Dyno comparison: Dynojet vs. Mustang - A civil discussion - Focaljet

**FocusSportVP** · 04-03-2005, 04:19 AM

I'd like to start a discussion on the topic of dynos. Too often do I see the words, "Oh wow that was on a Mustang dyno, too, that's even more impressive."

Please keep this civil, OK? I just want to discuss this since I think that most people don't have a good understanding of the pros and cons of each. And if we can include other dyno brands/types that would be great, too.

My take:

I use a Dynojet for all of our testing and tuning. Before we purchased our Dynojet, I looked into the Mustang brand, but decided against it. The main reason that I don't prefer Mustang dynos is because the operator is relied upon too heavily. It is required for each car's weight to be entered into the dyno computer in order for the output data to be correct. Also, you must calibrate the dyno each time in order to read RPMs. Again the dyno operator must do this.

In my opinion, there is too much human error that comes into play with the Mustang dyno. All too often do I see incorrect vehicle weights being used, throwing the power numbers off. And when you are tallking about the Focus, 100 lbs. can make a nice difference. Let's also take into account elevation. I'm not 100% sure about this, but from what I understand you can enter in corrections for elevation on the Mustang dyno. Too much room for error, again.

Before we had our own dyno, we used both Mustang and Dynojet dynos. The funny thing is, I usually hear about Mustang dynos testing lower than Dynojets. Sadly, it's been our experience that Dynojets test lower than Mustangs. Why? Human error. Now that we have our own Dynojet, we can take the same car and run it on a local Mustang and our own Dynojet and compare. One of our own cars tests around 20 HP higher on the Mustang at shop ABC than it does at our own Dynojet. And we can also go to shop XYZ and get more numbers that are incorrectly too high.

In my opinion, the number one cause for inaccurate Mustang HP and TQ is the data entry. How many Mustang dyno shops have a vehicle scale or corner weights, and use them? Next to none. Because the Mustang requires that you enter in the vehicle weight, it should come with corner weights. Instead, you get a guy asking you how much your Focus weighs. And an owner that is off by 75 to 150 lbs. - if you're lucky.

So what does it take in order to trust Mustang data? I'll tell ya...honest, intelligent staff who care about what they are doing. And staff that have time to care. You can't just guess what the weight of your car is, you have to know what it is!

It seems like the number one reason to get/use a Mustang is the ability to tune with applied load. And there is that cool 1/4 mile drag race simulator, that is kinda fun.

One thing I hear myself saying over and over again is, "You can take a car to 10 different Dynojets around the country and you're going to get very similar results, within just a few HP. Now try doing that with a Mustang dyno. Not gonna happen."

So that's my rant. I'm sure I've left a good amount of stuff out, so feel free to chime in and fill in the blanks.

**ZX3TUNING** · 04-03-2005, 04:45 AM

here is a good example of how much of a difference dynos can show....

this was done almost one year ago at the FC dyno day, mods were basic bolt-ons untuned cam gears and a generic Superchip from 2000. please note FC uses a Mustang dyno and was done in 3rd gear:
Mustang dyno 1

i just had this one done a few weeks ago at a local place in 4th gear, exact same mods, zero change to the engine setup. aside from the serious fueling issue i was having at 4500+rpm, you can plainly see that the numbers were way off:
Dyno Dynamics Dyno graph
here is the data sheet from the same dyno run:
Data sheet
as you can see i leaned out something crazy at 4500+ all the way to 16.5 right arount 6400. we had the raptor hooked up for this run and quickly traced the problem back to a plugged fuel filter. reguardless, if the fuelling issue wasn't there i would have seen around 165fwhp and close to 167lb/ft from a bolt-on motor. most people on here know those numbers come from focus' with quality head packages and a nice set of cams. even then they wont put down that much torque.

now i'm not saying Dyno Dynamics dyno's are junk, like anything it comes down to who is using/running the dyno you are taking runs on.

please take dyno numbers with a grain of salt.
pre and post dynos using the same dyno are the best way to propperly guage the results of your mods. forget about the total number as they may be way off but look at how much you gained and where you gained it. most importantly, always try and use the same dyno for all your testing to keep the margin of error as small as possible.

good idea for a thread!

