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  1. #1
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    Acceleration help/my day at the track was terrible.

    I went to the local track over the weekend. Well they changed it from a high speed, to a lower speed and tight layout. My 2wd with 7cell nimh, Titan motor and stock gearing did fine on the bigger layout. On the tighter layout I couldnt clear any of the doubles, I was constantly coming up short.

    I was wondering if switching to Lipo 2S batteries would give me the "punch" I need to get over these jumps. I wasnt missing by much. It is my understanding that the stock vx 5 ESC and the titan can handle 2S Lipo. Is this correct?

    I know I will also be switching to some clay specific tires so this should help too.

    Before anyone says "just go brushless", I just dont have the funds for it at this time.

    Thanks in advance for any advice,
    Rich

  2. #2
    RC Turnbuckle Jr. kdvanb's Avatar
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    Gear it 16/90 and if you can go lipo you can go brushless.
    My budget choice would be a sidewinder sct combo..
    Slash 2wd, Slash 4x4, 30th digger, Rustler VXL

  3. #3
    RC Turnbuckle Jr. 08kgraves's Avatar
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    not sure if it comes with one on that esc so you may have to add a low voltage detection possibly. and heres my question.... can your car get going fast enough to clear them if you had a longer runway? or is it just to slow at full speed to clear them even?
    because if you can clear them at full speed the biggest thing i can say right now is play with the gearing.
    there's no life like a LOW LIFE!
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  4. #4
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    Yes a 2s will help "punch" and would go good with any future brushless upgrade. Just make sure the xl5 has lvc or you can buy a alarm that plugs into the balance plug for dirt cheap.

  5. #5
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    I was thinking about trying that gearing setup.
    Yes the xl5 has the lvc that is to bu used if you are running lipo's.
    Yes, if I had more of a run way I could clear them easily.

    Speaking of the lipos, I saw some really cheap ones on Hobby Partz & Hobby King. Are you guys familiar with these?

    Thanks for the advice.

  6. #6
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    I used gens ace on a brushed set up, It was fine but ended up going brushless soon after.

  7. #7
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    I use the ones from hobby king no problems I hear that hobby partz is the same just as good. So which ever is on sale. Just don't get the black B grade from hobby king they even say in the description that they are only good for 60 cycles.

  8. #8
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    Love my hobby king packs. What a deal they are. A couple of cheap things you'll need to keep your lipos in top shape: Make sure you balance them EVERY charge. If you don't have a balance charger just order a Blinky Balancer ($10.00-$20.00). You will also want to spend the $6.00 on a low voltage alarm, this is for redundancy in case the internal one fails on your ESC (Even my VXL3S has not been completely accurate all the time when it comes to the low voltage cutoff.) Trust me, its worth it when it saves your new $40 lipo pack from overdischarging when your XL-5 doesn't shut it down quick enough-it happens to me sometimes. Get one with a built in volt meter and you will love how you're now able to see exactly how much charge is left. One like this:http://www.amazon.com/Battery-Tester.../dp/B005GJCJOA
    Last edited by lemansfanatic; 11-06-2012 at 06:05 PM.

  9. #9
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    I have a Primal charger that has the balance port/plug on it. From what I am reading i should charge at 1C which is 3.8 A. My charger does 1-4 A, so I would be ok charging at 3 amps and that would still be below the recommended charge rate.

    Just trying to not damage these new batteries I bought today.

    Also, my charger does not discharge. And it doesnt have a "storage" function for lipo's. Should I just get a new charger or are there other devices out there that will do this for me.

    BTW, I also picked up some spurs and pinions and a new set of tires, and a temp guage. This weekend is going to be test and tune at the track.

    lemansfanatic- are you saying that at times the stock esc will not detect the drop in voltage and fry your battery? How do you wire that device to your vehicle? I am not much of an electrician.

    I will make it over that double sooner or later.

    Thanks for the help guys.

