Close to RB20DET OR RB25DET...But...

[951's 330i]

Ok so like the title says, close to getting either. Well more like ready for the RB20 but might just get the RB25 instead.

Question though.
1. For a car that is going to be a DD and maybe start some drifting, should i get the 25? Or would the RB20 be enough? I am not really looking to get extreme numbers, maybe try for 300 plus to the wheels? Or untill i feel satisfied with my butt dyno lol. I've searched as much as i could by also visiting other sites for info. Just would like the feedback of someone who has experience this swap already.

2. Where can i purchase either one? I know there are vendors on here, but has anyone had any experience with them, or have found greater deals on other sites? Feedback on that would be appreciated as well.

3 If bought from a vendor, which either one sells a complete swap, what is the major differences between them? Is it just their own pricing because i have seen RB20's from 1000 to 1200. And then theres the RB25 between 1800 to 2400 before shipping on their advertised threads? Is it just plain mark up price? I know for the RB25 sometimes the difference can be whether it is a SI or SII.

4. On the Rb25det, i have read both sides saying the SI is better then the SII, and vice-versa. What is the real difference between the two besides the turbo? Or is it just all personal preference?

5. With the swaps that sell the uncut wiring, that just means i have to do the cutting and wire everything up right? But is this very hard to do? Where can i fine a wiring diagram for either swap? Or better yet, when i get started, can someone in socal help?!

Thanks to all who input on the questions asked. Hopefully i can get started on a swap very soon. By the way, i will be swapping it into a 95 s14.

[boosted98gst]

Originally Posted by 951's 330i

Ok so like the title says, close to getting either. Well more like ready for the RB20 but might just get the RB25 instead.

Question though.
1. For a car that is going to be a DD and maybe start some drifting, should i get the 25? Or would the RB20 be enough? I am not really looking to get extreme numbers, maybe try for 300 plus to the wheels? Or untill i feel satisfied with my butt dyno lol. I've searched as much as i could by also visiting other sites for info. Just would like the feedback of someone who has experience this swap already.

2. Where can i purchase either one? I know there are vendors on here, but has anyone had any experience with them, or have found greater deals on other sites? Feedback on that would be appreciated as well.

3 If bought from a vendor, which either one sells a complete swap, what is the major differences between them? Is it just their own pricing because i have seen RB20's from 1000 to 1200. And then theres the RB25 between 1800 to 2400 before shipping on their advertised threads? Is it just plain mark up price? I know for the RB25 sometimes the difference can be whether it is a SI or SII.

4. On the Rb25det, i have read both sides saying the SI is better then the SII, and vice-versa. What is the real difference between the two besides the turbo? Or is it just all personal preference?

5. With the swaps that sell the uncut wiring, that just means i have to do the cutting and wire everything up right? But is this very hard to do? Where can i fine a wiring diagram for either swap? Or better yet, when i get started, can someone in socal help?!

Thanks to all who input on the questions asked. Hopefully i can get started on a swap very soon. By the way, i will be swapping it into a 95 s14.

1. Depends on what you want out of the car. Doing an RB swap is not cheap by any mean's a least set 7k aside to make sure you do everything right( bone stock). Make sure all the maintenance is done water pump, timing belt, tensioners, gaskets, thermo, accessory belts, then what mount set up your going with.

2. On the engine since your in cali make sure you can go and check the motor out, make sure they leakdown and compression check the motor in front of you. If buying a clip they can start it for you also. Just start calling around and see who or what is in stock and then start pricing. Just remember you get what you pay for.

3. The price is going to vary from year to year, later year motors will prolly be more due to mileage.

4. The difference between the S1 and S2 are not very different. If your only looking for 300 rwhp just get a sr or turbo your Ka it will save you money in the long run.

5. when they give you an uncut harness it just means the skyline harness is complete with all plugs and no wires cut. You can to or pay someone to cut plugs and extend wires. I did my swap myself but ive done many swaps before if this is your first or your good with wires and reading diagrams then you should be fine. Not to sound like a dick but if your asking these questions your prolly not ready to do the swap yourself.

[951's 330i]

Originally Posted by boosted98gst

1. Depends on what you want out of the car. Doing an RB swap is not cheap by any mean's a least set 7k aside to make sure you do everything right( bone stock). Make sure all the maintenance is done water pump, timing belt, tensioners, gaskets, thermo, accessory belts, then what mount set up your going with.

2. On the engine since your in cali make sure you can go and check the motor out, make sure they leakdown and compression check the motor in front of you. If buying a clip they can start it for you also. Just start calling around and see who or what is in stock and then start pricing. Just remember you get what you pay for.

