1LikesHot Bodies D812
07-22-2013, 10:42 PM
#2686
you can use 43/13 crown and pinion from HPI trophy buggy. (same ratio as mp9) However, I'm not sure if the engine mount has enough adjustment range for a 13 clutchbell.
Here's the parts you'll need to convert diff ratios
http://www3.towerhobbies.com/cgi-bin...?&I=LXCJFK&P=Z
http://www3.towerhobbies.com/cgi-bin...?&I=LXCJFM&P=Z
(optional, stock d812 crown gear *should* work) http://www3.towerhobbies.com/cgi-bin...?&I=LXCJFL&P=Z
(you will need 2) http://www3.towerhobbies.com/cgi-bin...?&I=LXCJGB&P=Z
http://www3.towerhobbies.com/cgi-bin...?&I=LXCJJN&P=Z
http://www3.towerhobbies.com/cgi-bin...?&I=LXCJJP&P=Z
http://www3.towerhobbies.com/cgi-bin...?&I=LXCHZN&P=Z
There's some "theory" behind 43/13 crown and pinion which is supposed to "smooth out" power and brake delivery by reducing the center drive speed/RPM.
for example at 35,000rpm (full throttle)
46/13 spur and clutch = 9891 rpm center drive speed
48/16 spur and clutch = 11,666 rpm center drive speed
I would like to try out the 43/13 crown and pinion, but I'm not sure 100% if a 13T CB will mesh even on the stock 48T spur. If someone could check for me I'd highly appreciate it!
Here's the parts you'll need to convert diff ratios
http://www3.towerhobbies.com/cgi-bin...?&I=LXCJFK&P=Z
http://www3.towerhobbies.com/cgi-bin...?&I=LXCJFM&P=Z
(optional, stock d812 crown gear *should* work) http://www3.towerhobbies.com/cgi-bin...?&I=LXCJFL&P=Z
(you will need 2) http://www3.towerhobbies.com/cgi-bin...?&I=LXCJGB&P=Z
http://www3.towerhobbies.com/cgi-bin...?&I=LXCJJN&P=Z
http://www3.towerhobbies.com/cgi-bin...?&I=LXCJJP&P=Z
http://www3.towerhobbies.com/cgi-bin...?&I=LXCHZN&P=Z
There's some "theory" behind 43/13 crown and pinion which is supposed to "smooth out" power and brake delivery by reducing the center drive speed/RPM.
for example at 35,000rpm (full throttle)
46/13 spur and clutch = 9891 rpm center drive speed
48/16 spur and clutch = 11,666 rpm center drive speed
I would like to try out the 43/13 crown and pinion, but I'm not sure 100% if a 13T CB will mesh even on the stock 48T spur. If someone could check for me I'd highly appreciate it!
(43/13)*(48/14)=11,2 rollout=31,1
(43/13)*(48/13)=12,1 rollout=28,8
otherwise same numbers of kyosho ...
(43/13)*(46/13)=11,5 rollout=30,5
...what do you think?
Last edited by bryan71; 07-22-2013 at 11:26 PM.
07-23-2013, 03:07 AM
#2687
you can use 43/13 crown and pinion from HPI trophy buggy. (same ratio as mp9) However, I'm not sure if the engine mount has enough adjustment range for a 13 clutchbell.
Here's the parts you'll need to convert diff ratios
http://www3.towerhobbies.com/cgi-bin...?&I=LXCJFK&P=Z
http://www3.towerhobbies.com/cgi-bin...?&I=LXCJFM&P=Z
(optional, stock d812 crown gear *should* work) http://www3.towerhobbies.com/cgi-bin...?&I=LXCJFL&P=Z
(you will need 2) http://www3.towerhobbies.com/cgi-bin...?&I=LXCJGB&P=Z
http://www3.towerhobbies.com/cgi-bin...?&I=LXCJJN&P=Z
http://www3.towerhobbies.com/cgi-bin...?&I=LXCJJP&P=Z
http://www3.towerhobbies.com/cgi-bin...?&I=LXCHZN&P=Z
There's some "theory" behind 43/13 crown and pinion which is supposed to "smooth out" power and brake delivery by reducing the center drive speed/RPM.
for example at 35,000rpm (full throttle)
46/13 spur and clutch = 9891 rpm center drive speed
48/16 spur and clutch = 11,666 rpm center drive speed
I would like to try out the 43/13 crown and pinion, but I'm not sure 100% if a 13T CB will mesh even on the stock 48T spur. If someone could check for me I'd highly appreciate it!
Here's the parts you'll need to convert diff ratios
http://www3.towerhobbies.com/cgi-bin...?&I=LXCJFK&P=Z
http://www3.towerhobbies.com/cgi-bin...?&I=LXCJFM&P=Z
(optional, stock d812 crown gear *should* work) http://www3.towerhobbies.com/cgi-bin...?&I=LXCJFL&P=Z
(you will need 2) http://www3.towerhobbies.com/cgi-bin...?&I=LXCJGB&P=Z
http://www3.towerhobbies.com/cgi-bin...?&I=LXCJJN&P=Z
http://www3.towerhobbies.com/cgi-bin...?&I=LXCJJP&P=Z
http://www3.towerhobbies.com/cgi-bin...?&I=LXCHZN&P=Z
There's some "theory" behind 43/13 crown and pinion which is supposed to "smooth out" power and brake delivery by reducing the center drive speed/RPM.
for example at 35,000rpm (full throttle)
46/13 spur and clutch = 9891 rpm center drive speed
48/16 spur and clutch = 11,666 rpm center drive speed
I would like to try out the 43/13 crown and pinion, but I'm not sure 100% if a 13T CB will mesh even on the stock 48T spur. If someone could check for me I'd highly appreciate it!
with 43/13 the situation improves .... but I think that in this configuration you should use a clutch with 14 teeth ...
