I have been out of the 240sx circle for a few years because I purchased an STI and sold my 240 to pay for frequently broken axles. I recently purchased a 1990 240sx with 91' KA24de swap. I just gutted the interior minus door panels, dash, center console. This is going to be a daily driver, but I am not concerned with comfort as much as driftability .

I was talking about the RB and how great it is blah blah...I was dead set on this swap. Then a friend started arguing with me giving me the no replacement for displacement speech. I argued that I can get the same HP and I don't want all that weight up front, but I think he might have a point? I have been doing research for countless hours and can't find everything I am looking for nor can I find a general LSx vs RB25DET debate.

I'm not doing a KA24DET or an SR or CA so don't bother trying to sell me on them :P

What I am looking for for the LS1:

-Can you keep power steering? Pretty sure I saw an adapter in this forum section for this but wanted to be sure.

-Heating and A/C? I could really care less about the A/C but the heat is a must for defrosting/defogging/etc.

-How much harder is it than the RB swap? I can fabricate, weld, etc... I even get sheetmetal and stuff free so not as concerned about stuff like that. Just the hassle in general compared to an RB.

-Most important...Weight? How much do they weigh in the car with everything? If everything I have found so far I owe my friend an apology and the LSx motors are 300lbs lighter!!!!!!!?????

-Is there anywhere that has decent prices on swap parts for the LS motors? Hinson seems expensive. I can fab stuff, but its so much better to just bolt it in

-Electronics/engine management...When you start to mod the LS1 are there standalones or ways to change the S13 computer for this? Is the wiring harder/ more expensive?

I have pretty much been anti American Muscle since I was 16 and rode in my first SR swapped 240 so I have very little knowledge on V8s so any info is appreciated...Thanks

Would also like to know what weak points need to be replaced like differential etc...

motohead446 wrote:
I was talking about the RB and how great it is blah blah...I was dead set on this swap. Then a friend started arguing with me giving me the no replacement for displacement speech. I argued that I can get the same HP and I don't want all that weight up front, but I think he might have a point? I have been doing research for countless hours and can't find everything I am looking for nor can I find a general LSx vs RB25DET debate.

What I am looking for for the LS1:

-Can you keep power steering? Pretty sure I saw an adapter in this forum section for this but wanted to be sure.

-Heating and A/C? I could really care less about the A/C but the heat is a must for defrosting/defogging/etc.

-How much harder is it than the RB swap? I can fabricate, weld, etc... I even get sheetmetal and stuff free so not as concerned about stuff like that. Just the hassle in general compared to an RB.

-Most important...Weight? How much do they weigh in the car with everything? If everything I have found so far I owe my friend an apology and the LSx motors are 300lbs lighter!!!!!!!?????

-Is there anywhere that has decent prices on swap parts for the LS motors? Hinson seems expensive. I can fab stuff, but its so much better to just bolt it in

-Electronics/engine management...When you start to mod the LS1 are there standalones or ways to change the S13 computer for this? Is the wiring harder/ more expensive?

I have pretty much been anti American Muscle since I was 16 and rode in my first SR swapped 240 so I have very little knowledge on V8s so any info is appreciated...Thanks

Power steering is super simple

Heat is super simple

Fabrication will be about the same...nothing too complex at all

LS1 is lighter than an RB (aluminum lighter than iron)

Make your own mounts (carshop-inc.com has some nice universal ones you can cut up)

The LS1 computer is more advanced than the RB computer (from what I can tell) and can easily be tuned by any domestic shop around you. The wiring is also simpler I believe (LS1 wiring is VERY simple)

The LS1 is a dream to work on. I was also anti-Chevy for a long time until I really started to look in to the LSx series. Most parts have "o-ring" style gaskets and it has a very "import" feel to it...very high quality and you can't go wrong with it.

Hope that helps.

