Ofna Ultra MBX R2 center diff

[burnskevin58]

Would anyone know if the Hobao center diffs will fit the Ofna Ultra line.
I can't find a 46 or 48 tooth center diff gear so I figured maybe a Hobao might fit and just change the whole diff.
Problem is I don't have a hobby shop near me that's into nitro so I can't just go and get hands on.
Hopefully someone will have swapped out the center diff on a Ofna Ultra and can help me with the correct one.
It doesn't matter if it's a locked diff or spider gear diff. I have a one way bearing front diff on the way so the center can be a simple solid diff.

Sorry if I spelled Hobao wrong.
Thanks in advance

 

[coldvod]

Hobao is ofna as far as my research tells me. I read that ofna is the american distributer of hobao https://www.rcuniverse.com/forum/rc-1-8th-scale-buggies-244/7837936-hobao-ofna-whats-difference.html

 

[burnskevin58]

Hobao is ofna as far as my research tells me. I read that ofna is the american distributer of hobao https://www.rcuniverse.com/forum/rc-1-8th-scale-buggies-244/7837936-hobao-ofna-whats-difference.html

Yeah I know Ofna was the distribution but something happened and Ofna is no longer. Hobao is now the distribution.
That whole deal was strange.
I'm just wondering what Hobao diff will fit.
I can't afford to buy diff after diff hoping one fits.
I was going to contact Hobao but figured they would say they don't know as my ultra MBX R2 is older.
So I figured ask on here maybe sooner or later someone will have installed a Hobao diff from a newer car into the older ultra. And be able to tell me the correct diff and bearings to fit my diff carrier.

I have the 51 tooth diff gear, and 16t clutch bell, over revs. I run on road, long straights.
I have a 18t clutch bell but I'm sure that will be to much 18/51. Overheat the engine and take forever to get up to speed. This is why I'm looking for a 46 or 48 tooth diff. I think the 18/46 or 16/48 will be just right.
Thanks. I'll check out the rcuniverse been a member there for a long time.
I can't wait to buy this. Trying to run a heavy buggy on road is just goofy.
All GT types of cars are still a buggy.
I had a serpent gt 3.5cc on road that serpent built around the buggy chassis. Didn't like it as it was not really fast. Even had a Nova Top 5port engine and 2speed tranny. Just to heavy.

Same with the Ofna gtp 14/51 gearing.


Eventually I'll be at the speeds I'm looking for.

 

[coldvod]

I think you should try to contact hobao or a smaller nitro thats more focused on nitro rc it takes a few minutes and could save you lot of research. What are the dimensions of the spur/ center diff assembly

 

[burnskevin58]

The spur is one of the older ones that looks like a old school BMX chain ring. Thanks but I was able to run a 18t pinion with the 51t spur. The ratio is 2.83 so the engine isn't over revving anymore.
I don't have a radar gun but it put the car around 55-60 mph range on road.
Now just have to dial it in.
I have power to spare as it accelerates on the spot. I figured 18t pinion would make acceleration slow. But it didn't. so maybe 19t will be next. I just don't want to overwork the engine either. But I like it now, I'm not wanting blistering speed just enough to have fun.