RB20DET vs RB25DET vs RB26DETT FAQ

Discuss the RB20, RB25 and RB26 series engines.
rednissan180
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rb20-s13

Postby rednissan180 » Thu Apr 05, 2007 7:26 am

I have a s13 shell sitting at my friends house. I need to get it running and im trying to figure out what i want to put in it. He said it wasnt worth the trouble of putting a rb20 in it because of the work/parts. What does it take to put a rb20 in a s13?


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jmwenick
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Re: (eh?)

Postby jmwenick » Thu Apr 05, 2007 12:15 pm

eh? wrote:A built KA-T is not going to cheaper than an RB25 swap. 1)AC can work it's been done before.2) I don't know why you'd tear into the dash for a trip computer (lol)3) Search the KA forums for all the lovely snapped rods.4) The RB25 tranny is a much much stronger than the KA/SR's. Almost half the cost of the RB25 is due to it. 5) Sure the displacement is almost the same but 6 pistons see less stress than 4 pistons at the same HP level.
You can always mount a Z32 Trans to the KA with an adapter, and a built KA is still cheaper than an RB25

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eh?
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Re: (jmwenick)

Postby eh? » Mon Apr 09, 2007 12:26 am

Right because machine work is free You can almost buy an RB25 for the cost of rebuilding an KA-T.

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jmwenick
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Re: (eh?)

Postby jmwenick » Mon Apr 09, 2007 2:45 am


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Sil_LadyRB25
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Re: RB20DET vs RB25DET vs RB26DETT FAQ (krayton)

Postby Sil_LadyRB25 » Tue Apr 10, 2007 10:16 am

I'm kinda questioning my car right now, don't get me wrong she's got balls, RB25DET but i'm wondering if it'll make much of a difference if i add a second turbo or if i just upgrade to a RB26??? i'm just wondering what the powerband difference will be and if it'll even be worth the swap or if i should just continue upgrading my RB25

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Joe
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Re: RB20DET vs RB25DET vs RB26DETT FAQ (Sil_LadyRB25)

Postby Joe » Tue Apr 10, 2007 10:25 am

you dont need a 2nd turbo

just get 1 big one and youll be happy.

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eh?
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Re: (jmwenick)

Postby eh? » Thu Apr 19, 2007 1:11 pm

That's a SHORT block. Do you know what a SHORT block is?http://www.amsperformance.com/...=1042That's $4059 for a KA LONG block that not even balanced(WTF) and doesn't include a $500 core charge.

**** I got an RB25 LONG block for the same amount as that core charge from Venus auto.

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thenillaz
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Re: (eh?)

Postby thenillaz » Thu Apr 19, 2007 3:16 pm

No no eh?, let the random, invading KA-T whores continue. I'd love to hear their rebutle on the 4cyl vs 6cyl. And then they say put an Z32 tanny with a KA adaptor on the KA and magically spend less money on a want-to-be RB25. Were do people get the idea that a 4cyl POS can be legitiment to one of Nissans best performance engines?

Oh, and x2 for the rucus...

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jmwenick
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Re: (thenillaz)

Postby jmwenick » Thu Apr 19, 2007 4:04 pm

k, I'm done. I'm just secretly jealous of your RB awesomeness. Seriously tho. How much would someone spend to get a running RB25 swap?

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thenillaz
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Re: (jmwenick)

Postby thenillaz » Fri Apr 20, 2007 6:33 am

I'd say a little over $5000. Sorry my post was a little overboard, but to me its worth the estimated $5000 because you're getting something legit and pretty much factory. If anyone follows my opinions, they know I have a bias for anything thats not 4 cyl, but in all reality if you do everything in spec you'll get a much more reliable, much more nicer sounding 300hp car with the RB I6 rather than a back-yard modded 300hp KA-T, you know what I mean?

Of course my opinion isnt first hand, as I cannot and have not performed the swap yet due to I cannot afford it, yet, but logically it makes sense. You take aftermarket parts and your own knowledge and put a decent sized turbo on a KA vs. you take a JDM factory engine and install it to spec; which series of events is more likely to have a postive, long-run outcome? I read about people saying, "oh yeah, do an RB swap and drive it 4 months out of the year", but I never read any RB failure stories and I read a whole bunch of KA-T and SR failure stories. Stories of how their enigne blows up or doesn't work properly usually goes beyond the surface of just what engine it was, but knowing that factory parts are usually the best parts you can put in your car, a factory JDM engine with nothing aftermarket implied to it, like an RB, should run just fine in your 240 as it did in the skyline back in japan which it was taken out of(unless of course that skyline was totaled and doesn't actually run, lol). My opinion is, the best way to make a good hp number for your 155hp- 240sx(155hp- as in, your car now probably has less than what its suposed to have) is to get an engine that already makes a decent number in factory spec, and then go from there if you need to. Anything else, intake, exhuast, headers, turbo(as long as you don't run rediculous psi and blow the thing up), etc. is just a waste of time on your 155hp KA, unless you are happy with power the KA offers. Of course you can get a KA up to RB potenial, but look at all the money you have to spend, aftermarket parts you have to trust, work and time you have to put in, etc. An RB is just a more logical way to go when you look at the big picture.

