A replacement for KA tranny for high power applications - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

ghostuss · 06-08-2005, 09:32 AM

Since my tranny is going out and I am getting a rebuilt engine for turbo. I am wondering what other alternatives to other than getting another stock KA tranny or a rebuilt KA tranny. I am thinking the RB tranny and interchange the bellhousing. Or something similar. I know people at phatka-t are trying to make a C4 automatic tranny work but I would like to stick with manual. Anyone have any other ideas out there that can share?

Redsunz916 · 06-08-2005, 10:20 AM

just buy a nice 2 plate clutch and lightend flywheel

BigVinnie · 06-08-2005, 11:51 AM

You can use the 280z "Lseries" transmission for the KA. Use the KA bell housing and the 280z gear box. Or have an adapter plate modified for the 280z bell housing. I think that is as good as it gets. But you will need a custom drive shaft, since it is custom I would go with an aluminum driveshaft.

ghostuss · 06-08-2005, 12:05 PM

Quote:

Originally Posted by BigVinnie

You can use the 280z "Lseries" transmission for the KA. Use the KA bell housing and the 280z gear box. Or have an adapter plate modified for the 280z bell housing. I think that is as good as it gets. But you will need a custom drive shaft, since it is custom I would go with an aluminum driveshaft.

so it's gonna be a 4 speed? Or do 280z come in 5 speed? What is the power rating on those tranny?

BigVinnie · 06-08-2005, 12:28 PM

There were multiple 280z transmissions depending on the model year. But all bolt up the same and all were 5speed. I even believe there is one that is called the"dogleg 5speed". I think 500HP is the max output power these transmissions can take, and it has a much wider gear ratio than the KA's stock transmission. I used the 280z transmission on a L16 build up for a 510 that I did. Top speeds were pretty good it wasn't done toping out and had gotten scary at 150mph, possibly with the VLSD gearing of the 240 you will hit a top speed of about 165, 170mph depending on the buildup and redline of your KA.

ghostuss · 06-08-2005, 12:04 PM

Quote:

Originally Posted by Redsunz916

just buy a nice 2 plate clutch and lightend flywheel

you are a fucking idiot.

Var · 06-08-2005, 11:59 AM

i heard somewhere you can use a t-5 from an older mustang but i dont know the extent of modification to make it work.

Bone · 06-08-2005, 01:19 PM

Tremec 5 speed but for most that will be getting alittle to custom. As several custom things would have to be done. Pretty much any transmission that will hold that power can be made to work with adapters and driveshaft modification. Maybe even some tranny tunnel mods. Its really not rocket science but does require some smarts and common since.

orion::S14 · 06-08-2005, 01:59 PM

Guys are making +400rwhp regularly on stock SR/KA tranny's, and having no problems. Occasionally you'll see someone break the tail shaft or an input shaft...but that's not strictly from power...it usually drag racing abuse that does it (wheel hop).

How much power are you looking for?

...

I'd rather replace 1 trans a year at a cost of $250/per...rather than buy a $1000 trans a custom bellhousing, plus custom driveshaft...just "in case".

- Brian

Var · 06-08-2005, 02:15 PM

seriously..plus David you're not even gonna push more than 300hp on your best day ever.

nismo101 · 06-08-2005, 02:21 PM

The stock KA transmissions have the same gearbox as the S13/S14 SR20DET gearboxes, same gear ratios too...and I have not heard of anyone complaining about the strength of either one.

Is your trans going out because of worn/bad synchros? If so, that is not a result of a "weak" transmission, it is usually because of misuse and neglect. I am drawing from about 6-7 years experience with the KA/SR platforms, and from what I have experienced and heard from others, the KA/SR transmissions are basically bulletproof. Now if you are doing hard drag launches on slicks with 400+ Hp, then you might want to keep a close eye on your transmission (and the rest of the drivetrain for that matter!). It is the impact loads that kill parts (i.e. clutch drops, wheel hopping, etc.), not normal acceleration.

