Can anyone tell me the positve and negatives for both ? Im doing the swap kind of soon and cannot make a decision . Just trying to gather some more info is all .

I had an rb20det in my car and i just hauled it out since its kinda dieing and putting in an SR20. I can tell you than an rb20 isnt worth it. If you mentioned rb25 vs sr20 then hell yeh rb25 but both are 2 litres. One is 4 cylinder and one is 6. The sr20det makes more power than the rb20det for the same displacement. There are many more aftermarket parts available for the abundant sr20det and very limited amounts for the rb20det. The rb20det is 200 or more pounds heavier than the sr20det. The rb20 is a cast iron block and the sr20det is an aluminium block with cylinder sleeves which are easy to change and get stronger ones. The sr20det internals can handle alot more power than the rb20det internals. If u want RB go rb25 but not rb20. I had one and i can tell you it isnt worth the cost and trouble to get one to fit into a 240sx. to waste a straight 6 on 2 litres makes no sense. Go SR20 or rb25.

Rb20 200 lbs heavier than Sr? hmm, I dont bleive the diference is that large..

I had a fast and reliable SR, but always felt a RB20 would be a "cool" alternative..

-Inline Six..-Awesome internals ( not that the Sr is weak or anything)-Cheap to buy ( albeit significantly more labor to get to work well in S Chassis install, also may need aftermarket crossmembers)-An often overlooked and rarer swap ,which is kinda cool and appeal sto the purist in me..-parts <are> harder to come by, but this very website has a couple of RB savvy parts sponsors.

i'd go sr20det,even though you'll be following the sheep you still gonna get more power out of it,now it it were rb25 i'd say jump for the extra power of the rb25

lol if not 200 then very close. The rb20 internals are not great at all. You must be thinking about the rb25. Seriously if u need to go straight 6 go rb25. The sound of a straight 6 is amazing. Most parts out for rb's are for the rb25 and 26 and not the 20. I had a completely different from subframe for my rb20 but i head you can buy top hat mounts and most os the small stuff like that is what brings the price of the swap up. ghetto is deffinantly right when he says the sr20 will put out more power than the rb20 alot easier.

Well there is a big difference in a 6-cylinder versus a 4. Its called Mechanical Advantage.

You can, according to this theory, you could coax more torque out of a RB20 than a SR20 just because of the number of contact points the rods have on the crank.

Also, the RB20 weighs just over 100 lbs heavier than the SR20, and has about 10-15 more HP stock.

RB20DET Bore: 78mm Stroke: 69.7mmPower: 220 HP @ 6400 RPM Torque: 194 @ 4800 RPM Compression: 8.5 to 1 Redline: 8000 RPM

SR20DET Bore: 86mm Stroke: 86mmPower: 205 HP @ 6000 RPM Torque: 203 @ 4000 RPMCompression: 8.5 to 1Redline: 7500 RPM

Modified by 2BN_S13 at 12:18 PM 6/15/2005
Modified by 2BN_S13 at 12:20 PM 6/15/2005

can u give proof of those horse power numbers please? And the rb20 will not make a more substantial amount of torque to make a huge difference. The fact is that people are still getting alot more power out of the sr20's than the rb20's and the aftermarket support is biased for the sr20det. People that get high HP out of an RB do it with the rb25 or rb26. Forum members have dynoed there rb20's at just under 200WHP.

zerothread?id=100856

zerothread?id=113408

The sr's hit higher than that stock.

zerothread?id=92710

zerothread?id=86029

zerothread?id=84185

That is what i have found so far. Some have stock numbers and some have just raised boost everything else stock.

2BN_S13 wrote:Well there is a big difference in a 6-cylinder versus a 4. Its called Mechanical Advantage.

You can, according to this theory, you could coax more torque out of a RB20 than a SR20 just because of the number of contact points the rods have on the crank.

Also, the RB20 weighs just over 100 lbs heavier than the SR20, and has about 10-15 more HP stock.

