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

[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]

Originally Posted by 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?

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:

Originally Posted by 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?

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.

Originally Posted by 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.

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]

Originally Posted by 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.

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]

Originally Posted by 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 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.

[THeokaYsLider]

:-) what a ass..^^

[boosted98gst]

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.

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]

Originally Posted by boosted98gst

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]

Originally Posted by GSXRJJordan

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]

Originally Posted by 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?

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]

Originally Posted by GSXRJJordan

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:




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]

Originally Posted by 951's 330i

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]

Originally Posted by SuicidnS13

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]

Originally Posted by 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.

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]

Originally Posted by boosted98gst

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]

Originally Posted by 951's 330i

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? 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]

Originally Posted by rc1honda

Isn't the RB20 just a SR made of iron with 2 extra cyclinders? 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]

Originally Posted by GSXRJJordan

You'll have to cut the front bumper support (the reinforcement) at a minimum. Takes 10 mins with a sawzall. .

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:







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