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MT ET streets for track, tire pressure

Discussion in '2013-14 Shelby GT500' started by WicK, Sep 4, 2020.

  1. WicK

    WicK 2 fast 4 u Established Member

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    Been a while but think I used to run around 18 PSI at the track with BFG DRs on my 03 cobra. I now have MT ET streets for my 13 gt500 and was wondering what tire pressure I should shoot for. No tune and nothing done to the motor as for right now so was thinking the same thing at 18 PSI? launch at 3k and slip the clutch?
     
  2. biminiLX

    biminiLX never stock Established Member

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    What size tire? Wheel? Bias ply or radial?
    I’m going to assume street radials and tell you honestly not to do it.
    Unless you use a bias ply or unless you are ok with serious gear whine, this car and specifically it’s 8.8 doesn’t take to drag strip launches.
    That said, of course I did it too.
    I ran 315/35/20 NT05R on 11” wheels and ran 15.5-16psi with low 1.7 60’ with a 2500-3000rpm clutch slip/aggressive foot swapping. Better with 16psi in 325/45/18 Hoosiers on 10.5” but serious gear whine.
    Now if you go bias (the smart move), I ran 17x10.5 Darkstars with 28x11.5 ET Rs at 15psi with 1.60s on the 8.8.
    Finally easy 1.5 60’ in 28x12.5x15s with the 9” and no longer gear whine.
    It’s still fun, just don’t expect the stock 8.8” to make you happy.
    Good luck.
    -J
     
  3. WicK

    WicK 2 fast 4 u Established Member

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    Thanks for replying! They are on 18s et street r. I know I won't cut great 60 foots with the 331 gearing but would like to cut at least a 1.9 lol. Anything under 2 is what I'm shooting for. I cut 1.8s with the 355s in my cobra with bfgs so would just like sub 2s lol. Kind of a grudge match between me and a 15 hellcat challenger on street tires. Just has a cold air and never been to the track at all so I have that going for me lol. So I figured as long as I can get out the hole I have a chance of 11s lol. Hope for 11.5 stock with the drs
     
  4. WicK

    WicK 2 fast 4 u Established Member

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    And seriously thank you for the rpm technique as I'm still figuring out the car! All this helps and figured somewhere around that rpm range and slip /gas. Punch!
     
  5. biminiLX

    biminiLX never stock Established Member

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    616D4E87-CB6A-4FAA-9811-0171A4AAB49E.jpeg You’re welcome.
    Once you’ve had some Hellcat fun, seriously consider upgrading the car with a properly built 4.10 8.8. Then live with easy street launches at the track to save the rear whine and make the car work down Track.
    I can probably tell you all about my progression.
    Last year at 1000rwhp it went 9.50s at almost 155mph.
    This year with 100rwhp more I’d like to improve that :)
    Do you have any mods other than tires?
    I went [email protected]+ on a 4.10 gear, 93 Lund tune and 315/35/20 on 20” Shelby Alcoas as the only 3 mods, still stock paper filter. Great balanced street car, but mid-high 10s near 135mph is the jam.
    If you’re willing to run that 18” ER R daily, you’ll love it on the street around 750-800rwhp with just a few mods. And that’ll get you that 10.5/135 zone.
    Good luck.
    Pics?
    -J
     
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  6. WicK

    WicK 2 fast 4 u Established Member

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    Sweet ride! And awesome times with so few mods! I have a mgw shifter, bmr lowering springs and panhard bar.(gotta read up on that as idk what it does) and a oil catch can. I must say the amount of love I get while driving is crazy,people giving thumbs up and checking it out at the car show. Been hearing people say it's their dream car and I tell them dreams do come true just give it time and work hard. Glad I've gotta some more seat time with it and feeling more comfortable with it. Since the motor is stock shift at 6500?
     

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  7. RBB

    RBB Well-Known Member Established Member

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    Yes, definitely shift at 6500, or possibly before.

    @biminiLX didn't you shatter your OPGs shifting at 6500? I know someone here did it.
     
  8. WicK

    WicK 2 fast 4 u Established Member

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    this might sound silly but what is OPG? Even at stock still shift low I guess!
     
  9. WicK

    WicK 2 fast 4 u Established Member

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    oil pump gears. found it! Thank you.
     
  10. WicK

    WicK 2 fast 4 u Established Member

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    Clutch protection killed my launches. Come out and bog right out.
     

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  11. WicK

    WicK 2 fast 4 u Established Member

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    Weather
     

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  12. biminiLX

    biminiLX never stock Established Member

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    I was shifting at 7000rpm with shift flair to 7300-7400rpm.

    And Wick the basic Lund tune should disable clutch protection, which sucks.
    -J
     
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  13. WicK

    WicK 2 fast 4 u Established Member

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    It was absolutely horrible. Start coming out good then car literally falls on its face. Well now I have my baseline so now mods time. Was thinking jlt 123, maybe 67 tb, o/r x pipe and tune. Good to trap 130?
     
    Last edited: Sep 10, 2020
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  14. WicK

    WicK 2 fast 4 u Established Member

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    Maybe i was shifting to soon at 6200 with stock motor also?
     
  15. biminiLX

    biminiLX never stock Established Member

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    Yes, way too soon. I had a friend that used to post here, but we went to the track when his car was stock, and just upping the shift point from 6200 to closer to 7000rpm picked up 3-4tenths. Basically you have to drive it like you stole it and recognize Ford put a 7000rpm over-rev in for a reason.
    Your mod plans with a 3.73-4.10 on a good tire with good driving is mid 10s over 130mph. I’d say easily, but these are not easy cars to drag race.
    Good luck man, good to see other people using these cars where they’re best, on a track.
    -J
     
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  16. SlowShelby_TX

    SlowShelby_TX Member Established Member

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    Thanks for the posts here. I am not a drag racer but do try to enjoy the car on the street. I bought a virgin 2014 with 7 miles in February but am affraid to mod it. I am at a solid 2k now, lol. Tires are safe...gears would require the tune and then all bets are off. I will keep it simple since I really wanted a 2020, and I have been around enough to know you can ruin a true street car with too much rwd power. I just need to sack up and do it...maybe after winter...lol. DRs and gears could get problematic in cold and rain.
     
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  17. WicK

    WicK 2 fast 4 u Established Member

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    Those weather conditions can be problematic for any car though. Once my f1s are done I will never have a street tire on the rear again and only drags due to the power of the car even in stock form. Thanks for being a part of the community! Enjoy that 14!!
     
  18. WicK

    WicK 2 fast 4 u Established Member

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    Thanks bro. Might be going back up with new toys on her to see how she does now with higher shift points and no clutch protection with the added intake
     

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  19. biminiLX

    biminiLX never stock Established Member

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    Well done.
    Enjoy.
    -J
     
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  20. gimmie11s

    gimmie11s Don’t be an idiot Established Member

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    Looks fun... enjoy!!


    Sent from my iPhone using svtperformance.com
     
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