I've been researching threads/reviews on the 4.083 and plan on getting these very soon.

I saw a comment on my350z saying that's its not a good idea to have these in the future if your gonna go F.I

(My goal is no more than 400 WHP anyways)

Can someone please explain why it wouldn't benefit an F.I car

 

you're going to have trouble getting traction with those gears and FI.

 

that and you want to hold boost longer so you want longer gears. those gears are very short

 

the 4.08 would be ok with a supercharger but not recommended for a turbo IMO

 

yea with oost you will be like Jeremy Clarkson with his Diesel jag nurburgring

 

Assuming you're talking about a turbo, you should be considering 3.3 gears. A turbo significantly increase power under the curve, therefore, you don't need the extra torque multiplication. Too much gearing with a turbo car and you're going to zip through the powerband too quickly and probably wrap the car around a tree when the turbo(s) come online.

If it's a centrifugal blower you're looking at, then deeper gears would be desireable because power under the curve really isn't as increased, but rather high rpm breathing, therefore, you want to get into that elevated powerband quicker.

When it comes to gearing, there is a very fine line between too much and not enough. The motor needs to be geared to fit it's powerband.

 

If you're boosting you want to stick with 3.3 as DaveB said.