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SB Hardtail tire and pressure
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DRR Trophy
posted
Hello,
We are running the 33x16x15 DO5 Hoosier on a 245" Hardtail with a small block. Weight is 1760 lbs and launch is at 4800. For years we have run this tire and used about 4.9 to 5.1 lbs of air with pretty good success. This new set (26 passes) seems to be different. We have been as low as 4.5 lbs and up to 6.5 lbs. Results vary, but we get less bounce out the car with less air, but more shake. With more air, we get less shake and more bounce.... What are you guys doing with similar set ups?
 
Posts: 8 | Location: Michigan | Registered: August 22, 2017Reply With QuoteReport This Post
DRR Sportsman
Picture of Quick Dawg
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I run a hard tail altered and I know you don’t want to hear this, and I am not trying to be an ED or a smart a__, but switch to MT 3071S or 30771S and your car will love it. I am not sure what you mean by bounce but I have always gotten a little bunny hop at launch if that is what you mean. When I ran Hoosiers with low air pressure the tire wrap up caused inconsistent 60’ times on my car. The DO5 compound became more unpredictable on hot tracks for me also. With the MT’s which are stiff side walls which hard tails love, I run 6.3 lbs and print 60’ times and the reaction times are consistent. In my mind for hard tails it is all about compound and sidewall.
 
Posts: 166 | Location: Salt Lake City | Registered: January 16, 2012Reply With QuoteReport This Post
DRR Sportsman
Picture of TD3550
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Not a DO5 here, but a CO7. Fought these CO7's for 3/4 of a season on my HT. Broke more ** than i can tell you. Less air and you will wad the tire up. I always had the GY D2A's. but they weren't available. I finally went back to GY Stiff SW 2053 and s`smooth as glass.You know how it goes, T@T with your checkbook with tires. ouch..Most of the guys we run with with their HT's run a stiff sidewall.
 
Posts: 1409 | Location: Under a Truck | Registered: August 23, 2013Reply With QuoteReport This Post
DRR S/Pro
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I am all for the MT's and for small block cars, using larger tires than needed is not the ticket. A smaller tire will work better. Sounds like your combo is not strong enough to transfer and HOLD the weight back with those tires so the tail is wagging the dog.
 
Posts: 2161 | Location: Tewksbury, MA,USA | Registered: November 03, 2000Reply With QuoteReport This Post
DRR Top Comp
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Man, that's a lot of tire for a small block car. Unless you have a couple of nitrous plates stacked under the carb you'd pick up an absolute minimum of 2/10ths with a Goodyear 1288 tire. Probably more.
The 1288 was developed for C and B dragsters years ago and is still the go to for sb hardtails. To bad you're back east I'd let you borrow a set. You'd be amazed. Look around the pits and see if you can find a set to use for a pass.
Or just buy a set and live happily ever after. AND go faster/quicker as a bonus.


.
Dave



F J B

 
Posts: 4480 | Location: Earth | Registered: February 08, 2006Reply With QuoteReport This Post
DRR Trophy
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I have the C07 of that tire. Blown Altered at 2200 lbs. I run 7 psi. Went 7.55 and 7.52 at 178 mph (4.76 1/8 mile). (We run a 7.50 index) I haven’t ever shook them, but I do have a 3.90 gear with that tall tire.

I would agree it’s quite a big tire for a small block. I used to have a hard tail small block and I ran the MT 33/10.50.
 
Posts: 291 | Location: Midwest  | Registered: January 12, 2015Reply With QuoteReport This Post
DRR Top Comp
Picture of Curly1
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First off I think that tire is totally wrong choice. The DO5 compound is very soft and does not not work well. It dead hooks, spins or shakes and does not work well on really hot or cold racks. Plus I think the 33x16 is way too big for that car. On my 4 link altered the MT 3074 worked great but on my hard tail front engine dragster not so well. I think you should try the 3074S stiff sidewall tire which is a 14x32. Goodyear may have a good tire but I do not have much experience with them. I have ran a bunch of Hoosier and MT tires and can tell you. I think you will really like the MT stiff sidewall 3074S.


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"Dunning-Kruger Effect"
-a type of Cognitive bias where people with little expertise or ability assume they have superior expertise or ability. This overestimation occurs as a result of the fact that they do not have enough knowledge to know they don't have enough knowledge.

Before you argue with someone ask yourself, "Is this person mentally mature enough to grasp the concept of a different perspective?" If not there is no point to argue.

4X NE2 CHAMPION. 2020 TDRA NE2 Champion
 
Posts: 4062 | Location: United States of Texas | Registered: April 02, 2011Reply With QuoteReport This Post



DRR Trophy
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Thank you racers. Very good feed back. Now, what to do before a giant race? SFG comin up hot!!!
 
