Some RB Help For A Friend Of Mine

[side waz]

Hey guys what's up.

Well a buddy of mine has decided to put an RB in to his 91 240sx and I'm helping him out gather some intel. I could'nt think of a better place then right to do that. Always go to the experts I say.

Here's the plan as it stands right now. He's gona use an RB26dett engine with an RB25 transmission. I've told him to get the mounting kit from McKinney Motorsports for an easier install and placement as well, to grab the one piece drive shaft from them too. Since he's just about as bad with wiring as I am, he might as well take advantage of there wire service too and grab there downpipe so he can keep the twins. With all that I think he may even get a little package deal from them, no harm in asking.

So what we need to know is, are there any other parts he's going to need out side of the list below?

1. RB26dett Motor2. RB25 Tranny3. RB26 ECU???4. RB26 (uncut) Wire Harness5. Mounting Kit6. Driveshaft7. Downpipe

We know to upgrade the fuel pump and to get some kind of engine management which will either be an Apexi Power FC w/t Commander or GReddy E01 w/t Emanage. Then of course there will be the other odd little piece's like lines, fittings, gauges, fuel filter and so on.

What part of the KADE harness needs to be removed to splice in to the RB26 wire harness?

If the RB ECU is needed to replace the KA ECU, does the rest of the harness get plugged in to the new ECU? Meaning will the RB ECU take over running the entire car for all the lights, interior and so on? I'm guessing this will be just like swaping an SR in to a 240 as the SR ECU is needed but I just want to verify these things before starting.

Well that's about it for now but if there's any other items, info or advice you can add to this PLEASE post it up.

Thanks so much for this help guys, both my buddy and I really appreciate it.

Take care.

Easy

[DriftingisLame]

I'll wait for someone more knowledgable than me to answer most of your Q's... I believe you need to add an oil pan to the list of parts. The rb26 oil pan houses the front diff, does it not?

[skillzilla]

Yes Yes, you need an RB25 oil pan, and it has to be modified to fit the oil pick up and a couple of the bolts dont match up perfect. In fact, Ive heard this is the hardest part of the install

And yes, the RB ECU is used. The Lights and everything are run on seperate circuits on an S13, might run through the F3 plug on an S14 (not sure). On an S13 the wiring is very straight forward. Anyways, if youre sending your wiring off to McKinney, dont sweat it, they will make it work for you.

As far as other parts, Id add a new aluminum radiator to that list with some electric fans, since the slutch fan wont fit. Also, add an FMIC if you are getting a motorset. Its too early to really ponder this, so have fun with that

[gawdzilla]

definitely do all the basic maitenance mods first. Thermostat, timing belt w/ new tensioner and idler, water pump, new belts, clean injectors, new spark plugs, etc.

you'll need to either modify your rb26 oil pan or get a 25 pan and modify it.

No car controls interior lights and interior through the ECU. Thats what the body harness does, and you arent touching any of that for the swap. If you're getting mckinney's wiring service, just send them the entire KA engine harness and RB harness. they'll know what to do with it.

most likely your motor isnt going to come with all the intercooler parts and pipes. you'll need to custom those.

dont upgrade just the fuel pump without getting a regulator.

[side waz]

Thanks guys for the help.

Based on what your saying, do you think it may be better to just get full RB25det motor set instead?

[gawdzilla]

Thanks guys for the help.

Based on what your saying, do you think it may be better to just get full RB25det motor set instead?

that is up to you. the main differences in the 2 swaps is PRICE. rb26dett has a lot more initial costs, and the twins are more annoying to fit. Future upgrades are also more expensive just b/c thats the way their aftermarkets work. You probably won't find someone selling an rb26 motorset with an rb25 trans either, so thats probably another 500-1k on top of the motor cost. It is possible to get the rb26 awd transmission to work though... but mckinney's mounts/driveshaft dont support it to the best of my knowledge. Custom work is needed.

besides that, the oil pan modification and downpipe/steering column clearance is the biggest difference between the 2 swaps. it really comes down to personal preference.

[side waz]

Well the motor issue is'nt really a problem as I'm having another friend of mine who imports cars from Japan toss the motor in to the container. He's also going to gurantee that the motor was in perfect working condition and warrenty it as well so none of those parts will need to be changed. That's a really good idea though and something people should always do.

Now based on the oil pan issues and what not, my buddy has decided against the 26 and opting for the 25det. He knew this was'nt going to be a simple drop it but did not know about the oil and I did'nt think about it either, given the gtr is of course awd, so just to make things a little easier the RB25 is his, "final answer"

I'm gona search around here and see whats up with that swap instead but honestly, thanks guys for everything. My friend really appreciated it.

Take care guys.

Easy