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?!:bowrofl:

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]

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?!:bowrofl:

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]

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]

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]

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]

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]

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.

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.

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.

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.

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?!:bowrofl:

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]

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]

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]

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 (http://zilvia.net/f/sale-items/279408-cheap-new.html)
rb25det $2700 installed and running

[drift freaq]

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]

check this out looks like a good deal http://zilvia.net/f/sale-items/279408-cheap-new.html (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]

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]

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.

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.

[951's 330i]

With a FMIC, am i going to have to cut anything to allow it to fit? Or will there be enough room?

[THeokaYsLider]

hey man i wouldnt mind giving you a ride but right know am adding a lil things too it but will when am done with it man dont trip but i think that the rb20 is the best on prices a lil more cheaper for parts harder to find but cheaper the rb25 is so popular that people want a arm and a leg for the parts these days know and yes i did do my swap like 3 years ago when i was 16 years old
yup am a gangsta rb20
no not spoiled brat lol hard worker that all

[RBSilvia1406]

Go for the rb25 man. thats the route im going in feburary. im getting a complete motorset with r33 crossmember from venus auto for $1900.

[GSXRJJordan]

With a FMIC, am i going to have to cut anything to allow it to fit? Or will there be enough room?

You'll have to cut the front bumper support (the reinforcement) at a minimum. Takes 10 mins with a sawzall. You can see here that the bumper "support" itself is intact, but the reinforcement is cut in between the frame rails:
http://wut2dg.bay.livefilestore.com/y1pDdPjfVeVqs6DKN6F8Jjws9hJkrXm7-DXG968Jr0VKBWgaWt_3ztGW59VozscA_T7dn8QoxLCUsbaNfsz zVdz_w/JustDrift%20Clinic%20089

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?

Yes, you can still use your exhaust - the RB elbow has a slightly different exit than the SR elbow, but most people are able to use it with a 3" SR downpipe/catback. As for FMIC's, which one you get depends on which intake manifold you're using.

Go for the rb25 man. thats the route im going in feburary. im getting a complete motorset with r33 crossmember from venus auto for $1900.

That's a great way to go, as long as the R33 motor mounts are in good shape, but you'll still need a tranny mount and driveshaft.

[karl wasabi]

Go for the rb25 man. thats the route im going in feburary. im getting a complete motorset with r33 crossmember from venus auto for $1900.

The motor will sit really high and far away from the firewall. The shifter will not be in the stock position. I had the... nvm. haha. I had an R32 crossmember for my RB20. Got rid of it for Top Hat mounts.

[fliprayzin240sx]

hey man i wouldnt mind giving you a ride but right know am adding a lil things too it but will when am done with it man dont trip but i think that the rb20 is the best on prices a lil more cheaper for parts harder to find but cheaper the rb25 is so popular that people want a arm and a leg for the parts these days know and yes i did do my swap like 3 years ago when i was 16 years old
yup am a gangsta 16 rb20
no not spoiled brat lol hard worker that all

Gangsta 16 rb20 that needs to learn how to fucking type. Dont be afraid, periods are your fucking friend...helps you to sound educated. :duh:

[THeokaYsLider]

:-) what a ass..^^

[boosted98gst]

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.


and 250 for intake manifold ? yeah for some janky ass hong kong shit. 300$ for an intercooler kit? I bet everything on your car is from ebay or a knock off . If you are doing any type of rb swap and cant afford to do things right and buy name brand parts and support real companys. I dont know any reputable shop going to swap in a rb for 500-700 bucks lol do you know what labor rate at most good shops are per hour right?

IF your going to do the swap make sure you take the time and look everything over and expect to spend more, it always works that way. Do not turn your car into what 80% of the hacked up pos 240's that run on the road. Do it right the first time.

[GSXRJJordan]

and 250 for intake manifold ? yeah for some janky ass hong kong shit. 300$ for an intercooler kit? I bet everything on your car is from ebay or a knock off . If you are doing any type of rb swap and cant afford to do things right and buy name brand parts and support real companys. I dont know any reputable shop going to swap in a rb for 500-700 bucks lol do you know what labor rate at most good shops are per hour right?

