rb20 vs sr20 swap.

[nate29]

I would go sr unless u wanted to do a biger rb platform like 25 or 26.

[JVDSKYRINE]

I liked my RB20det. I put down 250whp stock everything except for intake and exhaust and fmic. It was fun and sounded hot! everyone knocks RB's but I bet almost no one knocking them has driven one. I have driven both sr and rb and the gearing is way different. RB i found first was super short almost useless and once you get higher in the gears it was a beast where sr's would die off. Also mine took a beating and kept running strong after 160,000km.

And it is not hard to find parts for RB's you guys just don't look in the right spots lol a skyline forum has loads of RB parts. And lots of them are interchangable if you knew anything about them you would know this. Also some stock GTR parts are a straight bolt on upgrade which can be had for cheap. Heads can be mated to bottom ends. Ie RB30, 25 bottoms.


And everyone is right RB's sound so nice! if my bro sees it maybe he can post a vid of how my car sounded. I love RB series engines which is why I am building one now.

[s13 @ fullboost]

Originally Posted by burninskulls0911

ive had both

and the rb sounds better

See I wasn't the only one who thought so. Not trying to say it makes for a better motor but if I had to choose which one I would want to hear every day deff the RB and I have always been a big fan of straight six motors. I would also like to throw in if you do decide on the rb my first mod would be change the intake mani.

CrimsonRockett Quote:
Originally Posted by s13 @ fullboost
I would do the RB just to be different and it would sound sick. Just do it right and it will be reliable and make a decent amount of power spend your money wisely

Different how?

All SR/RB motor swaps are played out, and if you want a motor swap just for the "sound"....

If you're that set on doing a motor swap, go with something easier with crazy simple parts access. The last thing you want is for something to go wrong and have to wait 2+ weeks to special order that part(compared to SR's and easy parts access). Hell, a lot of local Nissan dealerships even stock SR parts because of their popularity.

If it were up to me, I wouldn't run either.

VQ would be my personal choice.

I think its different because all I ever see are SR's everyone and there grandma has one. I hardly ever see rb's There is only one guy who is somewhat local to me who has one vs the other 8 guys I know around me with SR's maybe different in your area but I was just giving my

[Chernobyl]

Originally Posted by JVDSKYRINE

RB i found first was super short almost useless and once you get higher in the gears it was a beast

I love this about my little RB20. 3rd gear pulls HARD. Putting around town in 1st and 2nd kind of sucks, however, with the 4.11 gears in the back.

[doug200t]

RB valve train in the 20 is better then the 25 and is same as rb26dett. You can rev a RB20 in stock form to 9k all day long. try that in a SR everyday, also the sound is amazing everyone running sr's at the track all sound the same then you hear the RB car and everyone turns their heads

[hostyS 14]

step 1: buy your own stock chassis
step 2: swap in rb25
step 3: injectors/t67 or gt35

//thread

[Sileighty_85]

Originally Posted by doug200t

RB valve train in the 20 is better then the 25 and is same as rb26dett. You can rev a RB20 in stock form to 9k all day long. try that in a SR everyday,

Im confused, how is the RB20 Valve train better than the RB25 when they both use the same Valve train design, they are both cam over bucket style.

Of course you cant rev a stock SR that high , the SR was only designed to rev at 7500 rpms, but nothing that a Tomei Soild lifter kit cant fix.

[SuicidnS13]

Originally Posted by s13 @ fullboost

I would do the RB just to be different and it would sound sick. Just do it right and it will be reliable and make a decent amount of power spend your money wisely

Years ago I would have said go with the SR like everyone else here for all the same ya ya reasons:

SR- easier to find parts, more people have experience with it, ya ya ya

But years later and 4 240's later I wouldn't even think of ever wasting money on an SR swap ever again.

SR Cons-
-Everybody and there moma has one
-Sounds like Poo Poo no matter what you do to them
-Fragile and spin rod bearings like no other engine
-Most parts that are available(that people care fore) are all just knock off crap anyways

RB Myths
-hard to find parts - actually shares just as many parts stateside as SR's
-Less aftermarket parts? - Really what do you plan on doing? Turbo upgrades cost the same or less on an RB swap than SR's. Bolt ons all cost the same.
-Rb20 swaps are very easy and cheap to move up to an rb25 swap while still using your rb20 tranny. Actually RB25 long blocks cost less than sr20det long blocks.

