rb20det vs sr20det

[vvaffle]

i was just wondering what effect the number of cylinders has since the displacement is the same. is one engine faster stock than the other one and does one have more aftermarket suport than the other one? any other differenences?

[240DRFT]

the rb is faster stock than a stock sr... the rb20 has 220hp and the sr20 has 205hp. although the rb is already higher, the sr has much much more aftermarket support than the rb.

[Gold Digger]

the rb is faster stock than a stock sr... the rb20 has 220hp and the sr20 has 205hp. although the rb is already higher, the sr has much much more aftermarket support than the rb.

The hp depends on what platform you get the RB out of. The skylines had 215 stock, and car like mine, and the A31 were 205, so as not to out do the skyline.

[lovenismo]

RB20s are diamonds in the rough. There lighter than the 25 so theres not much to worry when it comes to "balance". It can be stroked later if desired with oem nissan parts anywhere from 2.0 to 2.4 and rev higher. (RB26 goodies) Lots of the RB series parts are interchangeable. It is a I6 over an I4. Also they also are like dirt cheap. Oh yeah and the sound of em will make you oww skeet skeet skeet skeet... One more thing dont give in to people saying s*** about parts are hard to find, thats want your friendly local Nissan dealership is for just get them numbers and you should be straight.

[mmatl16]

ive got a stock rb20 and i murdered my friend who has a sr20 with 3inch downpipe and no cat.

rb20 is always gonna have a better powerband to

[SeVa-S13]

SR has mor torque. SR is lighter. There's more room in the engine bay. It's easier to install, which would be much better-- judging on the noob question you're probabaly a noob.

Go SR.(Can we PLEASE lock/delete these threads that come up every other day? =\)

[mmatl16]

im sorry but its only 100lbs heavier than the sr...so i dont want to hear anything about "weight" or "balance" and as far as fitting it....get mckinney motormounts...problem solved

[Kr0n1k]

SR = OVERRATED IMHO. Yes the SR has many aftermarket parts, but that's because it has many areas that need improvement. The RB, you're pretty much getting a boost controller and away you go. And, as was said, has many interchangeable parts between the 25 and 26. Plus that beautiful sound that comes from your exhaust everyday... I guess you'll just have to ask yourself, do I want a decent four cylinder, or an inline 6 that is a part of one of the greatest cars ever made?

[SeVa-S13]

But with mounts, it's no longer cheaper than the SR.

[mmatl16]

But with mounts, it's no longer cheaper than the SR.

actually lets do some math real quick

average sr clip=2200-2500

rb20 clip=1200 + mounts 450 after tax =1650

[SeVa-S13]

You can get SR's cheaper than that and more importantly locally. Most people have to get their RB's shipped. Venus charged me like 800 for mine when I coulda gotten an SR locally for the same price.

[lovenismo]

You can get an SR for 800 buckaroos? Good for you and share the love. The Race Build is better though in my opininon. If you want a more "empty" engine bay stay SR dude. Why not get a CA in that case aint that lighter? Yes I agree the SR is overrated as much as that freakin B18 engine for the Honda crowd. Yes both are great engines but put that SR vs RB with and without mods and see where your at. The RB will be the victor buddy

[fspmx6]

the rb will rev smoother, and will have a quicker spool up time due to 2 additional exhaust pulses. the sr has an aftermarket supports as well as 100 lbs lighter, and that 100 lbs can make a difference. the really big thing is that the sr is a bolt in with minor wiring ecu changes, as opposed to an rb which will need different mount points as well as it will hang further over the nose changing the handling characteristics drastically. a2liter strait 6 wont have as much torque as the 4cyl, but will have the ability to rev much higher.

[vvaffle]

Actaully I don't know if I will go with either of these engines. I was just wondering the difference in balance between the two engines and the reliability when reving faster. You guys pretty much answered that so thanks.

[SeVa-S13]

Firstly RB doesn't stand for anything, much less "Race Build" -- although that is a new one.And Venus charged me $800 to ship my RB clip from CA to VA where I was when I installed it myself. I've had a running RB20 S13 before most people in this thread probably had their car.

[lovenismo]

Its Race Build or Race Breed Ive read from numerous places. Your point in bragging SeVa-S13 about you having something "first" ??? Brag about being the first to have an et nobody hit etc. Since youve had a runnig RB20 longer than most people had there cars does that make you some kind god. Sounds like a sucka... Who can give this man (vvaffle) some answers that are proven about the balance and reliability of both the engines once seated. From what Ive heard things like FRP and carbon aero parts up front helps the cause of the RB20. Next relocating that battery will do good. Also is you dont mind having no ac take that crap out. Should be around 50/50 then. Overall not as light as a SR20 powered 240 but will have somewhat the same balance. If you had a lightweight passenger next to you that would add as much weight as the RB would overall, but would that really matter when you start tuning and getting more power down? Seva-S13 if you had this RB20 powered 240 can you tell us all that since the RB is farther forward does its drastically change the handling? Hey fspmx6 said it, is he right. I heard something like that about the 25 but that thing is a whole lot heavier, but yeah youve had the pleasure of driving the RB20 so how does it act?