tunedS3rdteen
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Postby tunedS3rdteen » Mon Apr 23, 2007 8:12 am

what about emmissions, are any of the swap smog legal/street legal? which ones are and which ones arent? which are easiest to pass ref.

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Postby KingPastry » Mon Apr 23, 2007 10:10 am

none.. there is no swap that is legal by any means unless you have motor problems and swap in the EXACT same thing that came out

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RCA
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Re: (KingPastry)

Postby RCA » Mon Apr 30, 2007 4:56 pm

Well if you use every oem part from what every car you get your engine from (exhaust/converters and intercooler) then you should pass the emissions test. Maybe not a "legal" set up but you could pass emissons.

But because the RBs are all JDM they won't pass unless you throw on like 2 catalitic converters... Or you could pay a crooked inspection angent and he will slap a stick on there. =)

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Re: (rcabrita)

Postby zanilth » Wed May 23, 2007 12:59 pm

As far as the debate between fully build KA's and RB's, price wise here is something I have found interesting.

RB25DET half cut, with motor, tranny, driveshaft, and fuel pump ( read somewhere else it also includes ecu, but not sure because its not listed, just those four are) will run you $3,396.

http://jarcoinc.com/inventory/halfcuts/

Swap kit for use with the R33 mounts (from the clip) $585

http://www.sykoperformance.com/prod01.htm

There is your RB25DET swap right there. Super Street has an article about this swap, stock RB25DET in a 240 at 306 HP and 246 torque, on SR Motorcars' dynojet.

http://www.superstreetonline.c....html

So, that right there looks about $3,981. Add about $200 or so for random parts (driveshaft, fans, exhaust, etc) and shipping and such, and you have a pricetag of $5,481.

Now, for the KA longblock from AMS, your price tag is $4,059. That doesn't include your manifolds, tranny, clutch, oil pan, valve cover, turbo, or anything. Toss in at least 2500 for all that (gotta get all the best, or why else spend 4 grand on a 4 cyl longblock then cheap the rest?) That would run you right about $6,559.

Now, I could go look up every piece of accessory you will need and add them up, chances are they would be even more than 2500 together. I am not going to do that though, just giving a rough estimate. That is just to get you on your KA to the RB equivalent.

So, using this information, and the fact that you would be putting less stress on a 6 cyl to get 300 hp than a 4 cyl, and the fact that the rb25 has more future modding capability than the KA, I would say the RB is your best bet...

Unless you don't have the 5 grand or so for the swap, then just slap a turbo on your current motor and hope for the best.

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eh?
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Re: (zanilth)

Postby eh? » Wed May 23, 2007 2:28 pm

Youch and that's the extreme end of the price range for the rb25. back when I was looking clips were $1800. Venus auto still sells motorsets for about $2k.. so you can save yourself about $2k just by buying a motorset and not paying ~$800 for the freight shipping of that heavy *** clip. A motorset usually has everything you need for the basic swap. Don't think a clip is won't be mssing any parts because it does happen (shaddy sellers).

zanilth
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Re: (eh?)

Postby zanilth » Thu May 24, 2007 4:37 pm

eh? wrote:Youch and that's the extreme end of the price range for the rb25. back when I was looking clips were $1800. Venus auto still sells motorsets for about $2k.. so you can save yourself about $2k just by buying a motorset and not paying ~$800 for the freight shipping of that heavy *** clip. A motorset usually has everything you need for the basic swap. Don't think a clip is won't be mssing any parts because it does happen (shaddy sellers).
Well, I said front clip for two reasons. One is because you get the crossmember with it, which that swap kit requires, and two because I believe that website changes the water pump and all that random junk. It might have been another site who did the swap on accessories, I am not sure. I know I saw it somewhere when I was checking on the swap, which is what I plan on doing. I would much prefer a stock 6 cyl pulling between 250 and 300 hp than a 4 cyl pulling around 205. That is just me though. Besides, the wow factor for a rb is better than a sr or ka anyway...So, this post is really a differenciation between the rb and the sr or ka. Oh well.

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eh?
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Postby eh? » Fri May 25, 2007 3:41 am

It's your money but I'm just talking about the opposite end of the cost spectrum.