If I were in your shoes Id get the one with the Rb20 than later down the road pick up an rb25 longblock for around $900.00 and switch it over. Or just put a simple t3t4 turbo on the factory manifold and be happy with an easy 400whp setup. (with fuel off course)

T3T4 turbos cost half the price of any worth-a-crap t25 turbos.

[SuicidnS13]

Just for sound references-

Sr20 sounds-
YouTube - SR20DET Sil80 RS*R Exhaust (Night)
http://http://www.youtube.com/watch?v=5i4Q4FEAMhM

Rb20 Sounds-
YouTube - Gav's RB20DET S13 Silvia street drifting
YouTube - First RB ride evar!1!

[hOngsterr]

haha get the car that has the most hooked up things,
boost control, FMIC etc etc.

if not then get your own car and swap in a RB20 cheaper then a SR swap
lol

[lazysk8er2]

YouTube - S13 RB20DET 3'' Straight Pipe

^^nope sounds pretty lame-o to me.

on the fact of originality that doesnt exist anymore. everything has been done to this car except an ej25 swap or porche motors. i mean they have 4g63s and s2000 motors going into this chassis.

other than that there isnt anything original about an rb20 let alone a 240sx. either way your getting a quality product from nissan.


the sound factor shouldnt even be discussed it holds no value in choice.

[ChicagoS14]

I have done the research regarding an SR20 vs. RB20 as I am in need of a more powerful engine for my daily driven S13 coupe. I also plan to use the car at track events and do some drifting.

My reason for comparing the two somewhat vastly different engines was based on the relative swap cost.

On the one hand you have the SR20DET which is a 205hp - 215hp 4 cylinder turbocharged all aluminum engine. With a T25 / T28 turbocharger based on year and version of the engine. The swap process is pretty simple and straight forward reusing most of the same parts as a KA. Engines can be had for about 2-3,000$ shipped with all the parts and transmission. The difference in price being the type of engine (blacktop, redtop,S14/S15 etc.)

The RB20DET on the other hand is a 215hp turbocharged straight 6 cylinder engine with a cast iron block and aluminum head. It comes with a T25 style turbo that has a T3 flange. The swap process is the easiest of all RB engines because it can reuse the original driveshaft from a 240SX and will reuse the original engine and transmission mount as long as you get an R32 cross member from an RB20DET powered R32. Wiring is about the same for both the SR and RB swaps. Both can reuse the KA radiator, though the SR would be better off with an SR20 / Silvia radiator due to hose inlet/outlet placement. The engines can be had for about 1250 - 1300 $ shipped to your door. Thats MUCH LESS then the cheapest SRs i've seen.

Now as far as the power your getting from either engine in OEM form is about the same. The displacement is also the same. Both engines possess internals capable of handling around 400 hp. However here there is a pretty large difference between the overall engineering behind both engines.

As far as part availability and upgradability I wouldn't say one is worse then the other. Yes the SR has a huge aftermarket, but as mentioned by someone prior to me the RB has a large community as well and the fact thats its T3 flanged alone is enough to show that turbo upgrades are easier and more available, while an SR requires a different manifold.

I have seen dyno charts from various RB20 setups in skylines and 240s and they can put out lots of power for a relatively low cost. Most are capable of 300 whp territory with:

• fuel pump
• larger injectors
• larger turbo or stock turbo at higher boost
• front mount intercooler
• downpipe and full exhaust
• stronger clutch

The same goes for an SR. And if you research further you will note that there are relatively cheap upgrades for an RB20 from its bigger brothers the RB25 and 26. Now the reason why I did not mention those two engines was because the swap for either as well as costs of the engines are far greater then an SR or an RB. The overall cost of putting in an RB25 or 26 into an S-chassis rival the cost of an LSx series engine in which case I would much rather spend the money on an LSx V8 swap but thats a different debate.

