rb20 or sr20?

[Jon FLA]

what are yall's opinions?

[sci2000tech]

Depends on what you're lookin for in a motor. Both can make the same power and have a ton of aftermarket support.

The SR is generally easier/cheaper to find parts for, although RB parts are very easy to find too as long as you know where to look.

RB20's cost more to mod when it comes to injectors, pistons, rods, manifolds, etc...because they have 2 more cylinders.

My opinion is obviously biased, but here's why I like the RB20:

Nothing beats the sound of an inline 6 turbo'd engine

slightly more unique stateside than an SR

Lots of interchangability(sp?) with other RB's. If I wanted, I could get an R32 RB25de head with an RB30E block and bolt on the rest of my existing RB20 parts(manifolds, sensors, etc) and have a 3.0L beast without having to change my entire setup again.

Oh, and did I mention nothing beats the sound of a turbo'd inline 6?


When it comes down to it, they're both great engines. the SR is probably a bit more practical for a DD, but I'm sure you'd be happy either way.

[Jon FLA]

thanks for the input. I was looking at prices for rb20's and sr20's and it seems as if the sr20 is more expensive than a rb20. Ive looked on ebay and there are numerous amounts of engines to choose from, and to be honest ive seen some good lookin rb's for a couple hundred dollars less than a sr. I would love to do a rb swap but a sr seems so much easier. Does the manual transmission driveshaft work for a rb? or is a custom ds needed? Im also looking into getting the wiring done at WiringSpecialties.com so I wont have to worry about it. RB20 motor & transmission mounts at mckinney is I think $250 <- not bad. Does a sr downpipe work with a rb20? there are alot of parts that i already have bought/collected to turbo my ka that I know will work with a sr but unsure if they will work with the rb. its a hard decision and my wife is giving me the green light to get me a motor n stuff.

[sci2000tech]

The RB20 motorsets are usually a little cheaper than the SR's, but the cost of ownership on the RB can be a little more expensive when you mod it. As far as general maintenance goes though(oil changes, gaskets, belts, etc...) I would think they cost about the same.

I do believe the stock 5spd driveshaft will work fine, but don't quote me on that. I'm 99% sure you don't need a custom driveshaft.

The Wiringspecialties harness looks very nice. I don't have any experience with them, but if I were to do it again, I would give em a shot. I've broken a good amount of brittle plugs/connectors that are 15 - 20 years old.

As for the mounts, I've owned both, McKinney and OEM crossmember/mounts. Although I never actually bolted the motor in with the McKinney mounts before I sold them, they seemed to be great quality. However, I personally prefer the OEM R32 crossmember/mounts. You can't beat OEM quality and fitment and reliability.

Not sure on the SR downpipe, but I wouldn't count on it fitting. If you go with the OEM R32 crossmember/mounts, the OEM downpipe will work, but may need to be notched to clear the steering shaft. Otherwise a custom one shouldn't cost too much either.

Obviously I am biased, but I say use what you can, sell what you can't, and go RB. nothing like the experience

[Eikon]

The two motors are pretty similar in cost after you get them installed. The SR is more expensive, but pretty close to a direct swap. The RB is cheaper to get, but after paying for wiring help and mount stuff, you'll be in about the same shape at the end. The SR is lighter and easier to get parts for an maintain. It also runs cooler. Did I mention it's lighter? The RB sounds absolutely amazing and in a convertible.. that is worth something. But it can be a headache.

I had an RB20 in my 'vert and put an SR20 in my brother's 'vert. I can tell you that the SR felt faster despite being stock. I had a lot of work done to my RB, but it still didn't feel as quick. It did sound better.. and I got a bit more respect from people who knew what it was.. but if I were starting a new project from scratch and had to choose between the two.. I'd go SR.

[-RJ-]

Id say stick with KA. Granted it is a heavy motor but you can throw a rock from where your standing and you would probably hit KA motor. Parts are everywhere and pretty cheap as well. Plus a well maintained KA can take 300whp

[biggie]

I would agree that I wouldn't narrow to just those 2.

Out of those 2 I'll take the lighter one give they are the same displacement. If I do RB it'd be 25/26.

[Jon FLA]

the only reason I have to narrow it down is because of money.. it sucks..

to stick with the KA that would mean I would have to get it rebuilt, and it still wont be turbo.. or I can just buy a sr20 and call it a day.. Im still up in the air about it all.. I have also read that a stock sr can hold up to 300hp.

[biggie]

Your current KA is bad? Even then a decent stock KA wouldn't be over $400-500.

[Genpac]

I have an RB20 in my vert at the moment. My biggest gripes are all trying to keep its driveability intact. Between roasted coilpacks and their arc jumping issues, keeping the car idling at a set RPM (not wandering all over) and trying to troubleshoot an off-idle, part throttle cruise stumble... I'm about ready to ditch the whole damn thing. I'm not saying an SR would be any better, but atleast common parts would be a s***-ton easier to find. (like ECU temp sensors, AAC valves, TPS...) Regardless of what anyone posts, the USDM equivalents are not direct replacements. They mostly have different connectors so you would need to source the USDM connector ends in good order.

[-RJ-]

If your KA is in decent condition, I would get a compression test done and see where the numbers are. If it isn't too far off then I say boost the KA even if you go with a tiny turbo for now.

[jdms13rhd]

SR for many of the reasons already mentioned.

Tho, dont let parts availability bother you in your choice. You can pick up a rock and throw it and hit almost any kind of SR and RB engine part, up her in Canada. And for cheap too. Most people dont bother shipping states side. I could mention like 3 places and its your all in one, one stop to shop for S13/R32 JDM parts.

I've had many RB S13's and SR S13's. So I can tell you this. RB20 is trash. I dont waste my time bothering with those any more. Go RB25 for cheap, all round good engine. Can toss fuel, turbo and ecu and get reliable 400hp. SR is very similar. Save money for a rb26 as you should source out a rb25 trans and chances are, the engine could be tired or have a tired turbo. Id build all my own rb26s now rather then bothering with used ones these days.

Screw what people think about having an rb is more cool deal. Thats just BS. People up here laugh at a concept like that, point out the fact and recomend the sr as well because most of those guys learned the hard way too.

Just keep things simple and your build will be more reliable in the long run. So I recommend the SR

[ivenn]

beware the sr20 as been outlawed for street use in some states the one that i know of is cale i think the rb26 has also i dont know about the rb20
so cheak the laws in ur state

[biggie]

beware the sr20 as been outlawed for street use in some states the one that i know of is cale i think the rb26 has also i dont know about the rb20
so cheak the laws in ur state

All engines from Japan that were not also ran in the US are technically illegal in all US states, but its whether you can get away with it easily or not. Cali is just the hardest to get away with it.