Let us talk gearing?
 

I don't know much about the internals of transmissions hands on (I never took that class :(), so can you guys help me out?

I was poking around MFactory's website and I saw they offer replacement 3rd, 4th, and 5th gears for the Fit. I think it may be aimed at the GD since the 3rd gear is actually longer than the GE, but 4th and 5th are shorter.

Are the drive gears between the two models (GD and GE) interchangable?

Continued poking found a 4.928 final drive for a CRZ on MFactory, is this interchangable with our final gear? How about the other gears? Some of the CRZ gears are shorter than the Fit I assume because of the extra gear it has...

I calculate that with that final drive (4.928) cruising speed at 70mph motor would be at about 3800 rpm? I can live with that.

Possible? Impossible? Shut up noob?

Thx

id check with diamondstarmonsters since it's not front swaybar related. :D

:rotfl:

I was hoping he'd chime in sometime but I know he's usually on later.

Calling Blackndecker too, IIRC he's had some good input on related threads.


I'm also curious if an even shorter final like 4.9x would make 1st gear tremendously more annoying than it already is :confused: maybe just stick to changing 4th and 5th only?

I could've sworn someone had a 5.1 in their car, although I may be thinking of my friend's Miata or something on s2ki.

I imagine with a higher final drive 1st gear becomes solely for rock crawling.

It more or less is already!

Though now I really want to see someone try rock crawling in a fit. :rolleyes:

Hehe the comments above are funny! Well I am not DSM and I don't pretend I have your exact answer but there are a few things extra you could consider.

Any higher highway RPM on the GE is likely to be a bit unbearable so I would definitely not want to shorten 5th. Shortening 3rd (or whichever you feel "drops off" in terms of thrust when you shift up to it; I don't have one) makes more sense. I'd rather have 123 be short, 5 extra long, and 4th halfway in between .. but that's just me. And of course you're limited by what will fit and is available. If the final drive swap is the ONLY thing that is available, I would say almost forget it unless track work is your aim.

Check part numbers. Any two that match are the same of course, and any spindle numbers that match should accept each others gears. Short of asking someone who's actually done this, or a Japanese honda transmission engineer, that's your best bet .. but there's still a maybe. Lots of em. But if from the same engine/transmission family, chances are at least decent that a 3rd from a CRZ will slot in where a 3rd for a Fit goes. Of course, you could ask MFactory directly :)

I looked into a 6th gear addition to my CRV (which had the high highway RPM issue). Dropped the idea not because it can't be done (it can; you use the TSX 6th gear and there is a slot reserved for it in the K-series trans), but because unless you are prepared for the major, major task of stripping down your transmission, you are looking at $3k or something to pay someone else for this unenviable task. Swapping out one gear may be cheaper than an off-workshop-manual gear addition though; after all, gears and synchros do wear out from time to time.

Thanks Fuji, the only thing I would want to change on a street car is maybe make 4th gear shorter, I think the CRZ has a shorter 4th and MFactory has a shorter 4th gear as well.

I will probably end up contacting MFactory with some questions but I wanted to get some input on what, if any of this is beneficial or worth investigating.

Shorter 1,2,3 would benefit much less in the Fit.

1,2 are already quite short.
3 is a niceish gear IMO.
4/5 are quite tall, to me at least.

Ideally I'd want a tall 1st, medium 2nd, short 3,4,5

Essentially a motorcycle gearbox haha

:rotfl::rotfl::rotfl:

Being that the diffs can be interchanged, that would seem to open the door to the possibility of exchanging gear stacks. For stock NA and even full NA builds I wouldn't want to change the final when the option of a more aggressive 3-5 is available.

Only case where I would change the final gear (like a 3.73 or 4.10) is on a turbo application to get more load on the turbine and mph out of all five gears, but first especially..

For a Rotrex S/C Fit I would try to make 4th and 5th taller. For a Sprintex S/C I would want 1st and 2nd taller and a taller 5th.

On the GD 4th is D, 5th is OD

Is the GE 5MT 3rd really the D gear? (1:1) That doesn't seem right.

If gear splines, width and helical pitch is the same, maybe. This would also require that the diameter changes on both shafts clear the case and can be shimmed/preloaded properly.

A yet shorter first would make me a very sad panda :D

An LEA Transmission with an L15A1/7 bellhousing welded on would be interesting.

