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-   -   Want to start a brushless speed demon. (https://www.rc-monster.com/forum/showthread.php?t=23075)

snellemin 08.19.2009 11:21 PM

4000kv on 4S is the highest I would go in a GTP and the Tekin ESC handles it just fine. You would be able to push it harder with a high amp MGM ESC that Monster Mike sells.

Rivermaxx 08.20.2009 12:54 AM

Quote:

Originally Posted by brushlessboy16 (Post 314396)
taped HPI phatlines.

as for gearing, you might want to consider talking to mike- he might send you an rc-monster banner and some pinions :)




As for Shark.. your best bet is to find an 8th scale buggy... relatively durable (nothing is durable at over 50) and just work your way up from there

get a baseline setup for 60-70ish then work from there.


and make sure your tires are balanced or they will rattle the car to shreds.

Taped phaltlines are only good to about 75mph after that you need to glue 40# test carbon fiber thread fishing line on the out side of the tire. Custom foam tire on new pro-line vtr wheels is what I need. I sent mike a email telling him what I am planning I dont want any handouts but It would be nice if I could get a custom center diff out of him. If I break a record with his parts it could be good for business. A nice banner on my fifth wheel at the event. Magazine are going to cover it also. But if he is to busy to even answer my email maybe he doesnt need the extra business.

sharkattack99 08.20.2009 01:08 AM

Quote:

Originally Posted by brushlessboy16 (Post 314421)
high kv equals bad


Low kv and more voltage.


and you should really look for a smoother test location. blacktop is best.

so this would be better? http://www.amainhobbies.com/product_...r-Combo-1350kV

then gear higher as i want to go faster low spur and high pinion right for gearing up, still not really understanding this gear up or down stuff. what do you up or down?


why do you glue fishing line around the ouside of the tire, the part of the tire that touches the road or were the wheel and tire meet?

jayjay283 08.20.2009 01:14 AM

I used motorcycle twist line.. what do they call it ? you know how you have to drill a hole through every bolt and nut and wratchet thin metal wire to keep them from falling apart to race on a track? I had my buddy twist that around my wheels back in 1995 (before i knew about taping or cared) 55 mph old ofna gtp nitro and it handled so well keeping the center of the tire stuck and sparked the whole time ( 2 bands on each side of the center line) poor mans double radial.. just a thought


it only really sparks at the bowtie knot that you have to tuck in ..its really sounding like a good idea, but im drunk

speedracer1129 08.20.2009 01:35 AM

Quote:

Originally Posted by snellemin (Post 314423)
4000kv on 4S is the highest I would go in a GTP and the Tekin ESC handles it just fine. You would be able to push it harder with a high amp MGM ESC that Monster Mike sells.

4S will work for a 1/10, but 1/10 involves alot of setup work to get it right AND stay on the ground at those speeds.

For an 1/8, you need to be at a minimum of 6S to even have a shot!!! I have personally done 80+ on a LOSI 8T running a 5S, 3500kv setup but it is a 1-2 pass wonder!!

If you want my opinion, and don't take it personal, it sounds like you do not really have a clue of how an RC reacts at the speeds you may have seen on videos or anywhere else. I suggest you get yourself a decent 1/10 sedan that you can get ALOT of parts for, drop in a Mamba 6900 or 7700 on 3S (yes it can take it!!), and get back to us after several flips, broken diffs, and a whole lot of headaches!!! THEN you will have a very small idea of what it will take to build a 100+ car.

