Eagletree Data Recorder
 

ok, i am running the mgm 80amp and the feigao 6s in my t4. i am also using the eagletree system to monitor performance. well, the system doesnt seem to be given the right results based on the numbers an internet buddy of mine is giving based on his 8s motor and GPS. i trust this guys numbers, so does anyone have any idea what might be going on... all i can figure is that my sensor is loosing contact or maybe i am not getting enough power to the system???
thanks

What is wrong?

What numbers are not right?

yeah, i guess that would help..... the speed seems to be quite a bit lower. according to the system, i am only in the mid 30's on 6 cells, he is in the mid 40's with 6 cells and a novak 5800.

I have got no idea what you are talking about? the system doesn't show the right speed?

He's a load of bs if he says mid 40's with a novak system. So that might be your first problem.

i was wrong, it was 7 cells and he got 45 with the novak in a t3. well he is not some teenage kid trying to brag so i am pretty confident he hit that speed.
i noticed that my software is out of date, so i will upgrade and see if that helps.

www.eagletreesystems.com is where you can read all about the system

GIGO as they say (garbage in=garbage out). I would look at the numbers you entered in. The eagletree calculates speed based on rpm, so tire size is a factor in the calculation. If your tires are ballooning or the tire size is improperly calculated, the system will not show an accurate speed. I think you must determine exactly how far the car moves with one revolution (of the magnet-depending on where the magnet is located). My guess is that there is an info input error.

Yeah, I'd agree. BTW, the Novak ss5800 on my B4 with 6 cells has hit over 40 mph. That's with a 30 tooth pinion and 87 spur and stock tires. With 2s lipo, it went about 43 mph. I figure on 7 cells, it should hit mid to high 40's if geared for max speed. This was using Bushnell radar gun AND GPS. So, you're buddy is not BSing you.

You have to make sure the numbers are correct as Mike has said. I've never really trusted Eagletree or Venom for speed - expecially in monster trucks or STs due to their major increase in tire diameter. That's why I like GPS for speed, and ealgetree to monitor voltage and amp draw. I'm suspecting even that might be off a little too - my "2000" lipo packs had over 2400 mah using eagletree but my charger only says approx 2000 mah.

BTW, Mike, did you ever get it setup? What vehicle? What test?

No, Young, I haven't gotten it set up yet! I have looked at it a few times, but I mostly move the box out of the way when I am looking for something! This post has reminded me to get the eagletree I got from you hooked up. I will probably throw it on a couple e-maxxes and maybe my tc3. I think the speed would be fairly accurate in a tc with foam tires vs. the ballooning monster trucks, but I too am most interested in the amp draw data for calculating runtime with different setups. I would like to run some 15 minute mains with my e-maxx this summer.

well the system has two options: the basic option that you described and the advanced option where you enter the data. i know all the ratios are correct and measured the tires with calipers. i am sure tire ballooning is costing me some. i also think it might be that the software needs updating. so with a 6s and like 7-8 cells, shouldnt i be able to get into the 60's (give or take a couple of mph)

The 6s on 8 cells should get you into the 60s. I did it in a t2 a few years ago with the same setup.

You know, it's quite interesting... When I test 2wd vehicles, it takes about 200 watts to get about 40ish mph, but takes about 700 watts to get about 60 mph. My TC's seem to top out around 65-70 mph with my current Lipos. Almost a "general" rule here... And if you think about it, if it takes 200 watts to get to 40, it should take about 800 to get to 80! That's for most 3-4 pound vehicles.