16 replies to this topic

[G1Fanatic]

Here's my questions, and I do hope someone can help.

1. Is it possible to swap a ZC final drive (3.88) into a USDM 87 Integra 5sp?
Everyone seems obsessed with low gearing for acceleration, but I want top
end speed. The built 87 D16A1 I've got has more than enough torque for it.

2. If it IS possible as I suspect, then WHICH ZC tranny do I get the diff and R&P
from? Anyone? Sources?

There's tons of info out there for all the 2Gen guys on hybridizing the Si final into the ZC tranny for all-out acceleration, but what about us old-ass 1G speed freaks?

Hope to hear from you soon, as she's in the shop, on the rack, and I'm desparate for answers that few in this import-challenged part of Arkansas can provide. Help!

[TurboG1Rex]

I too would also be interested in this. seeing as how my Turboed D16 has horrible wheel spin until 3rd this would be a good way to take advantage of the torque and get some top end out of it too. haha 200 MPH G1 CRX

[eezerz]

they'll all have wheel spin unless you pour cement inside the car, they're sooo light. i don't understand? how much top speed are you loking for? do you want to kill yourself? i've been up to 185km/h pretty quickly and that's as fast as i wanted to go, believe me! but the car still had lotsa BALLS left. i just wasn't willing to try. it's too damn fast as it is. and you guys are putting in turbos and nitrous, building internals ect... a 84-87 civic/crx with a zc swap has more than enough potential to easily hit 220km/h. so i don't get it, how fast do you want to go with a street legal car??? there's really no point in changing the gear ratio, i'm sure honda/acura researched it's trannies for the best overall drivability and fuel economy. personally i think their tranny's are great!!! but we should be thinking more along the lines of stengthening them and making them last, rather than screwing them all up... there's not many left you know....

[sspcivic31]

housman can make you a custom ratio r/p for the tranny. he has made some similar final drive to what you are looking for. sorry cant tell you any more than that. i dont think the l3 style tranny shafts will interchange with the cg tranny.

a 84-87 civic/crx with a zc swap has more than enough potential to easily hit 220km/h

i've seen 7800 rpm in fifth gear enough times to know that.

[jsgprod]

OK , I posted something on here a week or so ago about something similar.

TJ, (an rpr member) has a lot of info on what you're asking about. As a matter of fact, before I actually met him, I discovered that the ZC and 1st gen Teg trans are not compatible. I was going by some information that I got from his site. They are similar, but different. I discovered that they were different because I failed to pay attention to everything that I was reading about what transmission he was using when he was showing how to change some gear ratios. I assumed he was using a 1st gen Teg transmission like the one I had. He wasn't .

What I did discover from his site, was that the ZC trans IS compatible with the 2nd gen CRX trans. (the point that I had missed)

Check out this link and see if it helps: tjshondas.20m.com/l3.htm

Oh, one more thing. You should be able to see a bit more than 220 kph with that setup . I know for a fact a well built STOCK, WITHOUT HEADERS, THROUGH THE MUFFLERS, '85 Si will do 130 mph! I've done it lap after lap at Daytona Speedway back when I ran in SCCA showroom stock racing. And I wasn't looking at any speedometer either. I calculated it with the rpm and tire diameter.

Jay

[rpr]

I discovered that the ZC and 1st gen Teg trans are not compatible.

You have to be careful when you say that. The ZC tranny that was on the 86/87 Civic/CRX's and 86-89 Tegs will work just fine with a D16A1. I don't know if the actual gears will swap easily, but the transmission itself will. I know because I've done it. I used an 87 USDM teg tranny on an 89 JDM Integra ZC.

[jsgprod]

You have to be careful when you say that.

Umm, yeah, you're right Tom. They do interchange externally as you mentioned.

It's the internals that I was really referring to. We bought a '90 Si tranny to get a better final drive for the early Teg gearbox. Till I took it apart anyway. Then I discovered that it wouldn't work.

THAT'S when I went back and read the article a little closer and noticed that he used a ZC gearbox to install the USDM 2nd gen final drive into.

