MT ET street R series tire pressure

Discussion in 'Tires and Wheels' started by redfirepearlgt, Aug 4, 2016.

  1. stkjock

    stkjock ---- Madmin ---- Staff Member

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    Agreed - confusing. IDK - about getting cited
     
  2. redfirepearlgt

    redfirepearlgt forum member

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    Though it is listed in the DOT section it is specified specifically for Drag racing only. See the web spec.
    http://www.mickeythompsontires.com/strip.php?item=ETStreetRadialPro

    Hoosier also offers DOT pros however they clearly state that their tires that fall under this classification are for racing purposes only and not meant for street running. Read the warnings under the Quick Time DOTS, Quick Time Pro DOT's, and DOT Drag Radials on their PDF after killing someone. It just better not be one of my loved ones.

    http://hoosiertire.com/assets/Drag%20Racing%2010%2011%2016%20b.pdf

    Several street classes have banned the use of Hoosier DOT pros because they do not comply with being street legal.

    Quoting the manufacturer. I'm not here to split hairs on technicality in writing. Leave that to a lawyer in the court room for the guy who chooses not to heed these warnings and finds himself in an accident with these tires on his vehicle that are not recommended for street driving.
     
  3. stkjock

    stkjock ---- Madmin ---- Staff Member

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    yea, I see that, I wonder how much of that is the company "CYA"
     
  4. bunits19714

    bunits19714 forum member

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    ^^^ yes you can get cited or towed- (first hand exp.) and the dot rating is for classes that require dot certified tires (grooves/tread so it isn't ruled a true slick)
     
  5. bunits19714

    bunits19714 forum member

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    And when the trooper points at the tire reads the words"not for highway use" don't reply by saying well this isn't a highway it's just a normal road; doesn't fly real far.
     
  6. 46addict

    46addict 13726548

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    Seeing as how the Street R and the Radial Pros are made of the same compound, I don't see how the latter would be more dangerous on the street. Neither would be safe to drive in the rain and I wouldn't do it myself.

    Yeah I am not one to make smartass comments to a cop. My plan is to keep probable cause to a minimum if I ever need to drive with these on the street. :whistle1:
     
    Last edited: Dec 28, 2016
  7. redfirepearlgt

    redfirepearlgt forum member

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    ^^^ I am assuming since MT professes the R series to be street legal, it has nothing to do with the compound and everything to do with the tread pattern which the pro radial completely lacks short of a couple of notches. The Radial Pro essentially has no tread at all. The ET Street R does and likely to minimum specification since MT states they are.

    Go to the MT website, get the phone number, call and talk to Mickey Thompson about it. They can give you the specifics as to why. I can only tell you what the web site datasheets specify.

    It's not worth the risk of getting into an accident with non street compliant tires on the car with data sheets the clearly specify "For RACING PURPOSES ONLY", or "NOT RECOMMENDED FOR STREET USE" in the technical data sheets. An injury lawyer would have a hay day with that regardless of who is at fault. Your insurer may not smile kindly on it either. Just food for thought. Some rich stock broker, hedge fund manager, or Goldman Sachs executive may be able to absorb a hit like that, but average Joe's like me sure as hell can't.
     
    Last edited: Dec 28, 2016
  8. 46addict

    46addict 13726548

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    Isn't the main purpose of having raised treads is to dispel water? When it's raining the track will be closed so driving in the rain is a non issue for me anyway.
    Unless I'm overlooking something very obvious, I don't see how having these on will cause an accident without reckless driving on my part. I understand drag radials have a much narrower temperature range than street tires so there won't be any tomfoolery coming from me with either the Street R or Radial Pro. I will find some time to call MT and see what they say.
     
  9. stkjock

    stkjock ---- Madmin ---- Staff Member

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    the belting material maybe different as well between the tires. with the "not highway use" tire having a softer & less puncture resistant material (just a guess on my part)

    FWIW - I have a friend with a 750whp GN that runs the 275/50/15 Pro 24/7/365, it's not his DD of course, IIRC he does replace the tires every year or so, he feels they lose grip after a year... :hmmm:
     
  10. redfirepearlgt

    redfirepearlgt forum member

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    Yes, that is how I understand it. If it were merely for traction Indy 500 tires and Dragsters would not be smooth. Further if you watch Formula 1 racing where they actually run in the rain, you will see that when they change to a rain tire they have grooves in them for the syping (sp?) effect.The more contact made by the rubber to the road (contact patch) the better the traction will be. Without tread, water cannot be displaced. This groove in the tire allows water to displace from the direct contact areas. Without this the water only has the outside edges of the tire to push to and creates a water cushion, which is never a good thing unless you are a hover craft. After the water moves into the tread area it has to be removed and that is where additional engineering of how the tread lays out comes into play. Summer tires will have a different tread pattern than all season radials, and snow tires. Compound also comes into play based on how it reacts with temperature.
    There is a great amount of information on tires on the Mickey Thompson website as well as other tire websites. It only takes googling it to learn more about it. My explanation is a paraphrase of actual theory so it may be slightly inaccurate in areas from an engineering point of view, but the basic concepts are there. Hope that helps.

