King of Cubes, show me dyno in real time data : V-Twin Forum: Harley Davidson Forums

turbotc · 04-30-2007, 12:49 AM

Quote:

Originally Posted by KingofCubes

I would like to see more dyno sheets in real time, I have seen some 4th and 5th gear pulls with similar power that were 3-4 seconds quicker in time.

I keep hearing this "X" amount of seconds quicker in time. Could you show me some examples of how you would display this type of info on a dyno sheet where we know data is straight up? I'd like to compare data as to why you think time for one build is revelant to time of another build.

**KingofCubes** · 04-30-2007, 08:41 AM

I thought you would never ask, I'll get some graphs together. I just returned from Laughlin. All dynos will give you graphs in speed, rpm, and time.

**HDWRENCH** · 04-30-2007, 08:49 AM

I have a few as well i would be MORE than happy to post. Take two bikes both have same grearing, and make same power but one can get to the power 2 seconds fasters . Which on would you want to own and ride??

**KingofCubes** · 04-30-2007, 09:36 AM

Steve, show some graphs, it will take me a day or two.

ejk_dyna · 04-30-2007, 10:13 AM

<<Take two bikes both have same grearing, and make same power but one can get to the power 2 seconds fasters . Which on would you want to own and ride??>>

..and they have to have the same size rear tire inflated to the same pressure so roll out is the same..and the clutches have to have the same lock-up...and they bikes have to strapped down exactly the same way...and the roller needs to be in the same condition...and the operator has to accelerate in exactly the same way...and the ref air conditions need to be really close since the correction factors get less accurate as the deviation is greater...

so if all these things are the same and one bike is 2 seconds faster than the other..then we need to figure out is it tuning (incl advance curve), pipes, cams, carb, heads...

springer 03 · 04-30-2007, 06:15 PM

EEK! can somebody say variables.

Hammer107 · 04-30-2007, 06:20 PM

Quote:

Originally Posted by HDWRENCH

I have a few as well i would be MORE than happy to post. Take two bikes both have same grearing, and make same power but one can get to the power 2 seconds fasters . Which on would you want to own and ride??

Wouldn't the time to reach peak power be a function of torque? I admit to being a novice in the dyno world but I would expect a "slow" revving bike would be overcammed or too big heads etc which I would expect would show in the torque curve.

If you were to compare two dyno graphs with similar peak power but one is "fast" and one is "slow" wouldn't we expect to see pretty different torque curves?

Are you guys talking about something else or is this the old analogy of power under the curve?

Hammer107 · 04-30-2007, 09:17 PM

I may not be saying it right but I think what they are referring to is power under the curve. The broader and taller the curve the better.

Nothing new....just never heard of it referred to as a fast revving motor.

Horse power is nothing more than a mathematical derivative of torque.

Torque can be measured while horsepower is calculated.

I don't even think being faster revving is a measure of much as you might rev quickly to peak and peak way too soon and then fall off etc.

I think you might be right...just another thing to bitch about.

**HDWRENCH** · 05-01-2007, 08:47 AM

Area under the curve or rate of acceleration is another way to look at it.

A dyno guy should be able to make 3 runs on a bike and have them lay over each other to look like one. Now that would mean that he is able to get his starting and stopping point the same. Now if you take a bike that can produce tq faster you can compare the two, as well as comparing other dyno runs in the same format. So if two bike both make in the same range of hp and tq, lets say bike "A" makes 110 tq and 105 hp and run time is 7.1 seconds from 2000 rpm to 6000 rpm, and bike "b" makes 109 tq and 105 hp but the run time from 2000-6000 rpm is is 5.9 seconds. So gearing is the same air pressure, CI, cam, carb, pipes and the only thing you ahve changed is the heads then we know that one head has a higher VE than the other. SO it is is able to reve faster and harder. Hands down the bike that gets there faster is more fun to ride.

Hillside · 05-01-2007, 02:15 PM

Quote:

Originally Posted by KingofCubes

Steve, show some graphs, it will take me a day or two.

Folks,
When we complete a dyno tuning session, for our carb clients, we send 'em home with data sheets, that include absolute barometric pressure,vapor pressure,intake air temperature,gear ratio,(spark count) and the correction factor.
On those same sheets, we record and print data at 100 rpm intervals. We can disect it down to every 10 rpms, but so the client does need a wheelbarrow to carry the information home, we use 100 rpms as a good reference.
It prints measured(actual) and corrected(SAE).
Also in the last row of data is the time in seconds, or actually hundreths of a second.
We monitor that very closely when tuning, and always have.
When an engine/gear ratio combo of a street driven V-Twin engine can rev from 2400 rpms to 6000 rpms in less than 4.85 seconds in high gear, you've got someting under the hood.( just finished one) We've witnessed the real time data for years and have applied that to what we do here.
Ancient Chinese Harley mechanic say, "He who makes most torque first, wins accelertion game."

turbotc · 05-01-2007, 03:50 PM

Quote:

Originally Posted by HDWRENCH

Area under the curve or rate of acceleration is another way to look at it.

