Race slicks, tubes or tubeless, stiff or soft sidewall, etc.

[jayb]

So I'm thinking that my Drag Week car could use a new set of tires to optimize traction.  The engine is pretty strong, and only 42% of the car's weight is on the rear tires, so the hook is a challenge.  The current tires are Hoosiers, 29.5/10.5 - 15, about three years old.  They have limited use, probably only a couple dozen passes on them, but at 3 years old I think they are not in prime condition anymore, so I've decided I want to replace them before Drag Week.  This past weekend I had the best luck running only 12 psi in them.  One of the guys who was at the track with me this weekend thought that the outer 3/4" to 1" of the tires was not making good contact to the track, so if anything I will probably need to go down in pressure.

Also, I'm considering going tubeless next time around.  Those tubes are heavy and take a fair amount of horsepower to turn, so I'd like to ditch them if possible.  Currently I'm running tubes in the tires, because I had a bad experience going tubeless back in 2007, but I think I'd like to give it another go. 

Finally, I want to stick with bias ply tires.  I've tried radials and found them to be very sensitive to suspension settings.  Since I'm just working out the suspension on this car, I don't want to add the variable of a radial into the equation.

I've kind of narrowed down my options to these three:

- Stick with the setup I've got, and just get new tires of the same size/brand from Hoosier.  Use the same tubes, and live with the extra rotating weight of the tubes.

- Get new Hoosier tires, but run them tubeless.  The issue here is that the tube helps stiffen the sidewall of the tire, so without the tubes the sidewalls will get even more out of shape than they do currently.  Add in the potential for a lower tire pressure, and the potential for the car to get out of shape on the top end is growing.  Also, I've been reading that heavy, higher horsepower cars like a stiffer sidewall, and of course going tubeless with the same tires is moving in the wrong direction.

- Try a different brand/size of tire.  I have my eye on a Mickey Thompson ET slick, #3068W, which is about the same size as the Hoosiers except for the diameter, which is about 0.75" larger.  As it is I'm very, very close to  hitting the fenderlips with the tires I've got, so that's a downside of the larger diameter.  But the M/Ts have the stiff sidewall, so I could run them tubeless.  Probably have to trim the back of the fenders to make these tires work, which I really don't want to do.

Any opinions on this?  Or any better ideas?

[machoneman]

Tough call but.....looking at your sig picture of the Mach 1 with wheels up, are these the same tires used on that car? Or, the same size, tubed, and brand if not?

Whatever you had on the Mach seemed to do the job both on the wheels-up launch and your e.t.'s IIRC.  I'd stay away for the larger tires unless you are willing (and have the time) to radius the wheel wells. JMO!

Btw, was that run a trans-brake launch?

[jayb]

The Mach 1 picture is with even smaller Hoosier tires, 28.0/10.0, no tubes, and a foot brake launch.  Despite the picture the car never did 60 foot like it should, only running around 1.38-1.40.  That picture was snapped at the start of a 9.30 pass though...

[cjetmech]

I don't think theres a right answer here, its more personal preference I think. A friend used to run without them and they wouldn't hold air from one race to the next, but he swore the car picked up when he removed the tubes. And he was prob right, its less rotating weight. I always ran them and liked that they held air for along time. In your situation your starting from scratch with the setup so you could go either way and adjust the car to make it work. Right?

[thatdarncat]

Jay, looks like Hoosier makes two versions of the 29.5/10.5-15. Do you know which you have? Two different compounds, one a little taller than the other. I can't tell you which you should use, might want to check with the Hoosier techs.

[fe66comet]

Most guys I see out at route 66 in Joliet ( the fat wallet boys) are running bead locks with tubeless soft compound. The tires themselves are soft wrinkle walls, no tubes. If you want to loose some weight and spend less cash use Gorilla glue on the bead. 8-10 psi is common.