Off the top of my head, I don't know the front track differences between the GD, GE and CR-Z but that would be an interesting experiment as well.

FRONT SWAY BAR :rotfl: OMG hehe CUSCO :) DSM

Easily my favorite thread of the week. I'd love a taller fifth (fif?) gear yet it seems not quite worth the effort and cost. Thank you, everyone, for the information.

On the GE both 4th (slightly, .950) and 5th gears are overdriven, but 4th is the closest to direct drive gear. The 4th offered by MFactory is 1.030, which isn't a huge change, or is it? I'm not sure how much of a difference that would make?

I'm having a hell of a time finding any information about the CRZ transmission online. :mad:

There's also the 6MT in the JDM Jazz RS, I think the final is much lower than the US Fit... I wonder if this is the same 6MT that the CRZ uses? I would assume that all three cars share the same basic transmission, just with different ratios?

555 had info on the JDM RS 6MT. 6th gear is at a ratio which is between the USDM 5th gears on the 5AT and 5MT. Probably about as tall as the L15 can handle without requiring a downshift on every headwind.

~SB

dayam japan's sites are so heavy. they use fiber optics there with super fast internet for streaming HD porn every night so to them no issue... :D

Honda„*ƒNƒ‹ƒ}„*ƒtƒBƒbƒg„*ƒXƒyƒbƒN

RS 6MT:

1ST - 3.461 -
2ND - 1.869 -
3RD - 1.235 -
4TH - 0.948 -
5TH - 0.809 -
6TH - 0.727 -
REV - 3.307 -

FINAL - 4.625 -

The 6th here is the 5th there, so no point in thinking of going that route. The CR-Z 6th is a much longer gear, it's final is also shit at like a 4.1. The MFactory 4.678 or 4.9 would really help the CR-Z. The 5MT final here is a 4.29, why I picked up MFactory's 4.678 to help accelerate the low powered Fitbox. The 4th here is not an over-driven gear and is about what MFactory offers. 5th here is shorter than 5th there, since speeds are lower here with a max speed of just 100km/h, but who does that? My top speed is now just 197km/h, down from 210km/h, but the better acceleration more than makes up for it.

not really versed on this topic but realizing my fit (my AT won't go much faster than 115mph)... I'm liking the "better acceleration" argument... not that there's an argument of course :D

ok that sucks... we wanted 6th to be taller so that we can cruise 70mph at sub-3K.

Thanks Ken, that is useful, so it looks like they get our final drive WITH a 6th gear and a shorter 5th. Interesting. I guess for performance application this would make 5th a more useable gear, but the top speed between USDM 5MT Fit and JDM Jazz RS would be the same?

Thank you for the clarification on these foreign things (to me haha) :)

So I guess the only question that remains is if the 4.9 final for the CRZ can go into the Fit, and would this be beneficial in a track oriented car? I think Honda did a pretty good job on the gearing and speed for each gear from the factory.

For a street car I guess the only "improvement" would be the slightly shorter 4th gear, but would it be worth the cost to tear the trans apart? Maybe if you're rebuilding it anyway it'd be worthwhile. The only gripe I have about the Fit's gearing is how 3rd feels so great and 4th is just not very inspiring.

Soo... JDM GE 6MT with CRZ 6th gear and either the MFactory 4.678 FD or USDM GD 4.29 Final would seem to be a pretty nice set for economy minded stock Fit owners.

555's JDM 5MT and MFactory 4.678 is probably about perfect for a street/track all-motor Fit stock or mildly modded.

The JDM GE 6MT with CRZ 6th and the CRZ 4.1 Final would be the tits for small supercharger or turbo Fits on low boost.

GD Base 5MT Ratios (Taller than GD Sport)*** with CRZ 4.1 Final and a 24.5" Tire would rock for KWSC Highboost or a high power turbo setup.

For my purposes a GD Sport 5MT, a 3.73 Final and a 26" drag radial or bias ply slick seems about perfect.

*** - Not confirmed

Yes, on the other side of the spectrum there is the longer gearing for boosted applications. I see that there are some interesting final drives for the GD 1.4L Jazz (Euro), there's a 4.11 from my online research. I could not find anything longer than that though. Same final that is in the CRZ?


So for me I think 4.678 M Factory Final with MFactory 4th and 5th gear plus LSD. Maybe if my company goes IPO :rotfl:

Thanks guys for the help, I am glad this could be a good discussion :)