Honda Manual Transmission Specifications & Gear Ratios

[mpg_numbers_guy]

Hm. What would be the best option for a 6 speed in the Insight then, but with a taller final drive? Basically trying to find what would give more linear gearing and a taller 6th gear.

[Ecky]

There isn't one, sadly, unless by chance the CR-Z and Insight FD are interchangeable. You could get an HCH transmission and put the Insight's final drive in it to have a more linear 5 speed (and no eventual gear grind problem). The L15B transmissions from 2015+ Hondas have a remote chance of fitting, but I'd give it 50-50 tops, and they still don't have great final drives. You could reach out to one of the communities who mod Hondas for racing/drag - often people pair turbos with taller final drive, and this *might* exist in the CR-Z. The CR-Z's FD might be interchangeable with the 2015+ Fit and 2016+ Civic 6 speed final drives.

The K series have so many gearing options only because there are a variety of cars which come with them, some with large engines and large tires and some with smaller displacement and small tires, ranging from the Honda Odyssey/Element/CR-V on one end, to the RSX/Civic EP3 on the other.

[mpg_numbers_guy]

Originally Posted by Ecky

There isn't one, sadly, unless by chance the CR-Z and Insight FD are interchangeable. You could get an HCH transmission and put the Insight's final drive in it to have a more linear 5 speed (and no eventual gear grind problem). The L15B transmissions from 2015+ Hondas have a remote chance of fitting, but I'd give it 50-50 tops, and they still don't have great final drives. You could reach out to one of the communities who mod Hondas for racing/drag - often people pair turbos with taller final drive, and this *might* exist in the CR-Z. The CR-Z's FD might be interchangeable with the 2015+ Fit and 2016+ Civic 6 speed final drives.

The K series have so many gearing options only because there are a variety of cars which come with them, some with large engines and large tires and some with smaller displacement and small tires, ranging from the Honda Odyssey/Element/CR-V on one end, to the RSX/Civic EP3 on the other.

I'm presuming the grind already got fixed by the PO since the car has 257k miles now and no grinding at all.

What about a 6th gen EX trans w/ the Insight FD?. 1st is taller, 2nd-4th are shorter, and 5th is a hair taller. Compared to the HCH1 where you either have higher cruising RPMs and lower MPG due to the shorter FD or barely improved acceleration with the Insight FD, this setup would have the taller 1st and shorter 2nd. 3rd and 4th are comparable to the HCH1:

Trans	1st Gear	2nd	3rd	4th	5th	Final Drive	RPM @ 70 MPH
Insight	3.461	1.750	1.096	0.857	0.710	3.208	2392
HCH1	3.462	1.870	1.241	0.912	0.711	3.600	2688
6th gen EX w/ Insight FD	3.250	1.909	1.250	0.909	0.702	3.208	2365

6th gen EX vs 7th gen EX due to the taller 1st gear and slightly taller 5th gear. The closer gearing, especially with the taller 1st and shorter 2nd, would allow for earlier upshifts without losing as much power.

[Ecky]

6th and 7th gen Civics both use D-series engines and the transmissions are completely different. Insight, HCH, Fit and the newest Civics (plus also HR-V, CR-V and maybe a few other models) use L series engines and have a lot of interchangeability.

[California98Civic]

Originally Posted by Ecky

6th and 7th gen Civics both use D-series engines and the transmissions are completely different. ...

I want to thank you for this interesting addition to the thread. These are cool details. If I get a little time I might use some of it to update the OP if that's all right.

FWIW, there is a guy who claims to have successfully swapped a d-17 transmission onto a D16 engine. He has a thread on "D Series" with lots of photos that ends with him saying it works and showing the photo of the complete project:
https://www.d-series.org/forums/show...ries-swap.html

[Ecky]

Happy to contribute!

I'm not surprised the D17 transmission could mate with a D16, but the L series, R series and K series are likely not going to be as easy. On top of that, the K and L series had significant changes in the 2010-2015 era, and probably are not backwards compatible with older K and L. The newer K24W's gained direct injection and an offset crankshaft, while the L15B's moved from SOHC to DOHC and were reinforced to be able to take factory turbocharging.

[California98Civic]

Originally Posted by Ecky

For those who care about K-series Honda engines...

Hi Ecky,
I just updated the final drive information for the 7th Gen EX in the OP above--something you brought up in a different thread as a correction to the OP. The 7th Gen EX obviously not a K series engine, but I want to update the original post with some of the information that you've posted here about K series transmissions too. I said before I was going to do that, but I haven't yet had time. As soon as I get some real time, I will edit the original post to include a lot of this information. Thanks Ecky.

[Mista Bone]

before I read through all the posts, the original post needs some updating/correction. I might have made them before, but I haven't been on Ecomodder in some time, the CRX has been retired.

88-91 Civic DX LX / CRX

3.722 was 88 only, 89-91 was 3.889

All 1992-2000 trans have one of two speedo gears: EX/Si/HX use “big bore” black one and others use white one but outer diameter is the same.

Honda used white big bore (40mm) speedo gear in the 88-89 transmissions, but also a few have shown up in 96-00 EX transmissions, seems Honda was raiding the left over parts bin.

98-00 EX HB

Those didn't exist in USDM market, might be a CDM chassis/trans? Were they 35mm (small bore) like the 90-91 EX Sedan's or 40mm (big bore) like the 92-00 USDM? Quaife never got their info correct.

I haven't worked with 2001+ D series trans., so I cannot comment on those.

California98Civic, if you need more info, a PM should work and get to my email address. Thanks for the work!

-Mista Bone "D" tranny guru

PS: Those casting codes and 35mm vs. 40mm info, those were found out when I had 15-20 transmissions in the three seasons room at my old house 20+ years ago.

[Mista Bone]

Also you should see what Andrew Bense has been doing with other transmissions....

[Mista Bone]

Originally Posted by Mista Bone

Bense, these folks like to argue about lugging the engine even though You, Aquafina, and I have gotten insane MPG by spinning these little motors at higher rpms.

Close ratio ZC trans getting 48 mpg for example.

OH yeah, google search brought me back to ecomodder

Guess I had visited this thread before.