FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: jayb on August 25, 2014, 06:22:42 PM
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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?
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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?
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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...
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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?
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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.
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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.
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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.
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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?
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Nothing better than fresh rubber.
It's soft and gooey. Almost sounds erotic. ::)
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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
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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..
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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.
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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.
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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...
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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!
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I did a little google research on this and found some good info like this article http://www.dragracingonline.com/technical/v8-tiretubes-1.html. And from reading a lot of peoples opinions, all say the Hoosier slicks don't leak period without tubes. Must be the way there made. Glad to hear your buying a new set though, they always bite the best when their new, and with all that power your prob going to need all the help you can get.
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When I ran my Hoosiers tubeless they didn't leak for the first 100 or so passes then they slowly started to leak... And gradually got worse to the point I had to leave the pits with more pressure than I wanted then set them in the staging lanes right before my pass... Then I had to put tubes in to finish out the season with that set of tires... My truck isn't that fast but it does punish the slick pretty bad on the start...
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I have run Goodyear and Hoosier and M/T. I have run without tubes for probably 10 years. On my car and with the size tire available that fits, the M/T work the best, and they are a stiff sidewall tire. I don't run any rim screws either. The Hoosier tires works OK but the sidewall would give out after awhile, a stick car will usually just crush the tire, and the sidewall would not last as long as the tread. The Hoosier's did hold air the best however. Stiff sidewalls were not available in the (Hoosier) size I was running at the time. I switched to M/T stiff sidewalls and they would hook until there was no rubber left (that was when I was running 10.80's). Now running in the 9's the tire will fall off after 3 years like other have said, before the tread is gone.
If I lived that close to a warehouse I would buy Hoosiers too. I would get the stiff sidewall Jay, and go through the stack of tires to get a matched pair. They will put "chalk marks" on them, write like 94 1/2 or 94 3/4 on the tread for example... this is the measured roll out during manufacturing. There is always a range of rollout on the same size, it may be from 93 3/4 to 95 inches for extremes as an example. I would air up your tires to 12# and measure yours first. Then try and find 2 at the warehouse that are the same number whatever that ends up (on the Hoosier stiff sidewall tire). You can lose that extra size you don't have room for this way.
Another thing is these tires are date coded, you want something made this year not 2 years old before the first burnout. It is a date stamp like on block and heads, right next to the bead on one side. It will have letters and numbers etc. the last 4 digits are what you are interested in. Let say they are 1214, that means the 12 week of 2014 as the first two numbers are the week and the last two are the year. If they allow you to look through them that would be a great thing, and you can get what you want after seeing the range of sizes on that particular tire, compared to what you have. Sometime they will air up a little different size, but there are ways to shrink and to stretch the tire to size before the first heat cycle and then they take a set (burnout).
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Thor,
You know damn well Jay should be running M and H slicks with tubes and screws just like I do. Actually Jay I ran Hoosiers for years and tubes and was happy as hell. Went to the M and H slicks 2 years ago and tubes and are even happier. I am a stick car and heavy. I have gotten to the point where I can raise tire pressure and still get 1.40-1.38 60 ft times on a 2 year old tire that is not a stiff sidewall. My next one will either be the same M and H or another set of Hoosiers. By the way when John @ M and H sent me the tires the were within 1/16th of an inch of each other. The Hoosiers QTP
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Sorry, the Hoosier QTP's were close to that in roll out but better than any M/T tire I have ever seen. Just a contiuation from above.
Bruce Faulkner
SSG U.S. ARMY (RET)
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"Thor,
You know damn well Jay should be running M and H slicks with tubes and screws just like I do."
LOL Bruce! I don't think he will and neither will I, ever. The reason being is... M&H doesn't even offer a 29 or 29.5" tire, zero... ziltch, nada, so no reason buying a tire that won't fit. My buddy had a set of 10.5x30 M&H and he went to order another set and they were discontinued. They go from a 91" roll out to a 97" and nothing in-between. I see they have a ton of 24" and 26" slicks available, Ricer's? Motorcycles? WTF?
Hey, I thought farm trucks had 16" split rims anyway? LOL.
Oh, and tubes are floating the river with a beer in your hand on a hot day, or sliding down a hill with snow on it on a cold day...
A friend of mine took his tubes out and his car went .08 quicker, seems like a lot but he said no other changes and similar weather conditions.
A stiff sidewall works much better than tubes in a standard slick, and weighs less. Grab a stiff sidewall slicks bead and move it around, it is really thick and strong, you can't wrinkle it at all, on the inner half of the sidewall.
In the end, use what you are happy with, no different than oil, spark plugs, lifters, etc.