IF your going to do the swap make sure you take the time and look everything over and expect to spend more, it always works that way. Do not turn your car into what 80% of the hacked up pos 240's that run on the road. Do it right the first time.

You must not know me. Hi, I'm Jeff.

I have a Godspeed chrome intake mani on my RB25, and the casting (except for the few "rises" I dremeled down on the inside) looks better than the casting on the Greddy IM I installed on a RB25 Formula D car 4 years ago, when I worked for a F-D team. Yes, I've seen them both, up close and personal... no, it's not worth the extra $800.

The fucking guy is debating between a RB20 and a RB25, do you really think I should give him prices for a HKS intercooler and a real Greddy intake mani?!? Combined they cost more than the whole motorset. Obviously doesn't apply here.

He lives in Socal - I know multiple reputable mechanics that would do a simple swap for $700. Go to a top-end shop like SP Engineering, you're going to pay $100/hr, sure... but again, that's not what he asked for.

Pride in your car, doing it right the first time, etc is fine, which is why I don't take statements like yours (about me/my car, which you've never seen lol) personally - but I'm trying to kick down some knowledge about which motor to buy, and what the prices start at so he can have a minimum budget, not scare everyone off with brand name hype.

[boosted98gst]

If you go the route using the r33 cross member I will give you stock r33 mounts to help you out, I already have syko performance mounts so you can have my old stock ones if you just pay for shipping.

[boosted98gst]

You must not know me. Hi, I'm Jeff.

I have a Godspeed chrome intake mani on my RB25, and the casting (except for the few "rises" I dremeled down on the inside) looks better than the casting on the Greddy IM I installed on a RB25 Formula D car 4 years ago, when I worked for a F-D team. Yes, I've seen them both, up close and personal... no, it's not worth the extra $800.

The fucking guy is debating between a RB20 and a RB25, do you really think I should give him prices for a HKS intercooler and a real Greddy intake mani?!? Combined they cost more than the whole motorset. Obviously doesn't apply here.

He lives in Socal - I know multiple reputable mechanics that would do a simple swap for $700. Go to a top-end shop like SP Engineering, you're going to pay $100/hr, sure... but again, that's not what he asked for.

Pride in your car, doing it right the first time, etc is fine, which is why I don't take statements like yours (about me/my car, which you've never seen lol) personally - but I'm trying to kick down some knowledge about which motor to buy, and what the prices start at so he can have a minimum budget, not scare everyone off with brand name hype.


Its not really scaring him off, its reality. I'm pretty sure just by doing some research on the motors that they are not cheap by any means. If he is just wanting 300 rwhp then he does not even need a new intake mani or a FMIC. The only thing he should really worry about is all the maintenance, what mount set up, and drive shaft and wiring. First thing is making sure everything run's ok, and that his cooling system is working, his tranny is shift good, then mod the engine as he gets money or saves. I work for a big dsm shop that had a rb25 on the dyno a few weeks back and the guy made over 400+ RWHP on the stock intake mani, Yes at that power its holding him back but it flow's fine for any BPU set up.
I think everyone else chimed in on what is the better choice if hes going this far in a motor. 7k is really ideal on doing a good swap

[nathanong87]

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?

i know people aren't going to like this answer, but i have an ebay Fmic and it works fine for setup containing stock turbo, 3in exhaust, dp, etc. u could* easily spend more money on a FMIC but it really depends on what you want for the car

[951's 330i]

When looking for a FMIC or IM, what do i search under? Like when you go to greddy, which one would be the one? Do i still shop under the 95 240 parts, or is everything basically from here from vendors? Thanks again everyone

[951's 330i]

You'll have to cut the front bumper support (the reinforcement) at a minimum. Takes 10 mins with a sawzall. You can see here that the bumper "support" itself is intact, but the reinforcement is cut in between the frame rails:
http://wut2dg.bay.livefilestore.com/y1pDdPjfVeVqs6DKN6F8Jjws9hJkrXm7-DXG968Jr0VKBWgaWt_3ztGW59VozscA_T7dn8QoxLCUsbaNfsz zVdz_w/JustDrift%20Clinic%20089



Yes, you can still use your exhaust - the RB elbow has a slightly different exit than the SR elbow, but most people are able to use it with a 3" SR downpipe/catback. As for FMIC's, which one you get depends on which intake manifold you're using.



