I'm about to start swapping my d16a6 back into my hatch(taking out the LS) and will be boosting it. I will prob be around 200hp when fully tuned. I was looking for personal experiences with SI and ZC trannies under boost.

*******I DO NOT WANT TO BUILD A HYBRID TRANS*********

i'm leaning towards the ZC trans for the equal length axles and closer gears.
i was thnking with the ZC tranny beaing a closer ratio it would help keep me in boost better.

this will be a daily driver so having uber short gears isnt needed


opinions???


joe

 

hybrid si case with zc gears i did the to mine i like the pull in 3rd

 

89 - Did you even read his post?


Racin - I'm going to assume you've played with this:
http://crx.honda-perf.org/math/index.html
If you haven't, its a good way to see what gears will do what at at specific rpms/shift points etc. Because they're performance is so similar in stock trim, its strictly a matter of personal preference.
I also like to play with gear ratios in GT4 or 1-3. Simply as a simulation. Take the two options and run them witht he same engine on a timed strait line course and see what does better.

Its getting very hard to find a Si tranny in good shape. On the other hand, low mileage ZCs are pretty easy to find. I'd stick with an importer and not a private party because they'll usually give you some kind of warranty.
Since you've already got a LS engine, theres no axles to buy. Just make sure you get a ZC intermediate shaft with the tranny purchase.

 

i have an Si trans at the house, it was fine when i pulled it out of my old crx

thats a great calculator

it looks like the ZC trans is slightly taller, which is what i assumed. though its not really a problem

will the closer gears help keep me in boost??

 

you should go with a stock dx 5 speed for boost

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Brownjd &raquo;</TD></TR><TR><TD CLASS="quote">you should go with a stock dx 5 speed for boost</TD></TR></TABLE>

Not really. The stereotipe of longer trannies for boost is bs unless you have large amounts of turbo lag. This would give the turbo time to build pressure while being in the same gear. You could use this if you don't like boosting from every stop light/ or if the car is a daily driver. ZC tranny from any angle you look at it, is a more sports oriented tranny for boost or na.
Yes it will keep you in boost more often therefore you would have faster acceleration

btw, what does the label say on the zc tranny? L3 or what...

 

can't argue with you on that, turbos aren't too much in my field of knowledge. i just thought the more time you spent under boost the better, so what good is it to have a turbo if your shifting gears so fast that you only reach full boost for a couple seconds. a lot of turbo gsr guys go with an ls tranny for that reason.....just what i always thought but i don't know much

 

hybrid si case with zc gears i did the to mine i like the pull in 3rd


holy crap thats the most educated post of the year damn you only made it 5 posts and there it is. LOL why the hell would anyone put the zc gears into an si case when the zc case is made for equal length axles? What kind of gain would that provide? Especailly when its cheaper to buy the zc trans then the gears itself. Im sure you like the pull in 3rd lol wow

 

Yes the ZC tranny is cheaper.

But with the hybrid you dont need to swap axles if you use the SI case. Plus to use the ZC intermediate shaft I'm pretty sure you have to have a mounting point for it. Also if you use the SI final drive the ratio is better (IMO). So dont diss the hybrid, I love mine.

But not to thread jack.....

I read this arguement in the forced induction area a week or so ago, longer vs shorter gears with boost. The only usefull info I could gather from their argument was that if you have traction, shorter gears are better. For boost my vote would be for the SI

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vegaskurt &raquo;</TD></TR><TR><TD CLASS="quote">Yes the ZC tranny is cheaper.

But with the hybrid you dont need to swap axles if you use the SI case. Plus to use the ZC intermediate shaft I'm pretty sure you have to have a mounting point for it. Also if you use the SI final drive the ratio is better (IMO). So dont diss the hybrid, I love mine.

But not to thread jack.....

I read this arguement in the forced induction area a week or so ago, longer vs shorter gears with boost. The only usefull info I could gather from their argument was that if you have traction, shorter gears are better. For boost my vote would be for the SI</TD></TR></TABLE>


all d-series blocks have the 3 bolt holes for the int shaft mounting, look under the alt. you'll see them.

shorter or longer gears isnt even the ??. both trannies are pretty much equal in that respect,
its just the ZC has shorter/closer gears w/ longer final drive
VS.
teh Si with longer gears and a short final drive.

so ZC it is, i figured my assumption was correct.

 

I learn something everyday on this board. And yeah I guess equal length axles would be a plus when you start generating some power.

 

my zc tranny will be here on tuesday and my last tranny was an SI so ill let you know which i end up liking better.

 

did you get your trans from hmotors???

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 91dxhatchswaped &raquo;</TD></TR><TR><TD CLASS="quote">LOL why the hell would anyone put the zc gears into an si case when the zc case is made for equal length axles?</TD></TR></TABLE>

I kind of like my peg leg trans and having to buy new axels = . Plus I've seen the ZC gears go pretty cheap on ebay and you could buy those and get a rebuild get and get a brand new tranny, whereas a HMO ZC trans will set you back $200[last time I called] and has been used/possibly beat. - Darrell

 

i would just take the zc tranny and swap in the si final, done deal.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1point5CRX &raquo;</TD></TR><TR><TD CLASS="quote">i would just take the zc tranny and swap in the si final, done deal.</TD></TR></TABLE>

if i didnt have to get on the highway everyday i would.

gas prices suck the nuts, especially when you are going 70mph at rediculous rpm's


edit: just called hmotors wont have any in stock for 2-3 weeks, $260 incl int shaft and shipping,

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vegaskurt &raquo;</TD></TR><TR><TD CLASS="quote">
I read this arguement in the forced induction area a week or so ago, longer vs shorter gears with boost. The only usefull info I could gather from their argument was that if you have traction, shorter gears are better. </TD></TR></TABLE>

Exactly

 

only thing i need to complete my car in the grip dept is traction bars.
i've already filled teh mounts and have poly susp bushings

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fast88std &raquo;</TD></TR><TR><TD CLASS="quote">

Not really. The stereotipe of longer trannies for boost is bs unless you have large amounts of turbo lag. This would give the turbo time to build pressure while being in the same gear. You could use this if you don't like boosting from every stop light/ or if the car is a daily driver. ZC tranny from any angle you look at it, is a more sports oriented tranny for boost or na.
Yes it will keep you in boost more often therefore you would have faster acceleration

btw, what does the label say on the zc tranny? L3 or what...</TD></TR></TABLE>
+1
well said

 

i don't know about boost, but i have a zc tranny and i think they are a lot better that a si tranny. i don't even have zc axles. i have si axles with accort cv joints on them. the only problem is that when you are going down the highway 65 mph is like 3500 rpms. i and going to put in the si final drive next time i have is apart and i would really suggest you do the same. if you are going to use zc axles on an si block you have to get a mount hole for the carier barring.