sr or rb

[robtackett]

I have a 89 s13 and am trying to decide what motor to swap in. I have seen s13 with skyline motors in them and I have done a SR swap. I am wondering which is better? Does the RB swap bolt strait up like the sr or are there a bunch of custom parts I will need. Any help would be much appreciated. thanks

[Chas]

I cannot say which motor is better, but i would contact gary at mckenny motorsports. He sells mount kits for rb's, and plug and play wiring harnesses.

[Ghost of Duluth]

Great idea. My brother is fabbing mounts for the RB swap and according to him you just need motor mounts. The tranny will go in the stock location and mount. Once again, I haven't done this swap so I am not 100% sure of that but he is usually right.

Plus he makes all sorts of stuff for the RB. The mounts, intake and exhaust manifolds, custom fuel rails that go with the intake to eliminate all that busy-ness on the side of the motor.

Hit him up, he can answer some stuff for you. Mike at www.tophatperformance.com.

[aphxero]

What's wrong with your stock engine? Did you blow it up? You can get another KA for cheap(like $100-300).

BTW, if you're doing this for no reason perhaps it's not the best idea. Have you modded your suspension? how about brakes/tires. LSD?

A more powerful motor swap won't make you drift better.

[VuDuDoc]

I have the RB20 in my s13. I chose it for many reasons but here is the answer to your questions.

Drops in with the use of the skyline crossmembers.
There really is no need for a mount kit..but here is what they do....
The mount kit utilizes the s13/14 crossmembersand allows for lowering of the engine by 1-2 inches. This helps as the BOV pushes on the hood.....that issue can be resolved with a washer or 2 on the hood bracket points.

The RB20det uses the skyline x member and KA driveline.

RB25 same as a bove with modification to driveline as the input yolk has a different spline count and transmission length.

RB26dett HIGHLY RECCOMEND MCKINNEY MOUNT KIT!!!! allows retention of twin turbos.

Advantages of RB's
engine layout puts more mass before the struts allowing for easier drifting(all RB's)
RB25 and 26 are good drag cars with good hp capabilities with little internal upgrading.rb25 can nail 12sec 1/4 practically stock.
performance!
you have to drive in one to appreciate

Disadvantages
easier drifts equal autox no no
not everyone wants a drag car
maintenance fees may be out of some peoples range along with upgrades.
SR provides good all around package

Recommended upgrades
Stiffer springs for cornering(front end dive in cornering pronounced)
Better pads or brake upgrade(rb25 can nail 12sec 1/4 practically stock)
VLSD!! one wheel wonders dont cut it

Recommend the RB20 as it is cheap but realistic goal is about 380hp. Then rb25 due to driveline mod. Dont recommend rb26 due to high starting costs.....you can have a highly beefy 20or 25 for the price.

[quickstyleRPS13]

good stuff vududok. i plan on doing the rb26 swap. and for the dude who posted this thread an rb25,or26 motor is alot of power to start off with but if you have already had an sr or built ka and you just want more out of a stock motor go for it. iv been looking for the stuff to do the swap myself and the best place iv seen is www.mckinnymotorsports.com for info and parts.

[robtackett]

r

Well the motor I have in it is the single cam one. It runs good and only has about 110k miles on it. I have a ultra light flywheel, act clutch, injen intake, short throw shifter, greddy sp exhaust, and the TEIN HE coilovers. I guess the next thing I need to do is get a good LSD. I just got my taxes back i can use that money. What is a good one to get? I want more power that is why I am looking into the swap. But I did just find a carb kit for that motor so I might go that way. I don't know and thanks for all the help and coments.

[hachiroku-fc3s]

If you get mikuni carbs, you will be my idol. I have dreamt about it for a while now. I wanna buy every KA24e powered 240sx I see and build it. NA style baby. Sounds like you have a pretty good setup as is. I would go with mikunis and lsd. But I think differently (for myself) than most ppl. Which RB are you thinkin? Not that it matters. I would still recomend it above the SR, but I guess I am just curious and could provide some info depending, though you seem to have a lot of good sources above too. Man, somewhere in time a lot of smart ppl showed up. Mad love for the KA. woot.

