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84.5mph X6 !!!!!!

tried & tested @ the weekend @ TRCC by Catch-Fire using the Mamba Max esc & 5700K motor geared on 28/81. Gear chart says it should run up to 84.5mph

tried 10 cells and suffered tyre delamination to the foam insert

then he went 12 cell an this happened, Adam's words via email,

Quote:

Big crash with X6 with 12 cells
Tire blow out and hit a curb everybody reckoned 60+

Cracked chassis
Smashed wishbone
Bent motor plate
Bent drive shaft
Not found anything else yet but I am sure I will do

Adam

Liam

you got any pics or video you can get of the camera ?

wooooooooooooooooooooooo.

This could be the fastest a buggy has ever been, the TC electric record is summat like 111m.p.h with a TC3. :D

Quote:

Originally Posted by chequred-flag.rc-products (Post 26952)

I have a 7200kv mamba motor, which is like 4t, you should try that for another few m.ph :D:D:D:D

Catch-Fire's got @ 7700KV but he had in the slower motor in from Sat night's racing

Put loads of lead in the front to keep it earth bound but the bloody thing still wanted to fly :mad:

We read this 1st from the Mamba Site

Quote:

Where are the “real” limits and what is the fastest?
In internal and beta testing, we were unable to find gearing options that would actually thermal the controller when used within spec:
Max input voltage for ESC: 3s lipo or 12 cell NiMH/NiCah
Max RPM for CM36s motors: 65,000 rpm
4600Kv motor max voltage: 4s
5700Kv motor max voltage: 3s
7700Kv motor max voltage: 2s
The Kv of a motor is the number of rpm’s it will turn per volt of input. So the 4600Kv motor will turn 4,600 rpm per volt of battery. On a 6 cell pack we can presume good cells are holding around 1v per cell, so 6v x 4600Kv = 27,600 motor rpm. If we use a 4s lipo pack, lipos carry about 3.5v per cell under load, so 3.5x 4 = 14v. And 14v x 4600Kv = 64,400 motor rpm . This is right at the top of the motor rpm limit and is OK, but is beyond the voltage limit spec of the ESC and cannot be used.
On the other hand, if we take a 3 cell lipo pack with the 7700Kv motor, that gives us 10.5v x 7700Kv = 80,850 motor rpm which is safe for the ESC, but well over the safe motor rpm limit so it cannot be used either.
So how can you get the most speed? You might think the 7700Kv motor having the highest Kv would automatically allow you to have the fastest setup right? Let’s find out:
7700Kv x 2 cell lipo voltage (max with this motor) = 53,900 motor rpm.
5700Kv x 3 cell lipo voltage (max for the motor and ESC) = 59,800 motor rpm
So the fastest 5700Kv motor setup is actually 6,000 motor rpm faster than the fastest allowable 7700Kv motor setup!
Now if you are racing with 6 cell packs only, then obviously the 7700Kv motor will be the fastest option for you, but we are routinely asked “what is the absolute fastest setup for my car/truck?” The answer in this case, is the 5700Kv motor with a high quality and high output 3 cell lipo pack made for 10th scale cars.
How fast will it actually go?
We are working on a speed chart, to show actual measured top speeds with 6 cells, 2s and 3s lipo packs in a variety of vehicles with “normal” or very conservative gearing. We have a confirmed measured speed of 62.4mph with a touring car on 3s lipo and the 5700 motor from one of our beta testers. From our best estimates, very near 60mph should be easily attainable in touring cars, as well as 2wd buggies and stadium trucks with the 5700 motor and 3s lipos.
On 6 cells:
4600 motor ~ 25mph
5700 motor ~ 35mph
7700 motor ~ 45mph
On 2s lipo:
4600 motor ~ 30mph
5700 motor ~ 40mph
7700 motor ~ 50mph
On 3s lipo:
4600 motor ~ 45mph
5700 motor ~ 60mph
Look for software updates with more tuning aids to totally dial in your Mamba Max for any driving situation being constantly added to our website, as well as additions to this tuning guide as we gather more user tips and experiences to pass along!
Now go pull the trigger and light em up!

If you want to do speed runs, then you have to belt the inside of the tyre, to try to reduce tyre growth, which is causing your blow out. Although theoreticaly you can acheive 84, the faster you go, the more exponential your problems arise.

Quote:

Originally Posted by chequred-flag.rc-products (Post 26963)

We read this 1st from the Mamba Site

Thanks for that I didn't know;)

That was a bit nuts like.

