[Smokin19]

One can go on line and read for hrs what others say are the differences between the Mustang and Dynojet tuning tools. Let me start by saying I know only some basic understanding of the two. Recently had my build tuned on a dynamic loaded Mustang dyno. This one has been used for about 10 years. Asking the builder who dynoed the car what it might pull on a Dynojet he sort of laughed and said pick a number.

He could only say some had gone to a different shop to get a Dynotune number and they varied from 6-10 % higher. So many variables involved to get a straight number. So I am asking here who has had a Mustang dyno and then had a Dyno jet run performed.

Again there would be obviously differences involved but, I am looking for more of a consensus from here on the site. Looking at other's signatures stating their numbers I am curious as to, what dyno tool was used to get those numbers. This would make the signature info clearer as to obtain those results.

[ZL1Atlanta]

To your point, there are so many variables beyond even just the type of dyno, it almost makes the HP numbers in signatures useless. Until recently my car was always ran on a DynoJet in STD, which by everything that is known about STD, should be high. The car on the track, however, shows a trap speed that suggests it’s right on, if not low. I’ve seen trap speeds of cars that were ran on Mustang dyno’s and they don’t line up with their claimed HP. For these reasons I try to not get too caught up in peoples dyno numbers unless they are using the same one to compare changes made to the car. I know for some the dyno number is most important, so to each their own.

[TXCSSU]

I'd go so far to say that even the handheld devices can be used reliably to measure HP, as long as you enter all your information correctly (weight, have a good level straightaway, and are in the right gear). Personally, I'd use a handheld, and go to just about any dyno shop, but preferably one that's been around for a while. One thing to keep in mind, some dyno shop owners know that if their dyno reads a bit higher, that more people will go to their shop repeatedly. I personally just want consistency. Also, I've heard that Mustang dynos tend to read a little lower than other dynos, which is fine if I go to that shop after performing my mods. The baseline is the key, which is why I also recommend a handheld device, which will give you a 2nd option to compare any possible gains.

[David Gordon]

I have always just figured trap speed is a very good reading on horsepower, Not ET.

[Gunkk]

Originally Posted by David Gordon

trap speed is a very good reading on horsepower

[BlaqWhole]

My 93 octane tune on a Dynojet in 6th gear made 745 RWHP.

I then had it on a Mustang Dyno at a different shop and it made 688 RWHP in 6th gear with 93 octane.

So yea that is roughly 6-7 percent difference.

Although the shop that had the Mustang Dyno did retune it before they got those numbers. But their tune was more for driveability so they didn't really touch anything to impact the power.

The problem with dyno shops is a lot of them simply plug in numbers here and there and factor in this and that and before you know it they're handing out inflated numbers like candy on Halloween. And they do that because if shop A builds 5 cars and they're all making "900+ RWHP" and shop B is building similar cars but they're making only "820 RWHP" then people are all gonna want shop A doing their work because they're getting inflated numbers. And now there is some new type of dyno that spits out even higher numbers than a Dynojet does. So I wouldn't put too much stock into what the numbers are. Track times, ET, and 60-130 will paint a much better picture than a dyno can.

[synolimit]

You can make a mustang read whatever your little heart desires by changing the perimeters. It’s an electronic load cell. By dragging the brake etc it’ll change the numbers. Great for tuning a car pretending it’s on a road, going up a hill, down a hill etc. For these reasons no mustang will read like another and tuners will always mess with them and who knows if they ever reset to factory. Not to mention the brakes or the cell can wear out over time and need service giving wrong numbers.

A Dynojet is an inertia dyno. Spin a big heavy ass drum up to speed in X amount of time and you get a number. You cannot change a Dynojet, you cannot mod it, there’s nothing to wear out but maybe a bearing. Dynojet has set the calculations and you cannot change them. Dynojets will always read true and extremely close from 1 to an other. If you want real numbers, it’s a Dynojet as long as you don’t cheat and use the SAE correction calculation. STD is old school and reads higher and your motor was tested using SAE so use SAE!!!!!!! Uncorrected is only useful to see your numbers in read time vs a perfect real world temp, humidity, barometric etc. Dynojet using your cars 1:1 gear using uncorrected will give you 100% accurate numbers if you pull off the dyno and go do a drag run since only a real HP number can move a x,xxxlbs object 1/4 mile in x.xx seconds. It doesn’t make sense to do an SAE or STD then go drag race when it’s not the ideal weather and temps. Your times won’t match you HP numbers.

[EDFHOBBIES]

Originally Posted by Gunkk

Okay... so what would a 141mph be in hp?

[ZL1Atlanta]

Originally Posted by Gunkk

This is true, but to be useful vehicle weight is needed. Most cars in here are likely stock weight and close to the same, but drivers could vary 150+ lbs. Haha.

[Smokin19]

My point in this is when people look at your signature with mods and whp it would help others trying the same build to get an idea of what's needed to obtain similar numbers. I looked at what others had done in order to get a feel for what I needed to get similar results. I think we have established the difference you can get from different tuning equipment. Can we see more members displaying their tuning by the various methods is my intention, a simple Mustang or Dynojet would suffice.

[JSH]

DynoComm and Dynojet

[clg82]

Originally Posted by BlaqWhole

My 93 octane tune on a Dynojet in 6th gear made 745 RWHP.

I then had it on a Mustang Dyno at a different shop and it made 688 RWHP in 6th gear with 93 octane.

So yea that is roughly 6-7 percent difference.

Although the shop that had the Mustang Dyno did retune it before they got those numbers. But their tune was more for driveability so they didn't really touch anything to impact the power.

The problem with dyno shops is a lot of them simply plug in numbers here and there and factor in this and that and before you know it they're handing out inflated numbers like candy on Halloween. And they do that because if shop A builds 5 cars and they're all making "900+ RWHP" and shop B is building similar cars but they're making only "820 RWHP" then people are all gonna want shop A doing their work because they're getting inflated numbers. And now there is some new type of dyno that spits out even higher numbers than a Dynojet does. So I wouldn't put too much stock into what the numbers are. Track times, ET, and 60-130 will paint a much better picture than a dyno can.

Isn't 7th gear our 1:1?

[arpad_m]

Originally Posted by clg82

Isn't 7th gear our 1:1?

This may have been done to limit the max speed, many dynos do not like 200 mph or more.

[clg82]

Originally Posted by arpad_m

This may have been done to limit the max speed, many dynos do not like 200 mph or more.

Got it, I believe who dynoed my car said he got it up to 190mph.... that's insane!