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View Full Version : 89-92 240sx tranny same as s13's??



**DONOTDELETE**
03-07-2002, 11:55 PM
my friend just told me this, is this true??

KenFuji
03-07-2002, 11:59 PM
??????
89-92 240sx is a s13..... do you mean the silvia?? if so are you refering to ones with a CA or SR???

**DONOTDELETE**
03-08-2002, 12:28 AM
i meant the same as the s13 sr tranny sorry.

Mav1178
03-08-2002, 02:28 AM
The bellhousing is different.

-alex

240sxTurbo
03-08-2002, 08:03 AM
But they will still swap

03-08-2002, 10:21 AM
Yes, the bellhousings will swap. But the gear ratios are different.

Asad

AKADriver
03-08-2002, 10:31 AM
The gear ratios are the same.

This chart lists all the Silvia/180SX gear ratios:
http://www.nissansilvia.co.nz/tech/Silvia-180SX%20Table.htm

which for the S13 & S14 SR20DET are the same as the ratios listed as 'spec' for the '91-'93 240SX in these improved touring rules (scroll down):
http://www.improvedtouring.com/tech/rules.html

...and as far as I know, all KA transmissions are identical. The ratios seem to match up to my experience with my '90.

If anyone has any evidence that an SR20DET 5 speed and a KA 5 speed have ratios other than:
1st 3.321
2nd 1.902
3rd 1.308
4th 1.000
5th 0.759

I'd like to see it.

**DONOTDELETE**
03-08-2002, 01:22 PM
yes, my friend told me the only difference is the bellhousing. thats it?? makes me want to get a s14 for the better tranny instead. =I

me - who doesn't like the ka tranny that much and if its the same as the s13 sr tranny, it can kiss his azz.

03-08-2002, 01:59 PM
Search for Aubrey's post about swapping the SR bellhousing onto his KA tranny. He's got some RPM/mph numbers in there.

Asad


Originally posted by AKADriver:

If anyone has any evidence that an SR20DET 5 speed and a KA 5 speed have ratios other than:
1st 3.321
2nd 1.902
3rd 1.308
4th 1.000
5th 0.759

I'd like to see it.<font size="2" face="Verdana, Arial[/img]

AKADriver
03-08-2002, 10:28 PM
ah, found it... he says:

"S14SHOCKKER-Every gear is the exact same EXCEPT the final drive (5th). Fifth gear in my SR tranny was a much lower ratio (held the RPMS much higher) than the ka. Now my gas mileage should improve http://www.freshalloy.com/ "

There's some conflict among some sites about what the fifth gear ratio is. Some say it's 0.838 for the SR and this must be what he had.

I stand corrected, but it's a pretty inconsequential change, since I've never used fifth gear in any of my cars during any sort of race. A close fifth is nice for lazy passing maneuvers on the highway, though...

Edit: I just read a post that followed, and he mentions some things that shouldn't EVER happen. His rpm/mph comparisons are from video, and I wouldn't trust them... #1 reason, because he lists different engine speeds for fourth gear. Fourth gear should be 1:1 in almost any 5 speed manual transmission, and certainly in both KA and SR transmissions since they're based on the same design. some of the numbers he lists just plain don't make sense at all. I'd be more inclined to believe clutch slip or gauge error than differing ratios.

http://forums.freshalloy.com/forum/ultimatebb.php?ubb=get_topic;f=21;t=000397

[ 03-08-2002, 10:40 PM: Message edited by: AKADriver ]

ruf4play
04-15-2002, 02:32 PM
Compiled the the mph vs. rpm side-by-side in excel for easier viewing and comparison.

KA tranny vs. SR tranny spreadsheet (http://www.biznetworking.com/ruf/files/)

My observations? 1st and 5th are a lot taller on the KA. 5th is pretty much useless outside of overdrive in which case it's very effective. While all of the gears on the KA tranny are taller, 1st is a LOT taller than 2-4. The separations between 2-4 are pretty similar. I personally think this gives two benefits:

1) It closes up the gear ratios which makes 1st gear more usable in a tight corner and makes the 1-2 shift less of a jump (keeps you in the powerband).

2) Taller 1st gear will help reduce wheelspin on launch (given that you're launching at an appropriate rpm). You can also stay in it longer before the 1-2 shift (more usable).

Just mindless speculation on my part... http://www.freshalloy.com/

SuperHatch
04-15-2002, 03:11 PM
I heard that the SR tranny has double syncros on first through third whereas the KA only has a double syncro on first. Of course, this is only what I've heard.

- Steve

ruf4play
04-15-2002, 03:18 PM
Originally posted by SRSteve:
I heard that the SR tranny has double syncros on first through third whereas the KA only has a double syncro on first. Of course, this is only what I've heard.

- Steve<font size="2" face="Verdana, Arial[/img]Shift right and it won't matter if you have single/double/triple/zero synchros... http://www.freshalloy.com/

-holier than thou

SRFiveTen
04-15-2002, 03:29 PM
Originally posted by SRSteve:
I heard that the SR tranny has double syncros on first through third whereas the KA only has a double syncro on first. Of course, this is only what I've heard.

- Steve<font size="2" face="Verdana, Arial[/img]per jdm s14 and s15 fsm:-
sr20det 5 speed transmissions have double synchros for 2nd and 3rd.
sr20de 5 speed transmissions have double synchros for 2nd gear, not 3rd.
sr20det 5 speed 5th gear is 0.759
sr20de 5 speed 5th gear is 0.838

of course, this is only what's in print.

RDM_II
04-15-2002, 03:33 PM
Same transmission for the RB20, CA, and VG30E also. Anyone know if the ratios are different for these models?

SuperHatch
04-15-2002, 07:33 PM
Originally posted by ruf:
</font><blockquote><font size="1" face="Verdana, Arial[/img]quote:</font><hr /><font size="2" face="Verdana, Arial[/img]Originally posted by SRSteve:
I heard that the SR tranny has double syncros on first through third whereas the KA only has a double syncro on first. Of course, this is only what I've heard.

- Steve<font size="2" face="Verdana, Arial[/img]Shift right and it won't matter if you have single/double/triple/zero synchros... http://www.freshalloy.com/

-holier than thou</font><hr /></blockquote><font size="2" face="Verdana, Arial[/img]http://www.freshalloy.com/

For those of us who don't like daily driving dogboxes.

- Steve