I'm pretty sure there are a couple people wondering this.

I just want that on road dyno graph, as well as the over lapping graphs with a slide bar,

come on evo4mad i dont mean to rush you man, but i do recall you sent me a pm saying it would be right around chrismas,

 

yeah i need it so i can data log my bros subaru and my evo

 

If you buy the evoscan v.97 do you get free upgrades or is it worth it to wait for the .98 version? Im about to get the .97 but i would rather wait if itll be another $25 in a couple weeks..

 

Free upgrades...

 

Anyone that has purchased a previous v of evoscan gets free upgrades correct?

 

Yes, Free upgrades, he sends out links to new versions and whatnot to "Subscribers" aka guys who bought licenses through his site.

 

Any ETA on it though? I'm a subscriber and haven't heard anything on the new version.

 

ya we are all still waiting, using the on road dyno would be cool cause even though it isnt as accurate as a real dyno, you can use it as a benchmark on itself, and see weither your improving more by advancing timing, leaning out mixture, boost and so and so.

it would be awesome,

hopefuly soon

 

"isnt as accurate as a real dyno"

lol, do you know how a dyno works? EvoScan is as every bit accurate.

The advantage of a real dyno is that you can vary the slope of the road (load of the rollers) to get a full tune done in less time, and eliminates outside variances.

 

well thats what i ment, dosent a real dyno simulate actual load, so it can determine the actual torque of the car, and then put it in to a formula to give you hp?

but, besides that i dont want to argue with you man cause you know a **** load more then me .

i just want to know when the next version of evoscan is coming out haha.

and happy new years, hopefully we can get .98 to start the year off right

 

It depends on the dyno, some of them simulate a load, some of them can vary the load, some of them can calculate driving conditions.

The problem with a "road dyno" is the amount of variables you have to take into consideration whem calculating a number. Otherwise functionally a road dyno and a real dyno work more or less the same, which is the delta rate of change in speed, in the dyno's case its the calibrated mass of the rollers, and on the street its the mass of the car, taking aerodynamics, weather, and other losses into account.

A road dyno has one disadvantage, its impractical at high horsepower levels where you are hitting very high speeds. Not only does drag come into play, but so does your safety.

But if you always do your runs in the same location, and the values you use for your calculations stays consistent, then your improvements can be measured, though the numbers may not be easy to directly correlate with a real dyno.

The comparisons between a properly set up road dyno and a real dyno, are really the same type of issues with comparing different dynos in general, or even the same dynos in different shops..

This is where the difference of precision and accuracy come into play.. As the formulas for the calculations are precise, they may not be accurate for comparison with other dynos.

 

In the program I have been working on that is independent of Mitsulogger, the gearing doesn't have to be calculated as it works based on GPS Data if available, or Vehicle speed, and RPM, those to bits of data you can calculate the missing "final drive" value and not have to keep track of what gear your calculating in, you only have to worry about the constants such as frontal area, vehicle mass, Tire circumference (to allow for error) and some other friction loss sources.

 

any updates?

 

It should be clear by now that I am a huge fan of street/track tuning. But I still think it is important to understand the areas where a dyno is really the right tool.

I think coolguycooz is dead on in mentioning P and T. A dyno has dramatically few variables and is in a better position ot measure the ones remaining. If you look in another thread where I posted two different power calcuations my first point is easy to see. My first calculation is not really all that simple, the 'slope' function called does a spline, but while it can provide a surprisingly close measurement to a dyno - it under reports with a track log. Once the car is moving, aerodynamics have to be accounted for. Again, while the second, much longer, calculation that I provided can produce values quite close to a dyno - there are way more variables involved. Variables that are hard to control and precisely monitor.

Similiarly, getting good results out of DLL or my LogWorks calcuation highlights the second advantage that a dyno generally has. If you are taking RPM from an ECU via MUT, there is rounding (RPM is reported as a value from 0-255). Since the readings are course, the data has to be smoothed to get even a reasonably accurate slope measurement. The way most dynos control load (and monitor RPM) are both more precise, leading to more accurate calculations.

From a tuning perspective it is important to understand that, as much as we want to know an exact HP number - absolute readings are not what is truly important. It is the consistancy and repeatability that is truly important. When you are making tuning tweaks and testing them, you really want to know if the gain or loss of an HP or two is real, or just the side effect of one of the many variables beyond your control.

Again, I am a huge proponent of street/track tuning - I'm just not ready to call dynos obsolete yet!

-jjf

P.S. To Malibu Jake - you'll find some gear calculations similiar to what you are talking about on our forum. There is a user who has been getting some very good results in this area and posting his work.

Regarding taking GPS velocity or other speed inputs for P/T - good luck, but be forewarned that other folks have had some difficulty. It comes down to the courseness issue I mentioned above. A GPS is typically updating somewhere between 1 and 10 Hz (1-4 is typical), and each sample is typically +/- 3 to 10 meters. This makes for an even courser reading than ECU RPM.

P.P.S. I'd love to actually discuss this area in detail. Since I've tried experimenting with low cost accellerometers myself - but I suspect that my forum days here are now severely numbered. I've been making someone a bit aggravated and I think that my pointing out that he had confused an analog input with an analog output was the final straw. Still, feel free to hit me up offline - some of the GPS stuff I've done combines inertial data with GPS data and you might be able to take it a step farther.

 

Numbers mean little when tire size, pressure, car weight, and topography are off.

Go do a pull down a 7% grade and calculate with the datalog lab calculator and your stock 03 evo will have 500whp but can only pull 105mph at the track

Dyno's are nothing more than one tool to use for tuning