Dave, although I do not have a ton of time on evom, I have been around the industry a long time. I just have not always been playing with DSMs / Evos. I went from NA V8 cars to FI V8 cars to domestic turbo 6 cyls to import turbo I6 cars to turbo I4 cars.... I have been modding cars for over 20 years. I left my career as a machinist 10 years ago to work full time modding import cars.

Dave, you used a DJ for years. Does this mean that every car you tuned on a DJ left with a bad tune? Of course not. Like I mentioned time and time again, its about who is behind the keyboard. Putting cars on your dyno that have issue and saying its because of the dyno they were tuned on is only going to prove that the tune they got some place else was not good.

I read the info posted about the DJ numbers. They based it off of the VMax. The factory rated the motor at 145 HP. AFTERMARKET load cell dynos available at the time showed the motor making 120 HP. DynoJet's prototype chassis dyno would only read 90 HP measured at the wheel. The simple math they used just wasnt cutting it for the "mass equivalent" of the rotating drum. They fudged the numbers to get the numbers to read the same as the AFTERMARKET load cell dynos. While this was probably not the best way to do things, the price, simplicity and repeatability of the DJ made it the standard. The MD has a lot more features that nobody ever really uses. While MD touts "our numbers are accurate", everybody still wants to hear DJ numbers due to them being the standard.

Due to the fact that the DJ uses roller weight for load and there is no setup, PAUs to calibrate, roller weights to alter, etc, numbers from one DJ can be compared to another with a reasonable assurance that you are talking apples to apples.

The biggest issue with comparing numbers from one MD dyno to another is that the user can alter roller weights and change how the dyno measures HP / TQ. With just the click of a mouse, you can add or subtract hundreds of HP from a the way the dyno reads. For this reason, dyno charts from one MD to another are hard to compare. Proper PAU calibration is also nessasary for accurate dyno charts. If this is not done correctly, HP / TQ numbers will not be accurate.

From a tuning standpoint, you can tune just as well on a MD than you can on a DJ. To say that being able to put more load on a car will help you tune it better is not true. You and I both know very well that there is ONE major timing map and ONE major fueling map when tuning a car. The ECU does not reference what gear you are in, how much your car weighs, how many people you have in your car, how much stuff you have in your trunk, how much wind resistance your car has, or the grade of hill your going up or down. Having the exact same load your car would see on the street due to the weight of the car and wind resistance programmed into the dyno has no bearing on how well the car is tuned.

I have not said the DynoJet is the best dyno. I will say that it works perfectly well for tuning cars and getting repeatable numbers that you can compare with others. I have however pointed out that the MD does not do anything better than the DynoJet and that a lot of the features that are on the MD are in fact not very useful. I have also said that the MD also works perfectly well for tuning cars.

 

The reason for that post was to show that cars tuned on a DynoJet are tuned quite well. "People" were suggesting that cars tuned on a DynoJet did "not get the car close enough to call it tuned"

About 5 years ago at my last shop, we built and tuned a supra that made 1520 whp through an AT trans making it the most powerful MKIV in the world at the time. This was done on a MD dyno. I never said you can tune better on one or the other. They are both good tools to use to tune a car. What I have said since the beginning is that you can not tune BETTER on a MD than you can a DJ.

 

Since the notion of comparing dynos to each other is brought up. I love the fact DynoDynamics dynos have Shootout Mode which displays ALL the parameters of the run which could effect the hp reading. That way you can compare sheets very easy and know for certain no fudging was done.

Mustang should adopt a feature like this.

 

Ivan posting from Scott's account.

I agree. There should be some sort of "standard" that should be included in dyno sheets posted. It is posted on all DJ sheets (correction factor and smoothing). It would be nice though to see air temp, baro though.

For a Mustang Dyno, it would be nice to see roller weight so we could get an idea of who is fudging numbers. Car weight and CD numbers used should also be posted to get an idea of how the motor is loaded which affects spool. None of this rules out issues with PAU calibration though. It really is hard to trust MD numbers.

 

Now this thread has moved on to which dyno makes it easier to cheat on output numbers?

My whole 'purpose' of this thread has gone way over some peoples heads...

I don't post threads in "Evo Engine / Turbo / Drivetrain" much, now I am remembering why.

 

I understand your purpose and it is appreciated and interesting info.

 

bryan,

appreciate the data, ive been meaning to do this as well...

cb

 

Ivan from Scott's act again.

I am sure you also appreciate the fact that this thread provided the opportunity to dispel some misinformation.

Again, I do appreciate the testing that was done and the results that were posted. Now we need to see the same test from a DJ and this info can be useful.

 

pardon my ignorance, this is a legitamate question:

Doesn't the Evo's ECU determine the load on the car, therefore selecting which portion of the fueling and timing maps to use? Wouldn't the Mustang Dyno with it's greater "road" load (nice poetry btw) be more in line with what the car sees on a day to day basis.. there for making for a more "accurate" tune?

Again, not stirring the pot, just learning.

Also, one thing that would be fun to see with dyno sheets would be the averages instead of just the peak numbers. Really helps tell the story of not just power output, but power DELIVERY. Just my $.02.

 

The Mustang Dyno prints this out at the bottom of every dyno sheet.

 

9sec240, well we certainly do agree on one thing, there are Mustang Dyno owners who are seriously messing with their dyno's to make larger numbers! It is extremely well to do. For example a few years ago Al was tuning a basic EVO that was making around 300 whp. It was at the shootout if I remember correctly. We were discussing people changing the dyno parameters and I asked the owner of this particular EVO if he'd like to win the Dyno competition and he laughed and said "Sure". So I changed the roll weight and Al did another pull, the car made over 800 whp on the next run. The chart looks absolutely perfect and there is no way to tell if this was done. It is WAY to common for people to screw with those settings.

It is also nearly impossible to call someone out on it because even if you wanted to go to one of these other shops to put the smack down in less than 10 seconds the computer can be put back to its proper settings and it would read low again.

BTW, I think every single tune I did on my 2WD Dynojet, sucked.

 

I like you Dave. I envy your ability to say whatever you feel.

I am sure you can tell that I am also a no BS kind of person. I call things like the are and dont mind being the one to correct people. I tend to step on toes but thats the way things go.

I have a lot of respect for the business you have grown. Keep up the great work.

P.S. I think that your last statement is going to end up in a lot of signatures though.

 

haha, I'm just trying to keep it real

Seriously, maybe because the old Dildojet we had was a 2wd and we had to convert all the DSM's back in the day to 2wd to tune them they all ended up whacked but they certainly were messed up. The Conquest and Tube car weren't too bad, both of which of course were 2wd to begin with and light.

The AWD's we tuned though, when they hit the track they wouldn't run without spitting/sputtering and carrying on. Everyone of them ended up being tuned on the track instead.

 

Great work again razor.

I have always favored Mustang dyno.

Mustang dyno FTW.