3. The price is going to vary from year to year, later year motors will prolly be more due to mileage.

4. The difference between the S1 and S2 are not very different. If your only looking for 300 rwhp just get a sr or turbo your Ka it will save you money in the long run.

5. when they give you an uncut harness it just means the skyline harness is complete with all plugs and no wires cut. You can to or pay someone to cut plugs and extend wires. I did my swap myself but ive done many swaps before if this is your first or your good with wires and reading diagrams then you should be fine. Not to sound like a dick but if your asking these questions your prolly not ready to do the swap yourself.

Thanks so much on the info. This really helps out on the swap. First person to actually leave good feedback. Ill reply with kinda questions to your answers though.

1. So then no matter what, even if im not looking to push the motor, right from the start i should replace most parts then? Like all that you mentioned? Im guessing all with aftermarket parts, or try to get oem parts from some sites that i have seen selling them?

2. Well most of the the places i have seen that sell them are either in a diff. country(canada, japan, etc.) or on the other side of the us. I think there are some vendors on here that show the test of which ever motorset you will get but ill have to double check.

3. Ok no need to ask any questions on that.

4. From the prices i have seen, Sr's seem to be more expensive. Plus, even though i can obtain the same power on the SR, the RB sounds more reliable to me the either the SR or KA seeing as it is a 6cy vs a 4cy. Idk maybe i am wrong on this since i may not be looking to gain that much power, but then again.....I might want way more lol

5. So then the wires are already almost basically set right? If thats the case it shouldnt be that much trouble as long as there is a diagram. And i completely understand what you mean. Ill be having my uncle(mechanic) help me with what he can, plus i know it may not mean much to some, but my cousin has just graduated from UTI and has taken some classes on most of the things. He may not know as much as some on here, but he really does know a lot. Of course ill try to look for help here and there. Not trying to make it seem like i know everything when i am just learning myself on this swap and this car.

Thank you so much again for the help, really great member!!

[S14_Kouki]

Its 100% better to go with the 25

[DJDANGER24]

i didnt even read the thread.... but im gonna answer with RB25!!!!!!!!!

[roboticnissan]

rb20 are fine!!!!i have had two. price difference is nuts. you could get an rb20 in your car for like 3k-3500. rb25 is like 5k for the motor itself right???plus the mounts and fmic...
anything rb is pimp shit fo sho!!

[951's 330i]

Originally Posted by roboticnissan

rb20 are fine!!!!i have had two. price difference is nuts. you could get an rb20 in your car for like 3k-3500. rb25 is like 5k for the motor itself right???plus the mounts and fmic...
anything rb is pimp shit fo sho!!

Lol pimp shit.......

Are you including the swap done by someone else? Or are you talking about parts needed to replace?


Ok i know i said i had decided that most likely between the two. But i just now started looking at a possible ls1 swap. Is the swap on this easier or harder? Whats the avg. price on this. I am currently looking online(google) for prices but cant seem to find either vendors sellings or recent threads(most are back in 02-06).

[951's 330i]

Originally Posted by S14_Kouki

Its 100% better to go with the 25

Because the RB25 can handle more with less strain? Or more personal preference??

[THeokaYsLider]

hey i have the rb20
and it has never giving me problems people just think that is a crappy motor when
is not has all the dam torge you need for drifting and is a really reliable car
to get power out of any rb is all about tunning the car the best tune always wins in the end

[951's 330i]

Originally Posted by THeokaYsLider

hey i have the rb20
and it has never giving me problems people just think that is a crappy motor when
is not has all the dam torge you need for drifting and is a really reliable car
to get power out of any rb is all about tunning the car the best tune always wins in the end

Did you have to change any parts right away when you did the swap? Did you do the swap yourself or had someone else do it? Anyway i can get a ride in it lol i work in southgate, just off of otis st and firestone.. please ill pay gas!!!! lmao

[DJDANGER24]

i personally have an RB25 and the torque is there and i love the fact that i can throw an GT35 at it and be square... i had an RB20 with gt2530 and it was descent... yea,,, i want the RB25 over the RB20. fuck RB20

[951's 330i]

Originally Posted by DJDANGER24

i personally have an RB25 and the torque is there and i love the fact that i can throw an GT35 at it and be square... i had an RB20 with gt2530 and it was descent... yea,,, i want the RB25 over the RB20. fuck RB20

Did you do the swap yourself by any chance? Did you have to change out anything as you were swapping it?

[GSXRJJordan]

LOL @ people with RB20's saying "they're fine". Riding a pedal-bike is 'fine', walking is 'fine', but who the fuck wants to go slow?