Jay

[sspcivic31]

You have to be careful when you say that. The ZC tranny that was on the 86/87 Civic/CRX's and 86-89 Tegs will work just fine with a D16A1. I don't know if the actual gears will swap easily, but the transmission itself will. I know because I've done it. I used an 87 USDM teg tranny on an 89 JDM Integra ZC.

but the 86-89 integra with zc uses a cg tranny(if he can find one of these it has a different final drive ratio), not the l3 style tranny of the later zc's that fit the 88-91 civic/crx. really your best bet is to just pay the 1300 bucks(unless he came down on the price) to houseman and get the ratio for the final drive you want.

[shadowboy]

Here's my questions, and I do hope someone can help.

1.  Is it possible to swap a ZC final drive (3.88) into a USDM 87 Integra 5sp?
  Everyone seems obsessed with low gearing for acceleration, but I want top
  end speed.  The built 87 D16A1 I've got has more than enough torque for it.

2.  If it IS possible as I suspect, then WHICH ZC tranny do I get the diff and R&P
  from?  Anyone?  Sources?

There's tons of info out there for all the 2Gen guys on hybridizing the Si final into the ZC tranny for all-out acceleration, but what about us old-ass 1G speed freaks?

Hope to hear from you soon, as she's in the shop, on the rack, and I'm desparate for answers that few in this import-challenged part of Arkansas can provide.  Help!

the D16A1 doesn't have enough power to redline 5th even with the stock short gearing.

by going with a taller final drive you will actually REDUCE your top speed.

the 87 tranny 5th gear redlines at about 135mph. it would take about 160-180HP to go that fast.

Edited by shadowboy, 19 January 2004 - 09:10 AM.

[sspcivic31]

the D16A1 doesn't have enough power to redline 5th even with the stock short gearing.

umm, yes it does . maybe not in an integra but it does in a civic/crx.

by going with a taller final drive you will actually REDUCE your top speed.

not so much . you reduce the engine rpm you cruise at(compared to original f/d) and increase the potential top speed. now you do have to have enough power to reach the top speed.

the 87 tranny 5th gear redlines at about 135mph.  it would take about 160-180HP to go that fast.

based on a 22.8" tire diameter with 4.24 final and .848 5th gear 7000 rpm in fifth is 133 mph and it does not take that kind of power to go that fast(not in a civic/crx)
with the 3.88 final drive it is 144 mph

Edited by sspcivic31, 19 January 2004 - 10:10 AM.

[shadowboy]

the D16A1 doesn't have enough power to redline 5th even with the stock short gearing.

umm, yes it does . maybe not in an integra but it does in a civic/crx.

by going with a taller final drive you will actually REDUCE your top speed.

not so much . you reduce the engine rpm you cruise at(compared to original f/d) and increase the potential top speed. now you do have to have enough power to reach the top speed.

the 87 tranny 5th gear redlines at about 135mph.  it would take about 160-180HP to go that fast.

based on a 22.8" tire diameter with 4.24 final and .848 5th gear 7000 rpm in fifth is 133 mph and it does not take that kind of power to go that fast(not in a civic/crx)
with the 3.88 final drive it is 144 mph

weight has NO EFFECT on top speed. weight only affect ACCELERATION. at top speed your net acceleration is ZERO. the only thing your engine is doing at top speed is overcoming friction which comes in 3 forms:
1: aerodynamic drag
2: driveline friction
3: rolling resistance of tires

#2 is fairly constant, and #3 will increase with a heavier car. this is the ONLY way weight will have an effect. and both are NEGLIGIBLE compared to #1 at 100+mph. don't believe me? stick your head out of the window at 100mph and see how even the smallest debris in the wind hits your face.

it takes the 118HP of a g1 integra to go about 120mph, if that (mine has trouble breaking 115, its also down on power).

a g1 integra has similar aerodynamic drag as a CRX (slightly more, but not much almost identical Cd, slightly more frontal area. not enough to affect the top speed by more than 1-2mph).

the relationship between top speed and horsepower is MORE THAN QUADRATIC

in other words it takes MORE THAN 4x the power to double your top speed.