Going back to the mechanics of the two engines the RB shows significant advantage over the SR. The simple fact that its a cast iron block and straight six cylinder engine provide it with a greater ability to handle high horsepower and high load for longer periods of time. Thermal issues as well as engine harmonics play a role here. Granted the engine is "only" a 2.0L, but the fact that it can rev higher then an SR and not suffer the same problems the SR suffers makes the displacement less of an issue (thats where turbochargers come in > replacement for displacement )

The SR has rocker arms vs the bucket style lifters of an RB. As people that have pushed both engines to the extreme will atest that an SR will fail quicker when in higher rpms then an RB. (So long as engine health condition is equal).

The biggest con of the RB is the added weight, the added size, and the large and somewhat restrictive intake manifold. The SR is a bit lighter and will have a much smaller footprint in the engine bay making it a bit easier to work on.

But in my opinion the fact that the RB can be swapped in for less money, can make equal power and has a greater head / block design makes me choose it over an SR.

Now I am not going to go into detail over the condition and age of either engine. Thats a common issue with all JDM imported engines. What condition they are in, how long have they been sitting for, how badly were they misused is all a mystery that accommodates all imported engines. Also, the issue of replacing timing chains / timing belts, water pumps, seals etc. is all up to the person swapping the motor. I can only say that they should be done in both cases and the costs of OEM Nissan parts for either will run about the same. So even in that sense the SR wont be better or worse then an RB.

But in the end I would say drive both and see which one feels better to you. I chose my KA-T setup over an SR swap because I drove both engines and I just preferred the KA-T.

LOL sorry about the rant - Thanks

[SuicidnS13]

Then do like me- big boy power - 2jz!!!

[drift freaq]

I owned a RB25 powered car putting out 300 whp at a reliable 11 pounds of boost. It rocked and the sound of the Six is pure sex. I will say though that RB's in S chassis's constitute thought out installation procedures and actions in the cooling department. The engine is technically to large air flow wise for the design of our engine bays.

Oh and it does not cost the same amount as a LSX swap to put one in. LOL


That said I also do like SR's they are fun and different.
The SR20 is like a two stroke motorcyle nothing nothing bam there it is and its balls.
The RB25 is like a 4 stroke motorcycle smooth and consistent power all the way up.

Its really a matter of what type of power band floats your boat. I happen to like smooth power all the way up. Some of my friends like that nothing and then bam wind it up and its there.
Funny no one mentions the CA18DET its one badass little engine. 4 Cylinders of a RB26 that can rev to 9k and go like stink. Of course its the whole 2 stroke motor cycle analogy all over again but the difference is it has the revs SR owners can only wish for.

All in all I have owned CA's KA's SR's and RB's. I will take a 6 thank you and in V fashion.

Oh though I started with 4's in a 510 I migrated to 6's in 240Z's within a few years. SIx Cylinders Rule!

[chad91s13]

v-tec is the way to go
s2k motor

[SuicidnS13]

BTW 1jz swaps can now be done for as much as an rb20 swap. Well a tad bit more $$$, and that is compareable to an rb26 swap for a third the price. 2.5ltrs, 2 turbos and a head that revs and flows for about 1200.00. I can get toyota tranny's for less than 400 all day long and driveshafts are only about 350 at any decent drivetrain shop in most towns.

[ChicagoS14]

Originally Posted by SuicidnS13

BTW 1jz swaps can now be done for as much as an rb20 swap. Well a tad bit more $$$, and that is compareable to an rb26 swap for a third the price. 2.5ltrs, 2 turbos and a head that revs and flows for about 1200.00. I can get toyota tranny's for less than 400 all day long and driveshafts are only about 350 at any decent drivetrain shop in most towns.

Ive seen 1JZs for about 1300. So as long as the process of mounting it isnt too expensive then I can see how its possible to get one inside a 240 for about as much as an RB. And thats a serious engine!

[ChicagoS14]

Originally Posted by drift freaq

I owned a RB25 powered car putting out 300 whp at a reliable 11 pounds of boost. It rocked and the sound of the Six is pure sex. I will say though that RB's in S chassis's constitute thought out installation procedures and actions in the cooling department. The engine is technically to large air flow wise for the design of our engine bays.

