I "think" mine is carbon. Didnt the original B4 FT's use carbon racks and servo savers? I looked on amain and cant find the carbon servo savers anymore. I do know my rack is grey like the carbon top plate. I kept the rack when i sold my original b4 FT.

So if your running no boost with a 10.5 then start with the recommended ratio in the back of the manual?

The carbon and plastic is a pretty drastic difference..you should easily be able to tell the differnence...the carbon is on the left.

Would the aluminum rack in those st racing setups be better than the stock plastic? Not sure of their quality, I'm gonna switch to the avid bellcranks as soon as I can get them locally. Saw that brass one too but isn't brass heavier than aluminum?

ok, so i found 2 part numbers

B4 Rack = 9576 (I think are carbon)
B4.1 rack = 9659

What would your want an alum rack? I dont think I have ever broken the rack.

Not a big deal , the plastic rack performs the same .....

exactly. :)

The gear chart is wrong. the Final Drive is right (FDR).

use a 72 spur for 13.5 or 17.5 and then calculate which pinion gear you need.

Spur / Pinion * 2.6 = FDR

72 / 35 = 2.057
2.057 * 2.6 = 5.348

Get the idea??

Less slop

Yeah, it is an old part number that isnt manufactured anymore. The only rack nowadays is the newer .1 plastic #9659. But yeah, it doesnt matter, the main thing is to either glue the saver together or get an aluminum rack.

66- yes the brass is heavier than the aluminum and is designed more for the euro carpet or grass tracks.

Your still going to get slop if everything was aluminum.

Slop = fast

the heavier the car is the less traction problems your gonna have and traction is the name of the game. Thats how I see it

+1 I have the avid saver and the composite rack. The only slop I have is in the ball cups