If you're going to do all the work of putting a RB-series motor in (instead of a SR, which is drop-in), wouldn't you want something that's actually better than a SR? The price difference between the motors is usually $1000, and you need a new driveshaft (~$300) with the 25 (you can use a stock M/T driveshaft with the 20), but the performance difference is huge - plus, the "cap" on what you can get out of it with a turbo/injectors/maf/tune upgrade is MUCH higher.

As far as budget goes, you're looking at $2500 on the motorset, $600 on mounts and a driveshaft, $200 on a radiator, $100 on a timing belt, $300 on new water pump, oil pump, idler and tensioner pulleys, $300 on a intercooler kit, $250 on an intake manifold (stock IM + FMIC = lammmmmme), $200 on wiring (average), and say $200 for random shit like gaskets/fuel filter/fuel hose.

That's ~$4700 if you can do it yourself, another $500-$700 to have a reputable person swap it for you. WAY less than $7k.

Originally Posted by 951's 330i

1. For a car that is going to be a DD and maybe start some drifting, should i get the 25? Or would the RB20 be enough? I am not really looking to get extreme numbers, maybe try for 300 plus to the wheels? Or untill i feel satisfied with my butt dyno lol. I've searched as much as i could by also visiting other sites for info. Just would like the feedback of someone who has experience this swap already.

300whp can be done with a stock RB25. If you had a RB20, you'd need a new turbo/injectors/tune/MAF - it's no longer cheaper. Plus the torque of a RB25 is what's fun on the street, more than anything else - just ease into the gas and feel the smile creep over your face.

Originally Posted by 951's 330i

2. Where can i purchase either one? I know there are vendors on here, but has anyone had any experience with them, or have found greater deals on other sites? Feedback on that would be appreciated as well.

Lots of importers in socal, shop around and find one that you're comfortable with (good price, startup warranty, etc). Marco @ SR20store and G-Dimensions are the "good ones", and if they don't have any RB25's they can point you in the right direction.

Originally Posted by 951's 330i

4. On the Rb25det, i have read both sides saying the SI is better then the SII, and vice-versa. What is the real difference between the two besides the turbo? Or is it just all personal preference?

The biggest difference is age - all the S2's are fairly new motors, and are generally lower mileage. People that prefer S1's generally like the fact that there are many more S1's floating around, so it's easier to find parts. I have no preference.

Originally Posted by 951's 330i

5. With the swaps that sell the uncut wiring, that just means i have to do the cutting and wire everything up right? But is this very hard to do? Where can i fine a wiring diagram for either swap? Or better yet, when i get started, can someone in socal help?!

Uncut wiring is nice because you can be fairly sure that there won't be any electrical problems once you have someone convert the harness. I do these swaps a lot (and do swap wiring professionally), and charge more to inspect everything if you start with a hacked up harness.

PM me for pics of my work/etc and I'll talk pricing on doing the swap with you, or point you to some people that can help you locally.

[951's 330i]

Originally Posted by GSXRJJordan

LOL @ people with RB20's saying "they're fine". Riding a pedal-bike is 'fine', walking is 'fine', but who the fuck wants to go slow?

If you're going to do all the work of putting a RB-series motor in (instead of a SR, which is drop-in), wouldn't you want something that's actually better than a SR? The price difference between the motors is usually $1000, and you need a new driveshaft (~$300) with the 25 (you can use a stock M/T driveshaft with the 20), but the performance difference is huge - plus, the "cap" on what you can get out of it with a turbo/injectors/maf/tune upgrade is MUCH higher.

As far as budget goes, you're looking at $2500 on the motorset, $600 on mounts and a driveshaft, $200 on a radiator, $100 on a timing belt, $300 on new water pump, oil pump, idler and tensioner pulleys, $300 on a intercooler kit, $250 on an intake manifold (stock IM + FMIC = lammmmmme), $200 on wiring (average), and say $200 for random shit like gaskets/fuel filter/fuel hose.

That's ~$4700 if you can do it yourself, another $500-$700 to have a reputable person swap it for you. WAY less than $7k.



300whp can be done with a stock RB25. If you had a RB20, you'd need a new turbo/injectors/tune/MAF - it's no longer cheaper. Plus the torque of a RB25 is what's fun on the street, more than anything else - just ease into the gas and feel the smile creep over your face.



Lots of importers in socal, shop around and find one that you're comfortable with (good price, startup warranty, etc). Marco @ SR20store and G-Dimensions are the "good ones", and if they don't have any RB25's they can point you in the right direction.