Oh and it does not cost the same amount as a LSX swap to put one in. LOL

Well depends on how you price out the swap. How much did you spend or are you factoring in for an RB25/26 swap?

My math was showing me that:

$2000 - Complete harness / ecu / turbo RB25DET with transmission
$600 - Mckinney Touge mounting kit
$300 - Custom driveshaft
$400 - front mount intercooler

Roughly $3300 just to get it inside the engine the car.

RB26:

$3000 - Complete engine with harness / ecu / turbo
$300 - or more for RB25 transmission
$300 - custom driveshaft
$600 - Mount kit

Roughly $4200 to get it inside the car

Now with an LS1 swap there are a few different approaches. I factored in the LS1 cost since those are probably the cheapest of all LSx motors.

My estimate was:

$1500 - LS1 w / T56 ( I can buy a crashed / totalled camaro )
$500 - Mount kit from Daft innovations
$200 - GTO oil pan + sump
$300 - driveshaft
$120 - power steering line from Daft
$45 - Powersteering line return line from Daft
$65 - Swaybar spacer
$65 - Remote Clutch bleeder
$165 - LS1 CMC (clutch maser cylinder) kit
$300 - Clutch

Roughly $3260 plus a few more bucks for whatever else you need same as all other swaps.

Now I know I low balled the LS1 motor. Its true that on Ebay they sell for nearly $4000 just for a transmission and engine. But I have a friend who works for a small dealership that has the ability to buy wrecked and salvage vehicles so getting an LS1 is not hard. $2000 - $3000 is what wrecked Camaros go for and you can sell some parts off them to make some money back so motor and trans alone will run roughly $1500-$2000.

Also im not factoring in any fluids, radiators, fans, wires, electrical parts needed for rewiring, and no replacement parts such as belts hoses etc.

I am merely comparing the cost of the raw ingridients aka Engine, mounts, driveshaft, etc.

[ChicagoS14]

The only issue with turbo engines vs. a V8 is that when you add all the extras needed for a proper functioning turbo setup you almost surpass the cost of a reliable all motor V8. To achieve 400 hp out of any turbo engine you at least need a fuel pump, larger injectors, tuned ecu or some form of fuel management, some tuning time, probably larger exhaust and turbo etc.

With an LS1 you already start at 300hp and to get 400 you can use mostly bolt on power, such as a better intake, nicer cam, custom headers, and a few tweaks and you have almost 400.

[SuicidnS13]

While both of your above posts are correct, an LS1 swap simply cannot be done that cheap. Trust me I've priced it out, while even getting the whole motor set for free practically as I would have bought a totalled ls2 GTO and parted out the chassis. It leaves me with a free ls2 and a t56. But the wiring and all the other small parts alone came up to a total of over 6k at minimum. Plus all of your above posts are missing alot of electrical, like wiring prices and tuning prices.

Even though the ls1 (ls2 definately way pricier) is an over all simpler swap to live with day to day. For the same cost you would have a much more powerful 2jz swap. Forced Induction on an Ls1 is very costly. And it would take that to keep up with the big boys these days. A heads and cam package with full bolt ons on any LSx series engine costs over 4k(For maybe 450whp). Trust me I know, I am going to be building a C6 corvette next and have been prcing out all my mods trying to decide whether or not to spend the dough on the c6 zo6 or just get the LS3 and mod it.

4k on a 2jz is a nice single and fuel setup guaranteed to make over 600-800whp depending on turbo sizing and what you feel is streetable. I am a numbers geek and support a family so value per dollar is most important to me. Thus why my wifes s13 vert got an rb20 swap over an sr20 swap and my s14 is getting a major 2jz swap over any other swap available.

Value per Dollar is all that matters in the end. And how much dollars you really have available-

[ChicagoS14]

Originally Posted by SuicidnS13

While both of your above posts are correct, an LS1 swap simply cannot be done that cheap. Trust me I've priced it out, while even getting the whole motor set for free practically as I would have bought a totalled ls2 GTO and parted out the chassis. It leaves me with a free ls2 and a t56. But the wiring and all the other small parts alone came up to a total of over 6k at minimum. Plus all of your above posts are missing alot of electrical, like wiring prices and tuning prices.