**TXFO** · 04-03-2005, 08:08 AM

Quote:

the number one reason to get/use a Mustang is the ability to tune with applied load

**nordy200** · 04-03-2005, 10:31 AM

Quote:

.....
pre and post dynos using the same dyno are the best way to propperly guage the results of your mods. forget about the total number as they may be way off but look at how much you gained and where you gained it. most importantly, always try and use the same dyno for all your testing to keep the margin of error as small as possible.

good idea for a thread!

Amen to that, the most important aspect of dyno testing. I am getting my car dynoed tomorrow, same shop, same dyno, same operator, to test my reconfigured H2O system.

**CWCZX3** · 04-03-2005, 10:51 AM

I love the awd mustang dyno we have at Wagnermotorsports, A car tuned on a mustang dyno will run the same on the street versus a car tuned on a dynojet with fixed load will still need tuning afterwards to be correct for driving out on the street. And ours came with a huge pdf file that lists all of the vehicle weights and settings.

**TXFO** · 04-03-2005, 10:53 AM

yeah. but if you dont actually weigh the car then you are taking the book's word for it. The focus seats must weigh 100lbs together. If I replace them with sparcos, we could be looking at a 50lb difference.

**Yel900rr** · 04-03-2005, 11:18 AM

If you take peak hp and tq numbers out and just tune the car here is baseline and here is tuned see your gains. People worry to much about this guys dyno and I want more than him. If it leaves safe with more and better power then you did something. Your dyno sheet doesn't get raced at the track your tuned car does.

But Dynojet is the standard when checking HP and TQ.

**SRF** · 04-03-2005, 11:28 AM

Powerworks uses a Mustang, I'm convinced. Tech said something about the Dynojet only having one pulse for rpm vs six with the Mustang. From the gazillion dollars in equipment they have I'm sure cost was not a factor and they bought the best. As far as human interaction and required data points, I guess that's the price for accuracy.

**Yel900rr** · 04-03-2005, 12:06 PM

A mustang dyno is used for tuning and loading cars for diagnostics. I would probably get a dyno dynamics if I where looking into a diagnostics dyno. Our dynojet has the load feature. But it does not load like an eddy current.

**FocusSportVP** · 04-03-2005, 01:39 PM

Quote:

Powerworks uses a Mustang, I'm convinced. Tech said something about the Dynojet only having one pulse for rpm vs six with the Mustang. From the gazillion dollars in equipment they have I'm sure cost was not a factor and they bought the best. As far as human interaction and required data points, I guess that's the price for accuracy.

Last time I talked to PW, they didn't have a chassis dyno, only engine dynos. They just ran it on a Mustang, it wasn't their own.

We also have the load feature on our Dynojet, I prefer to take the car out on the street.

**CorvairMatt65** · 04-03-2005, 01:50 PM

I first had my car tuned on a mustang dyno and it was nice for tuning. Being able to put a load on the car and being able to find spark knock and all that. But I felt my peak number was off. With my mods listed below I only recieved 163whp. I garuntee my weight was off cause I just made a guesstimate. It doesnt really matter what dyno you tune on as long as you get a good tune but if you wanna compare to what others are doing with your setup. A dyno jet will be more accurate. I have to get retuned and I'm switchin over to a dynojet.

**Sonic04SVT** · 04-03-2005, 02:06 PM

So what is the weight of our cars anyway?

I don't think anyone really knows without using some accurate 4 point scales. I say 4 point because the larger the scale used the higher the error factor will be, so using 4 small range scales is better then 1 big scale for example.

For the record my title from Ford said 2499lbs on it, I weighed it at a truck scale and it said 2800lbs but has this huge error margin (something like %2 or 1000lbs whichever is higher) so I don't really trust that reading, other guys with the same option packages as me have said their cars weighed anywhere from 2700-2950lbs on other various other types of scales....