That's a great way to go, as long as the R33 motor mounts are in good shape, but you'll still need a tranny mount and driveshaft.


Thank you for the picture that really helps out a lot. I already have my mind set on the 25. Now i just need to get all the parts that you have all mentioned so everything can be ready when i finally do purchase one. BY the way, i think drft freaq already answered this to me in a pm, but do the syko or mckinney mounts work with a neo rb if its close to the same price range as a regular one? thanks all!!

[S14_Kouki]

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

25 is a way stronger engine everyone else pretty much summed it up for me lol.

[Yum-Yum]

my last car was a rb25 s13, it was fast and fun, blew the doors of my friends rb20, now I have a NEO rb25, it blows the doors off my friends regular 25, even on my stock 7 psi. just a fyi

[Chernobyl]

You can do a good running 230whp rb20det for well under 4k running.

I did this and don't regret it one bit. Look around for deals or used parts and you can get that number down to the $3k range. That's with all important maintenance parts replaced, too.

Edit: I see you've made up your mind to do the 25. Go for it.

[Not You]

Because buying a RB20 would be like buying a SR20 thats older, harder to find parts for, heavier, bigger, more expensive, and just an overall mess. RB25 if you wanna go RB, unless you got a RB20 for free.

[karl wasabi]

Because buying a RB20 would be like buying a SR20 thats older, harder to find parts for, heavier, bigger, more expensive, and just an overall mess. RB25 if you wanna go RB, unless you got a RB20 for free.

This is true. I bought the RB20 because I got it almost for free. If I were to do it again, I wouldn't go RB at all. lol. It's a pain in the ass trying to source simple parts like gaskets. But they sound amazing.

[Ghost240]

Its not really scaring him off, its reality. I'm pretty sure just by doing some research on the motors that they are not cheap by any means. If he is just wanting 300 rwhp then he does not even need a new intake mani or a FMIC. The only thing he should really worry about is all the maintenance, what mount set up, and drive shaft and wiring. First thing is making sure everything run's ok, and that his cooling system is working, his tranny is shift good, then mod the engine as he gets money or saves. I work for a big dsm shop that had a rb25 on the dyno a few weeks back and the guy made over 400+ RWHP on the stock intake mani, Yes at that power its holding him back but it flow's fine for any BPU set up.
I think everyone else chimed in on what is the better choice if hes going this far in a motor. 7k is really ideal on doing a good swap


You realize that all these "knock off" companies and ebay shops reverse engineer brand name products? There's not secret behind intercooler piping and theres no revolutionary discovery in FMIC cores. FMIC for the most part are the same and the slight variances only matter on HIGH HP applications. I will be doing this swap my self into an S14 and theres no way it's going to hit 7K before it's running. And alot of people change the IM inorder to do the intercooler piping more effectively and smoothly, not to mention the gains. And for the most part the greddy really isn't worth the $$$$$. As long as you can source a respectable and decent IM, theres no major deal UNLESS (again) HIGH HP application. The exhaust manifold on the other had you shouldn't really skimp out on simply because that see's alot of stress and high temperatures.

[boosted98gst]

Thank you for the picture that really helps out a lot. I already have my mind set on the 25. Now i just need to get all the parts that you have all mentioned so everything can be ready when i finally do purchase one. BY the way, i think drft freaq already answered this to me in a pm, but do the syko or mckinney mounts work with a neo rb if its close to the same price range as a regular one? thanks all!!


I know the syko mounts will should be the same with the mckinney.

[rc1honda]

Isn't the RB20 just a SR made of iron with 2 extra cyclinders:mepoke:? If your going to go RB then might as well go RB25 or RB26.

By doing the swap yourself you are already saving a good 1,000 bucks to use to buy aftremarket and OE replacement parts to get the engine running good.

The aftermarket is better for the 25, the tuning capabilites are better, power potential, resale, all are better with the RB25. RB25 FTW
And If it comes down to it you sell the motor and keep the transsmission to throw on a RB26. The RB25 trans sells for the same as a RB20 motor set. Then you will already have the mounts drive shaft and oil pan to have a freakin monster.

