/work. Do you still have to drill the wheels?
Beadlocks do not drill into the tire. The bead of the tire is squeezed between the two. I have no leaking issues at all with mine.
https://www.youtube.com/watch?v=2VaZZj1h9_4
Everyone I ever knew with a street/strip car had two sets of wheels and rarely did they matcj the front. My first slicks were recaps on stock steel wheels.
Hmm... With that much air pressure there might be two things going on here. One is that while a 8-10" wheel is recommended, anytime your wheel width is smaller than the tire width, you pinch the tire a bit leading to the center being more pronounced that the side areas. Secondly I would think that the sidewalls are pretty firm so I don't think that is an issue. You could be up on the crown of the slick down track which in turn could mean you are riding on maybe 5-6" of tire width on each tire. I also take that the rear suspension is basically stock? No air shocks right? Weight bias of the car front/rear could also be having an affect on the handling. Typical instant center point of a stock vehicle can be sitting out in front of it. If I remember correctly, a leaf spring vehicle is measured as an imaginary line drawn through the rear upper spring attachment bolt and the front spring attachment bolt. Traction bars will move the IC in much closer to the engine. Don't overlook the front suspension alignment and condition in relation to steering inputs (from you or worn components) that could be affecting keeping the car straight and true.
chas, when I had less air, doing a burnout in my driveway left rubber on only the left and right sides of the tire, nothing in the middle. Adding air made it more even across the width. As for the sidewalls, I "think" they are pretty flexible. Giving it throttle not much more than off idle easily wrinkles the tires. I have Caltracs and the front end is all basically still new and tight. With street tires it runs straight as an arrow on the street and track. No, no air shocks.
Tony
1955 Bel Air Sport Coupe
I have a couple 15x8 Vette Rallys set up for slicks, In nthe 70s I used 15x7 Monte Rallys..