**ZX3TUNING** · 04-03-2005, 03:34 PM

one more thing, dyno graphs and time slips are for one thing and one thing only, bragging on the net or to other people. all they are is a form of proof because nobody believes anything without them but that is only when they are being used to show the gains of part "A" over part "B" for selling purposes.

if all you care about is making more power than another guy, then i believe you're not in it for the fun of modding and driving your car, you're looking just to boast about what you have done.
running better times is something different but that should be about personal satisfaction, unless you truely live for the race!

**svtfocusguy** · 04-03-2005, 06:27 PM

Dynojet, most consistant system for number comparison. Mustang, much better for tuning b/c tune w/ applied load. If I'm going to dyno just to see what I'm putting down its a dynojet for sure, but for tuning its something different all together.

**DrTorque** · 04-03-2005, 10:50 PM

Nice job so far, and I hope this stays civil...

I have a Dynojet with the variable brake option for loading. All I can say is - it works great. In the hands of an experienced operator and tuner, this type of Dynojet can give your vehicle a perfect tune. Those that say it doesn't work as well as other dynos just need to experience what I described in the previous sentence. You want a perfect tune? Come in with different sized blocks to put under your gas pedal. I can set the feedback loop on the dyno to hold your vehicle at any rpm with the variable dyno brake. Put a block under the gas pedal and check the throttle position with a datalogger. Watch the a/f on the computer screen and listen for detonation. Make adjustments. Do it again with a different rpm. Do all the rpm's, then try a different throttle position (and therefore a different load.) Keep repeating until you're satisfied.

Once you're done, take the vehicle on the street and make sure everything is O.K. Those that say that performing the actual tuning on the street is best are just plain silly. There are too many variables, and it is way too dangerous. For many vehicles, it's simply not practical because the engine needs to be shut down to make changes to the tune.

I don't have any first-hand experience with other kinds of dynos, so I'm not going to say anything good or bad about them. I will say that they are just like any other tool - they are only as good as the user.

I was once told that Mustang dyno operators needed to enter the weight of the vehicle, but I wasn't sure. Since you guys say that it's true, I'll also add this - why the heck don't they come with a set of scales? Since they don't, why don't the shops buy them? I almost bought a nice set just so I could charge the customers that were interested in their weight - a good set can be had for around $1000 brand new.

**OJEngineeringSr** · 04-03-2005, 11:44 PM

Sport Compact Car did a secret dyno comparison several years ago. They tested their "mule" car on several Dynojet dynos around So Cal. including mine. They also took the same car to several Mustang and other model dyno centers. The Dynojet dynos all read very, very close to the same. The Mustang dynos were off by huge margins. This further illustrates that for the sake of comparison and accuracy the Dynojet dyno is the standard. Having said that Superflow has a new chassis dyno that they claim can be calibrated to give SAE HP or Dynojet HP. a local shop just put one of these new Superflows in recently. I guess I should go test my supercharged test "mule" on it and see how the results compare to FocusSports numbers and report back to everyone. I know Randy's Dynojet is always good. I'll report back in a few days with results.

**dimm** · 04-04-2005, 04:43 PM

To everyone so far: Thank you for starting this thread. It begins to erk me a bit when I see dyno's and the weight can be off. Dyna-paks can suffer from the same issues.

As of late i've been seing alot more mustang dyno sheets poping up. All have diffrent weight values for the car, this is what erks me.

One of the better tuners in maryland uses a mustang dyno. I have to say this, you dyno your car there then drive down to the dynojet and the numbers will be within +1 to -1 hp of each other. Thats saying something. Another tuner with a mustang dyno around here always shows way higher then either the dynojet or the mustang dyno that the better tuner here in maryland has.

The key for me is consistency. I've done some mystery dyno testing myself. You'd be amazed at how human error can scew numbers on a dyna-pak or a mustang dyno.

