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  1. #41
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    Mossie is right the merv is not really built for 60+ mph. It can be acieved but not safe at all. Adding a monster lx to a merv is almost insanity. Having a such big engine in a small car isnt really beneficial since weight doesnt affect speed, only acceleration, and a maxed out merv with big motor and lipos and aditional weight will be heavy anyway. The short wheelbase is not ideal either for stability I would guess.

    Put money in the right place, make a BB merv as it should be and it will probably be faster than the majority of RC out there anyways...

  2. #42
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    I agree even at 60 it's a job to keep it on the road..

  3. #43
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    Everyone gets so hyped over the 100 mph rustlers etc, that they want to put monster systems in all RCs. What they dont understand is that with more powerful systems and higher speeds, more problems occurs, not to speak about all the cash you need to spend. Many powerful builds fail because people dont have the stuff neccersarly to succed. Not only money but accecability to parts and good places to run.

  4. #44
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    Just because the speed calculator says a car can do over 70 does not mean it can.
    I found a long stretch up the canyon in Angeles crest in the mountains.have to get a pass to park first.
    Lowering it and foams w/drift gyro didn't solve my problem. Any little imperfection in the road and I mean little under hard throttle and it would still wheelie
    Last edited by 50togo; 06-28-2012 at 09:49 AM.

  5. #45
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    speed calculator is nice but theory and not pure real life stuff

    running real instead of theorie , you get point like whar surface , temperture outside , element like weather (wind)

    __________________

    also how much how much amp can you pull out the battery matters burst or constant , what kind of tires and how and how much resitance they have , but also element like euro dynamics are playing a roll in faster speed.
    why do you think formula one cars have such downforce and a rare shape ??

    on topic and to the point = from my own runs i know above 60+ which is insane fast for a merv is crazy and trust me its fighting to keep it on track and in a straight line


    i agree with TTThree = put money in a bigger and more steady thing then the Merv to do insane speed
    just think x-01 or even a stampede or Erbe would do the trick.
    dont get me wrong i like a merv much and addicted to speedruns but it has to end somewere with the little guy.
    just a little to smal wheel base and to light to do insane speed!
    but he 50 mph is qiut insane fun to for speedrunning and also bashing.

    and if you crash at that speed its not hard to repair
    did you ever see what happen if a X0-1 crashes , you got a lot more spare parts to get then

    also dont forget what a merv is build for original

    off road and bashing and not for hard surface and 100 mph
    Xtreme has no limiits

  6. #46
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    ok but my family owns a 1/4 mile drag strip that is practically perfect. ok so if i run a mmp esc what motor should i run? has anyone ever thought of carbon fiber rims with foam tires?
    Slash rocks!!!

  7. #47
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    Depends it u want higher rpm with less volts or more volts, also depends on how high u want to gear it..
    I'd recommend the 5700 or 4600kv. The higher the kv the less volts u need to reach top rpm, but u can't gear very high cause high kv motors will over heat fast.. Lower kv u may need more vorts but u can get same speeds with less heat and taller gearing..
    I run the 5700kv on 2s I tried a top speed not long ago geared 31/45 and rode behind it in a car, our speedodemeter said we was doin just over 60mph and I still had some throttle left, we had to slow down cause of a curve..
    A lot of people here don't believe me, but I have no reason to lie.
    Afterwards the motor was fairly cool.

    So think if I put it on 3s and of course I'd have to adjust gears a bit but it would get to 60 very fast..

    Lower kv = more volts + taller gearing for top speeds
    Higher kv = less volts - taller gearing (cause it'll get to hot) for top speed.

  8. #48
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    Having run both 4600 and 5700 motor there is VERY little difference between the two. You could say you can gear the 4600 or you could say you have to gear it higher and both would be true. At the end of the day both motors are going to be very close tot he same speed. Given your situation where you just want the fastest speed you can and have a 1;1 drag strip to use I would say go with the MMP with a 5700 on 3s, probably want two 3s packs in parallel. If you can find a way to keep the truck on the ground and going straight you will have the power you need to get he speed you want.

