Threshold for Billet Output Shaft?

[genarr3]

When is a billet output shaft needed? I have a 220hp, no bar, DOT tire, 64" Busa dragbike. I weigh 210lbs. The bike is raced fairly frequently. I plan on putting in billet shift shafts, new shift forks, and undercutting all the gears over the winter.
I know the easy answer is make everything as strong as possible. But I'm wondering if anyone has seen output shaft issues with a similarly set up bike.

I'd like to avoid the cost of a billet output if it would be considered overkill.
While we're at it, do I need aftermarket rods? Or just new Suzuki rods and some interval?

[sportbikeryder]

No need for it for your bike, What kind of short times and ET/mph are you running?

If you are worried, just put an 18 or 19t countershaft sprocket on it.

John

[genarr3]

No need for it for your bike, What kind of short times and ET/mph are you running?

If you are worried, just put an 18 or 19t countershaft sprocket on it.

John

Yea, should have included that.
9.30's
1.5* 60's
3.9 - 4.0 330's
Thanks for the info, what about the rods?

[sportbikeryder]

Well, as always, your results may vary, however, I work on two bikes that are both 1397's with stock rods
One has +5" arm with 200lb suited rider and 40 shot. Best et is ~8.90 Best mph is 160. ~1.51-1.53 60'
One has +10" with 255 suited rider and 15 shot with more agressive carpenter cams. Best ET is ~8.80 Best Mph is ~154. 1.40-1.45 60'

Both bikes have a stock output shaft.


Also work on a stock bore, stock piston turbo bike with Carillo A beam Rods and spacer. Best et is 8.30, Best Mph is 174with the stock bore. 1.36-1.38 60'. Also has a stock outputshaft, but I would NOT reccommend a stock output shaft at this level.


Make your own conclustions, but at your power level, I wouldn't do anything other than tune it. You COULD raise your fuel pressure if you se any issues, but you should be fine as is with stock rods (no need to replace them), output shaft, and fuel system. Take a look at your power commander and provided you have the bike tuned would bet you have something in the 18-20 range as your highest numbers. You should be ok up to about 25 in the PC (assuming a PC3, 3R, or USB).

Replace the shift shafts and forks and ge the trans cut, but I'd leave the rest as is, including keeping the same stock rods in that you already have,
John