Technical 1.4 16v gearbox swap 5 to 6 speed

[ConanDeDestroyer]

Hi everyone,

My voices in my head are telling me about swapping the 5-speed manual gearbox in my 2008 Lancia Musa (1.4 16v petrol, after FL) for a 6-speed one. I’ve searched the forum to see if anyone else has attempted this, but couldn’t find any relevant threads—so apologies in advance if I’m repeating a topic that’s already been covered.

Before diving in, I’d really appreciate your insights:

• Is this a plug-and-play swap?
• Will the ECU or wiring need to be modified?
• Are there any compatibility issues I should be aware of?
• Or is this heading into “custom work and duct tape” territory?

And most important question: are those 6 speed gearboxes worth it? I mean in a reliability point. My current 5 speed have about 270k and starts to develop problems with 1st and reverse gear, have 2 kilometers of slack on stick, sometimes it simply refuze to click in to gear. So I ll need to replace it soon. And the dillema: do I stick to 5 speed, or try to upgrade it to 6 speed? I did start to travel more on autobahn and reving to 3,5-4k rpm to have constant speed is hurting my wallet (this 1.4 doing 120 kmh is thirsty) and ears. So yea, that's the deal.

Also, sorry if this is a bit of a faux pas—I know this is the Fiat Idea section, and I’m talking about a Lancia Musa, (i feel a bit like cold war era spy trying to plend in, hello there fellow fiat owners) but since they’re essentially the same car under the skin, I hope I’m not causing a scandal here!

Thanks in advance for any help!

 

[rmjbn1]

Hi and welcome

I understand the Idea is based on 188 Punto (also Stilo), so might be worth searching that section as it has more traffic, example thread:

6 speed conversion | FIAT Punto (Mk2/2b)

Was looking into putting a 6 speed box into the car. Read that the linkages are the same as the 5 speed. But where would reverse then be with original linkage and gear knob?

www.fiatforum.com

 

[ConanDeDestroyer]

So, from what I understand, 6 speed box have almost the same gear ratio at 6th gear as the 5 speed on 5th. More over 5 speed should be a little bit more relible. That would defeat the purpose of swap. Well I gues it would make more sence to stick to the 5 speed box and try to repair/raplace it then. Anyway now I know what to do. Thanks a lot!

 

[rmjbn1]

Yes, that seems to be the message from the threads I found.

Fairly sure the 6 speed would fit, but people suggesting it doesn't give much benefit.

The C514 box was used on loads of different models with different gear ratios, sometimes different final drive.

Maybe have a look through the different ratios for Punto, Panda, 500, see if there's something that would give you a taller top gear - although you might then lose on acceleration

 

[ConanDeDestroyer]

I mean it would depand on ratios on 2, 3, 4 ain it? Nobody would accelerate on 6th gear... I think. My idea was that 6th gear would be more like overdrive. To drop revs during cruise. Whole point was to on cut mpg and noise at high speeds. But I don't know am I comfortable to loose acceleration for trade off like this. This 95 hp is not giving us much in that department anyway. Are there any tables about aviable ratios fore those boxes?

 

[rmjbn1]

There have been some gearbox swaps on here where a different final drive dropped revs but also acceleration.

I can't get the Idea page to load at the moment, but here are the gear ratios for the Grande Punto:
GEARBOX - Fiat - GRANDE PUNTO - eLearn - 4CarData
And final drive (given as 'rear axle ratio')
DIFFERENTIAL - Fiat - GRANDE PUNTO - eLearn - 4CarData

Interestingly, it shows the 6 speed box as having the similar gear and final drive ratios as 5 speed, but with a taller extra 6th gear. Which sounds like what you're trying to achieve?

Not sure how the Grande Punto final drive compares to the Idea.

This site also gives top gear and final drive ratios for different models:

https://www.carfolio.com/fiat-idea-1.4-16v-114532

 

[rmjbn1]

Here are the final drive ratios for 1.4 Idea, 1.2 &n1.4 Grande Punto and also 1.1 & 1.2 Panda as comparison, same C514 gearbox. Strangely they don't give details for the 6-speed Idea.