I speak from personal experience and I can say that all the fun is trying to get there. I am sure that everyone here including myself are willing to help you out in any way we can, but I definately suggest you try something like what I described above to get your feet wet so you can really see if you want to embark on the wonderful quest of the ever elusive 100 MPH!!!:yes:

Ryu James 08.20.2009 03:23 AM

how comfortable are you doing custom work? if you want off road and 100mph here is what i would do.

losi 8t 2.0 Tekno brushless chassis and conversion kit with 44mm mount

losi 8b 2.0 buggy a-arms front and rear. put the buggy a-arms and CVDs on the truggy chassis so you have a very long but narrow and low off road car. (RCM member has done this)

also, you will need to run those GP rally 1/8 tires cuz buggy tires will just come apart. my losi brushless 8 2.0 clocked at 56mph and 3 sets of tires were destroyed just to hit that. both AKA and proline sets. 100mph is a lot tougher than you think just a heads up.

anyway, in the motor dept. i would run a Neu 1521 1.5d F on 6s lipo with 35c 5000mah rating. the MMM should be fine for the esc.

then for gearing take the 2 speed center diff from the inferno GT and mount the inferno gt center diff mount to your losi chassis. now you have a 2 spd. get the 2spd pinion from RCM with the tallest gearing possible and you should be good to go. even doing all this you will be very hard pressed to hit 100mph. youll have to make adjustments to the body or a custom body to avoid flight. also many other unforeseen challenges will occur i promise you.

i would probably even use the inferno gt shocks and mount them on the losi for super low cg. so all in all it wont really be off-road.

really what you are asking for is impossible. a 100mph speed runner on one hand and a daily backyard off road basher on the other?? aint gonna happen. even at the World RC Speed Record races where people dedicated to RC speed come from all over the world there are dozens that show up but you can count on one hand how many break 100mph. and that is in perfect conditions and a prefectly smooth drag strip.

but if i was going for 100mph what i mentioned above is how i would do it if i wanted to do it cheap and just try it. good luck!!

Rivermaxx 08.20.2009 09:52 AM

The biggest problem is the tires at least that the issue I am having. I know that any stock mt rubber with internal foam donut tire wont last past 80mph. So basically thats your brick wall. The carbon fiber thread is glued on the outside of the tire and duct tape on the inside on the hpi phaltlines.Heres a pic: These are pics of OverevO's 91,2 mph brushless revo tires.
http://i153.photobucket.com/albums/s...x/P1040292.jpg
These are good for at least 90mph. At 100 they might explode because it hasnt been done yet.

B4maz 08.20.2009 10:35 AM

Brian Sigsworth has gone 105mph in a 1/8 OFNA GT2

http://fastestrc.blogspot.com/search.../1%2F8%20scale

http://1.bp.blogspot.com/_3N0hwXEVK9...nap-309426.png

Joe Ford has gone very fast in his Inferno GT2

http://fastestrc.blogspot.com/search/label/joe%20ford

http://1.bp.blogspot.com/_3N0hwXEVK9...16_vMedium.jpg

This was Joe's goal:

Quote:

I started out wanting to have an r/c car that would come close to 100...what I ended up with is one that is WELL capable of much more than that. I teamed up with Kyosho, RC Monster, Hitec, and CheapBatteryPacks.com to come up with one MONSTER of an electric conversion. The stock vehicle ran very well, great engine compression, handled well...just needed e-power, more speed, and it had to be worthy of the Castle name that would be going on it.

Hitec donated some of their 5645MG servos for the steering and brake/throttle control. More than enough torque, and are super smooth!

RC Monster Mike donated a conversion kit for the GT2 that keeps the 2 speed transmission as well as the mechanical brake. The parts are of the HIGHEST quality! He also sent me out THE largest pinion I have EVER seen...at first glance you almost think the pinion is the spur!!! It was rather tedious to install since the gear closest to the motor mount blocked access to the hex head motor mount screws. After removing the center diff, adjusting the motor mount position, and putting it all back in place over and over we FINALLY got it to mesh PEFECTLY!!!

CheapBatteryPacks was kind enough to offer up one of the 6s 5300 30C lipos for juice. This pack has TONS of punch, and handles the current VERY well. After a nearly full run the pack was barely warm! Can't wait to try some of their new 5000mah 35C cells in there!

My employer, Castle Creations donated our 2200kv Monster Max combo for the project. With a motor based on Steve Neu's 1515/1Y motor (arguably the best motor manufacturer in the world), I knew I could expect some serious power, but was surprised at just how much I got. With the gearing I am running and current it is drawing the motor does need some time to cool down between runs (but it's ok...so do my nerves!). If I can get a handle on all the power the 2200kv system provides I'll be going up to the 2650kv motor with the same battery and gearing. It's currently geared for about 140mph, the 2650 would take it up to about 170mph according to Mike @ RCM.