  10. #10
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    I always charge at 1C, some people tell you you can do 2C, which you can, but I still just do 1C. My charger also doesn't have a discharger, so I use the volt meter to get the battery into a storage range (people will tell you different levels to store your lipos at, because it depends on how long you will be storing them. Basically, you don't want your pack to EVER go below 80% charge or 3.0 amps per cell or you risk overdischarging your cells. WHen your low voltage cutoff kicks in, you should be right around the 3.5 level, but if you were to store it at that level you could risk the cells self-discharging even further and damaging them. So what I do is after my LVC shuts it down (and yes it will go slightly past 3.5 amps sometimes hence my need for an additional low voltage alarm which to install you simply plug into the balance port on the battery itself...), I put it back on the charger until it gets to around 3.7 per cell, then I know I won't have to worry about it overdischarging past a safe level. Lipos require a lot of delicate handling and care, but they will reward you with the kind of power to weight ratio that NIMHs can't match, with waaaay longer runtimes = more fun! Just don't downplay lipo safety either, those things can be dangerous if not handled properly. I keep mine in Lipo flame-proof bags, and then put those bags in a ceramic flower pot (can't be too careful with your family) Anyways, heres the website for anything you ever wanted to know about LIPO batteries.
    http://www.rchelicopterfun.com/rc-lipo-batteries.html
    Last edited by lemansfanatic; 11-06-2012 at 07:46 PM.

  11. #11
    RC Turnbuckle Jr. 08kgraves's Avatar
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    i dont think storage mode will matter as long as you cycle the packs regularly. how often im not sure. as for discharge mode...... just go run the car lol. but your safe to charge up to 3.8A if your charger does it. if not then anything lower will not hurt at all. just take longer. anew charger is ideal. i recomend saving some money and just getting a really good one that will do a minimum of 2 batteries at once.
    there's no life like a LOW LIFE!
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  12. #12
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    Thanks guys. Looks like I have some reading to do.
    I just bought the batteries today and I wont be running the truck till Saturday so I will prolly just charge them up on Friday night at a safe 1C(3A).

    I bought a used Slash from CL it is the AM transmitter one with the big antenna. It has the XL5 esc in it, but in the owners manual that came with it it makes no mention of how to get the esc into lipo friendly mode. If I follow the directions from my 2.4 Slash will the AM slash allow lipos too?

    Sorry for so many dang question. I just dont want to fry something. I do have a request into the lhs for them to get me a 2.4 rig for the older Slash and I will trade in $$ the old components. He said I just need to hand over the transmitter and reciever so I am assuming(I hate that word) that the old XL5 is lipo capable.

    Thoughts?

  13. #13
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    if it has the 27 mhz radio i dont think the esc is lipo compatible. only the newer slashs are lipo compatiable on the stock brushed system.

  14. #14
    RC Turnbuckle Jr. rag6's Avatar
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    The esc will have a black label(blue esc) if it is lipo campatible...

    EDIT: If running the stock tires on clay, loss of traction may be a big issue... Are you running the same tires as the faster trucks?
    Last edited by rag6; 11-06-2012 at 11:12 PM.
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  15. #15
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    If it does not say lvc with the black label you can still run lipo you just need a alarm to keep from over discharging the pack.

  16. #16
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    I will have to check when I get home but i am pretty sure the esc looks exactly like the one on the 2.4. They are both blue, woth say "waterproof" .

    The one differnce I notice is that when I have the 2.4 turned on the light glows red. When I have the AM one turned on it is green.

  17. #17
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    If it is glowing green that means it is in lipo mode or it does not have lvc. I would bet it doesn't have it.

  18. #18
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    I will have to read the manual closer when I get home tonight.

  19. #19
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    OK. So looking closer at the two esc's I did see a difference.
    On the AM truck the words TRAXXAS Waterproof are on a white background.
    On the 2.4 truck the words Traxxas Waterproof are on a black background.

    Other than that they look identical, neither one has the lvc on it. But the manual for the 2.4 talks about lipos and such. The AM manual doesnt even mention lipos.

    So the question remains, can I use lipos on the AM truck?

    Thanks.

  20. #20
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    http://traxxas.com/support/Traxxas-S...-Detection-LVD

    According to this article, if "TRAXXAS Waterproof" is on a white background, then you do NOT have low voltage detection and you'll need to find some other way to watch for low voltage.

    If you're not able to get up enough steam before hitting the jumps on a tight track, gear down a bit and see if you can get some extra acceleration off the corner. You may get your extra speed you need.

  21. #21
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    Thanks for clearing that up for me PushRod, I appreciate it.

