Forums/Z31P/z31-performance-upgrade-forums driveline-aa/Jatco 3N71B/4N71B (automatic trans) buildup information
Imported from Z31Performance.com Forums{{#if:Jason84NA2T| — original post by Jason84NA2T}}{{#if:2006-08-09 05:35:45|, posted 2006-08-09 05:35:45}}{{#if:68| · 68 post{{#ifeq:68|1||s}}}}{{#if:/Z31performance_archive/forum/z31-performance-upgrade-forums/driveline-aa/569-jatco-3n71b-4n71b-automatic-trans-buildup-information.html|
Local archive: view archived thread on dev.z31library.com}}
Jason84NA2T: (2006-08-09 05:35:45)
Both the KEAS and LevelTen valve body modifications along with other buildup information to make your automatic hold 400+hp is now located here for your enjoyment:
http://www.redz31.net/zip/zautomatic.zip
Special thanks to a mister bernard for sharing with us [archived image: biggrin.png]
300zxt: (2006-10-07 10:33:05)
KEAS rock, they're building me a drag transmission with transbrake when I got the coin because I'm not good enough to do it myself lol Good for 10s they say, and they're located close to me in Victoria! [archived image: smile.png]
Timbo_021: (2007-11-28 10:37:19)
Damnit,i buggered up somewhere.2-3 shifts excellent,1-2 shifts firmer but nowhere near as good as 2-3.Anyone done this?Im not sure where i went wrong..
Bernardd: (2007-11-28 13:22:32)
g
Timbo_021: (2007-11-29 07:53:37)
1-2 shift made 1 hole bigger to 9/64,but it was shit all.I shimmed the pressure regulator .125 and pinned the pressure modifier shut.Also driller a 1/8 hole for the 2-3 shift in the plate and thats about it.Reading the instructions,is there any hole sposed to be drilled in the bodys either side of the separator?I also have to get a turbo modulator before i go ripping it out again…hard to come by,those things.
Bernardd: (2007-11-29 12:08:07)
v
Timbo_021: (2007-11-30 08:26:12)
Wow,that is ALOT better than what i have..Thanks heaps champ!!Ill let you know how i go.
1SickZ: (2007-12-05 16:48:01)
will a 87 non-turbo automatic modified with this info handle 13 second Na2turbo passes?
Bernardd: (2007-12-05 18:24:52)
e
1SickZ: (2007-12-05 18:49:41)
Thanks. Is there a "rebuild kit" somewhere for this thing? So i can rebuild it and do mods at same time.
Sorry for all the questions, I'm on a new project for an auto and you know more about these auto's then i do!
Bernardd: (2007-12-06 01:20:31)
`
Timbo_021: (2007-12-07 12:24:06)
Modded the valve body again,love where it shifts and how little you have to press the throttle for it to upshift but it slips its ass off,mind you as far as i know it is an original auto..so gonna try tighten up the clutches..If thats a no go,shes getting parked till i get a manual…bugger the auto..lol
Bernardd: (2007-12-07 14:07:55)
`
Evil Z31: (2007-12-07 14:34:36)
You guys should offer this service to members. Or at least do mine. :lol:
Bernardd: (2007-12-07 22:59:00)
`
Timbo_021: (2007-12-07 23:44:15)
whats torque spec?ive looked around on google but not much comes up..
Bernardd: (2007-12-08 01:48:00)
`
Timbo_021: (2008-01-03 01:54:19)
Something went wrong somewhere,theres not enough pressure so once the fluid warms up it slips terribly.Gonna rip out the transmission today and put in the spare and leave it at that.What a waste of effort :-(
G-E: (2008-02-15 07:10:55)
was this a non-turbo auto?
Shady195: (2008-05-05 23:40:11)
I belive its for both
HowlerMonkey: (2008-09-16 17:39:33)
Turbos got a stronger tranny.
In terms of the 3n71b, you got more friction material and thicker output shaft.
I don't remember if the 4n71b got a thicker output shaft but I do know it has more friction material so the turbo implementations would be better starting points.
HowlerMonkey: (2009-04-24 23:30:21)
There are also some 4n71b with 4 planets instead of 3.
I believe one can peice together the strongest possible 4n71b using parts from both the RX-7 version and the Z31 version.
Bernardd: (2010-01-19 02:04:03)
x
Crazy: (2010-01-28 23:41:32)
Are these directions for building the auto trans into a manual shift?