The biggest difference is age - all the S2's are fairly new motors, and are generally lower mileage. People that prefer S1's generally like the fact that there are many more S1's floating around, so it's easier to find parts. I have no preference.



Uncut wiring is nice because you can be fairly sure that there won't be any electrical problems once you have someone convert the harness. I do these swaps a lot (and do swap wiring professionally), and charge more to inspect everything if you start with a hacked up harness.

PM me for pics of my work/etc and I'll talk pricing on doing the swap with you, or point you to some people that can help you locally.

Thank you so much. Again, another great member with a lot of info and feedback to give.

For the parts you mentioned, this is all prices without a state board of equalization license right? So with that said i may be looking at a lil less to spend. Dont think i can use it on a motor set, but on almost all those parts, most likely yeah.

Ill shoot you a pm about your work and other questions. Thanks again!

[fliprayzin240sx]

Jeez some of you guys in here are stupid. Why do RB20 cost $1k? Cuz nobody in Japan wants them, they are literally throw away engines out here. They are worth just as much as an NA SR20DE out here.

Go RB25, you wont fucking regret it.

[I LUV MY S13]

Originally Posted by 951's 330i

Did you have to change any parts right away when you did the swap? Did you do the swap yourself or had someone else do it? Anyway i can get a ride in it lol i work in southgate, just off of otis st and firestone.. please ill pay gas!!!! lmao

dude in any swat ur gona wanna replace water pump, thermo, belts,oil pump, tensioners, and anything else necessary...its just to be safe in the long run

[951's 330i]

Originally Posted by I LUV MY S13

dude in any swat ur gona wanna replace water pump, thermo, belts,oil pump, tensioners, and anything else necessary...its just to be safe in the long run

Oh ok, thanks, glad to know that

[Team DET]

check this out looks like a good deal http://zilvia.net/f/sale-items/279408-cheap-new.html
rb25det $2700 installed and running

[drift freaq]

Originally Posted by 951's 330i

Thank you so much. Again, another great member with a lot of info and feedback to give.

For the parts you mentioned, this is all prices without a state board of equalization license right? So with that said i may be looking at a lil less to spend. Dont think i can use it on a motor set, but on almost all those parts, most likely yeah.

Ill shoot you a pm about your work and other questions. Thanks again!

A Resale license is going to save you paying sales tax of course some of us can get you clips at cash prices. So the resale license really does not make a difference. It can be good for parts purchases depending on who your buying from. Some people will give deep discounts for resale license holders others will just knock off the sales tax.

As far as a RB goes stick with the 25 like Jordan said its all about the on tap power stock. I ran a RB25 with a GT2530 and at 11lbs boost I was pushing 300whp on a stock engine with a PowerFC. I did upgrade my injectors and maf though because basically anything over 11lbs boost with my turbo was pushing the AF ratio and the duty cycle on the stock injectors.

With that said If you want to go down the RB road I can get you a clip for around $2500 Series 1 or 2 or possibly even a NEO rated 280HP factory at 7LBs!!! They are from a very reliable source and can be compression tested.

[drift freaq]

Originally Posted by Team DET

check this out looks like a good deal http://zilvia.net/f/sale-items/279408-cheap-new.html
rb25det $2700 installed and running

Ah that has a RB20 tranny which is a very weak tranny for a 25. I advise the OP to get a clip where ever he winds up purchasing it from. It allows him to run the stock sidemount at first saving a lot of extra investment right off the top. That guys engine in the link is minus side mount and piping.

[I LUV MY S13]

i would also do new radiator and new hoses, clutch, fmic, oil cooler and catch can

[drift freaq]

Originally Posted by I LUV MY S13

i would also do new radiator and new hoses, clutch, fmic, oil cooler and catch can

Do not forget if he goes FMIC than he has to get a Greddy intake manifold or a knockoff. It starts adding up. The person that posted have around 7k if you want to go all the way is pretty much on target. To do it up right and nice is by no means cheap

Break it down like this

RB25DET clip $2500
install kit: around $500-600
Driveshaft made $200
FMIC if you choose to go $350 minimum maybe more
Radiator the inexpensive way is to run a S14 radiator $50
Oil cooler is not needed.
catch cans are optional
fuel pump $90 walbro
electric fans $200-300 you should run at least two
wiring $375
Greddy Intake $650
new clutch $200 minimum
hoses $50-100
electronic boost controller minimum $200 for a decent one.
3 inch downpipe $200
exhaust system $200-350

Right here with the list above its cresting 5k, and this is you putting it in yourself and doing it right.
I probably left something out as well as that was just off the top of my head.

