Swapping 5 Speed Gearbox For 6 Speed

[cell]

Had my 2.3 Ghia X gal for a while now & dont like driving over 70 as the revs are so high :rolleyes: ..

 

It is nice to have the power but was wondering if it was possible to swap the gearbox to a later 6 speed one. I've seen a few on Ebay for sale from late TDI models but not sure if they're compatible with the 2.3 engine.. been looking through the forum but couldn't find any topics about it..

 

Hopefully someone might know... :wacko:

[insider]

If you could get it to fit you'd probably have a much less driveable car. It's probably also more cost effective to trade it in for a TDI already with the 6 speed box. The 2.3 is pretty gutless if you floor the throttle at 70mph in 5th gear whereas, even in 6th gear, the TDI will still accelerate quite briskly. Adding higher gear ratios to the 2.3 would only dull the performance even further.

 

The 6 speed gearbox has higher ratios and is more suited to the diesel engine (and 2.8 petrol) as they have higher torque. The 2.3 engine would have to be worked much harder to accelerate through these higher ratio gears. Any fuel savings you made cruising at lower rpm would probably be cancelled out by the extra fuel you use during acceleration (depending on the type of driving you do). You'd also be changing gears a lot more to get back up to speed on motorways.

If it's engine noise that bothers you then sound-proofing would also be a cheaper option.

 

Gear ratios (mph per 1000rpm):

5-speed: 1st - 4.8, 2nd - 8.7, 3rd - 13.2, 4th - 19.3, 5th - 26.3

6-speed: 1st - 5.5, 2nd - 10.0, 3rd - 16.0, 4th - 22.8, 5th - 28.2, 6th - 34.0

 

Torque (Nm) figures:

RPM:- 2.3 1.9TDI (115)

1000 157 148

1500 171 260

2000 179 310

2500 203 283

3000 195 257

3500 190 229

4000 198 202

4500 202 162

5000 195

5500 186

6000 164

 

At 70mph in 5th in the 5 speed box, engine speed is about 2700rpm which is around where maximum torque is achieved in the 2.3 engine.

In 6th in the 6 speed box, engine speed would be around 2000rpm which is where maximum torque is achieved in the TDI engine.