RB20DET Bore: 78mm Stroke: 69.7mmPower: 220 HP @ 6400 RPM Torque: 194 @ 4800 RPM Compression: 8.5 to 1 Redline: 8000 RPM

SR20DET Bore: 86mm Stroke: 86mmPower: 205 HP @ 6000 RPM Torque: 203 @ 4000 RPMCompression: 8.5 to 1Redline: 7500 RPM

Modified by 2BN_S13 at 12:18 PM 6/15/2005

Modified by 2BN_S13 at 12:20 PM 6/15/2005

I have never seen stock RB20 power so high. Your figures makes no sense. U just said the rb20 would make more torque and u show the sr20 making more torque do u have the info mixed up or something? Guys from the rb forums on stock boost gets just about 185HP out of their rb20 and guys with stock sr20's are getting out about 205... why is that with stock boosts?

Big LIp:

Good arguements I concede your point.

Fred..

biglipzit wrote:I have never seen stock RB20 power so high. Your figures makes no sense. U just said the rb20 would make more torque and u show the sr20 making more torque do u have the info mixed up or something? Guys from the rb forums on stock boost gets just about 185HP out of their rb20 and guys with stock sr20's are getting out about 205... why is that with stock boosts?

Thats because he forgot to add there are two variants of the RB20DET

One that came in the R31 that had less power (190PS) and one that came in the R32 (220PS). The R31 engine has some differences like intake manifold runner variances, and a set of red valve covers. The R32 engine has silver covers.

if what i'm saying is what i gather from my past times a sr20det will also rev much faster than rb20detwhy you might ask is because the sr20det is aluminum which makes for less momentum to get going,and also it's 4 cylinders,the rb20det is a castiron(i think) has 6 cylinders and has much more momentum to get going

ghetto wrote:if what i'm saying is what i gather from my past times a sr20det will also rev much faster than rb20detwhy you might ask is because the sr20det is aluminum which makes for less momentum to get going,and also it's 4 cylinders,the rb20det is a castiron(i think) has 6 cylinders and has much more momentum to get going

LOL.

The block doesn't rotate chief.

The SR does have less mass to move, but the crank has a larger stroke, making inertia greater to overcome in that regard.

I don't think you would see a large difference in how quickly the two rev. It's not as big as say... KA vs. SR.

In my opinion, the SR is better in nearly all performance aspects on paper.

The only reason why I would get an RB20 is... 1. They are cheap2. They sound awesome

Nismo_Freak wrote:LOL.

The block doesn't rotate chief.

The SR does have less mass to move, but the crank has a larger stroke, making inertia greater to overcome in that regard.

I don't think you would see a large difference in how quickly the two rev. It's not as big as say... KA vs. SR.

sorry forgot about that doesn't affect the friction of the parts

Nismo_Freak wrote:2. They sound awesome

Definately.

6>4

I'd go RB, it's a more interesting swap.

I was thinking about that sound stuff too the other day. The VQ sounds freaking amazing, kinda high for a 6cyl, but still very much a 6cyl. The RB20 has to come across a lot like a Ferrari does - lots of small cylinders, so I bet it has an awesome note...

Now I want to hear one... where are our vid masters?

Well in Skyline GTS-T's and Cefiros that came with the RB20DET you see many Japanese guys (You know you wanna be JDM tyte ) taking out the RB20 and swapping in an SR. It's lighter and more parts are available. etc etc see points referred to above.

Now I read up on some Japanese sites (don't have the energy to pull them up) that there were more advantages of having an SR in the Skyline/Cefiro than an RB. The Skyline was mostly because of weight I believe.

But scince you want it in a 240, I guess you can pull off the extra weight of the RB. but like biglipzit said, he prefers the SR from experience. well that's my input

Biglipzit.... Your membership in Team Race Bread is about to be denied.

Such blasphemy!!!

SR's are certainly easier to install, work on, and get parts for. RB20's are less expensive to buy, but more expensive to maintain in the future.

We can argue all day over performance numbers. Can we agree that they are pretty close in terms of HP and TQ... at least close enough that neither has a clear advantage. I think they are pretty close at stock boost, and pretty close at top end potential (400-450ish). Honestly, I would guess that the RB20 is a little cheaper to get there with.

