Let's get a discussion on what is a better means to show potential: Dyno or Track?

Discussion in 'Fox 5.0 Mustang Tech' started by 5spd GT, Nov 12, 2005.

  1. It ISNT ET's !! It is MPH!! Go to www.smokemup.com
    and use their fomula for HP from MPH !! you have to know the weight of the car and the trans /drive train loss, and that will tell you the FWHP and the RWHP !! Cool?? Now if you add 1 MPH it will show the HP to make that... Or 5 MPH , again it will show the HP to get that... ORrrrrr... it will tell you the same as a dyno and will show small amounts of HP gains...
  2. "How can one possible shift at the same rpm, at same time, same engaging/disengaging of the clutch to apply power to the track, launch the same (same 60ft)...etc..."

    5spd - You are joking with this question, right? You've just described what GOOD drivers do pass after pass and lap after lap - at the drag strip, autocross and road course. If that stack of timeslips you have don't reflect that, it's not because it can't be done. It's just because you can't do it. And we now all know you have no experience with the other competiton venues. The simple fact is this -- that kind of consistency occurs all the time with good cars and drivers. If you're not capable of that driving skill, then the dyno is certainly going to be a better way for you to test/tune your car and compare changes you've made.

    In my racing schools and autocross schools, and in my actual competition in both of those venues the coaches/instructors/competitors who helped me grow as a driver were ALWAYS interested primarily in my consistancy as a driver, not my ultimate speed. Why? Because with consistency as a driver, I could begin to improve the car. And speed follows consistency and smoothness. Talk to the good drivers with good cars in any of the venues -- you'll see multiple runs within hundredths of each other at the strip, almost identical 60' times; autocross and lap times within a tenth or two of each other (and that's on 1-3 minute laps). That consistency is achievable -- and LOTS of good drivers do it. And that's when they can really help develop the car -- they're consistent enough to allow the results of changes to be seen in the times. As you would say -- simple really.

    As has been stated in the thread by most posters -- there is a place for both dyno testing and track testing. Neither is better or worse -- they are simply different. Both have pros and cons. However - one thing is true. If you check with the pros -- they won't test/tune at the track, and then finalize things on the dyno. They'll test/tune with the dyno -- and then finalize things at the track. They use both -- but the track is ALWAYS where the final decisions are made about what's helpful and what's not.

    And with that - I'll unsubscribe from this one -- have fun guys...
  3. It is more than "milliseconds" by the way.

    Time adds up and when you go thru multiple gears or you launch at 2200rpm instead of 2000rpm you can see a difference. Also what if you don't slip the clutch the same way? That is more or less time taken.

    Just because you run consistent, doesn't mean you will see accurate gains from your mods. What if you get a mod that breathes more up top but you shift at your previous rpm? What is it going to show then at the track? Nothing and might show worse, so now one goes around and says he got "slower" or "faster with that mod when variables weren't controlled or foreseen. The dyno would show where that power is gained...

    The more time under WOT or gears you go thru the more chance of "slippage" of consistency.
  4. Nope, wasn't joking. So good drivers in the classes were talking about ("us" enthusiast) pull consistent mph? Within .01 mph? All the time? Mph shows the power...lets see it consistently. It is very simple Mr. Yount. The dyno has less variables. You don't seem to agree on that. I do not see why...it is quite literally laid out...

    You have no clue to my driving skill...but you can speak with a few on here (I'll give you their screennames) that know me and see what they say.:)

    So are those consistent results consistent? I bet you would be hard pressed to find it as consistent as you lead on. So if you added from a 65-75mm TB on a auto-x car (assuming it is setup up for those parts) in a 3 minute lap you think you would notice a difference after the lap?

    The "simple" fact is that my point is to prove that many on here say "such and such gained 1 or 3 mph with such and such part". We all know (atleast from what I have seen) none of us are pros to the tune that you keep talking about. Your bringing up things that aren't "real" for those that participate in those comments.

    Now your showing more of a fairness between the two. You (at first) didn't show this.

    Just understand the original question before going on a track tangent:)
  5. Potential is such a dumbass word. Potential to do what? The track doesn't show if the car has potential to do really well on the dyno, and the dyno doesn't show how much potential the car has on the track. Potential to be fast? That's a function of horsepower, weight, and aerodynamics (heavier is better). Potential to be quick off the line, that is a function of horsepower and weight (lighter is better). At the track, a car can get moving up to a high speed, but that doesnt mean the car will do well at higher speeds, it may be an overpowered parachute! And cars that do well at high speed don't necessarily do well off the line either. Consider a beefed up mustang vs a ferrari, one will haul ass at 150+, the other will be sluggish at best.

