Ka Tranny Vs. Sr Tranny ???????

[RUTH'LESSDET]

I was having some problems with my tranny the other day and I spoke with a friend from Heavythrottle...and he told me that the KA Tranny is the same as the SR Tranny as far and part #'s goes. The only difference between the two are the bell housing's.

My question is: Does the KA tranny have the same gear ratio's as the SR (S13) tranny??? does any body know I would appreciate that info thanx





:confused:

[Flybert]

I would like to know this as well so I'm giving you a bump.

[Negreac]

I was wondering the same thing. I had to find some numbers to get a dyno and I couldn't find any for either KA or S13 SR. All I could find was the CA18DET and S14 SR20DET ratios. These two were the same so I just assumed the KA and SR S13 numbers were the same. If the KA and SR have the same tranny that would make it much easier for me to upgrade my tranny since I wouldn't have as much downtime.

[TonyC]

I've heard the KA and SR tranny have the same internals, so I would assume the ratios are the same.

[aeontony]

Did a little poking around, and yup, they're the same.

http://www.vibratesoftware.com/html_help/html/Nissan/nissan_transmissions.htm

http://www.200sx.org/faq_2.html

[Bolo]

Looks like 5th gear has different ratios: .759 ka vs .838 sr

I wonder how much of difference in freeway driving it would make having a ka tranny on an sr. I noticed my sr revs pretty high while cruising around 80. And I drive back and forth from the Bay to LA a lot, so a ka tranny should give me better gas mileage.

[RUTH'LESSDET]

Originally posted by Bolo
Looks like 5th gear has different ratios: .759 ka vs .838 sr

I wonder how much of difference in freeway driving it would make having a ka tranny on an sr. I noticed my sr revs pretty high while cruising around 80. And I drive back and forth from the Bay to LA a lot, so a ka tranny should give me better gas mileage.

So it is different ??? 5th gear is that a bad thing or a good thing?? will it give me a higher top speed or something??

[RUTH'LESSDET]

Originally posted by aeontony
Did a little poking around, and yup, they're the same.

http://www.vibratesoftware.com/html_help/html/Nissan/nissan_transmissions.htm

http://www.200sx.org/faq_2.html



The tranny I have is out of a 95 KA Manual of course....The info on the first website is for a 97-98....which i guess is the same becuase nissan was probably too cheap to change anything... The second website list ratios for the S14 and s15 which is probably the same thing except the 6 speed version.....Man what the F*ck :bash: Sh*t is confusing!!!!


Somebody elaborate please

[Bolo]

Yeah with a ka tranny you should have a higher top speed, but 5th might feel a little more sluggish.

[Var]

LMAO!! are you guys for real? Anyone know the final drive ratio on the JDM s13? 5th gear in a KA is short enough. i cant believe the sr equipped on has even shorter gears with more power.

[Negreac]

Final drive on a JDM S13 is 4.083 for a SR20DET and manual trans. I'm pretty sure it's different on different engine options.

If you do the math at 7000 RPM with 24" diameter tires and a 4.083 rear end your speed will be 152mph with the SR tranny and 167mph with the KA tranny.

[Jeff240sx]

Originally posted by Negreac
Final drive on a JDM S13 is 4.083 for a SR20DET and manual trans. I'm pretty sure it's different on different engine options.

If you do the math at 7000 RPM with 24" diameter tires and a 4.083 rear end your speed will be 152mph with the SR tranny and 167mph with the KA tranny.

Its nice you did math, albiet bad math. In the link above, 200sx.org, a good source of sr info, has the JDM s13 differential at 3.692 for a SR20DET and manual trans.
So with new numbers, the same 24" tire, and the same 7k rpm, a .838 5th ratio in a SR tranny with the JDM lsd, top speed is 167.45 mph. The KA will run 167.18 mph.
This does eqate to.. at any given power level, SR-240s in America are inherently faster in the 1/4 than Japanese silvias at the same power level, faster in 0-60, and have an ultimately lower top speed.
-Jeff

[MadChild]

Wasn't the SR Tranny built to have close gear ratio for difting????

[Var]

Do you really think nissan built the car just for that?

