Considering a transmission swap for my '92 Metro

[Crono]

I just finished reading through MetroMPG's old transmission swap thread for his '98 Metro as I myself am considering changing my transmission from the 3 cylinder to the 4 cylinder model. (I actually have to replace the transmission anyway, and I have to decide fairly soon).

I couldn't tell from his thread if he had the xfi cam installed at the time of changing transmissions, but I myself already have the xfi cam, and I'm just wondering if anyone has experience of how it will drive. (I've noticed since switching to the xfi cam, I change gears a lot earlier than I used to, so I'm thinking that this would probably put me back up to around where I was before, in terms of shift speeds).

Just wondering if anyone else has experience with doing the xfi cam swap + swapping in the 4-cylinder transmission as well / curious if it would be any different on an older model like mine. (From what I understand, they haven't changed much about it, given that MetroMPG used a 4 cylinder tranny from the 88-94 range for his '98).

Any advice or input would be greatly appreciated.

[MetroMPG]

Originally Posted by Crono

I couldn't tell from his thread if he had the xfi cam installed at the time of changing transmissions

I didn't at the time; I put the cam in later.

I'm just wondering if anyone has experience of how it will drive. (I've noticed since switching to the xfi cam, I change gears a lot earlier than I used to

The XFi cam makes more torque at lower RPM, so it's an ideal match for the taller gearing/lower RPM for a given road speed. Considering your car is also a bit lighter than the 95's and up, it's an even better candidate.

The only reason I might caution someone against doing the 3.52 swap is if they happen to live in a VERY hilly place (it takes a bit more clutch slipping to get going in 1st gear), or if you do predominantly start/stop urban driving. You get most of your benefit from this swap by cruising in top gear at a lower engine RPM for a given road speed than you could before.

If those cautions don't apply to you, I'd say: do it! You'll like the results.

Just make sure you're getting the transmission with the 3.52 final drive. That's from the SOHC 1.3L Swift, not the one from the DOHC 1.3L 100hp GT/GTi model.

[Crono]

Originally Posted by MetroMPG

The only reason I might caution someone against doing the 3.52 swap is if they happen to live in a VERY hilly place (it takes a bit more clutch slipping to get going in 1st gear), or if you do predominantly start/stop urban driving. You get most of your benefit from this swap by cruising in top gear at a lower engine RPM for a given road speed than you could before.

Hmmm, I see what you're saying. Well, I do live in a bit of a hilly urban area, (Victoria) and I do a bit more "demanding" driving (I deliver pizza for about 70% of my kms) so I suppose I do appreciate the little bit of torque I have right now, but, at the same time I do a fair bit of my driving in top gear as well, so I think I would see some benefit from it.

I find that before I swapped cams had to be going about 60km/hr to get into 5th comfortably on flat ground and now it's more like 50km/hr, would swapping to the 4 cylinder transmission make it feel more or less like it used to with the old cam, in terms of when I'd be shifting? If that's the case I'm pretty sure I'd be alright.

[edit]

I should add that I find my shifting speeds to feel super short ever since I swapped the cam, I'm usually in 3rd gear by the time I clear an intersection from a stop...

[MetroMPG]

Originally Posted by Crono

would swapping to the 4 cylinder transmission make it feel more or less like it used to with the old cam, in terms of when I'd be shifting?

Pretty much. Except first gear - you'll be slipping the clutch a bit more to get going, as mentioned.

Do you already have the transmission? Where'd you get it?

[Gasoline Fumes]

The 3.79 transmission from the 1995+ 1.3L Metro/Swift/Firefly is another option. Same as the XFi transmission. And I think the 1998+ 1.3L cars even had a slightly shorter first gear for less clutch wear.

[Crono]

Originally Posted by MetroMPG

Pretty much. Except first gear - you'll be slipping the clutch a bit more to get going, as mentioned.

Do you already have the transmission? Where'd you get it?

I don't already have the transmission, though I've found a local salvage yard that'll sell me a used one for $250; I've just been telling people I have a '92 4 cylinder SOHC Swift with a manual transmission. (Is there really any other way to go on this one?)

Originally Posted by Gasoline Fumes

The 3.79 transmission from the 1995+ 1.3L Metro/Swift/Firefly is another option. Same as the XFi transmission. And I think the 1998+ 1.3L cars even had a slightly shorter first gear for less clutch wear.

Would this actually be a better option, then? The other thing I should mention is that I'm in Canada, so I believe the years and models of Geos, etc. are slightly different here in general. (I've heard the xfi never came out here and some stuff like that)

[Gasoline Fumes]

Originally Posted by Crono

Would this actually be a better option, then? The other thing I should mention is that I'm in Canada, so I believe the years and models of Geos, etc. are slightly different here in general. (I've heard the xfi never came out here and some stuff like that)

I wouldn't say it's better, just different and easier to find. You'll get better highway mileage with the 3.52.

[Crono]

Alright, thanks to both of you, I will post after the swap's been done on the 27th and I've got some miles on it.

[MetroMPG]

You're probably going to see a very small improvement, since much of your distance is city driving. If you're going by tank-to-tank comparisons alone, the improvement might be lost in the noise of normal variability.

Not trying to discourage you - just doing a check on expectations. Hope they're realistic.

[Crono]

Just wanted to follow up on the transmission replacement even though it was some time ago. The transmission was replaced on May 27th, 2012 and you can see the fuel log for my Geo here. At first, it looks is worse, but I think that it may have been because, as I recall, I had a bit of trouble adopting a new driving style to suit the new transmission. However, after a month or so, I started getting a bit better numbers.

Overall, as suggested, with my mostly in-town driving habits, my gains have been pretty small, if any...still seems a little better compared to last summer, though there are always a number of possible reasons behind that.

As you can also see, since September-ish, my mileage has gone down a fair bit, but that's pretty typical with the lower temperatures and much heavier rain Victoria sees in the winter. You may also notice that there's a tank I got recently that was pretty high which was all highway driving, more around 60mpg imperial, rather than the 52ish I've been hanging around. Now, what I really want to see is how my mileage will be on the highway during summer! Previously, with the short duration cam but stock transmission I noticed that my highway mileage, going around a typical 110km/hr on the mainland, I would get very similar to in-town mileage, but from these numbers it's looking like with the new transmission I'm doing about 15-20% better, so that's pretty cool if it holds true. (I should also add that the weather was pretty terrible on that highway drive and I had a full load with 4 passengers plus luggage)