As far as the 280(Z or ZX) transmissions go. I would not explore that any more. THey are old-tech, and are inferior to the KA/SR transmission. Most of the ones you will find will be hi-mileage with loose bearings, sludge, and leaking seals, not good! I bet the 280Z(ZX) guys are trying to figure out how to use a KA/SR transmission in their Z-cars!
The "dogleg" transmission mentioned above, is a 5-speed, but it is from an old 200sx, with the L20B. There is no way in hell I would consider putting one of those behind a KA/SR. It is SUPER-old tech(1975?). I ran one in my Datsun 510 behind an L20, so I am speaking from first hand experience.
They call it a dogleg because 1st gear is left-down and reverse is left-up. Its a piece of trash though.

I would advise that you stick with a good KA transmission and keep it clean and lubed.

p.s. It was kind of harsh calling that person a "f-ing idoit".....maybe he didnt understand your question. Try not to be so eager to flame.

Var · 06-08-2005, 02:31 PM

I thought the Sr trans 5th gear was shorter than the KA trans 5th gear.

nismo101 · 06-08-2005, 02:34 PM

So did I, until I compared the info from this site:
http://www.nissansilvia.co.nz/tech/S...SX%20Table.htm

with my USDM S14 factory service manual. same ratios.

BeerBringer · 06-08-2005, 02:39 PM

Get a BMW M3 e36 gearbox. Its one of the best gearboxes around and can handle 700+hp. Probably is expensive thoug...

boosteds13 · 06-08-2005, 03:08 PM

Quote:

Originally Posted by BeerBringer

Get a BMW M3 e36 gearbox. Its one of the best gearboxes around and can handle 700+hp. Probably is expensive thoug...

Uhhh....yeah. I'm sure that bolts right up.

SpeedMonkeyInc · 06-08-2005, 03:13 PM

OS Giken makes strengthened input/output shafts and gears. The gears are close ratio though. SPL Parts can get that stuff for you, its on their website.
Nismo101 already said it, I don't think its horse power that is going to break the tranny. Its the shock of being shifted hard, clutch kicked, and what ever other abuse it takes. I wonder if bracing the tranny is the best way to go? Solid mounts or solid inserts to keep the tranny from moving around and giving it less chance to twist. I have the Tanabe transmission mount solid insert and it makes a huge difference. No more shifter bouncing around on the high way and smother, more solid feeling shifts.

*Jeff240sx* · 06-08-2005, 03:41 PM

OS Giken stuff is $2k for the rebuild. Wait until you break a transmission before planning to "waste" or "dump" (however you look at it) money into it. And if it's something dumb that broke.. like a synchro because you did a 4-3 shift at the track, don't blame the tranny. If you had slicks and welded differential and broke a shaft.. look at just a stronger shaft.
Like Orion said.. these things don't just fall apart because you looked at it wrong. If you want piece of mind.. get a backup transmission to store until something happens to your current one, then swap it in. Take it easy on the backup trans until you figure out what happened to the first one. And it'd cost you $100 and some garage space.
-Jeff

06-08-2005, 09:32 AM	#1
ghostuss Zilvia FREAK! Join Date: Jan 2004 Location: San Diego/San Francisco Age: 39 Posts: 1,337 Trader Rating: (0) Feedback Score: 0 reviews	A replacement for KA tranny for high power applications Since my tranny is going out and I am getting a rebuilt engine for turbo. I am wondering what other alternatives to other than getting another stock KA tranny or a rebuilt KA tranny. I am thinking the RB tranny and interchange the bellhousing. Or something similar. I know people at phatka-t are trying to make a C4 automatic tranny work but I would like to stick with manual. Anyone have any other ideas out there that can share? __________________ 96 all suspension s14 SOLD 90 s13 coupe - SOLD Currently rocking 2002 BMW M3 w/ custom suspension. ButtonWillow, CA entire circuit drift/grip event by shock drifting spot for sale. Take over my spot for $150 only.