[Ghost of Duluth]

Wonderful info VuDuDoc. I agree, there is nothing like driving an RB powered 240. Plus after its all said and done, it's shock value. SR's are a dime a dozen but RB's are not.

[hachiroku-fc3s]

Another 2 cents of mine:

Dont do anything to your car for shock value or bragging rights. I just flamed a guy this week for saying something dumb about bragging rights. Do it for your driving pleasure and your pride your automotive modification/fabrication/work. Make your car what you want it to be, not what you want other ppl to notice. I hate my S14 becuz its flash style (well rice to me, but def flash) and I get compliments everyday on stuff I want to get rid of. Make the car what you want it or it will make you sick.

[Ghost of Duluth]

Agreed. But I do like to see the looks on peoples faces when they ask about my car. There is a difference in making the car your own and making it for other people. My car is made for me, it just happens to wet everyone elses whistle as well. I think it's safe to say that most people on this forum, given free reign, would make the same thing. Something that they like that just happens to wet everyone elses whistle as well.

[hachiroku-fc3s]

I will never argue the fact that it is nice to get props, but I wanna punch myself everytime someone tells me, "those Lexanis are SWEET" (I know, I have chrome lexani wheels on my S14, give me a break, I bought it that way and if could find some 16" black mesh wheels with a polished lip they would be history but for now, they look better than the factory set I got too). Not a good way to live.

[mranlet]

Do what YOU want to.

If you like shock value, then that's cool, if you like driving value than that's cool too.

A lot of people refute crazy motor swaps if they think it's not practical, but I think that's just silly.

You will be looking at high maintenence costs with an RB, but if you have an overseas hookup then you will be ok at best. RB is more weight up front but will make lots more power.

G/L with whatever you do!

-MR

[R32GTST]

hi all

ok here's my 2 cents my comparison will be based on SR20DET and RB20DET. Same capacity, different torque/power/cylinders.

SR20DET
- lots of low end torque
- lots of aftermarket goodies
- parts easily available (provided you didn't get the SR20DET from GTiR)
- easy to tune, can achieved 400ps with stock internals (i've done it before)

RB20DET
- cast iron block can withstand lots of power.
- very good roll on response (anything above 2500rpm is a breeze)
- low end torque almost non existence.
- stock internals can withstand 1.1bar of boost, about 380ps.
- prone to overheating/oil starvation. make sure your oil-sump is not dented! easy remedy would be putting an oil cooler and use higher flow oil pump.


I've used the SR20DET before and I'm very satisfied with the power and torque. There's really nothing much in the market that can match the performance.

I'm just beginning to tap into the RB20DET potential. So far so good. boosted 0.75bar and no signs of detonation/fuel starvation. Power at 0.75bar is 250ps (at the crank) with stock internals/turbo/intercooler but turbo/intercooler was running beyond efficiency level, especially after 6000rpm. Stock boost is 0.6bar producing around 220ps (at the crank). My setup :-

1. Stock turbo/intercooler/internals
2. HKS Power flow intake
3. 3inch dump pipe into 3inch piping (No-Cat) but 2 box.
4. Greddy/Trust manual boost controller.

What I'm planning next will be as follow :-

1. FMIC
2. GTR injectors
3. GT2510 or GT2530 turbo or equivalent
4. Nismo FPR and fuel pump.
5. Apex-i S-AFC II or Greddy E-manage
6. HKS EVC or Apex-i AVC-R or BLITZ Dual-SBC.
7. custom oil cooler kit.
8. Nismo/OS Giken high flow oil pump.
9. lots of hours on the dyno/highway.

Also, I'll change the gearbox oil/diff oil using HKS or OMEGA oil. The suspension will receive treatment from TEINS or Kei Office, soon. I'm planning on putting a Nismo Rear Diff with active LSD, but most people told me it's not really needed since my target power level is still manageable with the VLSD.

My target power level will be 350ps @ 1.0bar of boost, on stock internals. my target torque will be around 450Nm. I believe this is achievable with careful tuning. I'm thinking of lowering the compression but still doing the research on that. From my understanding, the stock compression can withstand the boost.

I will post in here from time to time when I've upgrade my RB20DET.

-R32GTST-