Oh also...these diffs will take a beating. No need to worry about them. The axles, however, might not last through too many high rpm launches on sticky tires.

not to be a mr.d!ck but i got a foot in the mouth when i asked these questions when i first signed up.

go on search, type in ls1 240sx build. and there ya go, theres a few builds that are very good, shows pretty much everything. in my opinion its actually an easier swap then a rb or jz.they make kits that drop right in.

but to the basic.if you have the money.....ls1>rb25....why?....everything

ls1: 305-350 hp and tq depending on what year/ much lighter.made in US. easy to get parts, almost every shop will work on it

rb25: 250hp and i think 215 tq(quote if im wrong)/ very heavy.hard to find parts, not many will work on it.

now this is my opinion, not yours.do what YOU want

i`d say the ONLY reason why i`d go rb is to keep it nissan.

just to give you an idea of how much an ls1 would be is well.i`m trying to keep it well under 8k, this includes lsd and minor other things,im almost done with a total of 6200 right now.3900 for 04 with t56 shipped(400 alone)2200 for mounthing kit, then lil things like exhaust, spark plugs etc.

if you keep the rb stock im sure you can keep it under that, but if your wanting even 300whp and tq you`ll have to do some work.

cnichols:hey man, love the car. did i see it in super street? i seen one looks just like yours with the hood up, guess what it had, ls1.it was the dec 2007 issue. was it yours?

cnichols- really appreciate the info. I have been researching non stop and I'm coming up with the same info.

I was pretty sure the differential would handle the power. I've never heard of anyone changing the diffs on 240s for any swap or any horsepower. Im guessing driveshaft shop would probably do axles. Ill research.

I found where it only takes 5 wires to hook up the ls1 and its basically a standalone by itself and super easy to tune.

I haven't seen much on custom mounts but I'm going this way. A friend of mine and I are going to open up a local shop for fabricating roll cages, intercooler piping, etc...

I plan on fabricating as much of my own stuff as possible-headers, mounts, y pipe, etc...

1991ls13- I was waiting on someone to say something haha. I must have been putting in the wrong search because i wasnt getting much info but have since had some luck. I still havent seen a dead comparison against these two engines and still like the idea cuz they are bost beasts. I hate to admit it though, other than revving, the ls motors dominate in every way. Are you pleased with your swap so far? Have you ran into any major problems? Are you mounting so that you dont have to mess with the firewall and transmission tunnel? I read where you can mount it lower and farther back without the gto pan but you have to cut into those.

im in the process of my swap right now. im going to have to beat the tunnel to hell i know that loli have the got motor so i wont need to do anything with the oil pan.but skiiy makes a kit that come with one,you siad you`d be making everything yourself so its going to be a little bit more technical.if your good at fabbing i`d just custom make an oil pan.

I would also like opinions on solid mounts. I've been reading alot on this to and have heard alot of pros and cons.

My car is gutted so its obviously not comfortable, but I don't want to rattle my brains out. It seems like a solid mounted V8 in a little 240 would be pretty bad. I read where some supra guys didn't mind their 2jz, but wouldn't the LSx be worse?

I was definetly thinking about fabbing an oil pan. I was reading how the LSx motors need a special pan for road racing? idk like i said not real knowledgable on the V8s. They said the pan was expensive so I'm going to try to get something to mach one up. My area isn't big on imports, but huge on muscle cars. Probaly why Im an import turbo guy, i love to be different.

1991ls13 wrote:cnichols:hey man, love the car. did i see it in super street? i seen one looks just like yours with the hood up, guess what it had, ls1.it was the dec 2007 issue. was it yours?

I believe it was, yes...my car had been on the road for about 8 months by then. If it was Mediterranean Blue w/ a Kouki front end and LS1, it pretty much had to be mine.

motohead446 wrote:I was pretty sure the differential would handle the power. I've never heard of anyone changing the diffs on 240s for any swap or any horsepower. Im guessing driveshaft shop would probably do axles. Ill research.

There is a factory upgrade option. 1 Driver Side Q45 (G50) axle and 1 Driver Side Z32 TT axle w/ a Q45 (G50) Diff and either Q45 or Z32 TT hubs will give you thicker output shafts and thicker axles w/ more splines.

awesome I appreciate the help