Why 3.9 gears don't work with FI?
 

I always see this posted, but don't understand why.

They are too low. FI has alot of tq and with lower gearing, it just spins.
The higher the gears are the more power it takes to break them loose.

Yea if you have 3.9 gears and are FI you will accelerate way to fast!

so would it be beneficial for a company to produce a different gearing for FI cars since most the cars running big hp #s can't really get traction in 1st or 2nd?

uh what? :icon18:

no, you won't accelerate that fast, because you'll have no traction.

that's where the 3.3 pumpkin from the 5AT comes in.

It'd be nice to have a 2.5 final drive for FI.. then again that'd probably put us at top speed of 210 mph...

and that is bad because?:cool:

because going fast = bad... err something like that haha

It'd be way more than 210 :icon38: ... with 295/30/19s, 3.5FD, and a 7100 fuel cut.... I'm at 201 right now. It'd be alooot of fun though!

I have heard many say that if you have a TT or ST, then even 3.5 gears is too much let alone the 3.9s. On the other hand, if you have a SC, like myself, then you can possibly run 3.9s. I have swapped out my 3.3 with the 3.5 and love it so far. I havent run it at the track, but I feel more pull down low. Since a SC will make most of its HP and TQ up higher in the RPM band, its not as bad with wheel spin as a turbo is.