    And don't tell me that it is torque, torque and horsepower can be used completely interchangeably so long as you assume the person is including in RPM and final gear ratio into the equation.
  6. I will also say this...

    A dyno is not dead on every run. I have seen cars vary 5 hp easily from one run to another. No car will dyno a number, then dyno the exact same numbers again, so for a consistent driver the track is about as accurate as a dyno!
  7. Oh yeah, I know I understand that.

    The curve will be similar but the peak number on the sheet can vary.

    5 peak hp difference is probably like .02-.03 difference at the track roughly. Track has a lot more factors to make back to back runs and change that mph.

    Track time/mph are more varied when you use street tires (less forgiving) so driving can be different.
  8. last year before the charger i was running 13.70's with a bad clutch. I ran 3 passes one night and they were a 13.71, 13.72, 13.74 the track prep was consistant all night as were my 60ft times. At the track I use my 60' and 1/8 performace to judge my skills at driving and use the 1/4 mph to judge how much gain i got out of the tune or parts that were installed. 1 point that i noticed that wasnt brought up is that if your just at a dyno for base pulls almost always your first pull will be noticably better than your last due to heat soak. Ive seen some cars loose as much as 20hp due to heat soak.
  9. just4bob50 - That is why you do the "cool downs" afterwards. Your judging at the track isn't bad.

    With the track prep/weather conditions/and driver going to the track a week or two later after his next mod...it changes things more drastically than the dyno would. When you add a mod you don't do it at the track. You give it time for track prep/weather conditions/and mods that possibly change where it should be shifted at.
  10. I was just reading an interesting article somewhere a few days ago about dyno's. They compared the real world equivalent of a dyno run to "holding the accelerator to the floor going downhill." Sounds like the validity of a dyno run from a performance standpoint is at a minimum, debatable, if that statement is true.

    I think I found it on the Mustang dyno website.. good read.
  11. Holy Thread Taken Completely Out of Context, Batman! :eek:

  12. In a lot of cases #'s off the dyno are meaningless in the real world. If you want to see if a change, be it a part or some tuning, makes a difference, the track is best place to see it. The dyno is a helpful tool but only tells part of the story. How does a dyno compensate for drag? Even if you drive inconsistently you have a lot of mathmatical tools you can use to make calculations based on ET, MPH, 60ft, 1/8 mile, RT..... It's always nice to see what you make on the dyno but it won't even tell you true potential because the dyno doesn't factor in your actual traction and your actual suspension. Any ET estimates based on the dyno are purely speculative and could never really be as good as multiple trips down the track. Really you don't even need the dyno to set your A/F ratio. You could buy an FMS extender and its done! I'm not sure how the extender works- but it does....mine does.
  13. What if, what if, what if............ :lock:
  14. Thank you:Word:

    You actually understand the point of the thread. Some got offended and assumed on this thread...well we seen what happens:)

    To the ones not understanding and talking about the question under subjection. What has less variables that if one was to add an intake or throttle body, exhaust part (for example) what could show a more consistent gain?

    The track shows your power basically from 3,500 rpm and up 95% of the time...so how does it show your rpm down low? Answer me that:D

    Suspension, driver aren't a part in this. I'm talking about power. Not E.T. bias.

    So if the track is the "real world"...what is the dyno? Fake world?

  15. The track is a LOT more the real world than any dyno...

    At the track a 600 hp car on radials with a bad driver will lose to a 400 hp car on slicks with a good driver, this is true in the real world, yet on a dyno the 600 hp car looks like it would dominate!
  16. Yeah but the 600hp has the "potential" to win with slicks:) That was the point...

    I was talking about adding power...not racing...please understand that:nice:
  17. Not necessarily (I cant spell)...

    If you want to go into the potential thing, I will say it doesnt automatically mean the 600 hp car is going to win. If it weighs more, has worse suspension and a worse driver it wont win on slicks. I know you say it has potential just because it has power, but in the real world there is a LOT more to a cars performance than just power!
  18. Brain, I hope hope you of all people should know that I know what is in bold.

    It's all in implication of the post, it should have been inferred between us two.