hey i was wandering if any one knew of a planetary gear diff that can be used in the gt2 i was looking at the firestorm but its 55tooth
thanks in advance

None of them , you will have to stick with the ball diff like in the GT (they are exactly the same )but if you wan't to upgrade you can get an aluminium diff from RRP (robinson)that will be the only solution.

ok thanks do you race? how bad do you think it will be locked because i have already meted mine twice and its annoying
thanks for you help

Yes i do race mine but here in Finland we do not have a ST class ,so i race with the 1/8 buggies.
i have the RRP diff but i mainly use the plastic diff ,it's mostly a matter of the way you build it and of how much you take care of it,the rebuild has to be done really by the book other wise you will toast the diff all the time .
Locking the diff completely can be done in case of drag racing but on a track you will have really hard time turning in small corners.
When i rebuild mine ,i put 6 spots of AE silicone grease on the outdrives before installing the rings ,then install the rings and balls with just enough AE silicone grease,i also take care of the others ball and rings and install them with AE black grease , then put everything back together ,tighten the main screw and back it of 1/8 of a turn (no more, no less) and then everything should be perfect .
I use in my GT a OS18TZ and i rebuild the diff every 3 months ,so it's not really a matter of power but mainly how you rebuild it that will make the difference .

ok thanks maybe ill try again
how is the os .18tz is it to powerful and what cluch bell are you useing and pipe lol thanks for the help

Depends on what you want ,i wanted to be able to catch up with 1/8 and for that it's a winner ,i have on it 18 tooth clutchbell and 64 sprocket (keep in mind that it's a GT1) ,and the pipe is a THS one piece pipe for stadium truck's

what do you mean it depends on what you want to do becasue dont you still just want fast acceleration and good topend

"i have the RRP diff but i mainly use the plastic diff" lol sorry for all the questons but why do you mstly use the plastic

I use the OE diff ,just because i found out that mine (Hammad Guhman) aluminium diff is not exactly the same size than the OE associated one ,so i just preffer running that one aside that they are so cheap and i have so many spares that i can run them for years .
I said that it depends on what you do because in US you can not race with a 18 engine in a ST ,but as here in Finland i run it with the 1/8 ,no one cares about that and i can run my GT as i like it ,but to be honest ,a good 12 engine is more than enough for a GT2 or GT ,but i like to have lot of power in case ...

o ok well thanks and i havent been racing yet but last year they didnt have enought ST to have a class so you could race in the 1/8 but i think they might have enough this year
so if i get a .12 what do you think i should get i would like a pull start and im not sure on the specs but mine rides wheelies stock lol so i woulded mind a .18 but i want it to be controable and reasonable top end casue i bash alot

As i told you a 18 would not be legal for sanctioned races ,and the other thing is that there is allmost no good 12 with a pull start ,i would really go for a starter box that would give you much more choices in engines .
If you really want a 18 you would have to gear up your clutch bell to at least 3 teeth to not have something uncontrolable at low speed's but still you will get something that becomes stupid fast at high speeds for a real track .
After all it's your choice ,no one can decide for you and whatever you take you will have to live with it ...

If you really want a 18 ,here is a good one (i have it without the pull start ) ,reliable and easy to tune .
http://www3.towerhobbies.com/cgi-bin...?&I=LXHLV9&P=7
You will need a new manifold for rear exhaust :
http://www3.towerhobbies.com/cgi-bin...&I=LXTWH5&P=SM
You will also have to get a adapter from a NTC3 in order to put on your clutch bell and a cut off nut to cut the cranqshaft to the rigt length .
http://www3.towerhobbies.com/cgi-bin...?&I=LX3382&P=Z
http://www3.towerhobbies.com/cgi-bin...?&I=LXBMD5&P=Z
With all this you would have a rocket with the benefit of an easy to start and tune engine .

thanks of all the help i think i will probly get that motor casue thats what i was looking at any way
but one more how long of a run time do you get and im not sure on how to gear it because i can get up to a 21 clutch but idk about the spur the smallest they have for the gt2 is a 54 but i think i need about a 50

For mine ,i geared it 3 tooth up on the clutch bell and 2 tooth down on the spur gear .
I was thinking that you have to get a starter box as to put a rear exhaust engine you will not be able to pass the manifold over the pull starter .
This one would be a direct drop in and even the power would be more controllable .
http://www3.towerhobbies.com/cgi-bin...&I=LXGGP7&P=SM
And for this one you would only need the cranqshaft adapter and the cut off nut to cut the cranqshaft and no need of a new manifold and starter box and still the ease of OS engines with the power of a 18 .

ok thanks but i still have a problem becasue the smallest spur they make for the gt2 is a 54T which is sock and i also have a 20T CB and they make up to 21 for the GT2 but they also make a 23 for one of there other cars so the 23 doesnt fit right now casue i checked but it might work with a smaller spur so i need to find a spur that will work with my car any ideas
and why then they make a rear exost with a pull start ? if they dont have a manifold that will work

Just get the 21 and it should be fine with the 18 CV-RX , then you will be able to see if you need a bigger bell or not and afterward's you can get the 23 bell that should be direct drop in .I don't know of any smaller spur's for the GT2 .
OS makes a 18 rear exhaust that can fit many cars but does not fit the GT2 except if you are ready to get rid of the pull start and get a starter box ,i think that for your car the easiest will be the 18CV-RX that will cost you less as you will not need a new manifold and a starter box but still will get you very nice powerand you will be able to pull wheelies on demand .

http://www3.towerhobbies.com/cgi-bin...?&I=LXFUA5&P=7
do you think this will fit on the gt2? becasue if it does then i think i would gear it 52/21

i am not sure ,but i would say no,ask associated via their website .