Traqmate V2.15 out

Kevin Butler · **Posted:** Mon Dec 22, 2008 8:55 pm

Hey Guys and Gals,

Traqmate has new software version 2.15 out.

Pesonally, I am most impressed. They have added Horse Power and Torque graphs amongst other improvements. If you've already got Traqmate, these added features to the software appear to work with older data files.

Example: At VIR this past Dec 7, I set a personal best of 2:17.7. My max HP for this lap was 230(178 ft-lb torque) @ 6800 rpm on the back straight in 3rd gear right before I shifted to 4th.

However, I see some data that looks to be doubtful.

Example, Same lap: Mid Roller Coaster right before I brake for T16. Traqmate says I'm making 223 ft-lbs of torque, 207 HP @ 4900 rpm in 4th gear. I have a hard time believing I can make more torque than HP. But the trend is consistent between different between runs made at different times of the year, so I think it has something to do with the fact the car is in an arc.

They've also made provisions for data notes to be imbedded into the files, so you can record temp, tire sizes, boost, et al.

Traqmate gets more impressive with new features with every released update. The great thing about the product is all the improvements are free and the cost of the product doesn't go up!

Richard Casto · **Posted:** Tue Dec 23, 2008 12:05 am

Kevin Butler wrote:

Example, Same lap: Mid Roller Coaster right before I brake for T16. Traqmate says I'm making 223 ft-lbs of torque, 207 HP @ 4900 rpm in 4th gear. I have a hard time believing I can make more torque than HP. But the trend is consistent between different between runs made at different times of the year, so I think it has something to do with the fact the car is in an arc.

I know next to nothing about Traqmate. What I do know is that it uses onboard accelerometers + GPS. I am guessing it uses GPS mostly for actual speed values, but not for delta position as the accelerometers would be more accurate than regular GPS.

Does the output that is generated by Traqmate include changes in elevation? I am guessing that it doesn’t. So it assumes everything is on level ground. But that section of track is all downhill. So you may have been accelerating faster downhill than you would have on the level. The Traqmate analysis wouldn’t know that some of your acceleration was via gravity vs. engine. So it attributed it all to the engine and gave you a non existent torque bump? Just a theory.

Kevin Butler · **Posted:** Tue Dec 23, 2008 12:36 am

Traqmate does show elevational changes. They don't go into what sensors they use to accomplish this.

I have three seperate sessions from VIR saved together in one analysis file. Each session shows a different max and min elevation. The overall elevation changes between the 3 sessions range from 121.39 ft to 127.95 ft.

That makes me curious how they do it. They say it's an absolute elevation. I'm not sure exactly what they mean by that - I'm thinking ft above sea level.

Bernie Baake · **Posted:** Tue Dec 23, 2008 9:15 am

Most good navigation systems use both accelerometer and gps data concurrently. Accelerometer inputs are inherently more accurate over short term analysis and gps data conversely is more long term accurate. the navigation algorithm is weighted so accel data has more effect in the short term but is buffered by GPS data to insure long term accuracy

Donnie Barnes · **Posted:** Tue Dec 23, 2008 2:10 pm

And to add to that, it's at least three axis accelerometers, so elevation change is taken into account from that. GPS elevation exists, but it is so bad over the range that most tracks are going to see that hopefully it's simply ignored in favor of the accelerometer data.

That said, I still think Richard's theory is plausible...the software just isn't quite smart enough yet to take EVERYTHING into account on those numbers. Something is strange, and his theory sounds as reasonable as any. The programmers either forgot to take up/down hill into account in that part of the calculations -or- decided not to for some strange reason.

--Donnie

Bernie Baake · **Posted:** Tue Dec 23, 2008 2:29 pm

Z axis accelerometers are inherently unstable because of pitch and roll errors of the platform (auto). Roll and pitch make the accelerometer believe that there is less than 1 G on the accel which makes it think it's climbing. Manipulating software to correct this is difficult to say the least.
I'm sure that Richards assumption is correct. The accelerometers become less accurate when climbing or decending, hence the increase in torque values going down to T16. If that is the case then climbing esses should show greatly reduced torque????? Do they Kevin?

Kevin Butler · **Posted:** Tue Dec 23, 2008 5:54 pm

After looking at things some more, it dawned on me that, yeah, torque should be greater than HP until you pass, I think, 5252 rpm. That appears to be consistent throughout the whole chart.

The HP and Torque is calculated from the weight of the car and how fast it accelerates. The reason the values are highest approaching T16 is because the slope of the acceleration curve is the steepest for the whole circuit in the segment going down through the carousel.

This also throws out the max HP/Torque values I was so stoked over earlier - it was going down hill. :oops:

The most level section of the track with good long acceleration pulls is the front straight. I show 223 HP / 173 Torque there in 4th gear.

Donnie Barnes · **Posted:** Tue Dec 23, 2008 10:55 pm

Bernie Baake wrote:

Z axis accelerometers are inherently unstable because of pitch and roll errors of the platform (auto). Roll and pitch make the accelerometer believe that there is less than 1 G on the accel which makes it think it's climbing. Manipulating software to correct this is difficult to say the least.
I'm sure that Richards assumption is correct. The accelerometers become less accurate when climbing or decending, hence the increase in torque values going down to T16. If that is the case then climbing esses should show greatly reduced torque????? Do they Kevin?

I think that's also why some products have gone to 6 axis accelerometers...now you can tell roll and pitch from turning and such and thus factor that back out easier.

--Donnie

Ron Spencer · **Posted:** Mon Jan 19, 2009 5:39 pm

Kevin according to the traqmate manual (yes, worth reading!) the horsepower (and I'll assume torque) numbers are only valid when you are foot to the floor on a straight and level part of the track. All other numbers are suspect.

Using that my Honda shows a believable number of, if I recall correctly, 116hp. The torque numbers are still messed up. Off by a factor of 10 or more!

Ron

Kevin Butler · **Posted:** Tue Jan 20, 2009 2:37 pm

Ron Spencer wrote:

Kevin according to the traqmate manual (yes, worth reading!) the horsepower (and I'll assume torque) numbers are only valid when you are foot to the floor on a straight and level part of the track. All other numbers are suspect.

Using that my Honda shows a believable number of, if I recall correctly, 116hp. The torque numbers are still messed up. Off by a factor of 10 or more!

Ron

I don't need no stinkin' instructions!

Actually Ron, you're absolutely right. That's why I would only have faith in a Front Straight output (after thinking about it). But boy, big numbers sure can get you excited!

Power is the rate of change in Work, and Work = Force x Distance and Force = Mass x Acceleration. So the Traqmate power output is only as good as the weight you have entered for the car as well.

I have 2555 lbs entered as that is the total weight of myself in street cloths plus full, wet weight that the car measured on the scales at Roebling a couple of years ago.

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