06-08-2005, 11:59 AM	#7
Var Post Whore! Join Date: Sep 2003 Location: Norcal Age: 43 Posts: 5,032 Trader Rating: (0) Rides Gallery: Var Feedback Score: 0 reviews	i heard somewhere you can use a t-5 from an older mustang but i dont know the extent of modification to make it work. __________________ Hi

06-08-2005, 01:59 PM	#9
orion::S14 Nissanaholic! Join Date: May 2003 Location: Orange Park, FL Posts: 1,666 Trader Rating: (0) Feedback Score: 0 reviews	Guys are making +400rwhp regularly on stock SR/KA tranny's, and having no problems. Occasionally you'll see someone break the tail shaft or an input shaft...but that's not strictly from power...it usually drag racing abuse that does it (wheel hop). How much power are you looking for? ... I'd rather replace 1 trans a year at a cost of $250/per...rather than buy a $1000 trans a custom bellhousing, plus custom driveshaft...just "in case". - Brian __________________ www.KA24DEvelopment.com

06-08-2005, 02:15 PM	#10
Var Post Whore! Join Date: Sep 2003 Location: Norcal Age: 43 Posts: 5,032 Trader Rating: (0) Rides Gallery: Var Feedback Score: 0 reviews	seriously..plus David you're not even gonna push more than 300hp on your best day ever. __________________ Hi

06-08-2005, 02:31 PM	#12
Var Post Whore! Join Date: Sep 2003 Location: Norcal Age: 43 Posts: 5,032 Trader Rating: (0) Rides Gallery: Var Feedback Score: 0 reviews	I thought the Sr trans 5th gear was shorter than the KA trans 5th gear. __________________ Hi

06-08-2005, 10:20 AM	#2
Redsunz916 Zilvia Junkie Join Date: Dec 2004 Location: Sacramento Ca USA Posts: 403 Trader Rating: (0) Feedback Score: 0 reviews	just buy a nice 2 plate clutch and lightend flywheel

06-08-2005, 11:51 AM	#3
BigVinnie Zilvia FREAK! Join Date: Apr 2003 Location: Walnut Crizzle, Crackifornia Age: 46 Posts: 1,266 Trader Rating: (0) Rides Gallery: BigVinnie Feedback Score: 0 reviews	You can use the 280z "Lseries" transmission for the KA. Use the KA bell housing and the 280z gear box. Or have an adapter plate modified for the 280z bell housing. I think that is as good as it gets. But you will need a custom drive shaft, since it is custom I would go with an aluminum driveshaft.

06-08-2005, 12:28 PM	#5
BigVinnie Zilvia FREAK! Join Date: Apr 2003 Location: Walnut Crizzle, Crackifornia Age: 46 Posts: 1,266 Trader Rating: (0) Rides Gallery: BigVinnie Feedback Score: 0 reviews	There were multiple 280z transmissions depending on the model year. But all bolt up the same and all were 5speed. I even believe there is one that is called the"dogleg 5speed". I think 500HP is the max output power these transmissions can take, and it has a much wider gear ratio than the KA's stock transmission. I used the 280z transmission on a L16 build up for a 510 that I did. Top speeds were pretty good it wasn't done toping out and had gotten scary at 150mph, possibly with the VLSD gearing of the 240 you will hit a top speed of about 165, 170mph depending on the buildup and redline of your KA.

06-08-2005, 01:19 PM	#8
Bone Zilvia Junkie Join Date: Jan 2004 Location: Chattanooga, TN Posts: 337 Trader Rating: (0) Feedback Score: 0 reviews	Tremec 5 speed but for most that will be getting alittle to custom. As several custom things would have to be done. Pretty much any transmission that will hold that power can be made to work with adapters and driveshaft modification. Maybe even some tranny tunnel mods. Its really not rocket science but does require some smarts and common since.