If you want be cheap than go RB20 but it will not be as nice. If you want someone to do a cheap job that will bite your ass later? Go buy that engine posted for the $2700 install price.

Honestly I would not trust an engine that is being sold and installed for $2700, its to damn cheap to be good or done right.

[I LUV MY S13]

i wouldnt trust anyone other than a legit shop

[SuicidnS13]

Honestly everything depends on your budget for the time being. If you cant afford to do an rb25 swap in one purchase maybe an rb20 would work for you. Not to go against anything Jeff has to say (He definately knows his stuff, and he is doing all my harness conversions) but for some people a 5-7k swap is a little much. But 3k here then another 1k this month and another a few months later kinda works out better for them (or those who simply cant save large amounts of cash)

You can do a good running 230whp rb20det for well under 4k running. A few months later you can do a mild t3t4 turbo upgrade with fuel and run a MAP-ECU to get rid of the maf and calibrate for much larger injectors for less than another 1500.00(easily capable of 350-400whp). Ive built more than a few shares of swaps by this time. So I can attest to taking your time and finding ways to save a little bit of money goes a long way.

Heres a simple breakdown list with numbers also since everyone else here is doing it:

Rb20det swap - shipped all day for 1300.00 complete (Easily found for under that)
All gaskets and timing stuff - $300.00
Waterpump(n1) - $200.00
Harness - $250.00 or less
Clutch - $400.00
Downpipe - $170.00
Push fans - $100.00
Mount Kit - $300.00
Flywheel Resurface - $30.00
Fluids - $50.00
FMIC kit - $500.00 (hi-ballin that cost via ebay)

Total - $3600.00 installed (if you do it your self)

An RB25 with about 30-60whp more will run you another 1500.00 or more dollars on top of that. Sure the potential is there but for your power goals of under 400whp I wouldnt waste the dough. For another 1500.00 and searching forced induction classifieds like honda-tech you can get turbos, tial wastegates and injectors for dirt cheap these days. And you would make a guaranteed 350-400whp or more if you feel like pushing an rb20 way over its limits.

Anything over 400whp I would do a 1jz or 2jz swap. Costs about the same as an rb25 swap but with 10x the potential.

[951's 330i]

Thank you to everyone with all the info being added. This is such a great help, that none of you have an idea. This just opened my mind way more then i thought on a swap.

Money wise i should be ok seeing as i just got my insurance claim(dam flat beds). So thats not a problem, but just cuz i have some money doesnt mean i need to waste everything. After seeing the price break downs, i think i pretty much know what i want to be done. I will still think about it but well see by next month if anything.

Also, realized no one has answered this, but what about a ls1
swap? Is it cheaper or even more expensive to do so? I have seen the mounting kit for like 1300+. I think it might be actually be just cheaper with the rb, but seeing the power straight out of one of those seems a lot. But then again i think for that price, RB26 would be another option right? If thats the case, then nevermind lol.

Thank you all once again!!!!!

[I LUV MY S13]

friend of mine did an ls1 swap that cost him round 8k..still not done too, around the same price as an rb26 swap

best way to go is rb25

[GSXRJJordan]

Originally Posted by drift freaq

Ah that has a RB20 tranny which is a very weak tranny for a 25. I advise the OP to get a clip where ever he winds up purchasing it from. It allows him to run the stock sidemount at first saving a lot of extra investment right off the top. That guys engine in the link is minus side mount and piping.

Agreed, stay away from the RB20 trans. It'll kill the resale if you ever try to sell the swap, and it limits you on power quite a bit compared to the RB25 trans. The front clip saves a little money on not having to buy a front mount, and generally ensures a complete setup, but the cost difference is quite a bit more. I would just go Greddy-knockoff intake mani and front mount like I outlined in my price list.

Originally Posted by I LUV MY S13

friend of mine did an ls1 swap that cost him round 8k..still not done too, around the same price as an rb26 swap

best way to go is rb25

Agreed again, LS-series swaps are getting cheaper, but you still need $8k or so, and they're generally higher-mileage motors than the imported ones.

[steve shadows]

Get the RB25DET

then get a fmic and exhaust

then get an adjustable WG actuator to raise the boost

then get a Power FC L Jetro

Then hit me up for a race map timing map load it up and get antoher 50 whp//thread

[951's 330i]

Whats a good FMIC? Im search on it right now, but i wouldnt know what to search under? Like named such as greddy hks?

Also after buying my 240, i had purchased a hi-power hks exhaust system. Only have had it for barely a month. Anyway i can still use it?

[Sileighty_85]

I love Greddy came if everything needed to install the intercooler correctly without hassle.