    I run the 5700kv on 2s I tried a top speed not long ago geared 31/45 and rode behind it in a car, our speedodemeter said we was doin just over 60mph and I still had some throttle left, we had to slow down cause of a curve..
    A lot of people here don't believe me, but I have no reason to lie.
    People dont believe you because those with experience know you cant go 60+ on 2s in a MERV. I am not saying you are lying, you may well have been seen 60 mph on the speed in the real car but there is no way a MERV on 2s was ever going 60 mph. A chase car is not a good way to clock a RC car. For the sake of other forum members I really wish you wold stop inferring your MERV can do 60 mph on 2s lipo.
    Last edited by Dadx2mj; 06-29-2012 at 05:15 PM.
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  9. #49
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    i can do 100 mph on 6s lipo :P

    cuz i'm a boss

  10. #50
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    Quote Originally Posted by Jhsmith1987 View Post
    Depends it u want higher rpm with less volts or more volts, also depends on how high u want to gear it..
    I'd recommend the 5700 or 4600kv. The higher the kv the less volts u need to reach top rpm, but u can't gear very high cause high kv motors will over heat fast.. Lower kv u may need more vorts but u can get same speeds with less heat and taller gearing..
    I run the 5700kv on 2s I tried a top speed not long ago geared 31/45 and rode behind it in a car, our speedodemeter said we was doin just over 60mph and I still had some throttle left, we had to slow down cause of a curve..
    A lot of people here don't believe me, but I have no reason to lie.
    Afterwards the motor was fairly cool.

    So think if I put it on 3s and of course I'd have to adjust gears a bit but it would get to 60 very fast..

    Lower kv = more volts + taller gearing for top speeds
    Higher kv = less volts - taller gearing (cause it'll get to hot) for top speed.
    weren't you running on the small road rage tires back then?max mph on speed calculator with 3.3" tires is 56.1 mph

  11. #51
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    looks pretty top heavy! hows it run on the straights?

  12. #52
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    i don't know
    just put it on to take few pics for fun. no sense of using it
    My mini E-Revo.net and the BIG ERevo.net

  13. #53
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    Well, maybe not that much custom work to make it fit :P. The question is if its really any point doing this? Whats the goal putting such a over powered motor in a lil merv? Judging by the picture the whole setup seem to be unusefull for speed running.

  14. #54
    RC Turnbuckle Jr. Petertje60's Avatar
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    I think that the 1/8 Tekin motor is still smaller than the Castle 2028 motor.
    It depends on what you define for 'fit', but I agree with The VXL.

    Edit: Just checked dimensions. The larger Tekin is a baby compared to the 2028 motor. The 2028 will reach up to the rear body mount. You will have to remove that to make it 'fit'.
    I put this under the category 'Fun to talk about, but completely useless'.

    It would show something like this:
    Last edited by Petertje60; 07-02-2012 at 01:55 AM.
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  15. #55
    RC Turnbuckle Jr. jimbo74's Avatar
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    but... since the center of the motor isnt directly over the driveshafts, it would sit on the right side more

  16. #56
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    wow, didn't noticed you're talking about big block for the big revo

    even if you will cut the rear body mount
    Shaft Size: 8mm 30mm long
    and even with custom motor mount for such long shaft, where will you find 48p pinion with 8mm inner diameter?
    Last edited by Evgen; 07-02-2012 at 06:27 AM.
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  17. #57
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    Ok. A little move to the right. Im too lazy to edit it so the suspension on the right hand side will be compressed more.
    Nobody is born with experience.

  18. #58
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    WHOOO thats no motor , thats a Soda can
    Xtreme has no limiits

  19. #59
    RC Turnbuckle Jr. Petertje60's Avatar
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    I had it in my hands a few months ago. The size is absolutely impressive. The only difference with a filled coke can is that it weighs a lot more.
    Nobody is born with experience.

  20. #60
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    Shoot ya'll, I can't hold down a stock Merv with a 3S in it before it goes out of range!

    Am I crazy or is this a little insane for a Merv?
    Merv: Neu, MMP

  21. #61
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    Quote Originally Posted by chilidillo View Post
    Shoot ya'll, I can't hold down a stock Merv with a 3S in it before it goes out of range!