[karl wasabi]

Isn't the RB20 just a SR made of iron with 2 extra cyclinders:mepoke:? If your going to go RB then might as well go RB25 or RB26.

It's more like a CA18 with 2 extra cylinders. haha.

[Rick-95ZE]

You'll have to cut the front bumper support (the reinforcement) at a minimum. Takes 10 mins with a sawzall. http://wut2dg.bay.livefilestore.com/y1pDdPjfVeVqs6DKN6F8Jjws9hJkrXm7-DXG968Jr0VKBWgaWt_3ztGW59VozscA_T7dn8QoxLCUsbaNfsz zVdz_w/JustDrift%20Clinic%20089 .

Well don't ask me why I tried it, but ,I just flipped my bumper support upside down and reinstalled it... The bumper cover fit back over it like a glove.. I can only speak of the kouki front setup though:

http://i264.photobucket.com/albums/ii196/Ricksil80/73.jpg
http://i264.photobucket.com/albums/ii196/Ricksil80/72.jpg

http://i264.photobucket.com/albums/ii196/Ricksil80/12109030.jpg
http://i264.photobucket.com/albums/ii196/Ricksil80/DSC05557.jpg

Not the most flow friendly but I prefer the subtlety of my FMIC..




Even though I'm personally bias to the RB25, I'll punch the dead horse and echo the RB25 call..

[jeb1517]

Why in the world are you interested in doing an RB swap, or ANY swap for that matter, if you're only looking for ~300whp?? KA can do 300 no problem. If KAs aren't your cup of tea, you can buy complete 240s with SRs already swapped in and running for the price of just an RB motor. If you're not looking for big numbers, there's no point in spending all the time and money required for RB swaps.

My $.02.

EDIT: This is the first thing that comes up on google
http://www.jrautoparts.com/clip_nissan_RB25.htm
So I guess the motor is a little cheaper than a SR swapped 240...but still!

[MADE]

Normally I would say RB25, Ive owned a 25 in the past and damnit I miss it everyday. But with the price and power figured you mentioned I'd KA-T. If you seriously want an RB save the money go with the 20 and use the leftover money to mod it. But that depends on the price difference. There is no point buying a 25 when your not interested in making it worth it. Like mentioned an RB20 with a GT2535/40 is more than enough to hold you.

[Jtuned_andy]

this^^^^^^

[Tenchuu]

just a FYI here, if you take your time and buy some used parts, i did a stock (with FMIC) RB25DET swap for $4500. 1900 of it was the motor, has been running great for around 2+ years now. the only issue i have is that my state switched to ethanol added gas(10%+ unregulated, tested to be in excess of 45% in some cases ethanol gas). the RB25DET used to get 28-30 MPG, not it gets 20. on a trip to WA (5% regulated? eth) i jumped back up to 27 MPG.

moral of the story: high ethanol content kills TQ and mileage, but there is still gobs of it with the RB25.

[1GayDrifter]

RB>SRtwanky.... oh btw, www.rawbrokerage.com they have good price parts for whatever rb swap ur doing

[dsportsx]

I know this thread is old but I can purchase a low mileage rb25 for about 1700, 50 bucks more than my blacktop sr, the kit is about 500 for it to sit low and back in the engine bay, wiring specialties does a plug and play harness for the 240. I'm using one right now for my sr, I think your going to need a driveshaft also... i thinking just for a stock install around 3k or lil more. I have all the little stuff I need already to install it and I just have to sell my sr and my other 240 I have in the garage, me and my friends are installing it so that saves alot of money...but more than likely we'll have it rebuilt first even though it has low miles. that's the big money item right their

[GSXRJJordan]

Don't bother rebuilding the bottom end right away if the compression's good... they're generally pretty stout. Just replace oil pump and water pump, then belts and pulleys, and gaskets. Very reliable 300whp with a good-condition stock turbo. A new clutch is probably a good idea.

At that price make sure it's a RB25 trans... and you'll need a new driveshaft. I also do the swap wiring a little cheaper than that if you'd like to keep it within the 240 community :)