The whole conversion process took approximately 2-3 hours max from start to finish. Very easy to do...especially with the assistance of this vid, and any of you speed demons out there that are looking to break 100mph without spending any more than you would on any other 1/8th scale e-conversion, I STRONGLY suggest you give the Inferno GT2 e-conversion a try.

LOTS more work to do on the vehicle to get it more stable at high speed, but I'm confident we'll overcome that soon. Keep your eyes peeled for update videos!!!!!!!!!
This is what Joe said about his setup:

Quote:

Car is a Kyosho Inferno GT2, 2 speed tranny still in it, RC Monster conversion kit with special high speed pinion (dang near as large as the spur gears), 6s lipo, Monster Max 2200. Not sure how fast she's going, but it's not too shabby.
I have gone 83 mph in an OFNA GT2 with a Neu 2215 on 8s. (but that is a very expensive setup). http://fastrc.blogspot.com/2008/06/t...ay-83-mph.html

I would go with:

OFNA GT2 - $190 (http://www3.towerhobbies.com/cgi-bin...?&I=LXTCJ1&P=7)
RC Monster Motor mount
Castle Creations 2200kv/Mamba Monster combo - $300 (http://www3.towerhobbies.com/cgi-bin...&I=LXVHA5&P=ML)
Thunder Power 6s 30c li-po ~ $225 (http://www.rctoys.com/rc-products-ca...BATTERIES.html)
Large pinion (22t+)

Rivermaxx 08.20.2009 11:42 AM

Thats fast but that car in the isc event would be put in open class which it wouldnt have a chance doing those speeds. Currently 161mph is the record. I personally think a open wheeled revo doing 91 is more impressive then an on road car doing 105.Two different classes anyway so it doesnt matter.

nitrostarter 08.20.2009 11:56 AM

Quote:

Originally Posted by B4maz (Post 314524)


I have seen this car in person and have personally seen it run. Its amazing actually! He's doing it on a fat 4s MaxCramps pack, 1515 motor, and a huge pinion. Not a bad setup! Looks great as well!

snellemin 08.20.2009 11:57 AM

I've used 1400kv, 2000kv, 2700kv, 3000kv and 4000kv in a GTP and all are fast setups. The 4000kv setup is the easiest to learn how to handle high speeds in a 1/8 car within 250 feet of space. This space includes braking distance.

sharkattack99 08.20.2009 04:03 PM

Quote:

Originally Posted by Rivermaxx (Post 314512)
The biggest problem is the tires at least that the issue I am having. I know that any stock mt rubber with internal foam donut tire wont last past 80mph. So basically thats your brick wall. The carbon fiber thread is glued on the outside of the tire and duct tape on the inside on the hpi phaltlines.Heres a pic: These are pics of OverevO's 91,2 mph brushless revo tires.
http://i153.photobucket.com/albums/s...x/P1040292.jpg
These are good for at least 90mph. At 100 they might explode because it hasnt been done yet.

so glueing fishing wire around the tire helps with ballooning?

just out of curiosity, what if i hooked up a 3s 5000 and a 4s 5000 both 30c in series for a total of 25.9 volts, now the castle creations esc is rated for 25 volts could it handle the extra .9 volts. would it do some serious damage or just get really really really hot and would have to let it cool for like hours between each run? just curious

brushlessboy16 08.20.2009 04:05 PM

your forgetting that that is nominal voltage

when fully charged a 3s pack is 12.6 and 4s is 16.8

totalling 29.4

and thats not fishing line- its carbon fiber twine...

BrianG 08.20.2009 04:30 PM

^ +1. Also, there is a TVS device in the MMM which is designed to help clamp the voltage (during braking) to something around 28v IIRC. So, 7s lipo will likely blow that device and it will no longer help prevent voltage spikes.

sharkattack99 08.20.2009 05:20 PM

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


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