EVO8... how good/experienced a mechanic are you? If you are nervous about your abilility to work on the RB yourself, I would stay with an SR. I probably would have been wise to go SR as well given my lack of experience. On the other hand, if you are confident and adventurous, the RB rocks! It's a great project.

What is your budget? I think the RB20 is about a grand less expensive than the SR20. That might help. The RB20 is a little more expensive to install than the SR20, but less expensive than an RB25.

I personally wanted to be different than the masses. I want to be a bit unique. I always hated Hootie and the Blowfish because they were overplayed and everybody else liked them. I don't like Honda because they are a dime a dozen, so I decided I like Nissan better. I decided I wanted a convertible because they are rare and I like the top down. I decided I wanted to get an RB over an SR because they are less common and a little less expensive.

What do you want?

I would say Rb20 http://www.e-emotorsports.comhttp://www ... nc.comcall them they use a Rb20 in there Drift car

High revving straight sixes sound awesome.

lol it isnt blasphemy. I love the sound of the straight 6 and i love the rb and mine has died until an overhall but alot of rb members agree that an rb25 is alot better and a 2 litre straight 6 doesnt make much sense. That is just how it is. He wants the better engine out of the 2 and it is an sr20. If rb25 was on the list i would jump up and down and celebrate and say yeh go for it. And most of the members use the silver top rb20's. I don't know any member that has a red top one in the rb section.

So does anyone know a place where I can get a decent price on an sr20 blacktop or rb25 then ?

Thanks for the links . Im checkin on em now .

If you are going to deal with all the hassle of swapping, maintaning and owning a RB powered 240 dont get a RB20. why get an engine that will barley outperform a SR20 when you have a 10x harder time trying to get information and parts for the engine.

So then how much did your swap cost you after all was said and done ? Were there any issues you had after the swap or did everything work out pretty easy ?

RB25DET 1800 hit in the front of the carLabor 1200Motor mounts 350Driveshaft 250MAF 40 Alternator,PS pump intercooler with piping water pump pully and harmonic balancing pully 495Nismo transmission mount bushing 59Timing belt 90 R32 Rear sub frame 200 front 5 lug hubs and spindles 150Skyline R32 GTR wheels 150a set of purellies 205/55 R16's used 100walbro 255 90 usdECT my car is still in the shop where it has been for the past 12 days it should be out tommarow

Nismo_Freak wrote:
Thats because he forgot to add there are two variants of the RB20DET

One that came in the R31 that had less power (190PS) and one that came in the R32 (220PS). The R31 engine has some differences like intake manifold runner variances, and a set of red valve covers. The R32 engine has silver covers.

Actually, there are three variants of the RB20DET. The one in the R31, 190ps, R32, 215ps, and the one used in the HCC33 Laurel, A31 Cefiro, 205ps. If you go with the RB engine, make sure you buy a skyline clip so you don't get the 205ps version. The only differences were slightly smaller cams. Everything else is identical.

Also, the thread was asking about Black top SR's...which put out 250ps in the S15. So, like I have said before...depends on what you want to do with the car..i.e. drifting or drag...and how deep your pockets are.

PantherRacer wrote:Well in Skyline GTS-T's and Cefiros that came with the RB20DET you see many Japanese guys (You know you wanna be JDM tyte ) taking out the RB20 and swapping in an SR. It's lighter and more parts are available. etc etc see points referred to above.

Now I read up on some Japanese sites (don't have the energy to pull them up) that there were more advantages of having an SR in the Skyline/Cefiro than an RB. The Skyline was mostly because of weight I believe.

But scince you want it in a 240, I guess you can pull off the extra weight of the RB. but like biglipzit said, he prefers the SR from experience. well that's my input

The SR's are not that common in the R32's, but they are there, and they are extrememly common in the C33's and A31's. Mostly they are used to even out the center of weight distribution and for high speed wangan runs. Kinda like the Top Secret Supra a few years back. They used a highly modified 3SG...I think...and was able to hit 200 and change and keep it pretty well stable.

And yes, the RB sounds awesome under acceleration and boost, there is no question about that.