Even though the ls1 (ls2 definately way pricier) is an over all simpler swap to live with day to day. For the same cost you would have a much more powerful 2jz swap. Forced Induction on an Ls1 is very costly. And it would take that to keep up with the big boys these days. A heads and cam package with full bolt ons on any LSx series engine costs over 4k(For maybe 450whp). Trust me I know, I am going to be building a C6 corvette next and have been prcing out all my mods trying to decide whether or not to spend the dough on the c6 zo6 or just get the LS3 and mod it.

4k on a 2jz is a nice single and fuel setup guaranteed to make over 600-800whp depending on turbo sizing and what you feel is streetable. I am a numbers geek and support a family so value per dollar is most important to me. Thus why my wifes s13 vert got an rb20 swap over an sr20 swap and my s14 is getting a major 2jz swap over any other swap available.

Value per Dollar is all that matters in the end. And how much dollars you really have available-

Very true, me and you should get together and make some sort of large write up for this sort of stuff. I have been planning on building a 240SX Guide for some time. I had a small test site setup, but forgot to renew the domain and hosting and it all disappeared. Regardless now im aiming @ a Wiki style page so that its easier for people to contribute.

Plus I dont want the admins/mods to get upset about us going way off topic, since the OP did want to see whether an SR20 or RB20 swapped car was the better choice.

Also getting back to the issue of wiring, since you seem to know more in that sense, ( please explain here or via PM ) how much are you factoring for the cost of wiring in an LS1 swap. I am curious to know this as I was very close to selling my entire KA-T setup to prepare for an LS1 swap but if its beyond my budget I may reconsider, plus I never realized that a 1JZ/2JZ setup would be much cheaper.

[johngriff]

If the swap was already done, I would probably go with the RB20.

If I had to do the swap, even paying a shop, I would go with the SR20.

Intricacies too many to list.

[JVDSKYRINE]

Yeah no one is reading this and bringing 1J's and LS swaps into it?????


read the first post!!!!!

He is looking at 2 cars one with a RB20 swap and the other with an SR20.


Buy the RB20 one, Get a Rb25 turbo, GTR injectors, GTR fuel pump, and GTR fmic. Simple bolt on upgrades should make you good for 300hp on a budget

[SuicidnS13]

Back on TOPIC - Sorry

Rb20 swapped car for the WIN

[96Turbo]

Originally Posted by CrimsonRockett

All SR/RB motor swaps are played out, and if you want a motor swap just for the "sound"....

Originally Posted by Chernobyl

Probably two of the most pointless reasons to do one swap over another.

Sound was one of the main deciding factors for me & my choice to go with the RB25. Ur telling me the only important things about an engine is it's design & hp potential? I think an RB car has more "character" than the standard sr20 swap. My favorite part about driving my car is that rumbling idle note & the way the RB screams onto boost. 6cyl sound is so much more satisfying than the buzzy SR rasp.

RB has a fatter power curve, sounds like a choir of internal combustion angels, comes from a car most can only dream of owning, and most people don't really notice the extra weight.

If I were to build a stripped down track machine I wouldn't go with the RB due to the extra weight. I'd probably shove a VQ35 into the firewall, but I'd rather drive an RB for my street car

My vote goes for RB20

[SuicidnS13]

Originally Posted by 96Turbo

Sound was one of the main deciding factors for me & my choice to go with the RB25. Ur telling me the only important things about an engine is it's design & hp potential? I think an RB car has more "character" than the standard sr20 swap. My favorite part about driving my car is that rumbling idle note & the way the RB screams onto boost. 6cyl sound is so much more satisfying than the buzzy SR rasp.

My vote goes for RB20

Sound is one of the biggest deciding factors for many people. I love how 3 years ago on zilvia everyone would have been sr20 yada yada. Now people are starting to realize that:

The SR20Det is the b16a swap of the nissan world, cheap, effective but in the end.....same old borring story.

