Conversion Factor from Mustang to DynoJet?
Thread Starter
Safety Car
Joined: Apr 2001
Posts: 3,525
Likes: 2
From: Houston TX
Conversion Factor from Mustang to DynoJet?
I spoke with the Mustang Dynamometer operator/tuner, and he said the conversion is 12% (he says it may be more like 15%) between the Mustang and the DynoJet. All of my past runs have been on the DynoJet. If indeed it is 12% (or 15%) additional then I am happy with the runs. If the Mustang and the DynoJet are roughly equal (which I don't think so), then I am back to where I was roughly 4 years ago.
So.... if anyone knows the conversion factor, you might provide some relief or just lead me to further frustration.
Jeb, TJ, BTF, chime on in.
Aaron
So.... if anyone knows the conversion factor, you might provide some relief or just lead me to further frustration.
Jeb, TJ, BTF, chime on in.
Aaron
Drifting
Joined: Aug 2001
Posts: 1,500
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From: Holliston MA
Cruise-In VII Veteran
I can tell you my car dyno'd at 358 at the wheels on a MD 1750 DE and ran 123 mph in the qtr at 3400 lbs. Exact to the byte tune in similar conditions. On this particular dyno I think the difference is closer to 20%.
Thread Starter
Safety Car
Joined: Apr 2001
Posts: 3,525
Likes: 2
From: Houston TX
Hmmmm... Nobody has mentioned a 20% difference between the Mustang Dynamometer and the DynoJet. I do not want to get my hopes up to have them dashed. Though I would like to think that the additional port work and intake/TB change made a difference.
Hmmmm....
Aaron
Hmmmm....
Aaron
Team Owner
Joined: Sep 2001
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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I wouldnt worry about it either, 10-15% might be the average but there are always variances. If theres a problem with the engine, it should show on the curve, not necessarily the numbers.
Best thing is to just get it tuned, and find out where your power peaks end up.
Best thing is to just get it tuned, and find out where your power peaks end up.
Cruising
Joined: Jul 2006
Posts: 11
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From: Victoria BC
Originally Posted by Alvin
I wouldn' tworry about it too much.
A dyno is good for before/after runs or seeing trendlines in power/torque curves.
A dyno is good for before/after runs or seeing trendlines in power/torque curves.
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From: Northern, VA
St. Jude Donor '15
"In honor of jpee"
Originally Posted by snootworks
Agreed. We run a Dyno Dynamics (load) dyno in our shop, and started out supplying customers with straight-up numbers. Despite months of attempting to educate the masses on a) the slew of important and valid information we could provide them regardless of peak numbers and b) the differences between intertial and load dynos, we ended up caving in and using a 17% correction factor. (17% since the closest dyno to us, which happens to also be a DD unit, uses 17% as well.)
Thread Starter
Safety Car
Joined: Apr 2001
Posts: 3,525
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From: Houston TX
The conversion factor is important to me, as it will show me where I stand vs all of the other runs that I have made on my '87. The curves looked good, but I would just like to know that I have not gone backwards with all of the changes I have made in the last 3+ years. My peak numbers on the MD almost matched the DJ numbers from before the intake, TB, portwork, and much tuning.
Thanks,
Aaron
Thanks,
Aaron
Burning Brakes
Joined: Nov 2004
Posts: 800
Likes: 3
From: Port Orange FL
I dont think there is a correct answer to your question. You can get substantial differences between same brand dynos when running the same car. It can be altered by the input the operator puts in when he runs your car. Lots of things can cause them to be different.
So what you are really wanting to know is what is the correction factor between this particular mustang dyno the way it was set up vs the Dynojet I ran on before and the way it was set up?
IMHO anything you use is just a guess and really doesnt have any validity other than easing your mind.
Roy
So what you are really wanting to know is what is the correction factor between this particular mustang dyno the way it was set up vs the Dynojet I ran on before and the way it was set up?
IMHO anything you use is just a guess and really doesnt have any validity other than easing your mind.
Roy
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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Originally Posted by LT4CompYell
What is the "correction factor"? What is it correcting for?
Neither reads wrong, they just read it differently. Dynojets are better for bragging numbers.
Race Director
Joined: Sep 2001
Posts: 14,682
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From: NEwhere Ohio
Originally Posted by vader86
Dynojets are better for bragging numbers.
If I'm talking with my friend that has a mustang GT or WRX, Id rather be the one talking the higher #'s.
Burning Brakes
Joined: Jan 2002
Posts: 1,228
Likes: 1
From: Dallas Texas
Originally Posted by tjwong
Here in my area I have a dyno jet nearby. I have had customers tell me that its about 12% to 15% higher than what my Mustang gives them.
Advanced
Joined: May 2006
Posts: 85
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From: SPRINGFIELD VA
Dyno Results
What I Was Told Was The Same Thing With The Super Flow Dyno, That Typically The 10-12% Factor Is Added To Get Close To Other Dynos. Stock Run Was 351 On A Hot 90 Degree Day And Two Weeks Later Put Heads And Cam In And Ran 431. So About 80 Hp Was Gained And If 10-12% Is Added It Is Right On Par With Those Getting 470-480 On Other Dynos. Still Got A 80hp Gain For Heads And Cam,"at The Rear Wheel."
Thread Starter
Safety Car
Joined: Apr 2001
Posts: 3,525
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From: Houston TX
I think the question has been answered. The difference between the Mustang Dynamometer and the DynoJet is ~12%, with the DynoJet reading higher.
As an aside, the dyno operator said that he can adjust the MD to read the same as the DynoJet, but then when you run in the 1/4, the trap speed will not match up with the HP that is indicated by the dyno. He feels strongly that the MD is a more accurate indicator of "real HP".
Thanks for all of the input.
Aaron
As an aside, the dyno operator said that he can adjust the MD to read the same as the DynoJet, but then when you run in the 1/4, the trap speed will not match up with the HP that is indicated by the dyno. He feels strongly that the MD is a more accurate indicator of "real HP".
Thanks for all of the input.
Aaron
Team Owner
Joined: Jun 2005
Posts: 46,295
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From: Northern, VA
St. Jude Donor '15
"In honor of jpee"
Originally Posted by vader86
The dynojets can't simulate aerodyamic and rolling resistance load that the Mustang can. Dynojet uses a drum of fixed mass, Mustang uses electromechanical resistance to apply the load.
Neither reads wrong, they just read it differently. Dynojets are better for bragging numbers.
Neither reads wrong, they just read it differently. Dynojets are better for bragging numbers.