5 Spd to 6 Spd Conversion DIY

[Mrhiguy]

Originally Posted by Bluevitz-rs

Not a chance. The F/D is part of the output shaft.

But is it possible to pull the gears off the output shaft?

[Bluevitz-rs]

Originally Posted by Mrhiguy

But is it possible to pull the gears off the output shaft?

Absolutely. That's the only way to do the swap.

The reason you can't swap them is because one caries 5 gears, and the other caries 6. Also, the C160 has an 8 bolt diff and the C150 is a 6 bolt. There would be no point in putting in the diff from the C150. It would defeat the purpose of the close ratio 6 speed.

[Mrhiguy]

Originally Posted by Bluevitz-rs

Absolutely. That's the only way to do the swap.

The reason you can't swap them is because one caries 5 gears, and the other caries 6. Also, the C160 has an 8 bolt diff and the C150 is a 6 bolt. There would be no point in putting in the diff from the C150. It would defeat the purpose of the close ratio 6 speed.

The reason for my question is the idea to use the 6 speed as a better daily driver. Because putting in the 3.526 F/D ratio to the c160 would give it a great o/d 6th gear to keep the revs low but still retain a close to stock 1-5.

Exmple: with 205/55/16 wheels
GEAR=------------------1-------2--------3--------4--------5----------6
c160 with 4.5 FD= 14.9 __ 23.1__ 31.9__ 40.6__ 51.6___ 65.3 @ 3000RPM
C160 with 3.5 FD= 19.2 __29.6__ 41.0__ 52.1__ 66.3___ 83.8 @ 3000RPM
c150 stock3.5 FD= 17.1 __31.9__ 46.4__ 62.7__ 71.7 _______ @ 3000RPM

[rob323]

With the 3.5 final drive, the engine would be far too low in the revs when cruising at 60 mph and probably use more fuel because of the lack of power available at those revs.

[Mrhiguy]

Originally Posted by rob323

With the 3.5 final drive, the engine would be far too low in the revs when cruising at 60 mph and probably use more fuel because of the lack of power available at those revs.

Then just keep it in 5th gear. Here in the states we drive 65-75mph Average even though the speed limits are generally 65-70 mph.

Plus if 3.5 is too low for you. You can get a final drive from a 4 door Echo c150 with a F/D of 3.850.

[rob323]

By ending up with taller gearing in each gear, all you do is make the car into a slug (more so). You lose the "close ratio" benefits of the C160 box.
Peak torque is developed between 4200 and 4400 rpm (depending on engine) so ideally, they are the revs you want to be doing while cruising for max economy.