sweet runs! don't understand why people want to argue over speeds that traxxas has claimed.
sweet runs! don't understand why people want to argue over speeds that traxxas has claimed.
The biggest thing i've broken: My wallet.
Hey powers are you in miami?!
Regarding the 70-75 mph comment... Go read the thread genius, the poster asked when it will float WITHOUT the high speed splitter on the front, Traxxas provides it with the car for a reason. Please impress me again with your great wisdom I can't wait for more.
Do the XO-1 tyres have these characteristics? I haven't noticed anybody reporting failures yet...maybe you will be pleasantly surprised with their durability??
This thread has been cleaned up. Please remember to keep post constrictive and helpful. If you MUST disagree or post a negative comment you NEED to do so in a respectful manner.
Rusty - MERV - Pede 4x4-Alias
SPC Lipo Power
This is definitely the most in control video I've seen of an XO-1 besides the traxxas videos. Nice driving. And man, what a narrow road. That would be scary to watch my $1000 bill go flying by like that. Hehe.
Im not a hater or doubter... I have ever believe the XO-1 can, will and does go 100mph and likely more as they get setup and tweaked in the next few months. I do NOT believe the argument about speed verification is the same as with a rustler or pede... its a whole different story.
With that said, I DO want to see a GPS verified run. Not because I doubt the car can do it in ANY WAY. Simply because I want to see more evidence of just how accurate the TQi telemetry system is. Im not a fan of mechanical speed measurement. Too many factors can change. I think the BEST add on to this car will the the GPS module when it becomes available. That will mean the TQi and its telemetry CAN be used a verifiable speed measurement system for proof. Until then, Id prefer to see a GPS under the hood.
But again, I MUST restate this, I do not doubt in any way this car is capable of 100mph... and after seeing this video I have all the faith I need in Powers driving ability... clearly the most in control driver I've seen so far.
Motley Crew, 1SQ
I agree with pav about verifying with GPS.
Sent from my DROID X2 using Tapatalk
I would respectfully remind you that this forum has a great many members and as such consists of a commensurately larger cross-section of the population than you are perhaps accustomed to posting alongside. The cheap shots above are not necessary and I believe they are beneath your standards.
Alt-248 on the number pad = °
Still waiting on new tires so I can go deeper into triple digits...in the mean time I'm still waiting for someone out there to post another video of the xo-1 goin 100+.... Anyone?
And u really have to use a gps for accurate mph.
And there is no way you got to 100 in 600ft. At 100mph your going almost 200feet a second and thats at 100. Not even possible in 600 or 800ft
Oh, and to silence the whiners once the new wheels and tires arrive i will use my gps on the next runs. MUAH!
Its impossible to go 100 mph in 800 ft from a dead stop. At 100mph the car covers almost 200ft a sec. You do the math
Yeah and my 105 is gps certified.
This issue of 0 to 100 to 0 distance is an interesting one. Anyone smart enough to work out the math or got a link that might be relevant. I found a road and track article where they listing times and distance for several high performance cars. They were all over 1000 feet.
The xo-1 should be able to crush these cars on the 0 to 100 to 0 test and the distance for the xo-1 shoukd be much shorter. Can anyone find a link reporting distance for something full scale that has performance comparable to the xo-1?
Last edited by iaanr; 02-26-2012 at 06:32 PM.
That was some seriously nice controlled driving. Looks like a blast to drive.
2x4 CC 3800 Pede
4x4 CC 3800 Pede
Seeing a glimpse of your X-01 driving by than seeing a GPS that reads 105 mph means squat to me, sorry to be blunt.
And the GPS reads 2.1 miles... that's a whole lotta driving !!!
And it's been proven that, when set-up as it should, the TQi's telemetry is very adequate in giving the actual speed.
But back on topic. Did you guys see that powers guys video? It was NUTZ!! I can't wait till he gets new tires and goes for more speed. SICK!!!
hey i dont want to rain on anyones parade cause this is def crazy and a good run but i ran my X0-1 past weekend and my iphone telemetry said 97 MPH and i have a onboard GPS that i bought to compare and the onboard said 87.5 MPH so there is a big diference between what the controller is telling us vs the GPS has anyone else compared the 2 side by side if so what results did you get.
A lot of the speed discrepencies have been related to the user not telling his iDevice wich gearing was in the XO-1
Also if your run was on cold asphalt and your tires were spinning like crazy it can also mess with the telemetry since it only reads spur / speed...
