SR20 tranny vs. KA24 tranny

[Unlawful 240sx]

If i was to use the sr20 tranny on my ka motor. (according to J spec SilEighty it will work if i swap bellhousings.) What will i gain and what will i lose, performance wise. And which clutch would i end up having to use. A clutch for a ka or a clutch for a SR. Also if anyone knows how to do this swap let me know exaclty what needs to be done.

[ghostchild316]

A clutch that bolts on to the flywheel that bolts on to whatever motor it is you're goin with.

IMO this is a waste of time

[J SPEC SilEighty]

SR tranny:
1st - 3.321
2nd - 1.902
3rd - 1.308
4th - 1
5th - .838

KA tranny:
1st - 3.321
2nd - 1.902
3rd - 1.308
4th - 1
5th - .838

As you can see, the transmissions both have the same gear ratio's so you won't gain/lose anything performance wise. If for some reason you still want to put the SR tranny onto the KA motor, then your going to need the SR bellhousing as well because the KA's bellhousing is bigger... Therefore the KA bellhousing and SR tranny wouldn't bolt up.

Now something that isn't the same is the Final Drive. You only have to worry about this if you are swapping the rear differential to an SR unit as well. If you want to keep the same gearing, then make sure the diff your getting from an SR is coming from a NON-TURBO model. The non turbo model uses the same ratio as the diff in the 240sx, 4.083. Now if you got a rear differential from a turbo model SR20, then your final drive is now going to be lower, 3.692.

Also, one thing to note while doing this... Before installing the tranny look inside the bell housing. There is a little button looking piece that can be in three different positions. Pushed In, flush with the bell housing, or sticking out:

Make sure that the button is Flush with the bellhousing or you will not be able to shift once the tranny is installed, which is obviously very important.

[gunluvS14]

from what I know, both of them are identical unit - w71C. (strength wise, both should hold up to 400-450ish hp)
And it is true about the SR has different bellhousing compare to KAs, just like what Jspecsil80 said.

But I can almost for sure the SR 5th gear is taller than the KA, but it doesn't really matter much.
Also, most people agreed that SR has triple sychro for 1st and 2nd grear, double sychro for 3rd and single sychro for 4th and 5th. Which seems to be better than the KA since the ka has single sychro all around. but it could be a myth.

Another thing, if u going to swap the SR tranny into the KA, the lower ka tranny harness will be use. But SR has a lot less sensor than the KA, so all u have to hook up is the speed sensor and the reverse sensor, and cap off the rest.
Ka has 3 extra one(neutral, 4th and 5th gear).

about the clutch, just match it with your flywheel application. KA has different flywheel diamter than SRs.

well, good luck