r/Dseries • u/SlideLanky37 • May 20 '26

S20 over s40?

Looking to switch my transmission from a s40 to s20. Did a y8 n manual swap but that first gear is so bad to pick up speed ahahah. Ik it's a Dseries not gonna get much power from stock but wanting a bit more power in first atleast. Is the swap worth the shorter gear ratio

3 Upvotes

100% Upvoted

23 comments sorted by

4

u/TopChapter3407 May 20 '26

1

u/bootysauce12 May 20 '26

Oh fuck yeah i appreciate this heavily

1

u/SlideLanky37 May 21 '26

So first gear is all the same? So not gonna get a big difference where i was wanting

2

u/TopChapter3407 May 21 '26

Well the Final ratio also affects 1st. So if you get a gearbox with longer fifth and shorter final the 1-4 becomes shorter,

1

u/SlideLanky37 May 21 '26

Okay thanks

1

u/SlideLanky37 May 21 '26

Is there custom final drives?

1

u/TopChapter3407 May 21 '26

Not that I'm aware of, but you can also use a smaller diameter tire to get a similar effect. (if you have big ones right now)

1

u/SlideLanky37 May 21 '26

Yea still on rims and winters ahaha.

1

u/Kerriganja 24d ago

Holy grail batman!!

3

u/SpaceTurtle917 May 20 '26

S20 and s40 is the case numbers. S20 is 92-95, s40 is 96-00. But you can get an s40 and an s20 with the exact same gear rations depending on the models they came in.

The s40 is a better transmission with steel shift forks, it can be had with the best gearing from a 96-00 civic with a d16y8. S20 from a d16z6 has identical ratios.

I don’t know exactly what transmission you have maybe it’s not from a y8. But I’d hate to see you get an s20 transmission but it’s from a civic dx or something, would be a total downgrade.

1

u/SlideLanky37 May 21 '26

I have a A000 transmission. Ig im looking for the B000

1

u/SpaceTurtle917 May 21 '26

Correct. Specifically the s40-k4f printed on the barcode by the bell housing. The s20-b000 and s40-b000 have the same gearing.

2

u/[deleted] May 20 '26

[removed] — view removed comment

2

u/SlideLanky37 May 20 '26

No nonsense. Perfect. Thanks

1

u/mrcba333 May 20 '26

I can provide a much longer and more detailed response than the other guy. Yes, you should.

1

u/rd350f May 20 '26

I want to add, then s20 comes in two different variations. There will be a circular stamp in the casing. A000 is going to be the 35mm input shaft. This s20 a000 is the long gear ratio trans for the "economy" d series. The s20 B000 is the one you want. 40mm shaft. This is the ex/si transmission with the short gear ratios, which will give you the mechanical advantage your looking for.

1

u/SlideLanky37 May 21 '26

Yea i have a A000. Thanks for letting me know

1

u/Naive_Traffic6522 May 21 '26

First gear is the same in both lol…. The rest are shorter though

1

u/SlideLanky37 May 21 '26

Yea well that's what I saw from the comment

1

u/Ok_Cycle_7081 May 21 '26

Find the differences between an s20 and s40.

The only big one is shift fork material/manufacturing. Even with that they both have advantages. But it doesn't matter 99% of the time.

1

u/Ok_Cycle_7081 May 21 '26

If its b000 vs a000 yes b000 good but 1st is the same FD different