Most people with the mustang dyno's in my area just recently purchased them and unknowingly make the small error of the weight issue's. Same for the dyna-pak setups.

**FocusSportVP** · 04-04-2005, 05:46 PM

The problem with testing load on the dyno vs. the street is cooling. For some intercooled applications this is not that much of a big deal, but for a lot of cars it's an issue.

Most dyno fans out there are not going to provide adequate cooling, at least not enough cooling to emulate the street or track, which is what you're trying to do. Right?

So you can load the car for just a short time, let it cool down, and repeat. Several times. This has it's place, but I've found that tuning WOT on the dyno and then making sure everything jives on the street works well, too.

**DrTorque** · 04-04-2005, 11:37 PM

Good point - that's why we've got a 30,000 cfm fan in the works

**dimm** · 04-05-2005, 09:10 AM

Need a way to hook the fan up to the throttle to simulate what the wind would be like at diffrent engine speeds.

Of course having a fan blowing at 60mph then 70mp, then 80mph then at 110mph could prove to do some damage in the shop.

Just for the record, and for everyone that reads this: You can scew a dynojets numbers with sae correction being on or off, having sensors in the wrong place, or purposely positioning sensors in the wrong place. I know a local shop here that got in a bit of trouble for altering a guys dyno by altering the sensors and using sae correction varinces for a before and after. All this to sell there own turbo setup.

**Ray** · 04-05-2005, 10:55 AM

Quote:

Good point - that's why we've got a 30,000 cfm fan in the works

how big is that gonna be, jon? or is that that new vent system you were discussing the other day?

**FocusSportVP** · 04-05-2005, 12:54 PM

Quote:

Good point - that's why we've got a 30,000 cfm fan in the works

Here's a question. And I'm not trying to be an ass.

Said fan has got to be pretty damn loud, right? If so, how are you supposed to hear detonation? Some cars cause the knock sensor to be active all the time, due to certain harmonics and vibrations. Some blowers have this issue. Ford actually doesn't use knock sensors on some FI cars because of this. So if you can't rely on the knock sensor data logs and you can't really hear it...

**EggYolk** · 04-05-2005, 01:05 PM

So I'm curous Randy. You picked a Dynojet because the Mustang requires too much input, which can lead to human error. However, the Mustang has more bells and whistles than the Dynojet does. So is your company not willing to go the extra mile to get a better tune? I think this should go in the Tuning FAQ at the top.

**FocusSportVP** · 04-05-2005, 01:20 PM

We chose a Dynojet for many reasons. I can list a few:

1. Industry standard - You can't mess with a Dynojet much and because of that you can rely on the numbers in comparison to a Mustang dyno.

2. You don't have to weigh each and every car to get accurate HP and TQ numbers, unlike the Mustang dyno.

3. You don't have to calibrate the dyno for every car to be able to read/pick up RPMs, unlike the Mustang dyno.

4. You can't add "other" variables/factors, like elevation, which can really throw of the numbers, unlike the Mustang dyno.

5. Though the Dynojet software is not perfect, the resolution of the Mustang graphs are seriously lacking.

6. Anyone "in the know" will always question Mustang dyno numbers, unless they are their own, because of the human factor error.

7. I don't care about bells and whistles. I care about respected, duplicatable, accurate, and reliable results. Every time.

**Ray** · 04-05-2005, 01:32 PM

Added to references thread.

