I have a d16a6 with stock L3 tranny and I'm not happy with it.

Every gear feels like a "granny" gear. I find myself using 2-4 and ignoring first gear, but these are just a bit too tall. Also, I would like 5th gear to be taller for highway cruising.

SO, here's my idea... I want to find an LSD JDM ZC, rebuild it to use an HF 5th gear and a CA HF final drive.

I've been searching and reading and as near as I can tell this hasn't been tried (at least not written up).

Here's the stock LSD ZC gears:

JDM Si LSD (ZC) Actual (ratio * FD)
1st 3.250 12.636
2nd 1.944 7.558
3rd 1.346 5.233
4th 1.033 4.016
5th 0.878 3.414
FD 3.888
Rev 3.153 12.259

If I replace the FD and 5th, here's what I'll get:

Hybrid (CA HF) Actual
1st 3.250 10.563 <- taller than Si first gear, not as tall as Si 2nd gear
2nd 1.944 6.318 <- taller than Si 2nd, not as tall as 3rd, etc.
3rd 1.346 4.375
4th 1.033 3.357
5th 0.694 2.256 <- nice tall(er) highway gear vs. Si
FD 3.250
Rev 3.153 10.247

I think this would be a nice improvement over the stock L3 tranny:

Si Actual
1st 3.250 13.813
2nd 1.894 8.050
3rd 1.259 5.351
4th 0.937 3.982
5th 0.771 3.277
FD 4.250
Rev 3.153 13.400


MY QUESTION:

If I get a ZC LSD and the HF FD & 5th gears will they go together? Are they completely interchangable? Will HF components handle 150-175 HP? Or, is this a pipe dream?

Thanks for the help!

 

Yes, they are all interchangeable.

 

so you want a long geared transmission, and are calling a shorter gear ratio a "granny" gear?
why not just put an HF transmission in there? or swap the hf findal drive into the si transmission?

and why would you worry about making more power? is that so you can make up for the gearing that is going to slow your car down?

 

yes its compatable. i bought a hf trans and swapped my old si final drive and 1-4 into it because i liked the short gearing. currently running an EX sedan transmission as one of my diff bearings seized and blew out my diff

 

I'm using the ZC 1-4, and Si 5th, Mine pulls well, and i'm near 200... Not sure what "Granny Gears" you're talking about. Maybe time to inspect your synchros?

 

Would love your FD.
Sedan has the oddball one that is somewhere in between.
That, with ZC 1~4 would be quick and still have a nice 5th to cruise on.

 

i think it's the 4.025 like the 92-95 dx's get. but has the si 1-5. the butt dyno says it's not quite as quick as the si fd. but i like it, revs are quick but not so much that im shifting every 2 seconds. the gap from 2nd-3rd is kind of big though, however it will be perfect for when i'm boosted.

 

Just put an HF 5th in the Si and call it a day.

 

pretty much. and there is a reason why it hasnt been done cause its not worth it.


better luck doing a rare 4.4 final drive then hf-5th with a zc 1-4th sounds better to me. but good luck i sold my last 4.4 final drive which took me a long time to find.