    Am I crazy or is this a little insane for a Merv?
    Not only a little insane. It just wont fit, not even a little
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  22. #62
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    Quote Originally Posted by chilidillo View Post
    I can't hold down a stock Merv with a 3S
    stock motor is 4000kv
    11.1v*4000kv=44400rpm
    castle 2028 is only 780kv
    11.1v*780kv=8658rpm
    so it will be 5 times slower!
    even at 6s it's only 17316rpm (stock is 29600rpm at 2s)

    so, finally, there's no sense of using this

    that motor is made for moving something very heavy
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  23. #63
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    But it would handle like a 50 pinion and a 10 spur to make up for it. Yes I know it's not possible

  24. #64
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    Quote Originally Posted by ttThree View Post
    Mossie is right the merv is not really built for 60+ mph. It can be acieved but not safe at all. Adding a monster lx to a merv is almost insanity. Having a such big engine in a small car isnt really beneficial since weight doesnt affect speed, only acceleration, and a maxed out merv with big motor and lipos and aditional weight will be heavy anyway. The short wheelbase is not ideal either for stability I would guess.

    Put money in the right place, make a BB merv as it should be and it will probably be faster than the majority of RC out there anyways...
    ok but you guys are saying weight of bats and such well this motor makes a Baja 5t with the weight of lipos go 50+ the merv is way lighter so it will be faster
    Slash rocks!!!

  25. #65
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    We have said that the weight doesnt affect the top speed if you have enough motor and battery power. BB conversion is more than enough for the merv anyways.

  26. #66
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    Quote Originally Posted by ttThree View Post
    We have said that the weight doesnt affect the top speed if you have enough motor and battery power. BB conversion is more than enough for the merv anyways.
    What are you talking about weight does effect top speed. If a 25+lb Baja 5t run this system and goes 50+ mph and that hole system with batteries is35lbs and this system in a merv would weigh like 15lbs. That's less then half the weight. The motor either way can only get to a certain rpm but the merv with less weight will run faster because = power to less weight will be way faster.
    Slash rocks!!!

  27. #67
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    Quote Originally Posted by boston2612 View Post
    What are you talking about weight does effect top speed. If a 25+lb Baja 5t run this system and goes 50+ mph and that hole system with batteries is35lbs and this system in a merv would weigh like 15lbs. That's less then half the weight. The motor either way can only get to a certain rpm but the merv with less weight will run faster because = power to less weight will be way faster.
    Close but wrong, you said it yourself the motor is only going to get to a given RPM. With less weight it will get there faster or accelerate faster but in the end the top speed will be the same. With more weight it just takes longer to get to that top speed whatever it is.
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  28. #68
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    Depending on traction. If its much heavier but alot more powerful and you can put the power to the ground it will be quicker. Kind of like a small block muscle car and the same model with a big block motor but we know when it comes to the merv we are already past the limit!
    Last edited by 50togo; 07-06-2012 at 11:58 PM.

  29. #69
    RC Turnbuckle Jr. Petertje60's Avatar
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    Like Dad said, it's possibly accelerating faster, but for top speed less weight doesn't make a difference.
    Nobody is born with experience.

  30. #70
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    Yes but the motors rpm is a solid factor like say x amount of rpm unloaded on the motor right the same Xl motor in a Baja 5 and in the merv the Rpm's are the same UNLOADED. But loaded the Baja will have LESS because it's heavier. The merv will have more rpm because the motor will be less loaded.
    Slash rocks!!!

  31. #71
    RC Turnbuckle Jr. Petertje60's Avatar
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    Quote Originally Posted by boston2612 View Post
    Yes but the motors rpm is a solid factor like say x amount of rpm unloaded on the motor right the same Xl motor in a Baja 5 and in the merv the Rpm's are the same UNLOADED. But loaded the Baja will have LESS because it's heavier. The merv will have more rpm because the motor will be less loaded.
    And what produces load? The acceleration does. So when that decreases, the weight influence decreases too. Slower on heavier cars, but in the end it will make no difference anymore. It's just that you need more runway for heavier cars.

    Other differences are more resistance in the drive line or resistance from the tires on the ground. But those have nothing to do with weight directly.
    Nobody is born with experience.

  32. #72
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    Quote Originally Posted by Petertje60 View Post
    And what produces load? The acceleration does. So when that decreases, the weight influence decreases too. Slower on heavier cars, but in the end it will make no difference anymore. It's just that you need more runway for heavier cars.

    Other differences are more resistance in the drive line or resistance from the tires on the ground. But those have nothing to do with weight directly.
    How does acceleration produce load? The load on the motor is things like weight and tire dimensions, driveshaft resistance. Do
    Many factors. Acceleration isnt load on the motor.