04-03-2005, 04:19 AM	#1
FocusSportVP Premiere Sponsor Join Date: Aug 2000 Location: The Lair of The West Coast Cult Posts: 20,819	Dyno comparison: Dynojet vs. Mustang - A civil discussion I'd like to start a discussion on the topic of dynos. Too often do I see the words, "Oh wow that was on a Mustang dyno, too, that's even more impressive." Please keep this civil, OK? I just want to discuss this since I think that most people don't have a good understanding of the pros and cons of each. And if we can include other dyno brands/types that would be great, too. My take: I use a Dynojet for all of our testing and tuning. Before we purchased our Dynojet, I looked into the Mustang brand, but decided against it. The main reason that I don't prefer Mustang dynos is because the operator is relied upon too heavily. It is required for each car's weight to be entered into the dyno computer in order for the output data to be correct. Also, you must calibrate the dyno each time in order to read RPMs. Again the dyno operator must do this. In my opinion, there is too much human error that comes into play with the Mustang dyno. All too often do I see incorrect vehicle weights being used, throwing the power numbers off. And when you are tallking about the Focus, 100 lbs. can make a nice difference. Let's also take into account elevation. I'm not 100% sure about this, but from what I understand you can enter in corrections for elevation on the Mustang dyno. Too much room for error, again. Before we had our own dyno, we used both Mustang and Dynojet dynos. The funny thing is, I usually hear about Mustang dynos testing lower than Dynojets. Sadly, it's been our experience that Dynojets test lower than Mustangs. Why? Human error. Now that we have our own Dynojet, we can take the same car and run it on a local Mustang and our own Dynojet and compare. One of our own cars tests around 20 HP higher on the Mustang at shop ABC than it does at our own Dynojet. And we can also go to shop XYZ and get more numbers that are incorrectly too high. In my opinion, the number one cause for inaccurate Mustang HP and TQ is the data entry. How many Mustang dyno shops have a vehicle scale or corner weights, and use them? Next to none. Because the Mustang requires that you enter in the vehicle weight, it should come with corner weights. Instead, you get a guy asking you how much your Focus weighs. And an owner that is off by 75 to 150 lbs. - if you're lucky. So what does it take in order to trust Mustang data? I'll tell ya...honest, intelligent staff who care about what they are doing. And staff that have time to care. You can't just guess what the weight of your car is, you have to know what it is! It seems like the number one reason to get/use a Mustang is the ability to tune with applied load. And there is that cool 1/4 mile drag race simulator, that is kinda fun. One thing I hear myself saying over and over again is, "You can take a car to 10 different Dynojets around the country and you're going to get very similar results, within just a few HP. Now try doing that with a Mustang dyno. Not gonna happen." So that's my rant. I'm sure I've left a good amount of stuff out, so feel free to chime in and fill in the blanks.

04-03-2005, 04:45 AM	#2
ZX3TUNING Senior TEAM Member Join Date: Feb 2001 Location: Vancouver, BC. Canada Posts: 1,702	Re: Dyno comparison: Dynojet vs. Mustang - A civil discussion here is a good example of how much of a difference dynos can show.... this was done almost one year ago at the FC dyno day, mods were basic bolt-ons untuned cam gears and a generic Superchip from 2000. please note FC uses a Mustang dyno and was done in 3rd gear: Mustang dyno 1 i just had this one done a few weeks ago at a local place in 4th gear, exact same mods, zero change to the engine setup. aside from the serious fueling issue i was having at 4500+rpm, you can plainly see that the numbers were way off: Dyno Dynamics Dyno graph here is the data sheet from the same dyno run: Data sheet as you can see i leaned out something crazy at 4500+ all the way to 16.5 right arount 6400. we had the raptor hooked up for this run and quickly traced the problem back to a plugged fuel filter. reguardless, if the fuelling issue wasn't there i would have seen around 165fwhp and close to 167lb/ft from a bolt-on motor. most people on here know those numbers come from focus' with quality head packages and a nice set of cams. even then they wont put down that much torque. now i'm not saying Dyno Dynamics dyno's are junk, like anything it comes down to who is using/running the dyno you are taking runs on. please take dyno numbers with a grain of salt. pre and post dynos using the same dyno are the best way to propperly guage the results of your mods. forget about the total number as they may be way off but look at how much you gained and where you gained it. most importantly, always try and use the same dyno for all your testing to keep the margin of error as small as possible. good idea for a thread!

