Cobra IRS wheel hop

Discussion in 'SVT Tech Forum' started by stangsalwayswin, Sep 10, 2007.


  1. Kilgore Trout

    Kilgore Trout Fried or Broiled ?

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    Nooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo :bang:
  2. Uncle Meat

    Uncle Meat Banned

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    It's not terribly difficult. Helps if you know someone with an SRA that wants an IRS though! The cat-back has to be swapped along with the rear end because they are rear axle specific. If you can find a Mach 1 owner who wants an IRS then the swap is damn near a one-for-one deal. There are some minor differences though...

    Read this: http://gt500.drive9.com/~snforums/showpost.php?p=7046706&postcount=6

    U.M.
  3. Kilgore Trout

    Kilgore Trout Fried or Broiled ?

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    Just be aware that the swap will KILL your resale value. The swap is for people who are never going to sell and want a car that is for straight line racing only.

    My GT had the SRA, my Cobra has the IRS. My experience with these two cars was that the IRS is vastly superior to the SRA.

    Do what you have to do, but do your research first so you can make a highly informed decision its your car :shrug:
  4. Uncle Meat

    Uncle Meat Banned

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    Not trying to pick a fight KT, but if the IRS is so superior then why do all the professional road race Mustangs use modified SRA's?

    I agree that my current IRS is way better around off-camber and rough corners when compared to the SRA in my '02 GT though.

    U.M.
  5. stangsalwayswin

    stangsalwayswin New Member

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    This is a hard decision. I have a buddy that will swap me rearends but the cobra is my daily driver and I have my fox body to race. I just cant stand the wheel hop in that vert, it is by far the worst I have ever seen. I guess I will try the bushings first and get some drag radials and see if there is an improvement.
  6. Uncle Meat

    Uncle Meat Banned

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    Try some stickier rubber and some stiffer rear shocks first. That's what I did with mine and it helped, but did not eliminate my hop. I have a set of the MM sub-frame bushings at home in the box right now. I bought them before researching how to install them. They shall forever remain in the box as far as I'm concerned.

    Check out this video.... on the 1-2 shift it sounds like I'm hitting the rev limiter when in actuality it's wheel hop! I had to get out of the gas and then back into it. :(

    http://www.knology.net/~unclemeat/unclemeat.wmv

    I hate wheel hop as much as any other Cobra owner afflicted with it... but I've learned to live with it.

    U.M.
  7. Kilgore Trout

    Kilgore Trout Fried or Broiled ?

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    I do not care why all the professionals use SRA. They use a lot of stuff I would never consider. The real question is for the OP: is it gonna be a trailer car or a daily driver?

    If it is going to be a trailer queen then sure, delete a/c, do axle swaps, install DRs, all that happy horseshiot that I would never even consider. Go for it :shrug:

    There are ways to get rid of wheel hop without doing a cheesy f'n SRA swap...
  8. Uncle Meat

    Uncle Meat Banned

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    Yeah, like buy a Corvette instead. At least GM can design an IRS correctly. :mad:

    U.M.
  9. stangsalwayswin

    stangsalwayswin New Member

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    That is a lot of wheel hop! What tires were you on? What was done to the IRS when that video was taken?
  10. Uncle Meat

    Uncle Meat Banned

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    Nothing, all stock right down to the F1's.

    U.M.
  11. grey03cobravert

    grey03cobravert New Member

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    yes i weight all the parts swapped out and it was dead on 160lbs. lighter , i just did mine but still haven driven it yet to see if i like it or not i got about about 1000 bucks on it all. after seeling some of my irs parts.

    i got the whole rear for free... work swapped out that is ..

    new trac lock 31 spl
    mosers ta cover
    mega bite jrs lowers
    m/b adjustable uppers
    3.73s

    i hope i like it cause i sold my axles and center center already.

    i alway had s/a cars

    i hated when i alined the irs , you cant even get to the top bolt unless you take the tire off , for every single adustment on camber . and camber effect the toe too , and vise versor!:bang:

    it tell you on the machinms to have a specail craddle some thing lies on / i just set my toe , and let it go..

    when i got home i adjusted the camber to the all way. straight up postion . :bang:
  12. WANNA_BE_GT

    WANNA_BE_GT Founding Member

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    Stiffer shocks, IRS brace from the 03/04 and some decent tires will help. I am running Bilsteins, 03/04 brace, and a set of 315 GS D3's out back and now all I do is spin.

    Just an FYI, spinning your tires is better than hop. Spinning your tires is better than gripping, for it is when you get that instant grip, that is when you will break something. You can still break an 8.8.
  13. grey03cobravert

    grey03cobravert New Member

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    but the 31 spl. axles beats the wimpy shaft pic showed above.
  14. midlifecrisis99cobra

    midlifecrisis99cobra Founding Member

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    Got to go with UM on this one. Everything I've read says the properly set-up SRA is superior to the POS IRS designed by Ford for this car. Both straight line and cornering performance is superior with the SRA. The only thing you give up is ride quality. I don't race mine enough to make any difference and the ride quality is important. Wish it wasn't so, but............
  15. thomas91169

    thomas91169 I'd donkey punch my sister.

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    IMO the biggest thing to change is your tires. like someone said, if they cant spin, they cant hop. I have Nitto555R out back and i can barely get loose in a 1st gear roll. launching is almost better than my buddies 06 WRX (20g turbo+support, race tranny, better axles, KDW2 all around) out of the hole.


    i would never go back to solid rear on a street car ever again. i love being able to go almost WOT over any surface without the rear end skipping all around on me like the GT used to do. even the slightest throttle and a itty bitty pothole and you got whiplash. Cobra, same road, more throttle, smooth as butter. i love how after i exit the corner, i get on it, the entire rear squats and sticks, and i jump out of the hole basically. i love how firmly planted i feel during the turn and out of it, no matter the condition. only in a pure drag only setup would i consider going full on Solid Rear.
  16. WANNA_BE_GT

    WANNA_BE_GT Founding Member

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    Spot on! These aren't race cars guys. They weren't even designed for it. The majority of your high end imports like BMW are sporting IRS suspension. I used to have a saleen before the cobra, and even with all of the suspension under that thing, I still feel more planted coming through turns. You also have to realize, that on the track, you are running some damn sticky tires, AS WELL there aren't any potholes, so it is a much more controlled situation and very ideal for a well built SRA. IRS FTW!
  17. tomustang

    tomustang Psychotic Member Founding Member

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    You only say that to a bumpy ride comparison daily driving, you take both of them to a road course and see the difference, which is not much, and when it comes to modifying them the Solid rear is cheaper
  18. thomas91169

    thomas91169 I'd donkey punch my sister.

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    i think ford is the last of the domestics to still utilize solid-rear on their RWD Car lineup.

    the GTO is IRS
    the Corvette is IRS
    the new Camaro is IRS
    the new Challenger is IRS

    Ford Mustang is SRA. its also lacking in almost every other department, it takes a blower and a 75k+ price tag to do what almost every other one listed above does without boost and at a much lower price.

    I wish ford would commit to IRS. they slapped it a SN95 chassis that wasnt designed for it, we got a somewhat decent IRS unit in an aged chassis. they then designed the S197 for IRS useage and ended up opting out for Solid Rear.
  19. tomustang

    tomustang Psychotic Member Founding Member

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    Oh Meat, it's only a difference of 70~ pounds, not 150
  20. tomustang

    tomustang Psychotic Member Founding Member

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    I think Ford is holding on to the known rear (8.8) that can hold up to abuse and they don't want to get rid of the machining, cheap build, and durability of it, you know how ford is, they never want to take the next leap:notnice:

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