Want to start a brushless speed demon.

[jayjay283]

Originally Posted by sharkattack99

so basicly i want a low kv motor like the tekin 1350kv and then play with gearing right?

not if your main goal is to hit 100 MPH unless you have $400 for lipos and want a heavy car. a 10k kv motor and 3s will get you there but it not going on the road you spoke of. If this is a real goal going 100 mph on $900 with a 4x4 or a truck maybe 4x2 you can do it... My Idea

emaxx lowered to ground scraping, monster mikes FLM diffs, 2 castle monster systems, a wing and a prayer and dont touch the steering

[snellemin]

Personally for speed runs, I like to keep my motor at around 50-60Krpm under load. So a lower kv and/or longer motor with more voltage(higher efficiency) would be able to handle a bigger load(gearing) to reach your top speeds. I suggest you get a datalogger to help reach your goal and not blow up stuff in the process.

Goofing off I keep motor rmps at around 30k or so.

[Rivermaxx]

Play around with the BrianG calculator and figure your optimum combination for the vehicle your going to use.

[sharkattack99]

well it really is a goal of mine but playing with some figures on the rc calculations site, just doing different combos with the 8th scale motors even on 6s i don't see them getting me to my goal, i don't even think they make that high of a pinion on some of the calculations i did, lol. guess it was a fools goal i guess.

[Rivermaxx]

Lower the spur gear tooth count raise the diff ratio if you can or raise the kv then run 8 or 10s lots of way to hit your goal just cost more money. I think the neu 1.5d 2650kv is the optimum engine for 6s at 59400 rpm on 6s 60000 is pushing the limit. I believe 25 tooth is the biggest rcmonster sells but there are other alternatives.

[sharkattack99]

were would i get a esc and motor that would handle an 8 or 10 lipo? well i found an esc that handles up to 10s theres one right here on rcmonster, but what about a motor that can handle that much power?

[TexasSP]

You can get one of the new phoenix ice or the phoenix HV110 and run up to 12s but will need an external bec (battery eliminator circuit, use mechanical brakes, and get a pistix adapter for your pistol grip radio to work.

[sharkattack99]

Originally Posted by TexasSP

You can get one of the new phoenix ice or the phoenix HV110 and run up to 12s but will need an external bec (battery eliminator circuit, use mechanical brakes, and get a pistix adapter for your pistol grip radio to work.

what is a pistix adapter? cool never thought about using airplane esc do you know of a motor i could use to go witht that esc cause im sure the mamba monster won't handle 12s?

[whitrzac]

Originally Posted by sharkattack99

what is a pistix adapter? cool never thought about using airplane esc do you know of a motor i could use to go witht that esc cause im sure the mamba monster won't handle 12s?

I'll take the leftover bits of whatever car you buy after you crash at 100mph...

driving that fast is a pain in the @$$ to keep it shiny side up and off of the curb...

your best bet is to get a HPI E-firstorm, drop in a MMM with a 9000kv on a 3s and have fun

FYI the motor "should" handle the RPM according to castle...

[sharkattack99]

[QUOTE=whitrzac;314749]I'll take the leftover bits of whatever car you buy after you crash at 100mph...QUOTE]

haha very funny,

i didn't see whether the motor is only limited to 25 volts is it? can i use that with a 12s pack, or do i still need to find a motor that can and says it can?

[TexasSP]

Realistically you have no idea what you are getting on too many levels.

I have rethought my suggestions and have two scenarios I will point you towards to get your feet wet.

A) Get the 1/16th BL Revo, a good 30c plus 3s lipo, some good street foams, and start there, get some extra bigger pinions and play with the speeds and get used to the idea

B) do the same but with a rustler VXL and a good 30c 5000mah 3s lipo and some street foams

I would stay off the rocks going over 50 mph period. Anything over that and it's smooth pavement only, I teel you thins from experience. Invest in either a small GPS or a radar gun so you know your true speeds. Also like snellemin said invest in an eagletree system so you can properly log what your system is doing.

Start this deal in baby steps and go from there. Who knows, you may get out there and get tired really quickly of speed, then you still at least have a good basher. You may love speed and go up from there but I think either of those is a logical scenario for you at this point.

If you start getting into a 12s system and all the needed accessories you will be over $1500.00 quick!

[Rivermaxx]

The motors are rpm limited usually up to 60,000 ( which is pushing it). kv of the motor your using x volt of the batts= rpm of the motor. example: So a neu 1.5d is 2700kv x 6s(22.2volt) = 59940 rpm.

[DwightSchrute]

I've gotten my losi 8ight to the mid 90's running a 1515 1.5D on 6S 30C lipos geared 43/25. I don't think a 2 speed is necessarily the way to go unless the 2nd gear is higher than any you can find in a single speed like most 1/8 buggies have. Mike's rcm mount is absolutely necessary for the 8ight as it allows for the biggest gearing.



I do use the losi rally tires, but sadly, they have been discontinued.



http://www.horizonhobby.com/Products...dID=LOSA17768B


there has been some rumor of them coming back, but nobody seems to know when or if it's true.

the part of Virginia i live in has alot of bad streets that never get cleaned from the winter's salt dumps. so running foams is not an option for me as all they do is slide. So now i have to go back to running buggy tires from ebay.

However, the good news is you can make virtually any pre-mount tire run the 100mph mark with the fishing line test method without them blowing.

OverRevo's fishing line technique is genius, but I do mine a little bit differently, but it works just the same. i don't cut the groove in the rubber. i just wrap the line around 3 times, in 3 different sections....each edge and the middle. i then tie it off and then put a drop of ca glue over the knot to keep it from un-tieing. incredible. it cuts down the ballooning by 80% imo. Technically i think it's even faster than the rally tires because the line does allow for a tiny bit of ballooning thus giving it a higher "theroritical" gearing due to the tire size increase.

i have tested every tire that the ebay store carries (i think) and my favorite for the street was the mohawks. i'm doing the same method with 4 rows of the braided line and they are rock solid.

i chose the mohawks for 2 reasons....they grip on everything and the tread pattern is very tall. (almost like the gladiators) This method will work as long as their is tread on the tire. after that, you'll have to cut grooves like OverRevo did.
I also glue beads of IC-2000 around the edges of the rim to meet the tire on both sides just to backup the factory gluing job.
this method has worked on every tire i own so far. i've tried it on the following:

1. crimefighters
2. mohawks
3. talons
4. HPI phaltliners
5. badlands
6. bowties

For my initial 90+mph test run I used the supra sales "crimefighter" style tires and used this for the re-enforcement...example:




it's Stren Sonic Braid fishing line. 65lb. I got it at Dick's sporting good store. it works AWSOME.

here's what it looks like done:




my next test to break the 100mph mark is to get a 1521 1D (2900KV) and run it on 5S with a custom made 30T pinion

[Rivermaxx]

Did you duct tape the inside of the tire too?

[DwightSchrute]

Originally Posted by Rivermaxx

Did you duct tape the inside of the tire too?

no, they came pre-glued.