[AceInHole]

everything exists for drifting. :bowdown: :bowdown: :bowdown: :bowdown:





:rolleyes:

[Jeff240sx]

Originally posted by MadChild
Wasn't the SR Tranny built to have close gear ratio for difting????

LOL! Just like the F-18s were built to be in airshows, and guitars were built to allow amplifiers to make noise. There is a cart, and a horse. Please choose again which comes first.
-Jeff

[Negreac]

Hmmm... I've been told multiple times that the JDM VLSD is the same as the USDM VLSD and open diff. I'm pretty sure it's 4.083. I'll double check when I go home on thursday, I happen to have a spare LSD from a 93 180sx in my garage.

[knghtryde]

Just to shed some light on this. I've used an SR20 gearbox on my KA and nothing changed. Not even my top speed. And this was a Turbo KA24DE. I also had my tranny guy tear the two transmissions apart and he told me that they where basically the same.

He then told me that the Z32 TT gearbox would fit on my bell housing and using the Z32 gearbox, with the Z32 TT VLSD by top end speed would increase drastically.

My brother just did this to his KA24ET. He hasn't had a chance to try to push it, but the car excelerates alot smoother.

I'm not going by numbers. I'm going by what happened when we actually tried it, and what happened when we tore the trannies apart.

[Var]

David. I remember you telling me about this. I'm concerned about the length of the drivsahft. You swapped the diff and the tranny at the same time. Did the driveshaft have to be modified?

[knghtryde]

You'd have to PM me. We have SR, VG, and KA driveshafts. My brother matched it up. There is actually a driveshaft that works, but off the top of my head I don't remember which one it was. There is one that will bolt directly in, and I'm almost certain its the SR driftshaft that fit, but like I said I'll have to go back and look at my brothers car to be certain. We did this motification about 6 months ago, and haven't done it since.

PM and I'll call you when I talk to my brother.

[RUTH'LESSDET]

Yes information I love it :aw:

[Jeff240sx]

Originally posted by Negreac
Hmmm... I've been told multiple times that the JDM VLSD is the same as the USDM VLSD and open diff. I'm pretty sure it's 4.083. I'll double check when I go home on thursday, I happen to have a spare LSD from a 93 180sx in my garage.

www.200sx.org. Longtime australian site dedicated to 200sx's, or Silvia's in Japan. They have 3.692.

Originally posted by knghtryde
Just to shed some light on this. I've used an SR20 gearbox on my KA and nothing changed. Not even my top speed. And this was a Turbo KA24DE.
He then told me that the Z32 TT gearbox would fit on my bell housing and using the Z32 gearbox, with the Z32 TT VLSD by top end speed would increase drastically.


1 - You're right. The sr20det gearbox won't change a single aspect of your car, due to the fact they are the exact same ratios, and you say gears and I wouldn't be surprised. The differential is the object in question here for sr topend.
The gear ratios from a 1996 300zx tt are:
1 - 3.21
2 - 1.93
3 - 1.30
4 - 1.00
5 - .75
FD - 3.69(2?)

Speed by gear:
300zx TT tranny / diff
1 - 41mph
2 - 70 mph
3 - 104 mph
4 - 135 mph
5 - 181 mph
With the aforementioned 24" diameter tires at 7k.
Compare these with the KA/SR tranny with stock 4.086 FD
1 - 37
2 - 64
3 - 94
4 - 122
5 - 161

So yea.. you'll get a bit slower acceleration through all gears in exchange for a lot more top end, and most people comming through the 1/4 mile at the top of 3rd with a 300zx tranny, versus 4th in a KA.
-Jeff

[Negreac]

That's the final for the s14 and s15, it even says so right on the web page you pulled that info from. I went out and tested the JDM VLSD in my garage and it is most definitly a 4.083 not a 3.692 final. The VLSD I have is from a 1993 180sx.


Here's some more info directly from some FSMs:

S13 CA18DET:
3.916 (europe)
4.363 (everywhere else)

S14 SR20DET:
3.692 (M/T)
3.916 (A/T)

S15 SR20DET:
3.692 (M/T)
3.916 (A/T)


Next time you call someone out for bogus info make sure that it isn't you who is wrong. All that'll do is confuse people and spread incorrect information.

[RUTH'LESSDET]

Thanx alot guys this is very helpful to me feel free to add more if you like