    This is just how I understand it. Sorry if you don't agree with me. I don't want to start a fight or anything but I see it like that. Another example is my 1/10 velineon brushless system is faster in my merv with the same batteries and gearing as my slash. I just moved the system over and it's way faster in
    My merv.

    Quote Originally Posted by Evgen View Post
    stock motor is 4000kv
    11.1v*4000kv=44400rpm
    castle 2028 is only 780kv
    11.1v*780kv=8658rpm
    so it will be 5 times slower!
    even at 6s it's only 17316rpm (stock is 29600rpm at 2s)

    so, finally, there's no sense of using this

    that motor is made for moving something very heavy
    Ok but those numbers are unloaded rpm loaded the big motor will be faster
    Last edited by cooleocool; 07-08-2012 at 10:00 AM. Reason: post merge
    Slash rocks!!!

  33. #73
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    Quote Originally Posted by boston2612 View Post
    This is just how I understand it. Sorry if you don't agree with me. I don't want to start a fight or anything but I see it like that. Another example is my 1/10 velineon brushless system is faster in my merv with the same batteries and gearing as my slash. I just moved the system over and it's way faster in
    My merv.
    Have you measured the top speed with a gps device? Couldnt it be that the acceleration is slower in the slash due to the increased weight? Could it also be that the wheels are different size, or ballon different? It could be many factors. Also using merv sized batteries doesnt provide enough power to push a heavy vehicle like the slash.

    You say the gearing is the same, but how about the internal gear ratio in the slash compared to the merv? 30/60 gearing for example in one chassis does not give you the same final drive in another chassis with 30/60. Its more complex than just pinions and spurs (if thats how you measured it).

  34. #74
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    My uncle is a cop and we used his very accurate radar gun. The track we ran on was a quarter mile drag strip that my friend owns. We were taking out as many variables as possible.
    Slash rocks!!!

  35. #75
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    You only ran a 1/4 mile, maybe the slash needed more lenght to come up to speed, this could be the case because other members have mentioned that the slash need longer distance due to weight and aero. You are only talking about reaching a certan speed in a certan distance, that does not tell us anything about the final top speed of these vehicles.

    How about the other things imentioned:
    - Tires
    - Ballongnin
    - Internal gearing
    - Battery power (did you made both runs on 100% newly charged battery)
    - Aerodynamics

    You have one big flaw in your argument and that is your distance..you only proved that the merv can accelerate to a certan speed faster then the slash, which probably run out of space before it could hit its final top speed.

    Also what speed did the merv and slash hit? I would perfer a GPS device mounted.

  36. #76
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    if it can't reach top speed in a 1/4 mile i don't think it will go much faster

  37. #77
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    That could be the case, so we can eleminate that one.

    How about the rest of my questions then? Unanswered...

    Basicly it could be many reason the slash is slower then the merv, not just the weight.

  38. #78
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    Lot's of discussion and some cool pics here. How about some videos of these speeds in a merv?

  39. #79
    RC Turnbuckle Jr. Petertje60's Avatar
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    Acceleration is getting your car up to a higher speed. That change in speed needs power.
    Running at a constant speed only asks power to conquer rolling and drive line resistance and, on higher speeds, drag.

    On lower speeds, where drag doesnt play a serious role yet, the amount of power used to get your car to a higher speed, is way larger than what you need to conquer rolling and drive line resistance.
    So if a Baja and a Merv have the same base resistance (rolling and drive line), keeping it on a constant speed asks exactly the same amount of power on both cars.

    We are talking about kinetic energy of the car that is increased during acceleration. Since the formula for that energy is the half the mass multiplied by the square of the speed, the kinetic energy for a car that is 5 times heavier, is also 5 times bigger.
    So to produce 10mph more speed with a car that is 5 times heavier, you need 5 times as much energy.
    To produce that energy in the same time (which means the same acceleration), you need a motor that is 5 times more powerful. An other way to provide that increment is using the same motor power and take 5x the time (slower acceleration).

    So the difference in speed that you want, asks more power or more time, but that does not mean a less powerful motor is not able to deliver it.
    Last edited by Petertje60; 07-07-2012 at 11:38 PM.
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  40. #80
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    [QUOTE=DKO;5228093]Lot's of discussion and some cool pics here. How about some video. Video won't post
    Last edited by 50togo; 07-07-2012 at 11:43 PM.

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