Final Drive FI gearing: What's yours?
 

Looked around for a thread on this and didn't find a collection thread listing what final drive gearing FI cars are running and the results. It would be nice to have everyone's info in one thread for quick/easy future reference of others.

If there is another thread like this, please point me to it....but I spent 20 minutes with the 'search' button and didn't find what I was looking for.

I think it would be helpful to have the following info in each reply, I'll start.....

FI type: Vortech V2 SCI-trim
engine displacement: 3.5L
rwhp: 385
6mt or 5at: 6mt
rear tire size: 275/35/19
LSD type/brand/settings: OEM VLSD
half shafts: OEM
ring/pinion gearing ratio: 4.083
typical use: street & occasional track day (road race)
likes/dislikes regarding gearing: can't build boost in 1st gear before hitting rev limiter. Can only build 3psi in 2nd gear before hitting rev limiter. Can't hook up in 1st on hard core launches even though both wheels are pulling for the most part
plans to change final drive: Yes! Have 3.53 gears with Nismo diff set to 1.5way @ 60% lock. Installing it next week.

--Sk

as fast as the rpms move in first gear the pressure in the charge pipes and the intercooler doesn't have time to build up and pressurize the manifold.

652hp single turbo: 3.54 rear end (stock g35 6mt)

FI type: Vortech V2 SC-trim
engine displacement: 3.5L Stock
rwhp: 513 rwqt: 408
6mt or 5at: 6mt
rear tire size: 285/35/19
LSD type/brand/settings: OEM (Euro Spec) VLSD very few in the US
half shafts: OEM
ring/pinion gearing ratio: Stock 3.535
typical use: street & occasional Drag Racing
likes/dislikes regarding gearing: 1st gear is a little low

nice thread, in for more results. I was thinking about changing the gearing when I do a lsd upgrade.

Me too. I think I am going to wait till my car is running, and then make the choice on wheather or not I like the OEM VLSD... But also in for more results and feedback.

FI type: Vortech V3
engine displacement: 3.5L
rwhp: 458
6mt or 5at: 6mt
rear tire size: 275/40/18
LSD type/brand/settings: Quaife
half shafts: OEM
ring/pinion gearing ratio: 3.90
typical use: street (non-dd) and track (road course)
likes/dislikes regarding gearing: 1st gear is kinda useless? :o

Stock for F/I. 4.083 is better for N/A.

can you elaborate. Wouldnt 4.083 be beter for FI since RPM would rise quicker or do I have it backward?

No, because of traction problems.

FI type: APS TT
engine displacement: 3.5L 9:1 cr
rwhp: ~550 hp ~575 tq
6mt or 5at: 6mt
rear tire size: 295/35/18
LSD type/brand/settings: oem VSLD
half shafts: OEM
ring/pinion gearing ratio: 3.3 from an auto
typical use: street car
likes/dislikes regarding gearing: with the 3.53 stock, the car was useless in 1st and second. with the move to 3.3, the car is much more drivable, and I can actually use 1st gear.

I wouldn't move to the 3.3 with less than 475-500. it gives you a lot of gear. and for some, 4th and 5th might seem sluggish

Also less load and less boost in lower gears.

^^ This.

4.0 for N/A
3.5 for stock block F.I
3.3 or less for big boost

excellent. thank you sir. I'll keep the stock 3.5 then :thumbup:

i believe moving to 3.3 you must be above 650rwhp.

if you are having traction problems check your tires and suspension set-up. make sure you are not seeing any negative camber on your wheels.

a good set of r888 will be very good.

I know this is an old thread, but I don't want to get flamed for starting a new one. I noticed the other day that Nissan does have a 3.7 FD gear. Would that be too aggressive or just right for a single turbo DE at ~400whp, ~390wtq?

IMHO too agressive

it's a waste of time and money.
stock 3.54's will work better for you.

Some good info in here. Sub'D..Thanks guys

For FI applications, higher final drive ratios like 3.7, 3.9, or 4.08 only make sense for the select few guys who have done GM auto trans swaps like the TH400 or 4L80e who don't want it to be too sluggish in 1st gear. Standard first gear ratio on those transmissions is almost the same as 2nd gear on the OEM 5AT for the Z and the G.

3.9 FD @ 350-400whp is stupid fun. It makes the Z feel like a monster in any gear for a fraction the cost of building a high hp Z.

I'm on the fence for the 3.3 swap, if you want 200+ mph 3.3 seems like the way to go. I wouldn't make the gearing a function of power as much as use of the car.