04-03-2005, 10:51 AM	#5
CWCZX3 Senior TEAM Member Join Date: May 2001 Location: York, PA Posts: 3,279	Re: Dyno comparison: Dynojet vs. Mustang - A civil discussion I love the awd mustang dyno we have at Wagnermotorsports, A car tuned on a mustang dyno will run the same on the street versus a car tuned on a dynojet with fixed load will still need tuning afterwards to be correct for driving out on the street. And ours came with a huge pdf file that lists all of the vehicle weights and settings.

04-03-2005, 10:53 AM	#6
TXFO Not Special Enough Join Date: Jul 2002 Location: My sweet insanity Posts: 12,956	Re: Dyno comparison: Dynojet vs. Mustang - A civil discussion yeah. but if you dont actually weigh the car then you are taking the book's word for it. The focus seats must weigh 100lbs together. If I replace them with sparcos, we could be looking at a 50lb difference.

04-03-2005, 11:18 AM	#7
Yel900rr Associate Sponsor Join Date: Jun 2001 Location: Central Pennsylvania Posts: 2,807	Re: Dyno comparison: Dynojet vs. Mustang - A civil discussion If you take peak hp and tq numbers out and just tune the car here is baseline and here is tuned see your gains. People worry to much about this guys dyno and I want more than him. If it leaves safe with more and better power then you did something. Your dyno sheet doesn't get raced at the track your tuned car does. But Dynojet is the standard when checking HP and TQ.

04-03-2005, 11:28 AM	#8
SRF Senior TEAM Member Join Date: Aug 2002 Location: NJ Posts: 1,657	Re: Dyno comparison: Dynojet vs. Mustang - A civil discussion Powerworks uses a Mustang, I'm convinced. Tech said something about the Dynojet only having one pulse for rpm vs six with the Mustang. From the gazillion dollars in equipment they have I'm sure cost was not a factor and they bought the best. As far as human interaction and required data points, I guess that's the price for accuracy.

04-03-2005, 12:06 PM	#9
Yel900rr Associate Sponsor Join Date: Jun 2001 Location: Central Pennsylvania Posts: 2,807	Re: Dyno comparison: Dynojet vs. Mustang - A civil discussion A mustang dyno is used for tuning and loading cars for diagnostics. I would probably get a dyno dynamics if I where looking into a diagnostics dyno. Our dynojet has the load feature. But it does not load like an eddy current.

04-03-2005, 01:50 PM	#11
CorvairMatt65 TEAM Member Join Date: Apr 2002 Location: Grand Rapids,MI Posts: 545	Re: Dyno comparison: Dynojet vs. Mustang - A civil discussion I first had my car tuned on a mustang dyno and it was nice for tuning. Being able to put a load on the car and being able to find spark knock and all that. But I felt my peak number was off. With my mods listed below I only recieved 163whp. I garuntee my weight was off cause I just made a guesstimate. It doesnt really matter what dyno you tune on as long as you get a good tune but if you wanna compare to what others are doing with your setup. A dyno jet will be more accurate. I have to get retuned and I'm switchin over to a dynojet.

04-03-2005, 02:06 PM	#12
Sonic04SVT TEAM Member Join Date: Jul 2004 Location: Kansas Posts: 417	Re: Dyno comparison: Dynojet vs. Mustang - A civil discussion So what is the weight of our cars anyway? I don't think anyone really knows without using some accurate 4 point scales. I say 4 point because the larger the scale used the higher the error factor will be, so using 4 small range scales is better then 1 big scale for example. For the record my title from Ford said 2499lbs on it, I weighed it at a truck scale and it said 2800lbs but has this huge error margin (something like %2 or 1000lbs whichever is higher) so I don't really trust that reading, other guys with the same option packages as me have said their cars weighed anywhere from 2700-2950lbs on other various other types of scales....