  22. #22
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    Don't forget a lipo sack, safety first.
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  23. #23
    RC Turnbuckle Jr. harry697's Avatar
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    Quote Originally Posted by trashyrich View Post
    I went to the local track over the weekend. Well they changed it from a high speed, to a lower speed and tight layout. My 2wd with 7cell nimh, Titan motor and stock gearing did fine on the bigger layout. On the tighter layout I couldnt clear any of the doubles, I was constantly coming up short.

    I was wondering if switching to Lipo 2S batteries would give me the "punch" I need to get over these jumps. I wasnt missing by much. It is my understanding that the stock vx 5 ESC and the titan can handle 2S Lipo. Is this correct?

    I know I will also be switching to some clay specific tires so this should help too.

    Before anyone says "just go brushless", I just dont have the funds for it at this time.

    Thanks in advance for any advice,
    Rich
    Chances are, just switching to a good lipo will make the difference between casing the jumps or clearing them. I'm guessing you're running the Traxxas or other un-matched nimh pack? A 2S will give you some extra punch, but the even bigger advantage is that it weighs considerably less. As long as you don't lose too much traction from the weight loss, you should be able to clear everything with just a good 2S pack. If you still need a little more help, either try dropping a tooth or two on the pinion and get yourself a good set of tires on the rear at least.

  24. #24
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    Trashy,
    Your ESC is a non LVC model. So running a LiPo will require addition of a LVC warning system, there are a couple out there, very easy add.
    Regarding your main question: Yes the LiPo will improve low end acceleration, it increases the available current which equates to more torque. If the track has tightened up, you can make a gear change and improve acceleration as well. Drop the pinion 2 teeth from where you are now and see what you get. I imagine once you make these changes you may find that some attention to tire traction will be required. That is usually surface specific, so look what the leaders are running and copy them.

  25. #25
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    First off I want to say THANKS for all of the input. I really appreciate it.

    I bought a bunch of stuff at the lhs this week and will try it out tomorrow
    My plan of attack for tomorrow.
    Stock 2.4 Slash is going on lipo. See if I can clear those doubles
    Then gears, bought a bunch of gears to try on the 2.4 & the AM truck.
    Also bought a set of tires( I have been running the stock BF Goodrich) I am really looking forward to trying these on both the trucks.
    Wish me luck. I dont mind being the slowest guy out there, just means I have to marshall a lot.

    Thanks again.
    Rich

  26. #26
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    I run an ESC that I know has a LVC, and I still use a low voltage alarm, you can't be too careful. (They're only 3 bucks)

  27. #27
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    Well this weekend was much better. I put the 2s lipo in and i really noticed a difference. Then the gears went in 16/90. I could tell it was quicker when I hit the gas and boy did it hurt it in the long straight away. Then I put on some Duratrax Line-Ups. THe tires helped a bunch. ]

    Now I just have to become a better driver. The big double still eludes me. But as long as I have a good line I am able to clear everything else.

    Thanks again for all the input. YOu guys have helped a lot.

    PS, yes, I got a lipo sack.

    Question: I ran both batteries down to where the esc started to slow blink red, Is it ok to store the batteries in this condition? My charger doesnt tell me when they are at the storage voltage and I dont have a volt meter.

    Thanks,
    Rich

  28. #28
    RC Turnbuckle Jr. kdvanb's Avatar
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  29. #29
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    Radiant Primal.

  30. #30
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    Quote Originally Posted by trashyrich View Post
    Well this weekend was much better. I put the 2s lipo in and i really noticed a difference. Then the gears went in 16/90. I could tell it was quicker when I hit the gas and boy did it hurt it in the long straight away. Then I put on some Duratrax Line-Ups. THe tires helped a bunch. ]

    Now I just have to become a better driver. The big double still eludes me. But as long as I have a good line I am able to clear everything else.

    Thanks again for all the input. YOu guys have helped a lot.

    PS, yes, I got a lipo sack.

    Question: I ran both batteries down to where the esc started to slow blink red, Is it ok to store the batteries in this condition? My charger doesnt tell me when they are at the storage voltage and I dont have a volt meter.

    Thanks,
    Rich
    Depends on what voltage level they are at, hence the need for a cheap voltage meter.