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Got my new tires; I ended up with the Hoosiers with the stiff sidewall. One thing about the stiff sidewall version that surprised me, and that Thor mentioned above, is that the entire sidewall is not stiff, just a portion of it. My old tires were stiff from the bead out about 1.5" towards the outside of the tire, and then were really light from there to the OD of the tire. The stiff sidewall tires are stiff from the bead out about 3.5", and then are light from there out to the OD of the tire. I had expected the entire sidewall to be stiff, but that was not the case. You learn something new every day... :D
Also I decided to pick up a tire durometer when I bought the tires. The old tires read between 52 and 56 on the durometer, depending on where on the tire I check. The new ones read between 42 and 44. FWIW...
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Sticky!
Read this article Jay on durometer, 'bout 1/2 way down the page. FYI.
http://racecarbook.com/articles/traction.shtml
On edit: almost forgot. Put'em in the sun for a few hours, note the ambient air temp and take another reading. Book it and try to repeat the sun and local temps for the next durometer reading. Most tire reps/techs at the events do note both as one should attempt to duplicate local track conditions, hence the temps and sun.
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What's the circumference of the new tires compared to the previous tires?
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According to the spec sheets they were supposed to be within 0.2" in diameter. However, when I measured them in the old tires were 92" in circumference, and the new tires were 94.25". That translates to a difference in diameter of three quarters of an inch, which was more than I'd been hoping for. After putting them on the car, I decided to do a little wheelwell trimming, and now they fit just fine ;D
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Where do you guys find the specs on the sidewalls and what are the different compounds?
I'm Looking at Hoosier #18140 because it's about ALL the tire I can fit under the car without surgery. Specs that I see say it's a D06 compound but nothing about the sidewall. Looking at the specs on Jay's new tire I see that one is a C07 compound but again, nothing about the sidewalls.
I'm expecting about 4200 lbs race weight, stick shift of course, and I've got 4.30 gears in now. I'm planning on doing the Texas Muscle Car Club Challenge next year, which is about 12 Sunday morning races at a few tracks in the Dallas area. I'm also hopeful that I might be able to get a pic of the Galaxie going wheels up like Cody's truck!
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Go here, Wade; down at the bottom is a key for askerisks after the tire, that gives a little information on the sidewall.
https://www.hoosiertire.com/Drtire.htm
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Thanks Jay. Looks like maybe I should go with the 18155 instead of the 18140 then? It's only .2 wider in section and has the stiff sidewall and C07 compound. The stiff sidewall I understand is really a good thing for a stick car? Also the 18155 shows 10.2 tread width vs 9.0 which HAS to be a good thing. Does kind of make me nervous though since according to my measurements I can fit 11.4" width and that one lists at 11.3". If it runs a little over spec I'll be screwed. Guess I'll have to chat with the Hoosier guy when I get ready to place an order.
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Is it possible to roll the fender lip a bit , i remember seeing a 69 boss 302 track car at a car show and fender lips were rolled front and rear , maybe more of a road coarse setup but car had slicks ..
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Stick cars like stiff sidewalls, so I'd definitely go that route. I'd also think about stepping down a size, Wade, because based on my experience the specs don't exactly follow the actual tire size...
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Ah crap, I was looking at the wrong tire anyway. The 18155 is a 12" section, no way that's going to fit. The 65 Gal seems to have particularly small wheel wells. Frustrating!!
I may just get the next BIGGER size and MAKE that sumbitch fit, lol
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I may just get the next BIGGER size and MAKE that sumbitch fit, lol
Attaboy, Wade LOL! Now you're talking like a hot rodder!
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Late to respond. Did not really pay much attention to the "tire thread"... ;)
But I was running the M/T 3068 in my car and it seemed to work very well - and rubs pretty much everywhere.
I changed to the similar sized softer sidewall ET Street tire for class legality and its a lot "touchier" getting it to work. I can get similar results but I need to work a lot harder.
Both time running with tubes - my junk sits more often than it runs and I don't like it leaking down.
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Late too and didn't see what the wheel width was 8", 10"? If you're not having contact on the outer edges I'm thinking the rim may be too narrow (too much air can also be the culprit, but not 12/14lbs). My 10.5 M/Ts are on a 10" wheel, which in my thinking puts the bead in, or close, the vertical plane of the outer edges of the tire...Just a different POV, RodC.
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I found it amusing in the article about the durometer changing several points due to ambient temperature changes when they were measured... All I could think of IF the reading changes several points with a minute temp change, what in the world happens with five-seconds of scorching burnout to the durometer reading?...............or a AA/F motor dumping flames and plasma level gasses on/at the tire surface.
Personally I always thought holding at the line with basically only 1/5 of the tires surface being roasted for what sometimes seems like forever in fuel cars has got to for make variations in tire grip at the tires surface and perhaps encourage "shake" .