04-03-2005, 03:34 PM	#13
ZX3TUNING Senior TEAM Member Join Date: Feb 2001 Location: Vancouver, BC. Canada Posts: 1,702	Re: Dyno comparison: Dynojet vs. Mustang - A civil discussion one more thing, dyno graphs and time slips are for one thing and one thing only, bragging on the net or to other people. all they are is a form of proof because nobody believes anything without them but that is only when they are being used to show the gains of part "A" over part "B" for selling purposes. if all you care about is making more power than another guy, then i believe you're not in it for the fun of modding and driving your car, you're looking just to boast about what you have done. running better times is something different but that should be about personal satisfaction, unless you truely live for the race!

04-03-2005, 06:27 PM	#14
svtfocusguy Senior TEAM Member Join Date: May 2003 Location: San Deigo Posts: 1,584	Re: Dyno comparison: Dynojet vs. Mustang - A civil discussion Dynojet, most consistant system for number comparison. Mustang, much better for tuning b/c tune w/ applied load. If I'm going to dyno just to see what I'm putting down its a dynojet for sure, but for tuning its something different all together.

04-03-2005, 10:50 PM	#15
DrTorque TEAM Member Join Date: Dec 2004 Location: CT Posts: 142	Re: Dyno comparison: Dynojet vs. Mustang - A civil discussion Nice job so far, and I hope this stays civil... I have a Dynojet with the variable brake option for loading. All I can say is - it works great. In the hands of an experienced operator and tuner, this type of Dynojet can give your vehicle a perfect tune. Those that say it doesn't work as well as other dynos just need to experience what I described in the previous sentence. You want a perfect tune? Come in with different sized blocks to put under your gas pedal. I can set the feedback loop on the dyno to hold your vehicle at any rpm with the variable dyno brake. Put a block under the gas pedal and check the throttle position with a datalogger. Watch the a/f on the computer screen and listen for detonation. Make adjustments. Do it again with a different rpm. Do all the rpm's, then try a different throttle position (and therefore a different load.) Keep repeating until you're satisfied. Once you're done, take the vehicle on the street and make sure everything is O.K. Those that say that performing the actual tuning on the street is best are just plain silly. There are too many variables, and it is way too dangerous. For many vehicles, it's simply not practical because the engine needs to be shut down to make changes to the tune. I don't have any first-hand experience with other kinds of dynos, so I'm not going to say anything good or bad about them. I will say that they are just like any other tool - they are only as good as the user. I was once told that Mustang dyno operators needed to enter the weight of the vehicle, but I wasn't sure. Since you guys say that it's true, I'll also add this - why the heck don't they come with a set of scales? Since they don't, why don't the shops buy them? I almost bought a nice set just so I could charge the customers that were interested in their weight - a good set can be had for around $1000 brand new.

04-03-2005, 11:44 PM	#16
OJEngineeringSr TEAM Member Join Date: Mar 2005 Posts: 302	Re: Dyno comparison: Dynojet vs. Mustang - A civil discussion Sport Compact Car did a secret dyno comparison several years ago. They tested their "mule" car on several Dynojet dynos around So Cal. including mine. They also took the same car to several Mustang and other model dyno centers. The Dynojet dynos all read very, very close to the same. The Mustang dynos were off by huge margins. This further illustrates that for the sake of comparison and accuracy the Dynojet dyno is the standard. Having said that Superflow has a new chassis dyno that they claim can be calibrated to give SAE HP or Dynojet HP. a local shop just put one of these new Superflows in recently. I guess I should go test my supercharged test "mule" on it and see how the results compare to FocusSports numbers and report back to everyone. I know Randy's Dynojet is always good. I'll report back in a few days with results.

04-04-2005, 04:43 PM	#17
dimm TEAM Member Join Date: Aug 2003 Location: good ol balmore merland Posts: 679	Re: Dyno comparison: Dynojet vs. Mustang - A civil discussion To everyone so far: Thank you for starting this thread. It begins to erk me a bit when I see dyno's and the weight can be off. Dyna-paks can suffer from the same issues. As of late i've been seing alot more mustang dyno sheets poping up. All have diffrent weight values for the car, this is what erks me. One of the better tuners in maryland uses a mustang dyno. I have to say this, you dyno your car there then drive down to the dynojet and the numbers will be within +1 to -1 hp of each other. Thats saying something. Another tuner with a mustang dyno around here always shows way higher then either the dynojet or the mustang dyno that the better tuner here in maryland has. The key for me is consistency. I've done some mystery dyno testing myself. You'd be amazed at how human error can scew numbers on a dyna-pak or a mustang dyno. Most people with the mustang dyno's in my area just recently purchased them and unknowingly make the small error of the weight issue's. Same for the dyna-pak setups.