I dont understand all the people giving negative reviews on the telemetry. I have seen posts of people stating that GPS is the only way to accuratly measure your speed. In fact GPS is not nearly as accurate as the stock RPM sensor or radar gun. GPS is first only accurate within 5 ft and when you are going 70+ mph in under a few seconds those few feet matter, also depending on your GPS device it measures how quickly you went from point a to point b. If the location is gathered every 2 seconds on a car like the XO-1 that data will be useless. However the stock RPM sensor calculates your speed depending on you gearing settings, so if you change your gears be sure to update that in your garage, otherwise your speed calculation will be off. I really like the TQi transmitter and link app, job well done traxxas.
What snapshot said..
These cars just speed up and slow down too quickly for GPS to be accurate.
Radar gun, properly set telemetry or pace it with a full size car.
Telemetry Rules GPS DRools
Changing pin/spur has no effect on telemetry speed...
No it does have an affect here it is right out of the help of the Traxxas app in the garage:
Traxxas Link relies on specific information about your model to generate accurate telemetry data. If you are operating a stock Traxxas model and have selected that model from the Select Model screen, there is no need to make any changes to Model Setup. However, if you have made changes to your model's gear ratio, tires, or battery, you will need to input new data in Model Setup or your telemetry results will not be accurate.
Here is the equation which gets used:
(0.00595) * (RPM * r) / (R1 * R2)
RPM = current rpm from the sensor
r = radius of wheel to pavement
R1 = gear ratio
R2 = diff ratio
So if you change any of items referenced in the help you need to make the changes in your garage.
Last edited by snapshot4; 02-28-2012 at 09:02 PM.
What if we use different tires that are a bit smaller in diameter, is there a place we can entire that into the tqi app ?
Ok dude, I gotta assume you own a XO-1, you do right?
Ok good, now go look at the RPM sensor, where is it? Oh its built into the spur gear? Just like mine eh?
Right, so its measuring the rpm of the center shaft, and then using the gear ratio of the diff, and the roll out of the tires to calculate speed.
It does not take into account motor rpm... If you don't believe me, put the car in locked mode, then raise the ratio and go drive, still locks at the same speed doesn't it?
Thats because its based off center shaft speed.... so changing the pinion/spur doesn't change the speed formula...
Changing the tire diameter, or the diff ratio will effect the speed reported by telemetry.
I maintain changing the pinion/spur will not.
However.... if you don't update your ratio in the app, the RPM will be off, since thats backwards calculated off the center shaft speed.
Traxxas could give us actual RPM if they simply updated the app to support Castle Link Live.... something I've been not so patiently waiting on.
No the rpm is not figured by the center shaft the sensor is just built into the motor mount. The magnet however is in the spur gear so as the gear rotates the calculation is done there. If you change the spur gear the gear is the bigger or smaller and the time it takes to do a full revolution is increased or decreased accordingly.
Think of it this way if you roll a soccer ball and a basketball down a hill which one goes faster? The answer they go the same speed however the soccer ball has a higher rpm then the basket ball because of size, it takes more revolutions for the soccer ball to maintain the same speed as the basketball. If you don't take the size into account you will get the wrong answer.
Tires you can also change in the garage. The tires have the radius/diameter built in so the can do the proper calculation. If you tire isn't listed you will have to choose something close to the size you are using. Unfortunately you can't manually enter in a tire a size, my guess that may be in a future update to the app.
Stickin to your guns eh.
Tell you what, how far does the car roll when you turn the spur gear 1 time? 1 turn only.
Now change the spur gear, turn it again, one exact turn, how far did the car roll?
The answer is the same distance! Because the spur is on the center shaft.... and one turn is one turn is one turn...
Changing the spur, or pinion has no effect on the rollout of the center shaft, which is the rpm the sensor is reading....
However I was working out the math from one of my previous runs where I did change my garage settings. The math wasn't working out at all, because my recording was reaching about 30,000 rpm going 71mph. But my math was coming up with 99 mph using my gearing. I then came across my setup sheet which was still set to the default of 25 pinion and 50 spur. I used those in my math and that worked out to 70mph. So I wonder if you have to load a setup sheet to get the right calculations. I will do some testing on this, but gotta wait for it to warm up a bit.
BTW I think we high jacked this thread :-)
Here is an example of how a different size pinion affects the spur rpm.
So you see, changing the pinion or the spur for that matter, will definitely affect center shaft rpm which will in turn affect wheel rpm. The faster the center shaft turns, the faster the wheels turn.
Last edited by ponie1992; 02-29-2012 at 03:13 AM.
True ponie but it's still reads at the spur and calculates motor rpm backwards from there. IMHO
Last edited by BL-Bob; 02-29-2012 at 06:39 AM.