I want to get an Si tranny that is 20 spline since there is more aftermarket clutches for it since i have a 88 dx tranny.

i can get a si tranny for $200 cdn....

which one is faster with a turbo with a d16y7 engine?

 

i would think the Si. but the DX has longer gears. hmm...

 

thats what im trying to find out.....

dx you stay in turbo longer

si you boost the turbo up faster and change gears faster....

 

Up to a point, the tranny that accelerates faster(shorter gears) will be faster. Pick the Si trans. It is a MYTH that longer gears like in a DX or LS trans are better with turbo. My car picked up .5 by switching from a US S1 to a JDM S1.

 

A lot depends on how much horsepower you are running. If you were running 300+, then the DX is probably the best choice. I am running a DX right now with an est. of 130hp, and when I shift into second during a race, the engine revs down to almost 2k and has to work its way back up. Not very good with a car that doesn't have much torque.

 

yeah im not planning to make that much power.

thanks, i think il get the si now

im kinda interested in doing a hybrid tranny. but who knows

 

what about a hybrid zc tranny?

 

If it were me, I'd use the ZC trans with the Si fd.

 

It's never better to have longer gears. Longer gears accelerate slower. What kills the LS, DX, etc.. trannies is the longer gears. Please read this thread:
https://honda-tech.com/zerothread?id=358403

 

si plain and simple. It is the best geared tranny honda ever made. very good acceleration and very good highway. If you want even faster find a jdm zc tranny.

 

I dont agree nascars have long gears because the average 160mph speeds and have lots of power, street cars dont benfit from from long gears except for the occasional top end race and if thats not something U do everyday, you are really limiting your car by having a really long tranny with little hp. if your street races are from 0-130 or 50 punch to 130 ( which i assume is what honda people do) then the closer ratio tranny is better.

 

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

but if yuo can do that in fewer gears, ie less gear changes, it would be optimal for acceleration. </TD></TR></TABLE>

how so?? if tehg b16 tranny is getting into 3rd and 4th faster, the mph will be significantly higher than the other car that is still pulling in one less gear behind, unless you average speeds of over 150 I dont see in ANY way how the longer tranny i sbetter. sure you will be in 2nd or thired longer, but I am in 4th doing over 130 and still accelerating faster

 

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

and what was i originally talking about? nascar, and other high hp cars. for anything involving high speeds, longer is better. </TD></TR></TABLE>

but why? this is a crx forum. how will they benefit a from top end tranny like a Nascar? dont apply High hp v8 setups with cars that dont race past 125.

 

In terms of acceleration a shorter geared tranny is faster, period. If you think that your slower bc you have to shift one more gear in an si than in a dx then you cant shift. You should be quite ahead with the Si tranny for that extra shift. Tranny setups are different for each application. In the 1/4 you should be just at the top of 4th gear when you hit the end. If your shifting into 5th its much easier to use a slightly larger diameter tire/slick to get it just right. As far as F1 is concerned they have long gears because they actually reach speeds high enough to warrant them but still mantain great acceleration. And as for nascar they need an optimal powerband (3rd and 4th) more than pure acceleration. Good link by Jared.

 

Longer gears are better on boost, Instead of zooming right through the power band, It allows you to stay in boost range, Now it wont make any difference with no power, But yeah long is good... As far as a si or dx tranny, If you like tearing your tranny apart to put new bearings in it, Stay with the dx... If you want reliability get the si. I say get the si. Before some self taught Honda mechanic on here starts flapping his jaw, The dx tranny has smaller bearings, Which don't hold up to power at all... If I had a digi cam I could show you the extent of this damage on my dx tranny. But yeah, Stick with the si man. Save yourself the headache later...

 

Zooming through the power band = that power has been put down to the wheels sooner. As for staying in "boost range" with longer gears, your rpms drop more when you shift, not exactly what you want with a honda. But I agree greatly on the bearings and diff...the dx is a weak tranny.

 

i have a dx tranny and i been down the track over 100 times and its still as good as ever. this is with around 180whp and slicks. i prefer the si tranny over dx though, the dx lags going into 3rd and 4th.

 

The 5speed ( longer geared ) tranny is better for drag racing than the 6-speed ( shorter geared ) tranny, when it comes to stealth/3000Gts.. The 5-speed trany only uses 1-2-3 and the 6-speed has to shift into 4th..

Shifting = time

Is your car makes enough power to get you to XXXmph using 3 gears vs 4 gears, the 3 geared tranny is better.

BUT we are not talking about 500-600Hp 3.0L twin-turbo V6 motors...
I have a DX tranny, and I'd change it to an Si if i got the chance to do it for free.

It still took my DX 4 gears to get though the 1/4 traps, so I'd say the Si would be better until you started needing to shift into 5th ( which isn't very likely AT ALL ) before the traps..

Smaller/larger height tires can effect your gearing a lot, so If its that big of a deal, just get shorter tires with your DX tranny. ( tires will only effect the final gear ).

 

does anyone have a comparison of 1/4 mile times of a dx tranny vs si tranny with boost?

id think faster gearing is better since u engage boost faster and accelerate faster.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 89dxhunchback &raquo;</TD></TR><TR><TD CLASS="quote">Shifting = time</TD></TR></TABLE> Correct. I have a B17 in my EF hatch with a LS tranny. My friend has a B16 in his EF hatch with the JDM J1 close ratio tranny. Mods on both our motors are the same. Now before anyone goes off sayin the b17 is way more powerful, etc., its really not, at least not by much. b16 = 158hp, b17=160hp...torque figures only differ by like 7 or so ft. lbs. I beat my friend everytime we race, but not by much. Now beofre anyone goes off sayin i beat him by only a little because my motor is only a little bit more powerful...remember that LS trannys are WAY WAY different from the JDM J1 trannys....i mean WAY different at least towards mid to top end. When i do pull away from him, its always when he has to take the time to shift. Now i know i too have to take the time shift but not as often as he does. I was considering swapping in my JDM S1 tranny but i think i will wait on it. LS trannys (longer ratios) arent all that bad even if u dont have ALL the more hp/torque to pull u thru the gears. i guess u can somewhat relate this to a DX versus an SI D series tranny???

BTW my friend and i have run on the street and freeway and i get him everytime time


Modified by fourthgenhatchB17 at 8:52 AM 8/13/2003


Modified by fourthgenhatchB17 at 8:56 AM 8/13/2003


Modified by fourthgenhatchB17 at 8:59 AM 8/13/2003

 

in my case i should get an SI tranny because of bigger bearings?

 

if peeps say its stronger..then YES go with it cuz the extra power from the turbo will put more stress on the tranny.

 

I've heard that the Si is stronger, BUT I put 9 bottles of 75shot though my DX/Si civic H/B ( heavier ) and my friend went though 3 Si trannies during the same time in a HF ( D16A6 )Crx with boost (5-6psi).. I'm still beating on my DX...

 

so many mixed replies.. dont know what i should do

 

Just get the si... Shorter is better... Go into the forced induction forum and they will say the same...