Bernardd: (2010-01-29 13:57:27)
x
Crazy: (2010-01-29 16:19:45)
Are there any other supporting mods that that must be done to use this valve body? Vacuum modulator and or governor circuit?
Bernardd: (2010-01-29 18:11:32)
v
Grr: (2010-01-29 22:58:19)
how much?
Bernardd: (2010-01-29 23:51:42)
a
Crazy: (2010-01-30 02:42:47)
What holes were blocked off on the separator plate?
When you say the modulator is disconnected, is it just as simple as disconnecting the vacuum line?
Bernardd: (2010-01-30 15:21:06)
x
Crazy: (2010-01-30 15:57:47)
What did the manualized Keas valve body cost. Modding the separator plate looks like a lot of work and would be a lot easier just getting one from Keas.
Bernardd: (2010-01-30 16:42:02)
j
Crazy: (2010-01-31 02:07:25)
This looks like a good shop http://www.gzm.com.au/transmissions.htm
Bernardd: (2010-01-31 12:43:18)
h
Crazy: (2010-02-07 01:37:10)
Here is the email i recieved:
Hi Jason Prices Below
Stage 3 shift kit valve body only $220.00 c/o
Full manuel valve body $462.00c/o
Bilit Servos must be fitted with full manuel valve bodies for shift quality
Billet servo $110.00 Each 2 are needed Regards Goran GZM
What does c/o mean??
Bernardd: (2010-02-07 14:32:53)
x
Crazy: (2010-02-08 02:36:39)
I'm just getting ideas together for my 240sx build. What i have so far is a rust free clean 240sx with no motor a vg30, a turbo jatco 4n71b trans, and a Holset HX35. At a estimated 2500 lb race weight i may have some wheel spin issues so i was thinking about using a manual valve body to prevent wheelspin up shift problems.
Bernardd: (2010-02-08 14:04:35)
x
3rd Party: (2010-04-22 03:10:35)
i just want to say that this is AMAZING!!!
3rd Party: (2010-04-22 05:38:03)
i guess too i was kind of curious about the torque converter, 'cause it seems like you guys have the valve bodies figured out but what are you guys doing with the stock torque converter??
Bernardd: (2010-04-22 12:43:16)
x
3rd Party: (2010-04-23 08:28:26)
3k seems a bit high…i'm looking for no more than 2200 rpm for stall…
maverickxeo: (2010-06-10 07:53:05)
Stupid question:
Can these mods (or rather, the valve body mod) be done with the tranny still connected and everything or does it HAVE to come off the engine/body? If I gave this information to a mechanic (a good one) would he be able to build it like that?
Bernardd: (2010-06-10 22:48:56)
x
maverickxeo: (2010-06-10 23:07:44)
Ah… are they hard to do? Ive honestly never even taken the filter or pan off (my dad has though…).
87TurboZ: (2011-01-26 21:34:28)
Is there anyone making big power with these tranny mods? Anyone ever break this tranny with mods and at what power? I ask beacause ive got my 84 turbo with rebuilt vg33 and supposedly "built" auto trans it chirps 2nd gear so i know its not stock but im installing a holset hx35 and trying to get at least 450whp out of it and i dont wanna spend money on having jim wolf tune an auto ecu if the trans is just gonna break on the first run
JN210: (2011-08-25 04:17:42)
So im getting this done to my auto transmission, am I going to notice any big difference?
mods are, 3 row rad, intercooler, NA2T, and 3in stainless CM all the way through.
am I going to be putting down some good power through the level ten mods on the trans?
Rick88ss: (2011-08-25 05:25:00)
Don't forget a good transmission cooler.
JN210: (2011-08-25 05:34:38)
[quote]Rick88ss wrote:
So im getting this done to my auto transmission, am I going to notice any big difference?
mods are, 3 row rad, intercooler, NA2T, and 3in stainless CM all the way through.
am I going to be putting down some good power through the level ten mods on the trans?
Don't forget a good transmission cooler.
Will I really need one with the 3 row rad? I will probably get one because anyone knows more than I do about this, but im wondering.
shromy: (2011-08-25 12:53:09)
[quote]J18199 wrote: [quote=Rick88ss]
So im getting this done to my auto transmission, am I going to notice any big difference?
mods are, 3 row rad, intercooler, NA2T, and 3in stainless CM all the way through.
am I going to be putting down some good power through the level ten mods on the trans?
