Max Speed on Dyno ?

Discussion in 'Mustang Chit Chat' started by Pentalab, Oct 9, 2019.

  1. Pentalab

    Pentalab forum member

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    Typ the car is wound up to redline in whatever gear provides for a 1:1 ratio.
    Has anybody seen or heard of winding the eng up in OD ?? (dyno).

    On paper, top speed should be aprx 200 mph in OD. On the track/hwy/mexico, the wind resistance would kill it way before 200 mph of course.

    On a dyno, there is no wind resistance. This is all just theoretical bs, no practical value. I wouldn't try it myself, since the DS might start to vibrate / wobulate, tires coming apart/damaged speedo, etc.

    It's a more out of interest concept.
     
    Allan Hastings likes this.
  2. MrAwesome987

    MrAwesome987 forum member

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    I've seen guys on youtube run a 8 second 1/4 mile car out in 2nd gear (powerglide) and I think the car traps at like 165+ mph.
     
  3. Dino Dino Bambino

    Dino Dino Bambino I have a red car

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    It would be rather pointless to run a car on the dyno in OD unless you can get just past peak HP rpm. Even then, the HP/TQ readings would be lower and thus no help at all.
     
  4. fdjizm

    fdjizm Drag Queen

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    What would be the reason for doing that?
    Sounds weird.
     
  5. drive_55_not

    drive_55_not forum member

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    We ran mine out to 7200rpm on a 4th gear pull with 3.08's that was 185. Made 620rwhp at 6400rpm. Made 590 @7200.

    Max dyno speed depends on the operator, most do not like spinning their's that fast ...

    I've hit 194 in 5th [6400rpm ,T-56 with .84 OD, 26.3" tire] down by the Mexican border ...

    Theoretically my car should hit 200 with a 27" tire on the same run ...

    .
     
  6. Dino Dino Bambino

    Dino Dino Bambino I have a red car

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    Maybe this has something to do with it:

     
  7. MrAwesome987

    MrAwesome987 forum member

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    What an idiot.
     
  8. fdjizm

    fdjizm Drag Queen

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    I don’t think that’s how you use a Dyno lol
     
  9. drive_55_not

    drive_55_not forum member

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    That's why you aren't supposed to run DR's on a dyno...

    I remember seeing that when it was 1st posted,,, I thought then they were trying to blow something up on purpose by holding it WFO for 30+seconds. And they did.


    .
     
  10. Pentalab

    Pentalab forum member

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    You can't use drag radials on a dyno. (we don't know what tires he had on).


    Typ DR's are not speed rated. In that video, it was a 2011/2012 6 speed automatic 5.0L. To dyno an automatic on a dyno, you have to either manually shift into 4th gear (11+) or 3rd (05-09). Another method is a temp software tune, that locks the car into 5th (11+)...or 4th (05-10).

    Putting it into 'drive'.... then auto shifting up to 4/5 gear (05-10 / 11+) .... then getting off the gas pedal..till rpm drops down to 1000-1500 rpm..then mash the gas pedal is pointless. The tranny will just shift down into 2nd gear.... then wind up in each gear. Dyno results will be useless. If instead you auto upshift to 4/5..... then slowly mash the gas.... slow enough so it won't kick down a gear.... sure it stays in 4/5.... but dyno results are useless.

    If you look carefully at the roller in these dyno videos, look closely where the tire contacts the roller. Tire goes from convex..to concave..then back to convex....forming a 'S'. If straps are too tight, it just gets worse. IMO, that flexes the tire..and it's sidewall too much. DRs are worse, with their softer sidewall.

    On the street, the tire is flat,where it's contact patch meets the asphalt.

    How much roller resistance is there ? How is a dyno calibrated.
     
  11. 01yellerCobra

    01yellerCobra forum member

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    When was this decided? My car has been a dyno a few times with drag radials. As have a few other cars around here. None have had issues with tires blowing. I think this video was more about trying to prove something.
     
  12. drive_55_not

    drive_55_not forum member

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    I've dyno'd mine with M&H DR's also knowing it wasn't recommended.

    No I do not know that tire that exploded was a DR but It happened at a track and the car had a number on it so it's a presumption.

    Mickey Thompson explicitly warns their drag tires are not to be ran on a dyno.

    https://www.mickeythompsontires.com/tech-bulletins/tire-use-on-a-dyno


    .
     
  13. Pentalab

    Pentalab forum member

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    Most dyno places I know of, within 100 miles, won't allow DR's....'bye bye'. Can't use DR's at the Texas mile and similar events.
     
  14. jewc75

    jewc75 Cant Stop, Wont Stop

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    Lots of cars at the texas mile run dr's.
     
  15. Pentalab

    Pentalab forum member

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    Last time I looked at their rule book a few years back, they stated...."no dr's". Reason cited was most DR's are not speed rated...and the ones that are...are typ rated at 150 mph.
     
  16. jewc75

    jewc75 Cant Stop, Wont Stop

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    MT are the only banned dr's