Currently i am playing with a 39/8 crown and pinion set that i should be able to 'graft' easily into one of my spare T2 LSD diffs. Yes that does mean a 4.875:1 diff ratio, sounds nuts yes, but for all but one of the events i will be competing in, 230 odd kph is the max speed i need. 8000rpm in 5th gear with a 4.875 diff will give me around 240kph.

anyone else played around with different crowns and pinions?

with a partial bridge port, good sized T04 and FMIC - a set up which i am hoping will bag at least 500HP at the flywheel, my car should accelerate like a bat outta hell with that diff ratio

anyone else doing this crazy ****?

 

I build my cars for top end speed...200mph (320kph?) is a goal for me one day in my FC.

Your 4.80 rear ends is going to give you one swift kick in the pants.&nbsp I know guys who are running the J-spec 4.30:1 rear ends, and they are complaining it gets to 150mph (250kph?) too damn fast and want more top end speed.

Hell, if you don't want the top end speed, I'd say go for it...



-Ted

 

the circut which i'll be seeing most of my time on, the full house 12A PP 1st gen race cars are pulling 190kph down the straight, with their 250odd HP. that gearing should be pretty much perfect for that track, only one event per year will i ever see over 240kph and for that i'll either put in the 4.1 or find something arounf 4.3 or 4.4 and use that

 

Take a look at this webpage. The Suzuki Samuri Grand Vitara 4wd uses 4.875 and 5.12 gears. Probablly on the front axel like the Kia Sportage and the 87-88 Mazda B2000 trucks do. Since these are the same axel ratios as the MazdaComp sells, do you think, perchance, they are the same size ring and pinion as the first gen Rx-7? Might be an alternate source for such gears.
Page 17.
http://www.greenhouse.gov.au/fuelguide/fcg99_00.pdf

-bp-