  31. #31
    RC Turnbuckle Jr. harry697's Avatar
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    Quote Originally Posted by trashyrich View Post

    Question: I ran both batteries down to where the esc started to slow blink red, Is it ok to store the batteries in this condition? My charger doesnt tell me when they are at the storage voltage and I dont have a volt meter.
    If the LVC kicked in, chances are they're below storage voltage. Without knowing what the cell voltages are, I would throw it on the charger for at least 10 minutes to bring the voltage up a bit, just to be on the safe side.

  32. #32
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    I bought a Hyperion ESO Sentry today and put the packs on it. They were both right around 3.6. So they say to let lipos sit at half there votage so I should be ok. I also use it to balance the packs I got them down to .08 between each other on each battery.

    I bought a 13 tooth pinion hoping for better acceration. However the pinion seems to have square cut teeth and the Traxxas spur is pyramid cut(sorry if I am using the wrong terminology) I am thinking they gave me the wrong pinion.
    they wont even match up on my workbench so I will be taking the pinion back.

    I know sooner or later I will be going brushless. But it is a lot of fun to be under powered on this track an beating the guys on the twistys, only to lose to them on the long straght away . They wreck all the time.

    Just sayin'

    Any advice? will 90 spur + 13 pinion give me the UPPHF I am looking for? I am pretty much stupid when it comes with gearing. I was using a 16 pinion and it seemed to help , so i am looking forward to trying the 13.

    Thanks in advance.

  33. #33
    RC Turnbuckle Jr. rag6's Avatar
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    You picked up a quality battery checker, and can be sure it will be accurate. Good job. Get those packs up to 3.8 for storage. It could be at 20% charge at 3.6, and 60% at 3.9. I love my Hyperion charger .

    Any one with a cheap china charger or a clone, should pick up one of these checkers.
    Last edited by rag6; 11-13-2012 at 07:28 PM.
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  34. #34
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    rag6,
    They are only going to sit for a week. Does it make a huge difference between 3.8 & 3.6?

    I just ordered the MaxAmps low voltage alarm to put on the truck.

    Do you have any advice concerning:

    I bought a 13 tooth pinion hoping for better acceration. However the pinion seems to have square cut teeth and the Traxxas spur is pyramid cut(sorry if I am using the wrong terminology) I am thinking they gave me the wrong pinion.
    they wont even match up on my workbench so I will be taking the pinion back.

    Thanks,
    Rich

  35. #35
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    Bump to rag6

  36. #36
    RC Turnbuckle Jr. 08kgraves's Avatar
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    they probably gave you a 32 pitch when yours stock is 48 pitch. the 32 is much stronger, so if you have funds just swap over the other gear to match it instead. thats an option atleast. i just run the 48p myself though............. for now lol
    there's no life like a LOW LIFE!
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  37. #37
    RC Turnbuckle Jr. rag6's Avatar
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    Quote Originally Posted by trashyrich View Post
    rag6,
    They are only going to sit for a week. Does it make a huge difference between 3.8 & 3.6?

    I just ordered the MaxAmps low voltage alarm to put on the truck.

    Do you have any advice concerning:

    I bought a 13 tooth pinion hoping for better acceration. However the pinion seems to have square cut teeth and the Traxxas spur is pyramid cut(sorry if I am using the wrong terminology) I am thinking they gave me the wrong pinion.
    they wont even match up on my workbench so I will be taking the pinion back.

    Thanks,
    Rich
    You should follow what the battery suppliers instructions say. My packs are all from the same company, and they want the packs to be put to storage voltage within 24 hrs. Other companies may say something different. It would be best to contact the battery supplier if you cannot find the original instructions that came with it.

    If your 13t pinion does not seem to match up with the spur, it could be that you picked up a mod1 pinion, which has teeth slightly bigger than the mod .8(32p) gears. Not sure if the mod1's have square cut gears. I like the 5mm losi 32p steel pinions.
    Wanna bash at Greenwood Bashplex in Pittsburgh ???

  38. #38
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    rag6,
    Yea, not sure if it was 32P or a mod1 gear. I got a 14T and tried that . It had quite a bit more punch, but really slow on the straight.

    I think I am going to stick with the 16T for the time being and just learn to become a better driver.

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