How far into redline is still safe?

Discussion in '1996 - 2004 SN95 Mustang -General/Talk-' started by spederman, May 10, 2006.


  1. spederman

    spederman Member

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    I'm getting 3.90's put in this saturday. I was thinking about 4.10's, but i am thinking ahead for when i get my procharger by the end of the year, and i dont want to run out of gear at the track. I was doing an online gear calc. and it said with 3.90's and 6k on the tach, i would be trapping right at 120mph with my 18's. Is running the rpm's to 6K bad? Or is it ok to do at the track every once in a while (1 or 2 times a month)?

    Also, what is the average a 2V with bolt ons and a procharger trap at in the 1/4? I am hoping less than 120mph so i dont run out of gear even with my 3.90's.
    #1
  2. helty

    helty some Ukrainian's enjoying a handjob via my credit

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    Ive shifted at 6k my fair share and the car runs fine. Just dont come to me if something happens :)
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  3. BurningRubber

    BurningRubber Active Member

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    Im scurred to go past 5500.

    Redline starts at what... 5700 RPM? When does the rev limiter kick in, 6200 or so? Whenever the rev limiter kicks in is when youve revved too high..:D
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  4. Dope 97GT

    Dope 97GT New Member

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    I bet ill be up there with my s/c and 4:10s in the 1/4 but i have msd with no rev limiter so i may blow up:shrug:
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  5. RoadconeTuning

    RoadconeTuning New Member

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    idk if i would take the stock valvetrain over 6k...

    gernerally factory redlines are not a "past here is sure destruction" mark... if you watch road racers and such some times they will dig 3,4 sometimes 500rpm past redline if it will help them brake into a turn... so i think that 6k shifts will be fine.
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  6. Ruckus46Gt

    Ruckus46Gt New Member

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    i dont have a blower but i have cams and full bolt ons. My car see's 6300 during the launch and my shiftlight comes on at 6200....i shift most gears at around 6500. My car has seen 7,000 a couple of times. It's all about how brief you are up there. Is 7k safe no but brief hits probely wont have a problem. I was to stay at 7k i'd be picking up pieces. I guess thats why when i seafoamed for the first time with 80k on the clock i had barely any smoke

    btw i know a couple of guys with 4.10s and a blower. They love the combo and push the car up top. If you dont feel safe can always go to a 27 or 28" tire
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  7. BurningRubber

    BurningRubber Active Member

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    Wtf!!! On the stock bottom end?

    Thats 4v territory, lol.
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  8. thomas91169

    thomas91169 I'd donkey punch my sister.

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    thats on deceleration(if thats what you mean by "digging" into a turn.

    its alot harder on your valvetrain to be up that high in WOT, but aside from floating springs, i dont see any reason a motor like the modular 4.6 (stock, non FI) cant see 7k.

    though you really dont have much of any power past 5500, your motor is starving for air. adding forced induction remedies this situation, but puts added stress on the rotating assembly, especially in higher rpm's.

    my redline is 6500(moved up via diablo tuner). i know i have nothing up there, and i shift at 5500 most the time. its raised for those special nights i might have to stick to 4th gear for longer to avoid the 5th gear "slump" as i call it, when you shift from 4th at 5700 and get into 5th gear at like 3700 and it bogs and you end up losing cause theres neither enough torque nor hp to make up for the low gearing and load at those speeds. staying in 4th longer not only gives you an edge by staying in a "pulling" gear longer, but you can shift into 5th and fall into a higher powerband.

    also rear gears can help this equation. by increasing the torque multiplication you give the motor less load to work with, and also changing the rear ratio to higher, you are shortening the time you spend in a gear in relation to the mph each gear could see at redline. both factors allow you to run though the gears faster, but youll reach your top speed at a lower mph as a result.
    #8
  9. Ruckus46Gt

    Ruckus46Gt New Member

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    yup stock bottom end:nice:
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