bds81175 - the track is a big outdoor track with approx. 80 ft straights. Ambient temps have been in the mid to high 80s. The mains are 8 minutes. There is about 45 min to 1 hour between qualifiers. We pit inside with air conditioning. And yes, there is lots of wheel spin. I did update to the new firmware a few weeks ago.

Mmm...pitting inside with air conditioning....sorry, got distracted. It doesn't seem to me like you are missing anything obvious on the setup. 8 minute mains with these monsters will probably be a bit of a challenge when the temps are hotter outside. We can rule out the motor as you have tried multiple motors. Your gearing seems about right. A badly machined or worn pinion doesn't seem like the problem as you have tried at least two. How does the spur gear look? Does it look like it has been drug behind a truck down a dirt road? Do you have another that you could try swapping in? Also, you can't use the paper mesh setting technique for these things. That much play would be too tight. Might you be setting the mesh a bit too tight? I just incinerated a motor this weekend because the motor moved during the course of racing and squished into the spur gear. If you are still getting a lot of wheel spin (are you ballooning tires out of the corners?) you might still be running too much punch, although I can't imagine turning it down much past 50%. Never had to go that low myself. Hope I'm helping some here.....

I can't see an issue with the settings either, though I use Profile 1 myself. I do 7min races regularly and have done a few days of 10min mains when it's been an all EP field and no worries.

Do you have any air holes in your body?

Can you turn the motor temp cutoff off?

Surely if you have lots of wheel spin it may be good to turn down the current limiter? I have no idea about gearing but have you tried going up a tooth to 16t pinion as I have seen under gearing cause brushless motors to get hot, sounds daft but seemed to be the way. This may calm down the wheels pin as well.
Is there any chance you could do some testing not on a race day to experiment a bit with different settings?

Just wanted to post a thank you to Viper for making great ESCs. I watched 2 guys in 4wd mod buggy drop out 3 different times during heats and mains because their Tekin ESCs over heated while my Viper had me flying all day.

The spur gear is new and this set up did the same thing in my other truck with a new spur. I have lots of air flow through the body. I'm afraid to disable the temp cut off. If the motor can't stay below 230 degrees I don't want to risk damaging it. I started with a 15t pinion and got higher temps. That's when I went to the 14T. The first few packs of the day I can run for 10 minutes and and only get 160 degrees outside temp. As the day goes on the temps rise and by the 6th or 7th pack the motor is overheating. Could there be something inside the esc going on? Like some kind of resistance that is building up throughout the day? Thanks for the help guys!

Did you do a radio calibration?


Viper, picked up a VTX10 BE fro my B4.2. Run VTX10R BE in my other 2 trucks but want to keep my setup lighter on the B4.2. Running on med/good grip indoor clay, 81 spur, TrakPower 8.5 motor. 23-24 sound like a good starting point for my gearing?

anyone have a vtx8 esc setup sheet on website for e-truggy ?

RapidRC, turn the forward power down by 10. So if you have it set to 100, set it to 90. See if that makes a difference.

I think Bob posted some pages back about setting up the cut temp for the motor 10% at a time

VTX8
stock is 160 deg

today it was hot 94 deg at the track
Buggy is tekno eb48.2

first run 5 mins in 16t cut off at 160
2nd run changed it to 170 deg cut off Cut off 6 almost 7 mins in the run
3rd run changed it to 190 cut off Made it 7 min then dead

so I was like man what is going on.

The motor is tekin 2050kv on 4s

So do I turn off the motor cut off item? and hope i don't burn up the motor?

what are my opt. when its hot out?

I also, drilled holes in the body to get more air flow inside.
thnax

I ran one of these on my car too when it was hot out. You can see as much as a 35 degree drop (which is huge)

http://www.integy.com/st_prod.html?p...8#.Uiz0I8a1HEs

yes, you just adjust the temp cutoff temp until it says 'disable'.
thats my knowledge of the vtx10/R. don't know about the vtx8.

I have the eb48 and vtx8, I have my esc set to cutoff at 210, a temp gun will tell me its about 180 when it cuts off at 210.
that pinion seems a bit big, but all you can do is use the least amount of brake power and thicken the center diff up if it is revving out a lot..do whatever it takes to get rid of wheel spin..
I also prefer to use thermal conduct paste between the motor and mount instead of a heatsink.

I bought a VTX8 with a quick programmer about a month ago for my Tekno eb48 and before I purchased I messaged Viper about running with a 6 pole Tenshock 2150 x812.
They suggested I start with 40% punch because of the large amp draw.

I installed it with a Hitec HS-7955TG V2 Servo, Futaba receiver, 4s turnigy a-spec 150c 6200mah batts, 15t pinion also set the speedo to 40% punch 33% brake.
Went out and ran it for about 10 minutes hard on a parking lot while I kept checking the temps....Temp out at 180 after hard accel and braking.
I was extremely happy with it so smooth and loads of top end.
Turned it off and let it sit for about an hour then I go to the track and turned it on as I started to roll out it didn't move I gave it full throttle and it kinda started to roll. Then it started to go I thought ok a little glitch and here we go... nope I got scared... had no top end or torque and when I stopped it got all kinda stuttUTUTTER. It was super hot after a 60 sec run from all the stuttering....figure the sensor side burnt up. So I RMA it back to Viper Where it is now. Hope I get one back.

So I bought another one for my short course Tekno SCT410 to run with a Tekin 4300hd pro 4 pole with a Hitec HS-7955TG V2 Servo, Futaba receiver, turnigy a-spec 2s 150c 6200mah batt,

Guess what it ran the first day for about six hours of battery after battery man was I feeling good. Good temps smooth power no lag all good had the track all to myself too....awesome day thanks viper it was really a good day.

.......RACE day!.....
I went race and boom stutter........OMG I was like no way.....pulled off on the first qualifier and slowwly turned the first lap. I ran back to the pit to check the sensor wire push? tugged? pushed again...? Everything looked good nothing loose ? turned it on and boom all good.
Put it back on the track and completed two laps.
........ went out on the second qualifier.........
Scared.... drove around made it through the second qualifier and was ok got that over with whew!
......went out for the Third qualifier.....
And guess what stut stut stut all my friends are now sitting in the stands watching me walk the walk of shame down the stand to the end of the grid before the race to pick up my truck and check the sensor wire when one of my friends suggested I cap the bec. He had one handy we threw it in position 3 on the rcvr and boom I completed 2 laps with no problems other than now I am completely shook up. Qualified 8th out of 9!
....The Main......
So I run the main completly with no confidence and all over the place and finish 3rd LOL! beat 4th by .015 of a second. Didn't feel as good as I did on the other day, mixed emotions I guess......: eek:!

Whats the moral of the story I think the Viper BEC are weak and need a capacitor when you run powerful motors with powerful servos with powerful Batteries. By the way Turnigy nano-tech and A-SPEC batterries are full of C's.
Wish I had my other VTX8 back and could cap it and see if that fixes that one.
Hope this helps someone. ( I predict in 6 mos when 1/8 scale E Truggy kicks off someone will read this)
When the VTX8 is working it is awesome.
The 6 pole tenshock and this esc were like a 10th scale buggy.
Super smooth, like buttah, I think I could rock crawl with it!!

I think Viper is makin a quality product and really love the quality of the VTX8.
Mine does Temp out if I put the motor temp at 180 but when I temp it with two different temp guns they are no warmer than 160. right after it shows flashing snake eyes.

Good luck Viper I want a really cool Tshirt! and let me test any new stuff!!!
I like Viper!

VTX8 Stutters, VTX8 lags, VTX8 barely moves