9 on 10
 

Do I need tubes if I'm running a 9" tire on a 10" wheel? What pressure would you recommend for a 2800 lb car, 400 trans, 488 gear, ladder bar, mono leaf with sliders.
It's not a stocker or super stocker, but you guys are the best source for tech info.

Re: 9 on 10
 

No need for tubes. Pressure depends upon whether or not it is a radial.

Re: 9 on 10
 

The primary difference between bias ply and radial slicks is that typically a radial will work better with a little more air pressure. But the range for either can be 10 lbs or more.
I run 21 lbs in my Hoosier radials, but have heard numbers as low as 14 and as high as 24+ for both styles. Radials are faster, but more sensitive to track conditions and can spin sooner and more than bias ply.

Pick a "high teen" pressure and adjust it based on contact patch on the track, tire surface and 60' times. Too many variables to be very specific. Tire may move a little until it "settles in" and you can watch it with a shoe polish spot across from the valve stem. Swapping them from side-to-side will keep it close to where it was balanced at. If the movement is considerable and constant, especially if using lower pressures, it may be necessary to screw the beads. Never run tubes without securing the beads first.

Re: 9 on 10
 

Thanks for the help. These are bias ply, 2 for 1, Toyo's. I'm trying a 6.50 index class that requires a 9 inch tire and I've never run a tire that small. The wheels came with Hoosier 30 tall bias tires that are feathered pretty badly. I've been told that a good hard burn out would clean off the feather, but that's never been my experience so I'm putting on new Toyos and hoping they work. I plan to screw them and run tubeless. Is that a mistake? I bought these with tubes in them, but I think the previous owner ran tubes because he picked up a pop rivet. Thanks again, you guys are the best.

Re: 9 on 10
 

yes

Re: 9 on 10
 

Why is it a mistake?

Re: 9 on 10
 

Swapping "feathered" slicks from side-to-side should help clean off the feathering.
Not sure how much track conditions or perhaps the wrong rubber compound may contribute to feathering. I haven't had a problem and swap sides regularly anyway.

Re: 9 on 10
 

Take Myron's advice and turn your tires around once and a while. I turn my Hoosier radials around every 4 to 6 passes. I have always had better luck with wheels 1/2" to 1" wider than tread area. You can hook harder with more air and more stability. I never use screws. If you use narrower wheels you have to use lower air pressures to get the foot print right, then often need screws to keep them from slipping on the wheels. Since I went to wider wheels several years ago I have not needed screws. When I ran 9" radials 10" wheels were quicker.

Re: 9 on 10
 

Just a note, but sometimes it depends upon the upon the wheel as to whether you use a tube, some wheels inherently leak. I had a set of Americans that leaked and I used enough silicone to double the weight of the wheel.

Just a thought.

JimR

Re: 9 on 10
 

I regularly turn the tires at 10 runs, or very close to it. The feathered Hoosiers that I have came on the wheels that I just purchased.

My question is, will hurt to run screws when they aren't needed? I don't like to see the tire mark 3 inches from the stem. Why is it bad to run screws?

Re: 9 on 10
 

We screw our slicks to the rim. We found out with the AA/SA car that the slicks moved on the rim if we didn't.

Re: 9 on 10
 

it's not a question of good or bad, it's just that you don't need them if you're not running tubes so why ruin a nice pair of wheels?

I've run a best of 1.17 60 foot on 32 x 13.5 Hoosier Radial slicks with my current 3130 lb. ride and a best of 1.28 60 foot on 30 x 10.5 Hooiser Radial slicks with my former 3880 lb. ride and the tires have never been screwed to the rim and I make north of 200 passes a season.

I also haven't swapped my tires side to side in over 10 years and my 60 foots are deadly consistent varying thousanths on any given day from pass to pass.

That said, walk the stock/super stock pits at any divisional and national event and you'll see the vast majority of those going rounds, winning races and championships do not have their tires screwed to the rim including the the winningest car in NHRA history.

Have your slicks mounted dry, meaning no soap/mounting lubricant. Yes they will move on the rim for a few passes which doesn't effect consistency nor is it anything to be oncerned about.

Re: 9 on 10
 

Ed, if these were new wheels, I'd take your advice and try to run them screwless. These are old Center Lines that have holes already drilled in them, so I'll screw them.

Re: 9 on 10
 

"sand" blast the bead areas with 80 grit aluminum oxide such as Harbor Freight sells cheaply. If you have trouble with the wheels squirming on the brake drums or hubs, blast those areas too.

Re: 9 on 10
 

When I was going to try the TOYO tires the rep I talked to recommended no bigger than a 9" rim. He said the sidewall was made to work on a narrower rim. When I raced my car I never had rim screws and it was a stick shift 3205lbs 7000rpm launch 3.19 first gear 5.57 rear. It would move the tire an inch or so every 6 passes then I would swap sides.

Re: 9 on 10
 

I wish I knew that before I bought these 10 inch rims. These weren't easy to find.

Re: 9 on 10
 

I talked to a Toyo distributor when they had the 2 for 1 sale and he cautioned me that a lot of the tires were 2-4 years old.

Re: 9 on 10
 

These are 07's, if you go by the last 2 digits. They didn't hook worth a damn tonight. Some of the problem is the track, but it's mostly me.

Re: 9 on 10
 

Ron, you could also try a compound called bead sealer that tire shops use. It is a tar like compound that is sticky and works well to keep tires from moving at all. it is messy to put on but easy clean-up once it dries. you just have to resist the urge to wipe it up while it is still wet. comes as brush-in-can like anti-seize compound.

Re: 9 on 10
 

Hoosier also says no wider that 10" wheels for my 10.5" radials, but 11.5" wheels made it a new car. I have mentioned that to two different Hoosier reps, both seemed very surprised. Absoluty no more "radial wobble". It's quicker, faster and likes more air in the tires.