RB25DET Auto into S13

[KyleSil40]

Within the next few months I am looking to swap an RB25DET auto into my S13 coupe. I'm wondering what exactly I need, or if it's the same as a manual swap. I can't find much info on auto RB swaps but I have a guy that can fabricate almost anything for me. Before bashing the auto swap idea, lets just say it's in my price range and that I will be getting a manual trans later on. Car has no engine or trans in it right now. Thanks guys :)

[Feast Japan]

Within the next few months I am looking to swap an RB25DET auto into my S13 coupe. I'm wondering what exactly I need, or if it's the same as a manual swap. I can't find much info on auto RB swaps but I have a guy that can fabricate almost anything for me. Before bashing the auto swap idea, lets just say it's in my price range and that I will be getting a manual trans later on. Car has no engine or trans in it right now. Thanks guys :)

Ive done several auto to manual swap on R32 GTS-t's. On the reverse swap you will need:

Prop shaft
Rad with ATF sub-tanks or run external cooler
ECU and sub-harness
Crossmember
Flex plate and thin shield
Shifter assy

This list is getting long. I suggest if your hard up for auto then to scrap the OE crap and get a bell adapter to run TH350/400 trans. Atleast that way the shifter is easy and you can throw a lot of power at it.

Ive been thinking ER34 Skyline for long time now as dedicated drag car. It would have to be set up with a dedicated trans.
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[KyleSil40]

Ive done several auto to manual swap on R32 GTS-t's. On the reverse swap you will need:

Prop shaft
Rad with ATF sub-tanks or run external cooler
ECU and sub-harness
Crossmember
Flex plate and thin shield
Shifter assy

This list is getting long. I suggest if your hard up for auto then to scrap the OE crap and get a bell adapter to run TH350/400 trans. Atleast that way the shifter is easy and you can throw a lot of power at it.

Ive been thinking ER34 Skyline for long time now as dedicated drag car. It would have to be set up with a dedicated trans.
Save

The engine (RB25det) and auto trans is already connected as one unit, with wiring harness and ecu, wouldnt that elimate the need for another flex plate and make things a bit easier? Maybe I am misunderstanding you not sure

[Feast Japan]

My bad ,understood. In that case just figure out member support, bit of wiring and you should be good. But do get a dedicated cooler for that unit.

[KyleSil40]

Awesome, thank you. It's hard to get a straight up answer when you are asking about an auto swap, people love to give you shit for it haha

[supersayianjim]

pick up my clutch pedal and master/clutch line for a s13

[Standard]

Not trying to bash on your plans here, these are solely my opinions and that's all.

If You're planning on eventually swapping to a manual trans, don't waste the time on doing this, it might seem like a good idea budget wise right now, but will probably be much more costly in the end. Do it right the first time!!

Is your chassis auto or manual?
Does it currently have an engine in it?

You're young, I know swapping in a RB series engine is like the best idea ever right now and it will be so badass, but I would encourage you to hold off on it. Save up your money man, do tons and tons of research and if your car is currently driveable as is just leave the engine alone and have fun with it! Don't get sucked into a money pit project that could very well never be finished, happens all the time. I wish you the best of luck, I've owned my s13 since I was 17, it has come a long way, but of course there are many things I wish I would have done differently when I was younger, nothing unfixable thankfully.

Not sure why I'm writing all this, sorry hahaha
For all I know you could be a millionaire trying to build a japanese drag car to add to his collection of cars! lol

[KyleSil40]

Thanks for the reply. I've thought about it and I'll probably just leave leave it auto, I really have no reason to get a manual other than the fun factor. The car currently has no engine or trans in it, and it's a manuals chassis. I bought the car as a project and I have no interest in drifting at all, I just want to cruise it and maybe go to the drag stip with my buddies a few times. The way I look at it, this will be the most fun to drive engine swap option on my current budget and it will fit my needs well. I was going to go with an SR20DE and 5 speed before this swap came up which was the same price, and since auto doesn't bug me I figured the extra 100 horsepower would be more fun. I'm not really concerned on getting stuck up on a few things during the project, as I have a good daily driver, but I was just wondering if it will be a big hassle and if it's even worth it.

[gaz_moose]

converting a manual chassis to auto will just be a pain. can you not source a manual RB gearbox? even a small casing box off an Rb20 or RB25de will fit on a 25DET engine and be ok providing you don't kick the cars head in doing drifting or dump the clutch stle drag launches.