Hey guyz, I used to have an Si L3 tranny and now I got a junk yard L3 tranny from a dx. Would it perform the same with my turbo setup? Would the gear ratios be longer (better for turbo) since its a dx tranny? Or would the si l3 tranny still be better? Needs opinions on both p.o.v.'s. Thanks!

 

the only difference in the 2 trannies is the final drive ratio. the si is 4.27 and the dx is 3.77. the gears themselves are the same ratio. so basically you are just looking at a torque multiplier/ tops speed issue. im not sure what other people do, but when i turbo my si, i am keeping the si tranny.

 

to clarify...........

88-91 Si = 4.25
88 DX = 3.72
89-91 DX - 3.89

 

Would it be possible to remove the final drive from my old si tranny and put it in my dx tranny? Would it be the same?

 

very possible to do.

Strip ALL gears and bearings off the DX countershaft, install on the Si countershaft, then swap the ring gear. LH threads on the ring gear bolts!!!!!!!

The only limit will then be a Si tranny with DX size bearings, no easy LSD upgrade later.

 

the dx tranny should be shorter gears and can perform better... atleast my friends ls-t seems to run better with ls tranny...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mista Bone &raquo;</TD></TR><TR><TD CLASS="quote">to clarify...........

88-91 Si = 4.25
88 DX = 3.72
89-91 DX - 3.89</TD></TR></TABLE>

88 dx had a different final drive. go figure... didnt know that.

 

it took opening a tranny from Acid Beav, then quick research to confirm.

That 3.722 FD took 3rd place in EP Solo Nationals last year, This year Fred ran a complete ZC setup, still placed 3rd

 

yeah, i immediately opened my 88 helms to verify when i read it.

oh yeah, dont forget the sedans (dx, lx, ex) came with a 4.058 FD. i learned that recently too. (had to buy a civic manual to verify! ive yet to find a EF civic manual online that WASNT the civic CRX.)

[edit]

oops, i meant "SEDAN (DX, LX, EX)", not "sedan (std, dx, si)" which obviously refers to hatchback models.


Modified by Tyson at 11:31 AM 9/19/2005

 

DX sedan = 3.889
EX sedan 90-91 = 4.058 small bearing case.........

 

i dunno about 88-89 sedans, but my 90 civic manual states all sedans are 4.058.

 

Question... what's the purpose of the FD? How does it differ in performance from 3.98 to 4.25?

 

the final drive is the last gear reduction before power is transferred to the axles. its the big gear on the differential, maybe youve seen before. so it affects all the gears 1-5 uniformly.

the final drive does NOT mean 5th gear... (i've made that mistake before i realized what it was myself)

 

So ... the higher ur FD the longer ur gear ratios? Or shorter?

 

larger the FD, the shorter the gear.

 

the lower your final drive the higher your gear ratios which also means more torque and faster acceleration... that torque comes at a price though... it means your top speed in each gear is lower... longer gear ratios are better for turbo cars and shorter gear ratios are better for N/A cars... i dont know which one is best for a supercharged car or a car on spray but my guess would be shorter gears... i just put the dx tranny on my z6 three days ago and im happy with it... each shift puts me right back in the powerband and the gears are long enough for turbo which is in my future plans dx tranny=
-Josh

 

higher, lower, shorter, taller, longer, faster, slower....

are we mixing terms here?

 

why I like quoting the gear ratio.........people get the terms all mixed up.........then mass confusion ensues......and the earth stands still!!!!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tyson &raquo;</TD></TR><TR><TD CLASS="quote">higher, lower, shorter, taller, longer, faster, slower....

are we mixing terms here?

</TD></TR></TABLE>

did i use the wrong termanology(sic)... if so i apologize... but my overall concept was correct at least... right?
-Josh

 

Okai... so I guess my dx tranny is perfect for me!!! HAHAHA. PWNED. Lol. I was just wondering that's all. I took a tranny out of a dx 88 jdm chassis with jdm tags. If I'm still at 80 miles an hour at 4 k rpm... then my gear ratios haven't changed that much... (its a 5spd tranny too)... iono... bewildered... need more info!!! =P

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Crimson_Tide &raquo;</TD></TR><TR><TD CLASS="quote">

did i use the wrong termanology(sic)... if so i apologize... but my overall concept was correct at least... right?
-Josh</TD></TR></TABLE>

no, not really. you contradicted yourself several times.

 

ok i think i see what i did...
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Crimson_Tide &raquo;</TD></TR><TR><TD CLASS="quote">the lower your final drive the higher your gear ratios which also means more torque and faster acceleration</TD></TR></TABLE>

that should look something like... the lower your final drive the higher your gear ratios which also means LESS TORQUE AND SLOWER ACCELERATION... correct?
-Josh

 

lets make it simple.

with a Si tranny, 4.25 FD, in 5th gear and going 65mph the engine will be revving at 3148 rpm.

with a DX tranny, 3.88 FD and same 5th gear, itll rev at 2880 rpm.

 

so does that mean that am better or worst off with my si motor and my hf tranny.

 

it just changes the wheel speed and engine rpm ratio.

its up to you what youre "better" off with.