A dyno guy should be able to make 3 runs on a bike and have them lay over each other to look like one. Now that would mean that he is able to get his starting and stopping point the same. Now if you take a bike that can produce tq faster you can compare the two, as well as comparing other dyno runs in the same format. So if two bike both make in the same range of hp and tq, lets say bike "A" makes 110 tq and 105 hp and run time is 7.1 seconds from 2000 rpm to 6000 rpm, and bike "b" makes 109 tq and 105 hp but the run time from 2000-6000 rpm is is 5.9 seconds. So gearing is the same air pressure, CI, cam, carb, pipes and the only thing you ahve changed is the heads then we know that one head has a higher VE than the other. SO it is is able to reve faster and harder. Hands down the bike that gets there faster is more fun to ride.

Quote:

Originally Posted by Turbotc

Disclaimer: First off, I'm not a Tuner, I've never been trained by Dynojet nor have I every operated a dyno. I'm only a customer for motorcycle performance products who loves to play with Dynojet runviewer software and dyno files, so I may be talking about dyno software and operators like the guy on ESPN commercial who kept talking about sport subjects before he got educated. It's most likely I'm talking out of the same place. Not that uncommon for me by the way..

The above said would you explain to me that because you can take XX number of dyno runs and using Dynojet's sofware with Engine RPM as the bottom line scale have each run line up rpm for rpm that all of those XX number of runs by any are all operators started at the same time and rpm?

Is it not possible that from the time the operator pushes the buttom to start the software recording that there might not just be a difference in both rpm and time he actually went WOT and that it's the rule and not the exception that majority of runs will be off more than .10th of a second and more than 100-500 rpm?

Show me proof I'm talking out my @$$ like the guy in ESPN commercial by showing me same run of two bikes with same power numbers with bottom scale as Engine RPM and then same runs with bottom scale as TIME and turn on the cursor function to show vertical scale so we can see engine rpm is same on both at 2500 rpm and time for both at 2500 rpm is same. 2000 RPM for smaller displacements is exceptable also.

Please show on bottom "Time" scale dyno sheet, gear ratio, engine rpm in seperate windows, AFR in gear ratio window would be nice for reference as to how well each was tuned, although engine should dictate engine's fuel needs . Also perfer that all run files have "dfr" file extension and weather conditions dispayed. It's exceptable to show runs with weather info displayed on another sheet if you are exporting files from software instead of printing them out and scanning. Too expensive for me so since I will be responding in kind, playing field sould be the same if you want to use exported graphs.

Also in and effort to make sure all members can see data, could you post your graphs from a web source that allows the graphs to be viewed here by all using the fourm's picture function to show graphs so people can compare data without having to jump back and forth between fourm screen and attachment screen. I like many can't view attachments anyway and I would like to vew this new way of selling products using "TIME" dyno sheets to level the selling field.

FXDRYDR · 05-01-2007, 05:23 PM

Ah Jere... a fresh Spring breeze!

claydbal · 05-01-2007, 05:58 PM

dayem turbo, do you really need that disclaimer?

turbotc · 05-01-2007, 06:39 PM

Quote:

Originally Posted by claydbal

dayem turbo, do you really need that disclaimer?

clay,

I sure do. I get myself in trouble all the time from talking out my rear. Just wanted to make sure some people don't go along with my way of thinking without knowing they might have to backup and start thinking on their own instead of listing to what I have to say.

Want to make sure people don't associate me with all the real dyno experts I've been reading post from. Give me temp, absolute baro pressure and humitity along with uncorrected numbers and I can convert them to SAE. Give me dyno's elev and I can get darn close to SAE numbers if you give me weather station baro pressure. V-Twin Nut showed me where to go to do that.

claydbal · 05-01-2007, 06:53 PM

Quote:

Originally Posted by turbotc

clay,

I sure do. I get myself in trouble all the time from talking out my rear. Just wanted to make sure some people don't go along with my way of thinking without knowing they might have to backup and start thinking on their own instead of listing to what I have to say.

Want to make sure people don't associate me with all the real dyno experts I've been reading post from. Give me temp, absolute baro pressure and humitity along with uncorrected numbers and I can convert them to SAE. Give me dyno's elev and I can get darn close to SAE numbers if you give me weather station baro pressure. V-Twin Nut showed me where to go to do that.

could you pm me that info? PLEASE? MY DYNO KEEPS SHOWING ERRONEOUS INFO. like tq/hp crossing at 4000 rpm. i need to learn more.