The second run with 10 cells was a bit mad, the road dried up, so he got it to about 2/3rds throttle, then full throttle and it would lift all four 4 wheels - only the wing was keeping it on the ground.

The next run was the 12 cell run, and it had rained - a LOT. Basically, it wouldn't wheelie any more, but on one blast up the road it did a Hammond, at easily over 55mph, and with it being wet Adam stood no chance at all at keeping it off the kerbs, it slid, hit the kerb and made a horrid noise! Quite suprised at the lack of damage really, on first sight I thought it had snapped into a few bits.

I have a video of it doing a run on my phone, and a photo of a U-shaped driveshaft. Bit crap though.

Quote:

Originally Posted by LiamD (Post 26992)

but on one blast up the road it did a Hammond, at easily over 55mph,

should have had a Hamster inside the shell :cool:
maybe next time:)

Quote:

Originally Posted by www.tyrc.co.uk (Post 26961)

I have a 7200kv mamba motor, which is like 4t,

Are you sure. I've got a LRP X11 5.5 that has 8100kv and is rated at a 7 turn.

Quote:

Originally Posted by LiamD (Post 26992)

would lift all four 4 wheels - only the wing was keeping it on the ground.

take off the wing....i want to see an X-6 fly :p

:D

He should try and put a big body on it off one of them big oval cars like the Assosiated L4 but bigger and nitro what are they called?

That would keep it on the ground.

A:rolleyes:

Quote:

Originally Posted by ashleyb4 (Post 27005)

He should try and put a big body on it off one of them big oval cars like the Assosiated L4 but bigger and nitro what are they called?

That would keep it on the ground.

A:rolleyes:

na,

put some wings on it...maybe a propeller...nd some rudders

fly like a plane

:D

Crazy! I like!

Is there going to be another attempt? Need a way of measuring the speed, how clear is the A33 at midnight, and Liam, would your Lupo keep up?? :confused:

Quote:

Originally Posted by Chrislong (Post 27008)

Crazy! I like!

Is there going to be another attempt? Need a way of measuring the speed, how clear is the A33 at midnight, and Liam, would your Lupo keep up?? :confused:

only just, if he puts it on charged 12 cell 42's :)

Quote:

Originally Posted by matt (Post 27002)

Are you sure. I've got a LRP X11 5.5 that has 8100kv and is rated at a 7 turn.

Mamba site says the following

Quote:

The 5700Kv motor is roughly equivalent in top speed to a very good 9t or 10t brushed motor on 6 cells

6900Kv = This motor is best compared to a 6T brushed motor

The 7700Kv motor is roughly equivalent in top speed to a very good 5t to 7t brushed motor on 6 cells

video it and send it in to topgear, lol.

this sounds amazing tho, id love to try this with my academy that is sitting to be sold, cos i dont like it nd have enough spares to repair it without money, but i dont hav a brushless fast enough [i have a nosram 6.5 storm evolution], i would even try wings for the guys who want the laugh.

anyways, whens next run?? or isnt there one?

but seriously, i never actually realised how quick these mamba brushless' are so quick though! you should maybe try jumping a house, ive seen it on a video on the internet of a nitro doing it, and it survived, no breakage, the only thing was the shell came off on landing. :o :p

welldone tho sounds amazing

I got invited to do this afew years ago with a pan car. Me and my Dad recieved a AE pan car, put an airplane brushless in it( this was before brushless) numerous cells and we went through so many tyres to try and make it grip on the cycle dome in Manchester. We had a lazer to count the average on the lap and it took a while to get it up to speed. I had a problem with the car falling down on the steep banks of the corners. The first lap I managed to get it completly airborn off the lazers cover, go up turn 1, half into the crowd and the other half ended up in turn 3. I eventualy got it up to 79mph which felt bludy fast. I did take my Traxxas at the time which got about 50mph on brushed. Would love to have a go at the insane speed run which I think is now about 130.

Quote:

Originally Posted by mattym0310 (Post 27023)

anyways, whens next run?? or isnt there one?

after a major rebuild of the car, driver & owner 'Hamster Catch-Fire' nas recovered enough & is brave enough for another attempt @ a secret location :)

Quote:

X6 now has proper foam rear tyres made from 8th scale tyres removed from the ring using a special technique.

bring on wednesday night

weather permitting or not he'll be on it:p

forecast is promising http://www.bbc.co.uk/weather/5day.shtml?id=3782