as an approximation of MOST compact cars, it takes about 120HP to go 120mph

1: an 87 teg has a 4.21 final drive, not 4.24
2: 195/60R14 tires (stock tire size for that engine) has a 23.1" diameter, not 22.8. the 0.3" won't make THAT much of a difference anyway. but 133mph isn't much anyways, so i will work with that anyway

133/120 means you need to go 1.108x our reference speed. which means you need to SQUARE this number to get the HP needed to go that fast.

which comes out to 147HP. ok, so the 160-180 was an overestimation. It was JUST AN ESTIMATION. not an exact calculation.

my point is that no REMOTELY STOCK D16A1 OR ZC is going to have anywhere near enough getup to redline a stock CG tranny.

the 88-89 teg tranny has a slightly taller 5th gear, (good for about 5mph faster at redline).

the 3.88 final drive will reduce your top speed.

remember that an ITR with 195HP tops out at about 143 or so - drag limited.

it takes about 500HP to go 200mph.

Edited by shadowboy, 19 January 2004 - 10:40 AM.

[sspcivic31]

samuel l jackson said:

Look at the big brain on Brad

it takes the 118HP of a g1 integra to go about 120mph,

well if were gonna get nit picky the 86-87 teg has 113hp vs the 88-89 with 118.

1: an 87 teg has a 4.21 final drive, not 4.24

the final drive is 4.214. typo. sorry.

and the stuff i posted about this is MY experience with the d16/cg combo in a civic si. i have seen 7500 rpm(fuel cut) on more than one occasion. and it will do it and it will do it with 4 adults in the car. weight(as you assumed) was not the reasoning behind what i said. it because i never have driven a teg to redline or tried.

the 3.88 final drive will reduce your top speed.

um. no. like i said before it will increase your top speed potential and lower the cruising rpm's from the stock f/d.

[sspcivic31]

on a more helpful and less mathmatical side of things:

g1 fanatic if you can get a cg tranny from an uk crx 1.6i-16 it looks to have a 3.866 fd and same other gears as the 86-87 us cg tanny.
that data is from Autocar article in july of 1986

edit: www.honda.co.jp/HOT/ModelData/civic/cv3-k-309/line_up.html#siCivic Specs has all the specs for the jdm civics. they also got the 3.866 f/d that should work for you. paste the link into this and look at the si.

Edited by sspcivic31, 19 January 2004 - 11:56 AM.

[shadowboy]

a 3.88 final drive is a big increase in top speed potential. you'd need to make at least 18% HP over what it would take to redline the stock tranny. assuming 130HP will redline the stock tranny, you'd need to make almost 160HP to redline the 3.88 final drive.

the reason why that would DECREASE your top speed, is because if you aren't reaching peak power before redline, then your effective power is less. the 3.88 will work ONLY if you reach your HP peak at top speed.

i hope you're "substantial" mods include forced induction, cause it ain't happening with a streetable N/A car.

an 88-89 5th gear with taller tires (say, the integra's 195/60R14, or if you wanna be really crazy, 205/60R15) would be a smaller and more subtle increase of potential top speed

86-7 teg = 0.848 5th
88-9 teg = 0.823 5th.

7000rpm in an 88-89 CG trans with 195/60R14 tires is about 137-139mph.

my "118HP" comment was from MY experience with MY integra, which happens to be an 89. and it was STRUGGLING to break 115mph (as i said i know its down on power. i have approximated its power loss to about 5-10% which would bring to about the 86-87 power level).

there are SO MANY variables to top speed though. like:
incline?
inflation pressures?
clutch slippage?


as for the brains comment. NOTHING from that post came from anything more complicated than a high school physics course.



anyhow, all a mute point because how often will you need to make these top speed runs. i personally find acceleration when needed FAR more useful than having a 3mph better top speed.

[sspcivic31]

apparently reading wasnt your strong point(thank god it was math/physics) because the original poster said this:

Everyone seems obsessed with low gearing for acceleration, but I want top
end speed. The built 87 D16A1 I've got has more than enough torque for it.

now based on what he said what do you think?

by going with a taller final drive you will actually REDUCE your top speed.

a 3.88 final drive is a big increase in top speed potential.

well at least your coming around now.

Edited by sspcivic31, 19 January 2004 - 11:50 AM.