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Dyno differences


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I put this in another thread, but thought I'd make my own as the information is fascinating and could be useful for people trying to interpret their own dyno results...

 

I helped a friend install his Mustang dyno so we used my car as a test pig on his Mustang and on a Dynojet and Superflow, just to get comparisons.

 

I'm at altitude in Denver, which is HUGE power suck...

 

MAC (Dynojet) - 1.24SAE, 70deg day, corrected - 391 ft lbs, 361hp

Carz (Superflow)- 1.24SAE, 85deg day, corrected - 360 ft lbs, 336hp

Cryotune (Mustang) - 1.19SAE, 55deg day, corrected - 352 ft lbs, 292hp

 

Those look wildly different. I decided to plot the uncorrected (taking out accounting for altitude and temperature) for fun and that's where things start to look a bit different.

 

MAC (Dynojet) uncorrected - 315 ft lbs, 291hp

Carz (Superflow) uncorrected - 290 ft lbs, 270hp

Cryotune (Mustang) uncorrected - 295 ft lbs, 245hp

 

This is where things get even more fun, I tested the same dyno on different temperature days.

 

For reference, there was a 2017 STI on the MAC dynojet 62deg day before me, he had intake, full exhaust and a couple other things. His graph corrected was 352 ft lbs, 294hp. So we know the Dynojet torque reads high, again, just look at the changes vs the final number.

 

MAC Dynojet corrected at 1.24SAE (70deg) - 391 ft lbs, 361hp

MAC Dynojet corrected at 1.23SAE (62deg) - 444 ft lbs, 373hp

Carz Superflow corrected at 1.24SAE (85deg) - 360 ft lbs, 336hp

Cryotune Mustang corrected at 1.19SAE (55deg) - 352 ft lbs, 292hp

 

Now for the uncorrected numbers....

 

MAC Dynojet uncorrected (70deg) - 315 ft lbs, 291hp

MAC Dynojet uncorrected (62deg) - 362 ft lbs, 304hp

Carz Superflow uncorrected (85deg) - 290 ft lbs, 270hp

Cryotune Mustang uncorrected (55deg) - 295 ft lbs, 245hp

 

On the exact same dyno with the exact same tune and exact same parts, my car picked up 47 ft lbs and 13hp on a Dynojet by just an 8deg change in ambient temp. Damn... Corrected the number was even bigger, 53 ft lbs and 12hp.

 

The knowledge I gained from this is that you can't really compare dynos from one place to another, as I've heard so many people say, it's a tuning tool for your car specifically to see how changes affect your powerband. It's great when someone prints you out a sheet, but without context it doesn't mean a whole lot.

 

The other thing I learned is if all you want is a big number to impress your friends, seek out a Dynojet in the winter.

Edited by SSpeed
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LOL. Want HUGE numbers from the Mustang? Put a hair dryer on the outside air temp sensor. I caught a few shops posting BIG gains and figured out they were artificially increasing the calculated air temp to raise the power numbers.

 

 

 

I have posted so many times in so many places that a dyno is a tool to be used to verify the gains on your car pre and post mods. Not to be used for bragging rights or ego checks. The numbers provided are based on a mathematical equation. The different dynos use different equations.

 

 

 

In a nutshell..

 

 

 

A Mustang measures the amount of load placed on the rollers.

 

A Dynojet measures the amount of power required to move a known weight (the rollers).

 

A Dynapak measures the amount of power at the hub.

 

 

All can be manipulated easily.

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Yep, to really find out power...that's what the drag strip is for.

 

;)

 

Even that, different drivers will get more out of the same car.

 

Even doing cones in a parking lot. One of my son's friend had a MR2 that he built and raced for years. My son got in the car and was much faster on the same course.

 

My son has been racing since he was 9y/o, had some good coaching over the years on how to "pick a line".

305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.

 

Engine Build - Click Here

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Trap speed tends to be a tell tale sign of power. How much does the car weigh and how fast was it going at the finish?

Dont worry about reaction, 1/8th, etc. Just how fast can it go.

 

I used to offer simulated 1/4 mile pulls to tune customers. Funny thing, rarely did anyone accpet the offer. When they did, they were usually drag racers. Some never agreed with the dynos power numbers, but did agree with the numbers when compared to the trap speed.

 

Most important take away is that it is a tool to assist in safely tuning a car (no public roads) and determine the positive or negative results of modifications to a specific vehicle under specific conditions.

 

Egos should be taken to the track.

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race wagon runs in a class that uses lb/hp as a fairness equalizer. Dyno numbers come from a dynojet and have to be current for the year raced or within 12 months of the day racing. Suffice it to say, cars tested in the summer are much faster than cars tested in winter. Not saying anyone is cheating, but some of the lap times are too good to be true.
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Only so "fair". Cars tested in lower temps will make more "power" and vice versa. To be more fair a range of test day temp and humidity could be included.

 

If winning means pushing the boundaries of rules then have your car tested on the hottest, highest humidity day of the year. A true "dog day" of summer. Leave your ego at home and justify the poor numbers with those embarrassingly fast lap times for your class.

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  • 3 months later...
From what I understand, you can calibrate a dyno to read quite a lot different than it actually should. Chris at Surgeline told me that, when Surgeline was a Cobb shop, a guy from Mustang calibrated it to be as accurate as possible. I don't know how different it would read from other Mustang dynos, but I do know that it read a decent bit higher than the Dynojet PRERacing tuned my car on prior (282 WHP on the Mustang vs 270 on the DynoJet).
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From what I understand, you can calibrate a dyno to read quite a lot different than it actually should. Chris at Surgeline told me that, when Surgeline was a Cobb shop, a guy from Mustang calibrated it to be as accurate as possible. I don't know how different it would read from other Mustang dynos, but I do know that it read a decent bit higher than the Dynojet PRERacing tuned my car on prior (282 WHP on the Mustang vs 270 on the DynoJet).

 

that's unusual. Dynojet is usually higher. Sounds like Cobb tuned their dyno instead of cars :eek:

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From what I understand, you can calibrate a dyno to read quite a lot different than it actually should. Chris at Surgeline told me that, when Surgeline was a Cobb shop, a guy from Mustang calibrated it to be as accurate as possible. I don't know how different it would read from other Mustang dynos, but I do know that it read a decent bit higher than the Dynojet PRERacing tuned my car on prior (282 WHP on the Mustang vs 270 on the DynoJet).
I think PRE uses a dyno dynamics dyno and not a dynojet.
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My own Mustang never read anywhere near as high as Cobbs.

 

Oh, and when you buy a Mustang Dyno a technician comes to your shop and assembles the dyno, performs all calibrations and then trains your staff on operarion and calibration.

 

I assembled my dyno myself, so my tech gave us an extra day of training as he did not have to spend that time on assembly. I had several LGTs on the dyno during the training days. I even learned how to recalibrate the dyno specifically for the 05-07 and 08-09 5eat with the trainer. We made 2 calibration files using two cars at my shop during training.

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