[fastback 427]

I'm sure your slicks are past their prime. I used to run mickey 29x10.5 slicks and after 2 years 60 ft would drop, below 12psi and the car would move around on the top end. Now we all run hoosier quick time pros or Mickey Thompson et streets. No tubes at 14 psi and the car drives Way better. My 60 ft went from 1.60 to consistant 1.54 or better. We put hi-tack sealer on the beads so they dont slip on the bead. Also they do not need a long burn out to hook. I won't run slicks anymore. One other note is it seems the hoosiers have a bigger bulge on the side wall and the mickeys are more sguare cut.

[jayb]

Jay, looks like Hoosier makes two versions of the 29.5/10.5-15. Do you know which you have? Two different compounds, one a little taller than the other. I can't tell you which you should use, might want to check with the Hoosier techs.

I'm only seeing one on their web site, #18192.  They have a #18175 which is a 29.0/10.5 - 15, and has the stiff sidewall, but is an inch shorter.  Are you seeing something different?

[ScotiaFE]

Nothing better than fresh rubber.
It's soft and gooey. Almost sounds erotic. 

[thatdarncat]

My paper catalog is a few years old, shows #18192 & #18193. I did a google search, see the link

https://www.hoosiertire.com/pb101706.HTM

But maybe it's been discontinued? I checked the link to Summit - they show it being replaced by #18194 which is available. That one doesn't show on Hoosier's online catalog either. Wouldn't be the first time a website is out of date. I guess I'd give them a call. Just a guess on my part, but I think both the #18193 and it's possible replacement the #18194 are a stiffer sidewall version due to being 3lbs heavier than the #18192. The stiffer sidewall would probably be more likely to be run tubeless, but I can't tell you if that's what your car wants.

http://www.summitracing.com/search?SortBy=BestKeywordMatch&SortOrder=Ascending&keyword=hoosier%2018194

Well, taking a second look Summit says #18194 is a radial, but no mention of that on Hoosiers product announcement:

https://www.hoosiertire.com/pb22210.htm

[bluef100fe]

Jay,

How much does the car weigh? I was a Hoosier tire guy because they worked good on my heavy truck... Then my buddy talked me into running a Phoenix tire... Well I went from the Hoosier 28-10.5w to the Phoenix 11.5-29.5 and the truck picked up 0.05 in the sixty and 0.15 in the 1/8... Despite the tire being taller... My truck has 4.57 gears so it's not like I was over geared.... I'd urge you to spend the money on them and run them tubeless...  They offer a 29.5 and a 28.5 10.5 tire size rollout is 90 or 95 tread width is 10.6 or 10.8 and section width is 13 inches... Part # ph 380 and the other is ph374... I got mine from summit racing... They work really well on my truck and my buddies truck that runs 5.50's in the 1/8... Good luck at drag week..

[BH107]

There is a drag car builder in the next building over from me that swears by the M/T tires with a stiff sidewall for an all steel car. He runs them every weekend on both cars we normally drives, and they are very consistant.

[JamesonRacing]

I'm using the Hoosier 10.5x30 bias slick (82105) on my Fairlane, with about 10 pounds of pressure.  Car is very stable down track, though I'm not running the mph that your car is probably running.  My slicks hold air, even over the winter with no tubes in them.  I can't imagine ever running tubes in slicks again; if you want stiff sidewalls, buy stiff sidewall slicks.  I would use the tallest tire I could, and modify the body to fit.  I think your car would really like a Hoosier 18221, stiff sidewall, 11.0" tread, 30.8" tall, 97.0" diameter, 10-12" wheel, 14.7" section, C07 compound.

[jayb]

Hmmm, I was looking at that 18221.  It does look like it'd be a good tire for the car, and nearly identical in size to the 18192.  I like the idea of buying a Hoosier tire because their Northern distributor warehouse is 5 miles from my house, so I can just go up there and pick out the tires...

[jayb]

Just talked to the tech guy at Hoosier.  He said if I went tubeless I would get better hook with a stiff sidewall tire, and suggested their 18221, which is one I'd been looking at.  That tire has nearly identical dimensions to the ones I've already got, but is 0.2" larger in diameter according to the specifications.  Hopefully I can tolerate that without any "bodywork" being required.  Also sounds like it might be less prone to leakage.  Thanks for all the help on this guys!