04-04-2005, 05:46 PM	#18
FocusSportVP Premiere Sponsor Join Date: Aug 2000 Location: The Lair of The West Coast Cult Posts: 20,819	Re: Dyno comparison: Dynojet vs. Mustang - A civil discussion The problem with testing load on the dyno vs. the street is cooling. For some intercooled applications this is not that much of a big deal, but for a lot of cars it's an issue. Most dyno fans out there are not going to provide adequate cooling, at least not enough cooling to emulate the street or track, which is what you're trying to do. Right? So you can load the car for just a short time, let it cool down, and repeat. Several times. This has it's place, but I've found that tuning WOT on the dyno and then making sure everything jives on the street works well, too.

04-04-2005, 11:37 PM	#19
DrTorque TEAM Member Join Date: Dec 2004 Location: CT Posts: 142	Re: Dyno comparison: Dynojet vs. Mustang - A civil discussion Good point - that's why we've got a 30,000 cfm fan in the works

04-05-2005, 09:10 AM	#20
dimm TEAM Member Join Date: Aug 2003 Location: good ol balmore merland Posts: 679	Re: Dyno comparison: Dynojet vs. Mustang - A civil discussion Need a way to hook the fan up to the throttle to simulate what the wind would be like at diffrent engine speeds. Of course having a fan blowing at 60mph then 70mp, then 80mph then at 110mph could prove to do some damage in the shop. Just for the record, and for everyone that reads this: You can scew a dynojets numbers with sae correction being on or off, having sensors in the wrong place, or purposely positioning sensors in the wrong place. I know a local shop here that got in a bit of trouble for altering a guys dyno by altering the sensors and using sae correction varinces for a before and after. All this to sell there own turbo setup.

04-05-2005, 01:05 PM	#23
EggYolk [FJ] Specialist Join Date: Jun 2003 Posts: 5,610	Re: Dyno comparison: Dynojet vs. Mustang - A civil discussion So I'm curous Randy. You picked a Dynojet because the Mustang requires too much input, which can lead to human error. However, the Mustang has more bells and whistles than the Dynojet does. So is your company not willing to go the extra mile to get a better tune? I think this should go in the Tuning FAQ at the top.

04-05-2005, 01:20 PM	#24
FocusSportVP Premiere Sponsor Join Date: Aug 2000 Location: The Lair of The West Coast Cult Posts: 20,819	Re: Dyno comparison: Dynojet vs. Mustang - A civil discussion We chose a Dynojet for many reasons. I can list a few: 1. Industry standard - You can't mess with a Dynojet much and because of that you can rely on the numbers in comparison to a Mustang dyno. 2. You don't have to weigh each and every car to get accurate HP and TQ numbers, unlike the Mustang dyno. 3. You don't have to calibrate the dyno for every car to be able to read/pick up RPMs, unlike the Mustang dyno. 4. You can't add "other" variables/factors, like elevation, which can really throw of the numbers, unlike the Mustang dyno. 5. Though the Dynojet software is not perfect, the resolution of the Mustang graphs are seriously lacking. 6. Anyone "in the know" will always question Mustang dyno numbers, unless they are their own, because of the human factor error. 7. I don't care about bells and whistles. I care about respected, duplicatable, accurate, and reliable results. Every time.

04-05-2005, 01:32 PM	#25
Ray Driver > Car Join Date: Jul 2002 Location: CT Posts: 26,768	Re: Dyno comparison: Dynojet vs. Mustang - A civil discussion Added to references thread.