06-08-2005, 02:21 PM	#11
nismo101 Join Date: Dec 2002 Posts: 23 Trader Rating: (0) Feedback Score: 0 reviews	The stock KA transmissions have the same gearbox as the S13/S14 SR20DET gearboxes, same gear ratios too...and I have not heard of anyone complaining about the strength of either one. Is your trans going out because of worn/bad synchros? If so, that is not a result of a "weak" transmission, it is usually because of misuse and neglect. I am drawing from about 6-7 years experience with the KA/SR platforms, and from what I have experienced and heard from others, the KA/SR transmissions are basically bulletproof. Now if you are doing hard drag launches on slicks with 400+ Hp, then you might want to keep a close eye on your transmission (and the rest of the drivetrain for that matter!). It is the impact loads that kill parts (i.e. clutch drops, wheel hopping, etc.), not normal acceleration. As far as the 280(Z or ZX) transmissions go. I would not explore that any more. THey are old-tech, and are inferior to the KA/SR transmission. Most of the ones you will find will be hi-mileage with loose bearings, sludge, and leaking seals, not good! I bet the 280Z(ZX) guys are trying to figure out how to use a KA/SR transmission in their Z-cars! The "dogleg" transmission mentioned above, is a 5-speed, but it is from an old 200sx, with the L20B. There is no way in hell I would consider putting one of those behind a KA/SR. It is SUPER-old tech(1975?). I ran one in my Datsun 510 behind an L20, so I am speaking from first hand experience. They call it a dogleg because 1st gear is left-down and reverse is left-up. Its a piece of trash though. I would advise that you stick with a good KA transmission and keep it clean and lubed. p.s. It was kind of harsh calling that person a "f-ing idoit".....maybe he didnt understand your question. Try not to be so eager to flame.

06-08-2005, 02:34 PM	#13
nismo101 Join Date: Dec 2002 Posts: 23 Trader Rating: (0) Feedback Score: 0 reviews	So did I, until I compared the info from this site: http://www.nissansilvia.co.nz/tech/S...SX%20Table.htm with my USDM S14 factory service manual. same ratios.

06-08-2005, 02:39 PM	#14
BeerBringer Join Date: Apr 2004 Location: Sweden Posts: 27 Trader Rating: (0) Feedback Score: 0 reviews	Get a BMW M3 e36 gearbox. Its one of the best gearboxes around and can handle 700+hp. Probably is expensive thoug...

06-08-2005, 03:13 PM	#16
SpeedMonkeyInc Zilvia FREAK! Join Date: Apr 2003 Location: Oakland Age: 45 Posts: 1,271 Trader Rating: (0) Feedback Score: 0 reviews	OS Giken makes strengthened input/output shafts and gears. The gears are close ratio though. SPL Parts can get that stuff for you, its on their website. Nismo101 already said it, I don't think its horse power that is going to break the tranny. Its the shock of being shifted hard, clutch kicked, and what ever other abuse it takes. I wonder if bracing the tranny is the best way to go? Solid mounts or solid inserts to keep the tranny from moving around and giving it less chance to twist. I have the Tanabe transmission mount solid insert and it makes a huge difference. No more shifter bouncing around on the high way and smother, more solid feeling shifts.

06-08-2005, 03:41 PM	#17
Jeff240sx I hate you too... Join Date: Jul 2001 Location: Tampa, FL Age: 42 Posts: 5,828 Trader Rating: (0) Rides Gallery: Jeff240sx Feedback Score: 0 reviews	OS Giken stuff is $2k for the rebuild. Wait until you break a transmission before planning to "waste" or "dump" (however you look at it) money into it. And if it's something dumb that broke.. like a synchro because you did a 4-3 shift at the track, don't blame the tranny. If you had slicks and welded differential and broke a shaft.. look at just a stronger shaft. Like Orion said.. these things don't just fall apart because you looked at it wrong. If you want piece of mind.. get a backup transmission to store until something happens to your current one, then swap it in. Take it easy on the backup trans until you figure out what happened to the first one. And it'd cost you $100 and some garage space. -Jeff __________________ Whatup?