S13/KA24DE Automatic Options

[Lord Umoja]

I don't know if this has been asked before, but I couldn't find much.

What are the options for automatic transmissions that bolt to the KA24DE? Mine is starting to slip when cold and I'd like to have a backup planned. I'd also like to do some performance work on the KA, so something updated would be preferred. I ran into the trap of upping the power of a focus and promptly found out that the atx was not built for any extra power.

Although I'd like to do the manual conversion, my wife needs to drive the car some times and although she can drive manual, she is a little gun shy after having to drive the Mach 1 in an emergency a while ago.

Any tips would be greatly appreciated. Thanks!

[AZhitman]

It'd probably be cheaper to teach her to drive manual than to beef up a Nissan autotrans.

Historically, Level Ten has been the go-to experts for doing exactly what you're asking (they've built a lot of beefy automatics for the Q45 guys here). Trying to swap in a trans from another vehicle means plumbing, wiring, and ECU issues that might add up and be a PITA.

[Lord Umoja]

Level 10? At least I don't have to deal with Lentech this time around. Royal pain in the a** for the focus. Ended up having a local shop build that trans.

This car is peppy enough so I guess I'll just deal until the trans finally dies. Then is RB25DET and auto for this car.

[centralcoaster33]

A couple of articles come to mind...
http://www.nicoclub.com/archives/turboc ... 240sx.html
http://www.nicoclub.com/archives/240sxp ... rsion.html

Also, I do see used automatic transmissions for very reasonable prices on CL pretty frequently. The first one I see today is $190 and comes with the full package (drive shaft, shifter, flywheel, some OEM parts, plumbing, etc.).

[Lord Umoja]

Has anyone figured out the maximum power a stock auto can handle? I know for instance in the early 2000s focus could withstand 270ftlbs before failing. That left precious little leeway when drag racing as the converter doubled the apparent torque at high stall (torque braking) and why I had to build a custom trans after putting in some go fast parts.

I'd really really like to improve the car's performance but I am not going through the BS of another custom auto trans again.

[AZhitman]

Seems to me the KA trans is pretty robust. Considering it's the same as the truck unit, I'd guess the weak point is cooling.

My S13 'vert (before it was 5MT swapped and boosted all to hell) was stone reliable at 190hp through the slushbox.

[SoundEfx]

My S14 was boosted on an automatic transmission and it held its own with no slipping.

I can't remember where I read it, but I think that the auto transmission can hold up to 300 or more hp. But be prepared to do some rebuilding if you're continuously romping on it.