(43/13)*(48/14)=11,2 rollout=31,1
(43/13)*(48/13)=12,1 rollout=28,8
otherwise same numbers of kyosho ...
(43/13)*(46/13)=11,5 rollout=30,5
...what do you think?
(43/13)*(48/14)=11,2 rollout=31,1
(43/13)*(48/13)=12,1 rollout=28,8
otherwise same numbers of kyosho ...
(43/13)*(46/13)=11,5 rollout=30,5
...what do you think?
I really do not know if you can use a 13 or 14 bell. I think you can not.
I think the car can use bell 15 or 16 or 17. And crown of 46 or 48 or 50.
Does anyone know Tessmann or Hara settings?
It's hard to believe that using the original settings.
thank you very much for the answers and sorry for my bad English
07-23-2013, 04:44 AM
#2689
Thank you very much, Nick! 
07-23-2013, 11:54 AM
#2690
Hi, i have tried the Trophy 43/13t crown and pinion on the D812 in the UK. the parts will fit directly, but the bevel gear (pinion) is not machined down on the end where your front cvd fits on.
so you either have to machine it down or use the trophy front shaft, which is not the correct length.....i ended up using the cvd joint from the Trophy shaft and the D812 front shaft joined together although this is not a good fit due to difference in sizes of the components. The shaft has a lot of movement on the cvd pin, it never wore or broke.
on track ( Wakefield national track) the buggy pulled better from the front and felt easier/safer to drive, but was no faster on the clock, the rear was very safe. i also run 48spur/17bell almost everywhere for normal size tracks in the UK.
having tried it, i have gone back to the kit diff/pinion gearing and found it much better, the only other difference from kit is no2 steering plates and green HB rear springs.
D812 is getting quicker and quicker :-)
so you either have to machine it down or use the trophy front shaft, which is not the correct length.....i ended up using the cvd joint from the Trophy shaft and the D812 front shaft joined together although this is not a good fit due to difference in sizes of the components. The shaft has a lot of movement on the cvd pin, it never wore or broke.
on track ( Wakefield national track) the buggy pulled better from the front and felt easier/safer to drive, but was no faster on the clock, the rear was very safe. i also run 48spur/17bell almost everywhere for normal size tracks in the UK.
having tried it, i have gone back to the kit diff/pinion gearing and found it much better, the only other difference from kit is no2 steering plates and green HB rear springs.
D812 is getting quicker and quicker :-)
07-23-2013, 12:02 PM
#2691
have a D812 for sale has ruffly 5 gallons on it... could use some tlc just put new arms on it couple weeks ago, $275.00 shipped....
07-24-2013, 10:15 AM
#2693
Thanks for the great reply nick.
My car has stock pistons stock bladders I was using pink megabytes and red hb foams which were feeling great on my Ebuggy (d8 tekno) I'm running a os max .21 and I'm thinking the 5k diff oil in rear was making me just blow the tires off which is why I was so loose . My Ebuggy just floats around the track so smooth but I'm running blue competition pistons and obviously heavier oil in it so I'm going to have to play with my shock oils slightly with stock pistons that or order me another set of comp pistons . Thanks for setup sheet ill throw that on it tonight and try my car out tomm . Thanks again for all the help bud
My car has stock pistons stock bladders I was using pink megabytes and red hb foams which were feeling great on my Ebuggy (d8 tekno) I'm running a os max .21 and I'm thinking the 5k diff oil in rear was making me just blow the tires off which is why I was so loose . My Ebuggy just floats around the track so smooth but I'm running blue competition pistons and obviously heavier oil in it so I'm going to have to play with my shock oils slightly with stock pistons that or order me another set of comp pistons . Thanks for setup sheet ill throw that on it tonight and try my car out tomm . Thanks again for all the help bud
07-24-2013, 10:16 AM
#2694
07-24-2013, 10:38 AM
#2695
07-24-2013, 10:41 AM
#2696
What springs you use? front and rear 
07-24-2013, 12:02 PM
#2698
My 12 in action at the Bring The Heat race in Flowood. Struggled quite a bit this past weekend. The rear of the car would not settle. I went with a 2.5 sway bar and lowered the shock oil from 30 to 27.5 and it felt a little better. My corner speed just wasn't where I needed it to be. There is quite a bit of slop in the rear end that attributed to the looseness. All in all it was a decent weekend.
07-24-2013, 12:24 PM
#2699
Tech Master
Is there any alternative to part number 109825 if you want a 46 tooth spur?
Can you fit anything off another brand?
Can you fit anything off another brand?
07-24-2013, 12:31 PM
#2700