[mmatl16]

rb25 is 400 lbs heavier than sr20

[hamsturbation]

some other thigns to think offor every 1 revolution of a 4cyl, only 2 cyls fire, for every 1 revolution of a 6cyl, 3 fire, so you will have a better powerbandalso, a 2.0l 6cyl will reuire less bore/stroke to make the same displacement as a 4cyl, which (in the case of a shorter stroke) results in slower piston speeds, which means better RPM potential, less friction, and less vibration.however, on the downside, an i6 has a fairly large crank compared to an i4 or a v6, so thats sort of a downside too..(in both weight and RPM ability)

[Eikon]

WOW!!! All kinds of crazy ideas flying around in this thread.

Here's what I know...

You don't have to have McKinney or any other mounts to put an RB20 in your car. The R32 stock crossmember will do the trick just fine.

The RB20 doesn't change the balance over the front wheels... it sticks out a little further in the front, and also a little further in the back, so while the total weight of the front of the car is slightly higher, it doesn't ruin the balance over the front wheels as someone previously stated.

The SR has more torque? I don't think so... I think the RB20 puts down 185 ft/lbs. I'm not sure about the SR as I have not seen a dyno comparison, but I would think a 6 would outdo a 4 in torque? Not that number of cylanders is the factor... it just usually happens that way.

I don't know of any SR's that you can get locally.. unless you are talking about front wheel drive SR20de's from Sentras and SE-R's.

Why are we talking about the RB25? The thread was to compare RB20 to SR20.

I can't talk to much about the SR20, but I can tell you about the RB20.

RB20's have poor cooling systems. If you get one, you would be wise to replace the radiator for an upgraded one, replace the water pump and thermostat, and also the heater core just to be safe.

RB20's have a pretty weak Turbo stock. They run out of breath at about 275hp. Upgrade to a t3/t04e and you can push 400 hp with other supporting mods.

RB engines sound amazing!!!

You can get an RB20 clip to your house for under $2k. You don't need mounts, you don't need a custom driveshaft. There is enough info out there on this forum to get you through the wiring yourself. You can do some pretty simple upgrades (fuel pump, radiator, fuel filter, power steering lines, etc...) You can easily have it in your car and running awesome for $2500.

From what I've seen SR20's cost like $2200 for the clip and then figure another 6 to 800 for shipping.

Parts aren't too hard. Most parts are available here in the US market. Some parts are specialized, and places like DDX, Phase2motortrend, RBmotoring, and others in the US carry them.

Some items are rare and hard to find.. but you can get in contact with American's in Japan, or Aussies or Kiwi's and they can help you find them. It isn't often you have that problem. The only part I have had trouble with so far is the ECU engine coolant temp sensor, and I wound up getting that for $20 shipped in 2 weeks time.

In the end do what you want. If you like SR, go SR.. you will love it. If you want RB, go RB! You can't loose on the deal. Both are awesome!!!

[mmatl16]

WOW!!! All kinds of crazy ideas flying around in this thread.

Here's what I know...

You don't have to have McKinney or any other mounts to put an RB20 in your car. The R32 stock crossmember will do the trick just fine.

The RB20 doesn't change the balance over the front wheels... it sticks out a little further in the front, and also a little further in the back, so while the total weight of the front of the car is slightly higher, it doesn't ruin the balance over the front wheels as someone previously stated.

The SR has more torque? I don't think so... I think the RB20 puts down 185 ft/lbs. I'm not sure about the SR as I have not seen a dyno comparison, but I would think a 6 would outdo a 4 in torque? Not that number of cylanders is the factor... it just usually happens that way.

I don't know of any SR's that you can get locally.. unless you are talking about front wheel drive SR20de's from Sentras and SE-R's.

Why are we talking about the RB25? The thread was to compare RB20 to SR20.

I can't talk to much about the SR20, but I can tell you about the RB20.

RB20's have poor cooling systems. If you get one, you would be wise to replace the radiator for an upgraded one, replace the water pump and thermostat, and also the heater core just to be safe.

RB20's have a pretty weak Turbo stock. They run out of breath at about 275hp. Upgrade to a t3/t04e and you can push 400 hp with other supporting mods.

RB engines sound amazing!!!

