Looking for a custom gear shop, wanting to swap out 5th for something smarter.

Hey all. Couple questions.

Looking to deal with the pesky highway rpms for a 2018 5MT.

How much work is it to access the 5th gear? And anybody know a custom machine shop (Maritimes, maybe Maine or Ontario) that might be able to make what I need?

Also how angry would the ECU be? That'll be the only deal breaker to me pursuing this.

Not much came up on searches for this, but as somebody running 40,000km a year and likely to replace with another once this dies, I'm serious about this assuming it can be done for under $1500 or so.

Lets actually get the conversation started here, unless I missed a more popular topic on the subject.

How crazy am I?

Yes, you are crazy.

But never mind that. I still like the idea!

What's your motivation? Is it primarily to save money? If so, you might want to research some existing gear swaps and do the math.

I re-geared my 1.0L, 3-cyl 1998 Pontiac Firefly. The 4-cylinder version of the car had a taller final drive ratio, and that's what's in my car now. I dropped top gear RPM by a relatively big number - 400 RPM at 80 km/h.

Compare "A" and "D":

https://www.metrompg.com/posts/photo...pare-RPM-z.gif

The end result was about 5% better top gear fuel economy on the highway.

https://www.metrompg.com/posts/tranny-swap.htm

Quote:

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Originally Posted by MetroMPG

Yes, you are crazy.

But never mind that. I still like the idea!

What's your motivation? Is it primarily to save money? If so, you might want to research some existing gear swaps and do the math.

I re-geared my 1.0L, 3-cyl 1998 Pontiac Firefly. The 4-cylinder version of the car had a taller final drive ratio, and that's what's in my car now. I dropped top gear RPM by a relatively big number - 400 RPM at 80 km/h.

Compare "A" and "D":

https://www.metrompg.com/posts/photo...pare-RPM-z.gif

The end result was about 5% better top gear fuel economy on the highway.

https://www.metrompg.com/posts/tranny-swap.htm

---

My primary motivation is longevity and fuel. If I can bring 3000rpm to 2000rpm, I can theoretically gain about 10, 15% economy, and since the engine will rotate 1/3rd as often, I should gain a bit of life. The car has so much gumption to spare in 5th, I need never downshift. I mean hell the car can get rolling from a stop in 3rd, my normal shift pattern is 2-5. That's... it. I'm in 5rh around town doing 40kmh and the engine is hardly bothered by it.

Also, fun project.

Post #23 in this thread suggests a taller 5th gear ratio already exists in the Euro market. Unfortunately the poster didn't reply back with part numbers for the gearset as he said he would:

https://forums.nicoclub.com/changing...d-t406416.html

Regardless, it won't be a 1k RPM change. A few hundred RPM is more likely.

If you're serious, I would start by investigating whether you can just get gears out of an existing Canadian market Nissan that will fit the Micra's gearbox. (Turbo Juke.) The 5th gear pair is a relatively easy swap in some cars. And the ECU won't care (just as it won't care if you change the gearing by putting on larger diameter tires).

Did a bit of quick poking around. I can't guarantee that these are the correct part numbers, BUT...

For the RHD Euro market

K13K MICRA IND MAKE 07/2010-

32310-00QAG GEAR ASSY-5TH,INPUT SHAFT
32341-00QAM GEAR-5TH,MAIN SHAFT

Again - I make zero guarantees that these are the right numbers, but at first glance...

Both are found in the RHD K13 for Europe, and both also are found in the LHD Tiida as mentioned in the nicoclub thread.

If someone wants to give it a try, please consult with your local Nissan parts guy first to confirm they go together.





Wait - this means the RHD and LHD Micras have different gearboxes. Does anyone know if they're from the same gearbox family?

I'll be contacting some local shops this weekend. Just keeping the 1 person interested up to date.

Last person I know of who did a custom 5th gear set for a taller top gear paid $1300 USD, if memory serves.

Which is more than I've paid for each of the last 3 cars I've bought! :D

And if that's the price point, it wont be happening.

I'll have to shop around at some creepy back alley shops. Problem with NB is I really, really dont have a lot of options.

I'd be interested to hear what you come up with. I'll be watching this thread

So, it's not a Skyline or a Camaro, which means nobody wants to touch it.

Haven't ever been offered a quote. Everyone has just said "not the type of thing we would normally do".

So, it's over.