i wanna do a sohc zc swap soon, and my dx tranny is PERFECT, no grinds what so ever, all gears go in smooth. Would i notice a big differnece if i swapped in a si tranny? I know it hard to get a si trans in good shape, so thats why i asked. should i stick with my stock transmission?

i may throw a 75 shot on it down the road and im sure a si transmission would be nice then.

 

the gearing is different, most say its the best bolt on mod you can do. if you can afford it do it, if you wanna wait till you blow your old one then go for it. or you can try and drive another si and see how that feels. personally i went for it and picked one up.

 

Only the final drive is different between a DX and Si tranny, gears 1-5 are the same. It will make a very noticeable difference in acceleration.

 

yeah, NA or lower power, the si is wonderful.

i have one on a higher HP sohc (300 ish) and i almost dont like it..too short sometimes, hard to control the wheelspin before 3rd gear.

you can also do a hybrid tranny using dohc zc gears (hard to find)

there are lots of combos if you really want to get into it

 

You should go with the Si trans, but they are becoming quite rare nowadays. I just found one that a guy sold to me over ebay and said was in great condition and I got it and all the bearings were **** . Anyways, if you find one, be prepared to do a slight rebuild because it was most likely beat on and DON'T GET IT FROM EBAY!!!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fireant &raquo;</TD></TR><TR><TD CLASS="quote">Only the final drive is different between a DX and Si tranny, gears 1-5 are the same. It will make a very noticeable difference in acceleration.</TD></TR></TABLE>
werd.

What you could do is tear your tranny apart and stick a Si FD in it

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by wiZCo &raquo;</TD></TR><TR><TD CLASS="quote">You should go with the Si trans, but they are becoming quite rare nowadays. I just found one that a guy sold to me over ebay and said was in great condition and I got it and all the bearings were **** . Anyways, if you find one, be prepared to do a slight rebuild because it was most likely beat on and DON'T GET IT FROM EBAY!!!</TD></TR></TABLE>

thats great...i ordered an "si" tranny off of ebay and i got a "dx." paid a 140 for it. btw...i went on paypal and said, "item not as described" and got that sucka to pay half of the price back..so dx tranny for 70 bux.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CRX MASE &raquo;</TD></TR><TR><TD CLASS="quote">i wanna do a sohc zc swap soon, and my dx tranny is PERFECT, no grinds what so ever, all gears go in smooth. Would i notice a big differnece if i swapped in a si tranny? I know it hard to get a si trans in good shape, so thats why i asked. should i stick with my stock transmission?

i may throw a 75 shot on it down the road and im sure a si transmission would be nice then.</TD></TR></TABLE>

Lol, ur setup is gonna be identical to mine. Def. get the Si. Your timeslips will thank you.

 

i thought that the crx si tranny was the longest geared?

why would you want that? i can cruise the freeway at 65-70mph in therd gear at 3k rpms. too long.

 

Not to threadjack or anything but...how many RPM's would you be running at cruising 75 on the interstate with a DX tranny? 3.5k at 75 with the Si tranny gets really annoying, really fast. Great little transmission for around town though.

 

CRX/Civic Si tranny and the DX tranny are geared exactly the same. But the Si tranny has a 4.25 final drive as opposed to the DX's 3.88 Final drive.

This makes the Si tranny rip through the gears quicker. Thus it is better for acceleration, but worse for gas mileage.

The DX, as you stated, doesn't have longer gears, but the final drive lets the car take it's time through them. Bettter for gas mileage.

Si = Acceleration
DX/HF = Gas Mileage

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1989CivicSi &raquo;</TD></TR><TR><TD CLASS="quote">Not to threadjack or anything but...how many RPM's would you be running at cruising 75 on the interstate with a DX tranny? 3.5k at 75 with the Si tranny gets really annoying, really fast. Great little transmission for around town though. </TD></TR></TABLE>

Install an HF 5th gear. this gives you the quick acceleration and good 1/4 mile times of the Si tranny, but once you shift into 5th it kills the acceleration and lets you cruise on the freeway.

Kinda like when B16 tranny guys install an LS 5th gear.

 

in my si i have zc gears 1-4 HF 5th, best transmission you can have. 3200rpm at 80mph

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SiRay13 &raquo;</TD></TR><TR><TD CLASS="quote">in my si i have zc gears 1-4 HF 5th, best transmission you can have. 3200rpm at 80mph</TD></TR></TABLE>

No ****. Si FD, ZC 1-4 and HF 5th.

Awesome setup.

 

Awesome info guys, thanks. Now I just need to find the super rare (in the bay at least) HF trans. lol

 

i dont understand when you say the si rip's though gears faster.

my si takes for ever to finish any gears. espsualy 2ed gear, i take that bitch to 90mph.

im still confused, sorry.

 

I have an si tranny im selling. it would be a great mod to your ef project. 100 bucks.

 

it doesn't make you go faster per se, just quicker, having shorter gears keeps you in optimal horsepower range as you go through the gears. If that makes any sense.

 

man expletive this im goin to d-serise.org. they know d engines.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1989CivicSi &raquo;</TD></TR><TR><TD CLASS="quote">3.5k at 75 with the Si tranny gets really annoying, really fast. </TD></TR></TABLE>

Sounds like my 4spd auto, except without the accelleration.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ’90 honda crx &raquo;</TD></TR><TR><TD CLASS="quote">man expletive this im goin to d-serise.org. they know d engines.</TD></TR></TABLE>
bwahahhahah

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ’90 honda crx &raquo;</TD></TR><TR><TD CLASS="quote">i dont understand when you say the si rip's though gears faster.

my si takes for ever to finish any gears. espsualy 2ed gear, i take that bitch to 90mph.

im still confused, sorry. </TD></TR></TABLE>

Lol, are you serious? I'm redlining 2nd by like...100km/h or sooner. Doesn't sound like you have a Si tranny.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ’90 honda crx &raquo;</TD></TR><TR><TD CLASS="quote">i dont understand when you say the si rip's though gears faster.

my si takes for ever to finish any gears. espsualy 2ed gear, i take that bitch to 90mph.

im still confused, sorry. </TD></TR></TABLE>

Then you don't have an Si tranny, end of story. I currently am running an HF tranny and I redline the engine in second at about 92-93. Therefore I would reason that you have an HF tranny.

Here: http://crx.honda-perf.org/math/index.html It'll tell u. Use it.

BTW: I have an Si tranny sitting in my trunk. I cna't wait for it to go in! And no it's not for sale!

 

do it, you'll like it.

your si is not in 2nd gear if you're at 90mph!! i have an si tranny on my hf motor...man it's much nicer, it feels like a car & not a donkey cart.

 

lol, if you think the SI has short gears, try driving around a B16 motor and tranny.. Talk about cruising at high RPM's!!!