S50 into s13

[rxm6]

Hey everybody,

I've been giving a lot of thought lately to doing an engine swap into my car. The issues are these, however, it must be california legal and must be completely unnoticed unless I pop the hood or accelerate. This has proven difficult.

So, I need some assistance from the brain trust.

Let me start off by saying the following:

I've looked into to the Ls1, Vq35de, and KA-T, all of which, under california law, are illegal to swap or make, because they all require modifying the headers, which is illegal. Otherwise, those engines would be perfectly fine and be legal. There is a gentleman trying to make his Ls1 s14 california legal, but I believe he modified his headers for his steering shaft.

Additionally, swapping those motors into the 240sx would mean that one would have to make the car OBDII compliant, which means more sensors and more junk that can cause you to fail a smog including having pre-cats on the down pipe.

So, I've embarked on a quest to find a swap that meets the criteria of keeping the car OBDI and doesn't involve modifying the headers.

I think I've found one, but no one in the US, to my google-searching knowledge, has done this swap, and there is little to no information on this and I'm hoping you guys might know something or know someone who might know something.

So the engine and transmission I'm planning on swapping would be an S50 mated to a ZF-5 speed transmission out of a 93-95 M3. So far, in everything I've researched, this seems to be the motor to end all motors as far as swaps go in terms of legality in california, especially for OBDI cars. However, I need to know certain information that I can't find, anywhere.

1.) What kind of signal does the 240sx gauge cluster use? I have to know if I can make the BMW ecu work with the stock cluster.

2.) Does the s13 ecu control anything other then engine function, i.e. I know that some cars route all information through ecu and then to gauge cluster.

3.) The final drive ratio of the s13 is too high for the s50. I need to know if I can swap the internals from an m3 diff into the nissan diff.

I've worked out everything else so far and if I just figure out the last of these issues then I'll be searching for a wrecked M3 before summer's end. Any help you guys can throw my way would be fantastic. Thanks.

[scooz14]

1.) What kind of signal does the 240sx gauge cluster use? I have to know if I can make the BMW ecu work with the stock cluster.

square wave

2.) Does the s13 ecu control anything other then engine function, i.e. I know that some cars route all information through ecu and then to gauge cluster.

no

3.) The final drive ratio of the s13 is too high for the s50. I need to know if I can swap the internals from an m3 diff into the nissan diff.

no, but the r200 is beefy. just look for a ring and pinion change, and a custom driveshaft which im sure you would need anyways.

[rxm6]

Thank you. Bmw ecu will work with gauge cluster.

And yes, I need a custom driveshaft and will look into ring and pinion change.

Thanks again.

[darens13]

that would be a pretty unique swap, good luck!

[rxm6]

that would be a pretty unique swap, good luck!

Thanks. I have a few problems I will need to solve when I actually get the engine and transmission, but so far everything seems to be falling in place as far as electronics and fitment is concerned. I think I will start a build thread for the benefit of anyone interested.

[Vetal]

Have you solved the problem with too high gearing in R200? I also want to swap in BMW engine but 3.69 gear in my diff is too high