Another year or two from now people are going to be saying things like-

if your broke - do an sr20 swap
if you have no mechanicle experience - do an sr20 swap
if your el cheapo - do an sr20 swap
if you like 4 banger sounds that dont rev that high - do an sr20 swap
if you cant fabricate - do an sr20 swap
if you dont know how to read a wiring diagram - do an sr20 swap
if you dont know how to hit the search button - do an sr20 swap


Dont be one of the above guys and just go for the rb swapped car and build from it.

[donabeast]

vs the other 8 guys I know around me with SR's
make that 9 guys around you dont know you but im local

[!Zar!]

Originally Posted by SuicidnS13

Sound is one of the biggest deciding factors for many people. I love how 3 years ago on zilvia everyone would have been sr20 yada yada. Now people are starting to realize that:

The SR20Det is the b16a swap of the nissan world, cheap, effective but in the end.....same old borring story.

Another year or two from now people are going to be saying things like-

if your broke - do an sr20 swap
if you have no mechanicle experience - do an sr20 swap
if your el cheapo - do an sr20 swap
if you like 4 banger sounds that dont rev that high - do an sr20 swap
if you cant fabricate - do an sr20 swap
if you dont know how to read a wiring diagram - do an sr20 swap
if you dont know how to hit the search button - do an sr20 swap


Dont be one of the above guys and just go for the rb swapped car and build from it.

Those are the most rice b0i idiotic bandwagoning super street shitty horrid piece of shit excuses ever.

[johngriff]

Originally Posted by SuicidnS13

Sound is one of the biggest deciding factors for many people. I love how 3 years ago on zilvia everyone would have been sr20 yada yada. Now people are starting to realize that:

The SR20Det is the b16a swap of the nissan world, cheap, effective but in the end.....same old borring story.

Another year or two from now people are going to be saying things like-

if your broke - do an sr20 swap
if you have no mechanicle experience - do an sr20 swap
if your el cheapo - do an sr20 swap
if you like 4 banger sounds that dont rev that high - do an sr20 swap
if you cant fabricate - do an sr20 swap
if you dont know how to read a wiring diagram - do an sr20 swap
if you dont know how to hit the search button - do an sr20 swap


Dont be one of the above guys and just go for the rb swapped car and build from it.

It really is Very funny to look at things from such a juvenile logic.

Scion advertisements must have a very strong impact on you.

While I am familiar with the roots of this logic, in that modifying an automobile is "supposedly" a form of artistic and personal expression, after years in this industry and working on just these cars, the reasons for and against are more pragmatic, scientific and mathematical.

The error in your logic is function following form instead of the other way around. The OP needs to look at the what the end game is, and take the straightest least expensive line there.

If I was going to build another track car today, it would probably be with an SR20. It is the straightest line to a reliable powerplant there is.

Doing things simply to be unique is unremarkable, which is entirely not unique.

[SuicidnS13]

Originally Posted by johngriff

It really is Very funny to look at things from such a juvenile logic.

Scion advertisements must have a very strong impact on you.

While I am familiar with the roots of this logic, in that modifying an automobile is "supposedly" a form of artistic and personal expression, after years in this industry and working on just these cars, the reasons for and against are more pragmatic, scientific and mathematical.

The error in your logic is function following form instead of the other way around. The OP needs to look at the what the end game is, and take the straightest least expensive line there.

If I was going to build another track car today, it would probably be with an SR20. It is the straightest line to a reliable powerplant there is.

Doing things simply to be unique is unremarkable, which is entirely not unique.

You are totally correct in your statements. I appologize for my Super Street Scion Advertisement statements. However, my opinion still stands the same. I really never said the technology or the foundation of the sr20 is inferior in any way. Just that it is the most bandwagon of swaps. I guess now I am part of a different bandwagon, the one against the bandwagon swaps. I have done multiple sr20 swaps as well and have based my opinion on (as you have) years of automotive build projects.

But I totally agree with your statement for the OP to find the straightest most cost effective route to his goals. This is how all of my build projects are planned out. Or atleast which person gives him the better deal in the car he chooses to buy.