You can get an RB20 clip to your house for under $2k. You don't need mounts, you don't need a custom driveshaft. There is enough info out there on this forum to get you through the wiring yourself. You can do some pretty simple upgrades (fuel pump, radiator, fuel filter, power steering lines, etc...) You can easily have it in your car and running awesome for $2500.

From what I've seen SR20's cost like $2200 for the clip and then figure another 6 to 800 for shipping.

Parts aren't too hard. Most parts are available here in the US market. Some parts are specialized, and places like DDX, Phase2motortrend, RBmotoring, and others in the US carry them.

Some items are rare and hard to find.. but you can get in contact with American's in Japan, or Aussies or Kiwi's and they can help you find them. It isn't often you have that problem. The only part I have had trouble with so far is the ECU engine coolant temp sensor, and I wound up getting that for $20 shipped in 2 weeks time.

In the end do what you want. If you like SR, go SR.. you will love it. If you want RB, go RB! You can't loose on the deal. Both are awesome!!!

ya the crossmember might work just fine....but ill tell you i didnt want my swap to be "just fine" i wanted it done right.

also ya the sr20 has got 205 torque so hate to tell you but ya they have more.

[SeVa-S13]

So many things to cover...firstly the RB20 weighs about 60lbs more than the KA. They have the same transmission but the extra weight comes from the two extra cylinders, naturally. The RB25 is where the weight becomes a factor, it basically has a TT 300ZX transmission which is enormous in comparison to the KA/CA/SR/RB20 units. So the majority of the extra weight is behind the firewall but it does make handling ever so slightly off. Chances are, most people won't notice it, much less be too terribly upset because it's not like we're drving F1 cars or something. The RB20 hasn't changed my steering that I can tell.

Like I said, the SR has more torque. It's not matter of cylinder count but of dimensions and physics. The SR is a square bore and stroke engine whereas the RB is not. Think of the RB as a blown up crotch rocket engine--high bore vs relatively short stroke for high revving reliability and the ability to make more power because of this. (Not to mention it's far superior valvetrain)

To address any weight distribution worries yes you can relocate the battery to the trunk and remove some uneccessary s*** like the AC because there's maybe 3 people in the U.S. with working AC on an RB 240. It's not TOO hard if you really know what you're doing, most just don't care.

As for mounts vs. no mounts, they weren't available when I did my swap so I had to go the kinda half-a** way. That being said, your turbo outlet WILL hit your steering shaft and your shifter will be about an inch forward of where it was but I got used to it pretty easily. The biggest problem I have with it is changing the clutch. Most people haven't encountered this yet because they still have the clutch they threw on during the swap but with the R32 Xmember, getting the transmission back on with the engine still in the car is an absolute b****. That would be my main motivation for mounts if I had money to burn.

I still suggest the SR to most people I meet because more often then not, they're just hopping on the bandwagon (and you can't really dislike people because of just that) but because they're new, they know just about jack s*** when it comes to swapping Nissan engines. This isn't like the Honda game where everything's like damn Legos. The SR is much easier to swap in and is overall supported more for those who are less than clever in finding things. And the biggest reason is, while most burger flipping highschool/college kids have dreams of some ubar sw33t jdm tyte DRFT whip with a bajillion hp and most importantly some awesome mesh wheels, the large majority stay mainly stock and come nowhere near pushing the limits of even a well-cared for stock engine. Thus, the SR is a better choice because everything's been done before and documented and everything is MUCH cheaper if they're just going to end up with 300whp anyway.

There are two types of RB guys: The ones that get it because it's a Skyline engine and they think they're being different (ha) than they're fellow bandwagoners with SR's and then there's the ones that either do, or are going to make gratuitous amounts of power. I don't like posers.

Edit: I sound like an ***, but that's mainly because I am. And don't take the 2 types of RB guys thing to heart if you've had your RB for a while, just kinda makin' a point.


Modified by SeVa-S13 at 12:44 PM 1/6/2005

[Eikon]

ya the crossmember might work just fine....but ill tell you i didnt want my swap to be "just fine" i wanted it done right.

also ya the sr20 has got 205 torque so hate to tell you but ya they have more.

I don't see your point about the crossmember being inferior. Unless somebody can prove to me that the McKinney mounts or another set of custom mounts make a difference in performance, I will insist that the R32 xmember is equal in duty and better because it's free! Way I see it, both accomplish the same goal of getting the engine secured in the car. If you just buy an engine set.. then get the mounts. But, you might as well buy the clip and use the crossmember that comes with it and save yourself the money.

I seem to remember a post about the RB20 torque numbers being measure SAE (in other words with all accesories attached) and due to this, the performance measurements are not the same as listed for SR20. I will see if I can find the post.

