I have a 1990 240sx Fastback 5 speed and I want to do a vlsd rearend swap. I was told there are three different gear ratios and a speed sensor. What ratio should I choose, and is the speed sensor only for automatics?
Any input would be greatly appreciated.
P.S. I heard I will also need a new driveshaft, is that true?
gear ratios are ratios.
the 4.10 gears that come stock in your 240 multiply the torque of your engine 4.1 times.
This is a steep gear. This is a gear set that muscle cars tend to stick to. Any higher (numerically) will kill your top end.
It’s a trade off.
Lower numerical gear sets will give you more top end, but hurt your torque.
The 240s came with 4.10s to make it accelerate with a fairly anemic engine.
So if your motor is stock … keep the 4.10 gears, and just swap a VLSD carrier in.
If you have a decently worked motor, the 3.7s out of a 300ZX would be a nice match.
If you have more power, and are sick of shifting gears every second, the 3.5s out of a Q45 would be nice.
But you don’t need to swap the entire pumpkin, just the carrier.