Don't forget a good transmission cooler.
Will I really need one with the 3 row rad? I will probably get one because anyone knows more than I do about this, but im wondering.
Yes.
reddzx: (2011-08-25 13:10:14)
I had this mod done to the auto 7/87 turbo I had earlier this year. It made a huge difference. Like adding a shift kit to a GM TH350 or TH400. I also used a brand new OEM turbo tourque convertor. I don't know about how it would hold up to additional HP because the car was stock otherwise. The transmission shop did not charge me extra to do the mod while doing the trans rebuild.
JN210: (2011-09-10 04:33:02)
So the shop in town doing this for me says that he saw debris on the internals of my trans, upwards to 2400 for complete rebuild…I dont have the money and its 280 for the mod. I of course just said do the mod and put it back together, will I be ok for ahwile so I can save up for a trans from level ten?
reddzx: (2011-09-10 13:02:44)
Hard to say if an otherwise used auto trans will hold up to a performance mod. I would not bet on it. I've had three auto trans rebuilt and never paid over $1800.
JN210: (2011-09-11 03:19:28)
Well its never been terrible for me and has been strong since ive had the car, and if its anything like the engine was (didnt have to be rebuilt at all ha) then I should be ok Im hoping, and even so, if it goes, it will be sometime in KC so I will be closer to some resources.
JN210: (2012-02-19 05:13:33)
Im going to quote myself here and say "you F*ing retard!!!" lol…trans took a shit and lost first and second gear, is on its way to level ten to be modified and built.
Was just wondering if anyone knows or has…any experience with their transmission in the Z? Im so excited to get it back in a week that I reaaaallly wanna know! haha
DMANN: (2012-02-19 15:27:31)
As soon as the weather lets up I can get mine on the road to let ya know.
Tracks here don't open again till end of April even then it is still cold to get real traction.
I did a complete rebuild on mine and all the mods from level ten and keas, except cryo treat, and the upgraded output shaft.
Also have a 3500 stall TQ that is waiting to be tried out.
I got max pressure, all the cushion out of it, set-up with a b&m rachet shifter.
87zxturbo: (2012-02-20 05:41:52)
Dmann, do you have pics of the shifter? I am interested to see what and how you did it.
thanks.
Sorry for the thread jack…
zmainiac: (2013-10-23 05:15:31)
What did u guys do about the ecu. Do u need to swap an auto ecu setup into a manual z or can u use the manual ecu. Also with the ugrades can u still use drive or do u have to shift manually from here on out. Its for a customer.
Tempast: (2013-10-28 04:54:48)
You can use a manual ECU only with a manual trans, and an auto ECU with auto and manual.
G-E: (2013-10-29 08:51:00)
Not true, your clutch/park lockout switch aside, the only thing you need for the auto ecu is the auto tps with the extra potentiometer output
zmainiac: (2013-11-01 14:20:28)
But would i need an auto engine and body harness for an auto too?
Tempast: (2013-11-04 05:29:05)
From my understanding the manual ECU needs to be swapped out if going from a 5 speed to an auto. I could be wrong, but I've read this from multiple places.
G-E: (2013-11-04 05:41:15)
I said for the auto ecu to run the car… yes you need an auto ecu to run an auto trans
260DET: (2017-04-09 10:22:10)
Just going to bump this mangled thread up because I may be going to get the auto out of the '87 turbo souped up. Depends on the minor detail of if it can be fitted behind a LS3 which has yet to be worked out.
260DET: (2017-04-10 21:31:23)
Might add that the people I'm in contact with build these auto's to handle 450hp so they should be fine for 99% of VG30/33ET's. These trans are way lighter than any alternatives which is why I'm considering using one, not cheap though.
260DET: (2017-04-14 22:10:23)
For any later readers, it looks like I won't be using this auto so nothing more from me. Unless I change my mind lol.
prax: (2018-12-16 08:58:15)
1-2 shift made 1 hole bigger to 9/64,but it was shit all.I shimmed the pressure regulator .125 and pinned the pressure modifier shut.Also driller a 1/8 hole for the 2-3 shift in the plate and thats about it.Reading the instructions,is there any hole sposed to be drilled in the bodys either side of the separator?I also have to get a turbo modulator before i go ripping it out again…hard to come by,those things.
some helpful pictures on the subject for anyone who might be curious about this old thread.
my link broke. thanks to dbruce for posting images of the same shift improvements below