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Re: (eh?)

Postby fanatic » Fri May 25, 2007 11:08 am

Just a question, what sway bars would I be able to put in if I was planning an RB26 swap? I heard the Cefiro fits, but they don't seem easy to get my hands on them.

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Postby nissan240sx90 » Sat Jun 16, 2007 12:18 pm

I have a rb20det motor in my 240sx I would like to know If anyone has over heating to in the motor. It is only when I am sitting in traffic.or at a long red light. I also have like four fans running to to cool it down.

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Coolwhip
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Postby Coolwhip » Tue Jun 19, 2007 10:46 am

there is alot more to your cooling system then just fans. Whats the condition of the radiator, antifreeze, thermo, water pump, radiator cap, resivor, hoses, etc. Are you running a huge FMIC and A/C? Did you bleed the system correctly? Check all those

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Postby jimmyloose » Tue Jun 19, 2007 8:08 pm

who was the gent who swapped an RB26 into the Z33?

katakmacho
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Re:

Postby katakmacho » Mon Jul 09, 2007 6:43 pm

Just wonder to know...What part of rb26 can fix into rb20? and how much power will increase?

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Re: Re: (katakmacho)

Postby Coolwhip » Mon Aug 20, 2007 9:33 am

katakmacho wrote:Just wonder to know...What part of rb26 can fix into rb20? and how much power will increase?
the bottom end rotating assemably. Crank, Rods, Pistons will bring you to a 2.4L ; power increase? = increased displacement

Valve covers; power increase = 0hp

there are other parts...just search around.

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Zippy69
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Re: (zanilth)

Postby Zippy69 » Mon Aug 20, 2007 9:40 am

This is not really a fair contest, you are comparing a used engine set with a newly rebuilt engine, of course the ka is going to cost more with all brand new components.There are many owners of ka-t"s that easily make 300+ hp with out any ill effects, most on stock 100k plus internals. No doubt the rb 25 is way cooler and will give more bang for your buck after mods, but it will cost you more to repair when something does break. I am in the process of making an rb 25 swap now but I am keeping my ka just in case.

rbfastback
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Re: RB20DET vs RB25DET vs RB26DETT FAQ (krayton)

Postby rbfastback » Mon Aug 20, 2007 10:53 am

all r fun engines tho epecially in a 240

painsylvio
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Re: RB20DET vs RB25DET vs RB26DETT FAQ (krayton)

Postby painsylvio » Sun Aug 26, 2007 6:51 pm

hey since it seems like you know more than i do about the RB engines i have a small question to asks, ok if i have a RB25det in my 240sx, can i boost the engine up to 400hp with the stock turbo, please and this question for me, i really need to know

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Re: RB20DET vs RB25DET vs RB26DETT FAQ (painsylvio)

Postby Coolwhip » Sat Sep 01, 2007 8:33 am

low 300's are the highest on the stock turbo. Sorry bud

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Re: RB20DET vs RB25DET vs RB26DETT FAQ (Coolwhip)

Postby Death By Thrash Metal » Wed Sep 05, 2007 9:24 pm

dude i am honestly confused... rb25det right? ok so u get one of those, what kinda hp are you looking at for bpu (including boost controller but not upgraded ecu) and a turbo?I mean cuz for that money (even though i LOVE rb and skylines) i could do a titan engine swap, or like a vq which would produce near same hp, but cheaper... but then again i dont have potentials for same hp on stock block ect...****ing california... ima bust those politician's nutz if i become a lawyer.

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Re: RB20DET vs RB25DET vs RB26DETT FAQ (Death By Thrash Metal)

Postby themadscientist » Mon Sep 10, 2007 9:32 pm

Death By Thrash Metal wrote:dude i am honestly confused... rb25det right? ok so u get one of those, what kinda hp are you looking at for bpu (including boost controller but not upgraded ecu) and a turbo?I mean cuz for that money (even though i LOVE rb and skylines) i could do a titan engine swap, or like a vq which would produce near same hp, but cheaper... but then again i dont have potentials for same hp on stock block ect...****ing california... ima bust those politician's nutz if i become a lawyer.
Bull****. Show us how guy. "I could do a titan engine swap". Yeah sure you could. Please stop it already.

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Re: RB20DET vs RB25DET vs RB26DETT FAQ (themadscientist)

Postby uber95 » Tue Sep 11, 2007 7:51 am

themadscientist wrote:Bull****. Show us how guy. "I could do a titan engine swap". Yeah sure you could. Please stop it already.
He posts EVERYWHERE on EVERY topic. Throw him to the lions for polluting NICO with B.S.
Modified by uber95 at 11:44 AM 9/11/2007


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