Posts: 8 | Location: Michigan | Registered: August 22, 2017Reply With QuoteReport This Post
DRR Trophy
Picture of Dead On
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I can relate sir I ran a hard tail 225 inch for 12 years 427 sbc. Ran 5.0x to 4,6x. I used both Hoosier and MT. tire size was 32x16.5x 15 roll out was depending on manufacture 99 to 108. I ran 5.5 with no shake and no bounce unless the shut down was bumpy then id just be light on the brakes till I got slow enough to put a little more pressure on the pedal. I'd dead hook every time. is it optimal I don't know but my 60's were very consistent. I'm sure you can go faster with different tires stiff sidewall and all that but fast doesn't really win a bracket race does it. Your getting lots of advice here you didn't mention where your bounce was. but that's my 2 cents from experience.
 
Posts: 73 | Location: Texas | Registered: March 18, 2015Reply With QuoteReport This Post
DRR Trophy
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The bounce we get is about .4 to .8 seconds out. It squats on launch and comes up on the rebound with slight shake which we see in tire tracks and on the lateral in the racepak. Like it has been said.... consistency is what I need to find out of this set up.
 
Posts: 8 | Location: Michigan | Registered: August 22, 2017Reply With QuoteReport This Post
DRR Top Comp
Picture of Curly1
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quote:
Originally posted by Quicksilver:
The bounce we get is about .4 to .8 seconds out. It squats on launch and comes up on the rebound with slight shake which we see in tire tracks and on the lateral in the racepak. Like it has been said.... consistency is what I need to find out of this set up.


Mine was doing same thing, I was told to go to the STIFF sidewall tire an it would eliminate it. I put tubes in there and it made it much better so I feel the stiff sidewall will do it. Bottom line is the tire selection is not the best right now.


https://postimg.cc/gallery/np3zpruo/
"Dunning-Kruger Effect"
-a type of Cognitive bias where people with little expertise or ability assume they have superior expertise or ability. This overestimation occurs as a result of the fact that they do not have enough knowledge to know they don't have enough knowledge.

Before you argue with someone ask yourself, "Is this person mentally mature enough to grasp the concept of a different perspective?" If not there is no point to argue.

4X NE2 CHAMPION. 2020 TDRA NE2 Champion
 
Posts: 4062 | Location: United States of Texas | Registered: April 02, 2011Reply With QuoteReport This Post
DRR Trophy
Picture of bill masiello
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quote:
Originally posted by imakehp:
Man, that's a lot of tire for a small block car. Unless you have a couple of nitrous plates stacked under the carb you'd pick up an absolute minimum of 2/10ths with a Goodyear 1288 tire. Probably more.
The 1288 was developed for C and B dragsters years ago and is still the go to for sb hardtails. To bad you're back east I'd let you borrow a set. You'd be amazed. Look around the pits and see if you can find a set to use for a pass.
Or just buy a set and live happily ever after. AND go faster/quicker as a bonus.
Dave I agree with you about the 1288 tire ! the bad news is Good Year stoped making that tire in 2014 and any you might find would be at least that old !M+H is making a tire that is close and might even be a little better than the old 1288 I just ordered a pair for my car ! Like Curly said there are not a lot of choices out there for tires and most are suited for high horse power cars !
 
Posts: 64 | Location: shelton ct | Registered: November 21, 2008Reply With QuoteReport This Post
DRR Trophy
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Tried 7 lbs of Air this weekend and it actually drove out of the hole better than ever. Maybe should try more air...
 
Posts: 8 | Location: Michigan | Registered: August 22, 2017Reply With QuoteReport This Post
DRR Top Comp
Picture of Curly1
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quote:
Originally posted by Quicksilver:
Tried 7 lbs of Air this weekend and it actually drove out of the hole better than ever. Maybe should try more air...


I agree with that because it costs nothing to try it. Now I will say this on my car when I raised tire pressure it made the bounce much worse and it made it bounce down the tracks and even in the shut down area so be careful. Comes back to having right tire for your application.


https://postimg.cc/gallery/np3zpruo/
"Dunning-Kruger Effect"
-a type of Cognitive bias where people with little expertise or ability assume they have superior expertise or ability. This overestimation occurs as a result of the fact that they do not have enough knowledge to know they don't have enough knowledge.

Before you argue with someone ask yourself, "Is this person mentally mature enough to grasp the concept of a different perspective?" If not there is no point to argue.

4X NE2 CHAMPION. 2020 TDRA NE2 Champion
 
Posts: 4062 | Location: United States of Texas | Registered: April 02, 2011Reply With QuoteReport This Post



DRR Trophy
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quote:
Originally posted by Quicksilver:
Tried 7 lbs of Air this weekend and it actually drove out of the hole better than ever. Maybe should try more air...


Wink
 
Posts: 291 | Location: Midwest  | Registered: January 12, 2015Reply With QuoteReport This Post
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