99 cobra with 4.10s not pleased?

Discussion in 'SVT Tech Forum' started by hotrodman, Jan 2, 2004.


  1. hotrodman

    hotrodman New Member

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    my 99 cobra i installed 4.10 gears not pleased at 3000rpms im going 82 mph. i drive at least 80 on interstate and that a littlt to much rpms for my liking cant go on long trips anymore ,wsa wondering does anyone have the same car but with 3.73s to tell me how many rpms you are doing at 82 mph. p/s/ my tire size is 275/35/18s thank you very much...

    * friendly reminder * - Please use our Classified Section (click me) in order to sell any parts on our forum please. Thx. :)
  2. isdnmatt

    isdnmatt Founding Member

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    Here's a link to the Corral gear ratio calc. http://www.corral.net/tech/gearcalc.html

    There difference won't be that substatial, at least not justifying the swap again. I have 4.10s and wouldn't put anything else. Should be spinfest with the blower, but just gotta feather it.

    At 80 mph with 3.73s and you're tire combo in 5th you would be turning 2666 rpms.

    Matt
  3. hotrodman

    hotrodman New Member

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    4.10 gears

    hey thanks for the advice i realy didnt want to change the gears again there had to do on an IRS suspension you have a super charger on your cobra ,do you have stock internals? how much boost/ i have mac longtube headers car smokes when drivin hard uses oil also do you no any thing about this the compression is good 170/175 on all cylinders ,was wondering if i but stock manifolds back on would this cure the proplem? priv.message me .so i can get back to you! thanks..
  4. 103

    103 Founding Member

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    I have 4.30s and my mpg on the highway is still excellent. The rpms aren't that bad for 80 in all honesty...
  5. isdnmatt

    isdnmatt Founding Member

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    Yes, I have stock internals. I will be running a 8lb pulley with powerpipe so I should see 8-9lbs after the IC. I ran nitrous on this motor earlier so I really dont want to push my luck. When I did my compression test I got 185-215 for all of them.

    So l/ts do have a tendency to draw oil. I have specifically heard about MACs doing it.

    How much oil does it use? Mine uses about 1/4 qt every 3000 miles.
  6. 99CobraJMS

    99CobraJMS Founding Member

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    From a launch 4.10s and a blower are a total PITA. See my Sig.

    But from a roll, exciting as Hell. Just got to be carefull of the DEAMON Rev LIMITER. Fuel shut down at 7K is a real MFr. Can't seem to over power the default REV LIMITER on the 99, have not seen anyelse that has done it either, even with the TWEECER.

    I am torn between the fun on the street with 4.10s from a roll verses the PITA launching this beast on the street or at the track. Add the IRS pain into that launch equation too.

    If I had to do it all over again, I would go 4.10s for NA and probably 3.55s for my car now.

    John
  7. hotrodman

    hotrodman New Member

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    im just changeing to 3.73s. 4.10 sucked bad 1st. gear was to damm short blew the tires off hit rev limter so fast.when broke lose,now changeing in progress. lrt will know if i did the right thing.thats the gear you want to go with a pro chargter any way right?
  8. 99SVTAddict

    99SVTAddict New Member

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    12.8 lbs of boost....numbers in sig.
    Just put in the solid axle and 4.30 gears. First won't be that bad for me as the Viper T56 has a 2.66 first gear ratio.

    Sticky tires will solve all traction problems. :nice:
  9. hotrodman

    hotrodman New Member

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    yea i got the T45 got the 3.37 1st. gear it like have a granny gear!
  10. hotrodman

    hotrodman New Member

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    do thay make a sticky 18 in tire :
  11. fiveofanatic

    fiveofanatic How to fuel a Mustang: Founding Member

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  12. hotrodman

    hotrodman New Member

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    just installed the 3.73s they have more pull though the gears.
  13. cobraghost

    cobraghost Founding Member

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    Not real impressed with my 4.10s either.
  14. blk32V

    blk32V New Member

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    I'm very impressed with my 4.30s!!!!!
  15. isdnmatt

    isdnmatt Founding Member

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    i love my 4.10s and that's the gear the car shouldve come with. I don't car about the 1st and 2nd gear spin fest since I love taking off from a roll and it'll never see the track.

    hey, if i get tired of lighting up the tires, then its sticky tire time.
  16. hotrodman

    hotrodman New Member

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    ..hey alright some been there before would you rather have 3.73s you think??
  17. chini42

    chini42 Founding Member

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    go over to BON and ask Joe Lynch. I am pretty sure he did it, but im not positive.
  18. hotrodman

    hotrodman New Member

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    with my 4.10 i was always hitting my limiter mine goes to 7200 ?
  19. Altered99GT

    Altered99GT Founding Member

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    I feel your pain.. I am not too impressed with my 4.10's either.





    I AM GOING 4.56's!!! :banana:
  20. hotrodman

    hotrodman New Member

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    you got to be fryin themgo withthe new 5.13 dont stop at 4.56

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