Planning Xray XT8

[Jabe]

So i sold my Hyper ST and got Xray XT8, its not '09 but it will do it.
My plan is to keep weight in minimum as possible.
Something i have planned to use:
-RC-Monster 808 motormount (if it fits, just getting info about it)
-HPI Vorza battery tray for its adjustability
-Tekin RX8 and maeby buggy motor (i have plans to get Xray buggy and be able to swap electronics)
-mechanical brakes with miniservo

Cant deside about battery, should i use 4S or 6S and how big, atleast 15min.
Comments about choices??

[BL_RV0]

Mike has a XT8 mount.
http://www.rc-monster.com/proddetail...d=rcmxraymount

If you're trying to keep weight at a minimum, use the motor brakes, saves weight and rotating mass. Also get some lightweight tires. I'd say run 4s, but will this be a racer or a basher?

[Jabe]

Im aware of that XT8 mount, but id like to have that 808 mount if it can be used.
I want mechanical brakes to keep things cool, thats only thing that is against light weight policy.
Im building it as races but it will do both races and bashing.
Can you tell some lightweight tires? I have Xray originals and those weight less than Proline LPR tires.

[Marvin]

Are you sure the Xray Thrax weigh less? LPR tyres have more rim and less tyre than the Xray tyres. Rubber is more dense than plastic, so the Xrays should weigh more. You aren't comparing them to MT tyres are you?

[Jabe]

Xray Thrax, Xray original rim= 198g, Werks Lugs MT, Xray original rim= 200g, PL Bow-tie LPR, PL LPR rim= 225g

Any thoughts on motor, should i get ~35k rpm or ~40k rpm total?

[Dafni]

They may be light, but pretty useless on any surface I have ever tried. Something in the rubber compound they use.

35K rpm or less is fine for most new high-end motors.

Mikes 808 mount wont work on the XT8 or XB8. IIRC they are a bit taller than the old one. (The XB8 mount will work on an 808 with some spacers, but not the other way around) I guess that's why he did it when the 808 appeared, could have used the old one otherwise.

[Jabe]

I think ill go Tekin 1900kv buggy motor on 5S it makes ~35k rpm, since using 4S id get 40k rpm or 30k rpm on tekin buggy motors.
Or should i go with 30k rpm on 4S and gear higher?
Could someone that has 808 mount, get me these dimensions?

[jhautz]

If your going 5s on the XT8 and going with Tekin, get the truggy 1550 motor. Its all you could ever need on the track, drives great, gives awesome run time, and runs cool. I am assuming this will be for track use. If you want to just bash and want a little more edgy feeling setup you can go with the 1700kv truggy motor. Still a great raceable setup but much better suited to the heavier truggy than the 1900kv buggy motor.

EDIT:

Originally Posted by Jabe

I think ill go Tekin 1900kv buggy motor on 5S it makes ~35k rpm, since using 4S id get 40k rpm or 30k rpm on tekin buggy motors.
Or should i go with 30k rpm on 4S and gear higher?
Could someone that has 808 mount, get me these dimensions?

To run the 808 mount you would need to run a smaller spur. Its sized to work with the 42T center gear on the 808. The XT8 runs 48T. I had to shim the 808 mount up 2mm to run the 46T slipperential in it so you would have to shim it anothe mm or 2 beyond that to run the 48T center gear.

[Jabe]

I cant deside what motormount to use, obviously 808 wont fit, so which mount to use Tekno or RCM.
Both has up and down side, Tekno needs holes to chassis but centerdiff is easy to remove. RCM is bolt on solution but removing centerdiff is PITA.
All rcm mounts should be designed like 808, its great desing!

Or should i get RCM mount and try to mod it, so that it uses stock upper part?

[RC-Monster Mike]

The 808 style mounts are cool, but 3 pieces instead of one - means 3x as many operations to make them and 3x as many fixtures and 3x as long to machine. This is a lot of work - especially when you consider that removing the center diff on a 1 piece mount only requires removing 1 more screw than the 808 style mount requires - basically about 20 extra seconds?