[Dirtylou]

Does the RB20 have a square bore/stroke?--- NO!Edit: DOnt mind this I have a small attention span so I skipped all of the useful posts.

[vvaffle]

Another question. Because of RB20s shorter stroke does that mean it's shorter height wise? Becuase if it is that would mean that technically you should be able to place it lower in the body and therefore lower the center of gravity.

[mmatl16]

your turbo outlet WILL hit your steering shaft and your shifter will be about an inch forward of where it was but I got used to it pretty easily. The biggest problem I have with it is changing the clutch. Most people haven't encountered this yet because they still have the clutch they threw on during the swap but with the R32 Xmember, getting the transmission back on with the engine still in the car is an absolute *****. That would be my main motivation for mounts if I had money to burn

solves ur questioning as to why do it right......think about it for long term uses....it makes everything so much easier

[mmatl16]

I don't see your point about the crossmember being inferior. Unless somebody can prove to me that the McKinney mounts or another set of custom mounts make a difference in performance, I will insist that the R32 xmember is equal in duty and better because it's free! Way I see it, both accomplish the same goal of getting the engine secured in the car. If you just buy an engine set.. then get the mounts. But, you might as well buy the clip and use the crossmember that comes with it and save yourself the money.

I seem to remember a post about the RB20 torque numbers being measure SAE (in other words with all accesories attached) and due to this, the performance measurements are not the same as listed for SR20. I will see if I can find the post.

torque for an rb20det---------185

here is the link you can check that on

http://www.rb20det.com/aboutrb20det.html

get off me

[dfw240_EE]

Someone shoot me for saying this, but:

from that website:" Combustion chamber type = Hemi-spherical"yeah, it's gotta hemi!

[OpeLok]

holy ****.. my first post in this forum and first thing I noticed is you people like to type alot. Anyways, I may be able to shed some light on this subject considering I own an RB20DET, and have driven the RB25, SR20, CA18... and in a couple weeks the RB26DETT. Anyways, as far as steering is concerned, you can't tell a difference at all. Especially if you keep your powersteering. Your car will still handle as smooth as a cadillac so to speak. I can't tell the difference at all between any of these motors. Sure, there are slight differences, but not enough to say, "damn this handles great.. or this ****ing sucks!". As for the SR vs. RB debate. Well it all comes down to preference and what the owner can do with it, because lets face it. Who leaves these motors stock after swapping them? Its all in how deep your pockets are. Power delivery in the RB motors IMO is much smoother with greater torque down low. Where as the SR motors feel like they are building their power more towards mid-upper rpms. Both have T25 turbos. Just different housings. Not sure about the A/R's though, so that could have something to do with it. SR's and RB's are about the same in skill level to wire up. You just have different steps. I personally chose the RB for my car over the SR because I don't ever want to own another I-4 in a car. Something to do with the noise. I love the growl of an I6. Also, the RB is much more impressive looking motor IMO. Just look. The redtop is where I got my SR impression. And the RB below it is mine. Notice location of the mastercylinder





I don't want to hear about, "well aftermarket support for RB's sucks"... because that is not true anymore. A year ago that would have worked, but there are numerous success stories with RB's and aftermarket parts. I've had harder luck finding SR parts than RB at times. It just depends on what the part is really. Everything is bolt in just like the SR with an RB. Only difference is you need to upgrade the radiator and run electric fans. Other than that every other upgrade is up to the owner and depends on what shape the clip is in. Anyways, thats my 2 cents.

[Nismo_Freak]

SR = OVERRATED IMHO. Yes the SR has many aftermarket parts, but that's because it has many areas that need improvement. The RB, you're pretty much getting a boost controller and away you go. And, as was said, has many interchangeable parts between the 25 and 26. Plus that beautiful sound that comes from your exhaust everyday... I guess you'll just have to ask yourself, do I want a decent four cylinder, or an inline 6 that is a part of one of the greatest cars ever made?

Biased a little?

Many areas of improvement just based on the number of parts available... hmm, less we not forget the the RB26 which has the most parts available of the entire Japanes market. I'm sure you will agree then that the RB26 needs more "improvement" than the SR? I guess that makes it "OVERRATED" in your opinion as well.

There is nothing overrated about the SR20, however I could stand to argue that the most commonly underrated thing in the Nissan community today is the ego (for lack of a stronger word than ignorant) that alot of the "anti-bandwagon" bandwaggoners have.

I can't believe that everyone has to be sold on ONE thing.

OpeLok and SeVa had two good posts, the rest of this thread is mindless crap.

[AmoebAssassin]

OpeLok, how did the RB25DET 240sx you drove handle? Was there any noticeable understeer/looseness from the front end due to the heavier motor? I am interested in this swap, but I still want a car that can rotate nicely on tracks and twisties. Thanks.