    Discount Tire direct has a great glossary as well as a tire size calculator I use quite a bit. The glossary link is posted below.

    http://www.discounttiredirect.com/direct/infoTireTerm.do
     
  11. 46addict

    46addict 13726548

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    I assume they lose their grip after a number of heat cycles, even if tread depth (or should I say notch depth) is still there.
     
  12. frank s

    frank s at Play

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    My very first accident as a driver resulted in bent suspension components on the family Buick: I drove around a familiar corner at a normal, conservative rate of speed, and lost control when the tires slid in an unseen patch of water. Only went a few feet off-course, but it was over the curb. It's just an example of how even non-reckless driving can bite you in the ass, given the right (wrong) not-out-of-the-ordinary circumstances.
     
  13. 46addict

    46addict 13726548

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    I just got off the phone with MT and the rep mentioned Pro Radials are not designed withstand sustained high temperatures (i.e. highway cruises). That along with the lack of tread is why they are not labeled for street use. We didn't get into tech specifics because that was enough to answer my question.

    Makes me wonder how guys at Drag Week make the cruise on wrinkle wall slicks/radials with no catastrophes.
     
  14. RED09GT

    RED09GT Senior Member

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    The pro's have just deep enough "grooves" to get the DOT stamp. as soon as they have been driven more than a few miles, they likely are no longer legal from a tread depth perspective.
    My regular MT ET Street R's have only a "B" rating for temperature so I would imagine the pros would be even worse.
     
  15. skaarlaj

    skaarlaj Probie Former Pink Bus Rider

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    I ran hoosier bias ply quick time pros to and from the track I go to that's 100 miles away from my town, and I just pumped them up to a bit over 30lbs of air to keep the sidewalls from flexing as much on the interstate, then back to sub 20psi for the track. Pumping up the pressure keeps the heat down for sure on these tires on my car at least. I did this 5 times to and from the track last year, and on my first trip with the additional pressure, I stopped a few times to feel if the tires were in fact staying reasonably cool, and they were indeed. surely if I was to do the same thing with 14-18 psi they would've gotten hot and probably popped on the interstate. And Yeah, I'm sure if you was to have an accident on a public road, you'd be on your own and screwed, even if it had a DOT stamp, but said "not for highway use"
     
    Last edited: Apr 20, 2017
  16. skaarlaj

    skaarlaj Probie Former Pink Bus Rider

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    I also believe they just give certain aggressive tires a dot stamp simply to sell to schmucks like me so you can say, I beat you with a street car, because I for one do agree that if you're trailering your car to and from the track it is not a street car. And swapping wheels / tires at the track is kind of a grey area between "street" or "track" car imo. But if you don't mind the extra work doing this every time you race, I guess it's legit. This next season, I'm gonna get the biggest/best tire for grip at the track and swap them at the track simply for wear reasons. My old quick time pros are now showing chords with just a little over a thousand miles, and that isn't cutting it, lol. If my track was less than 25 miles away, I'd still drive on whatever tire worked best at the track though, if I tested it with a heat gun and felt they wouldn't pop on the way to or from. But 100 miles each way is just too much.
     
    Last edited: Apr 20, 2017
  17. redfirepearlgt

    redfirepearlgt forum member

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    I just swapped over from my R series 17" setup to a 15x8 with the 275/60/15 Radial Pro (not the R - series). I drive on streets to the track now and swap out there. Yip, like a regular old tight wad, I throw the tires, jack, cordless impact, torque wrench, portable air compressor, and associated hardware into the car and head to the track. Swap out, race, swap back and drive home now. I'll make the drive on them in the True Street Class NMRA in June, but that drive is only 30ish miles and the road speeds don't exceed 45MPH I found. I know quite a few guys who have used this tire for that class. DOT is all they seem to care about. Same rubber compound as the Street legal R series BTW. Both are R2 compound on the MT Compound specs. Just notches. Oh tread depth new is 4/32's. I measured out of curiosity.
     
  18. skaarlaj

    skaarlaj Probie Former Pink Bus Rider

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    How do you think the "Rs" would compare to the "pro's" if the R's would've been 15 inchers instead of 17's? I'm not afraid of swapping wheels/tires at the track, but if it's feasible to run a similar 60' on the R's and not wear out too damn quickly, my back would surely thank me for not having to do all that work at the track lol.
     
    Last edited: Apr 20, 2017
  19. 46addict

    46addict 13726548

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    I can see how guys who are pushing the envelope (lots of boost on a stock block, etc) would want to trailer their cars. If it's a full interior car with valid state registration I don't see why it couldn't count as one though. The QTPs wearing out in 1k miles is a bit humbling. It just goes to show how narrow the scope of these tires are.

    Do you race with the street tires in the trunk or chain them to a pole?
     
  20. redfirepearlgt

    redfirepearlgt forum member

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    No idea. Not going to guess. I will be making more passes tomorrow night as long as the weather holds, so I can then at least tell you if I feel my change was worth the money or not 17" R (305/40/17) series vs. 15" Pro (275/60/15) series. Only made two passes on this setup so far. Tack was so green that night rail dragsters were losing traction.
     

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