Rb20det still worth it ?

[Josch]

I've done a lot of searching and it may be beating a dead horse but would just like some more opinions.

I have a Datsun 280z and I'm looking into putting either the rb20det or the rb25det into it. This car will be a street driven fun weekend car. I am not looking to push over 300 to the wheels I would say 300 to the wheels would be the Max I would go ( I'm not looking to make a rocket). I have heard that the rb20 is a great motor that can take abuse like no other and I also have read that the 25 is the weakest internally out of the group ( 20,25 and 26).

So my question is just getting the rb20det worth it? I've found one for 450 that just needs new rods and Pistons. Or should I deck out the money to buy from a online company for a complete "working" engine for 1400 shipped. Or should I shell out the extra money and go with the rb25 ( roughly 2200 shipped). Also is the rb20det ecu able to be reprogrammed with a chip? I had a z32 and there was tons of off the shelf ecu chips for larger injectors and single and dual intake set ups.

Again I apologize if this is a noob and very beaten topic. But any advice or suggestions are welcome and I very much appreciate them. Looking for experienced answers. Thank you guys again

[KAT-PWR]

Needing new rods and pistons means
Bore/hone
Head plane
New bearings
Gasket set
Timing components
Time/skill/tools to assemble

However you will be with a fresh motor that you know will hold up and isnt waiting to blow. Probably will end up running you about what the assembled running one wouldve cost but you'll have all that peace of mind.

[Josch]

Def appreciate it and yea that sounds about right. It comes with everything but the ecu which shouldn't be all that hard to find as well. Just got to find a good shop to send it to now.

[Sforteen]

RB20 is the weakest out of the group internally

With just a few mods and more boost the RB25 will make close to 300whp limiting factor being the Stock turbo. RB25 also has a Stronger trans but with a 300whp goal its no big deal for either trans.

The RB20 will do basicly the same but both need turbo upgrade or at least a steel turbine wheel replacement in the factory turbo to reliably make 300whp.

RB25 has VCT and will be alot more torqey driving around compared to RB20.

[Josch]

Rb20 I thought had the strongest internally where as the 25 was the weakest and yea from a lot of research I've heard that going past 350 on the 20 is pretty much I not worth it but 300 is more than enough for my car and for what it will be used for. And thank you for answering my question about the transmission I was about to ask about that! Appreciate the information man. I'm still leaning towards the 20 though.

[Kingtal0n]

no

.....



no

[ash16847]

Josch, take a look at this article, it may help you out a lot.
http://forums.nicoclub.com/rb20det-vs-rb25det-vs-rb26dett-faq-t135400.html
It has the pros and cons of the RB's. Also, the RB25 does have weaker ringlands...

BTW, I have an RB20, I absolutely love it, This january ill have had it for 5 years. The key is of course to maintain it properly and keep up with your maintenance.

[Croustibat]

RB20 is a crappy engine. It was the cheap entry level inline 6 from nissan, and it shows.

You want inline 6 sound only ? The rb20 is a good choice. You want decent power, reliability and torque ? An SR20 will do it better. Want even more torque and the L6 sound ? Go rb25.

Don't waste your time on the rb20.

[jr_ss]

I would say the lack of parts in general for the RB20 would be the deal breaker for me. RB25 and be done with it. Plenty of head room for growth later if you decide to get a wild hair up your ass.

As far as "weaker" any engine can be weak if there is a fault with it. A shit tune or bad gas or both can play havoc on an engine. Your best bet is to get the car where you want it and have it professionally tuned to run conservatively. If it makes 275-290whp, is that going to be a deal breaker? For instance, my car made 485whp with low timing number and I only revved it to 8250, I wanted 500whp and 8500. It can rev to 8750 or so, but power starts to fall off at 8250, why drag it out? Reliability becomes a huge factory when you start pushing the limits of the engine. Choose wisely.

[Corbic]

RB20DET was never worth it.

[Corbic]

Rb20 I thought had the strongest internally where as the 25 was the weakest and yea from a lot of research I've heard that going past 350 on the 20 is pretty much I not worth it but 300 is more than enough for my car and for what it will be used for. And thank you for answering my question about the transmission I was about to ask about that! Appreciate the information man. I'm still leaning towards the 20 though.


What?

Let's break this down.

RB20DET $1-1.5k
Crappy 2.0L
Crappy T25 Turbo
Crappy Aftermarket
Not a Direct Swap
Crappy S13 Transmission with RB bell housing
Less Torque then an SR
More Weight then an SR
Less aftermarket then an SR
Not as easy to install as an SR
Not as strong as an SR


RB25
Only $1k more gets you...
A T28 Turbo
1/2 a liter of displacement
Bigger injectors
A 300ZX transmission with RB bellhousing that will take a beating
A larger aftermarket


You want 300whp?

My buddy dyno'd 320whp with a tune and FMIC on his RB with a straight 3.5" exhaust. Stock injectors and stock turbo.

To do 300whp on the RB20 you'll need a turbo and injectors.... Which will cost more than the difference between an RB25 and a RB20.

At no point ever is the RB20 a wise, affordable solution.

Now the engines are also 10 years older than they where back in the day... So even less wise a decision.

[Koukiii]

lol yeah nobody on here will tell you to go rb20 vs rb25. After your done playing with stock turbo you can have a real mean stock block 450ish hp rb25 running reliably.

[Josch]

Thank you all for the comments. Been doing more and more searching and now I feel like the 25 is the better bang for the buck like y'all have mentioned. Stronger motor+transmission in case I do ever want to move up in the future. But I def will make this a reliable motor and not one that's got tons of power but waiting to explode. I really appreciate the advice guys y'all probably saved me a ton of money.

[spools420a]

I bet 98% of anyone who says its a crappy motor never owned one or even driven one.I say get it,rebuild it since its already needed parts and possably go ahead and replace some parts with forged for a lifetime of 300whp worry free.

[theboy]

RB20s are fun as shit to drive & and taken care of they will last you a while before you actually need power and move to a 25/26. But they are correct that an sr or rb25 would be the better choice. SR aftermarket is much bigger than anything RB and an SR is a LOT more responsive than an RB20 as you have a lot less to rotate.

[Corbic]

I bet 98% of anyone who says its a crappy motor never owned one or even driven one.I say get it,rebuild it since its already needed parts and possably go ahead and replace some parts with forged for a lifetime of 300whp worry free.


Why?

Seriously. Why?

Why would you do that when you can pay less then $1,000 more to have an infinitely better RB25?

This is like a Chevy 305 vs 350 argument. Sure a 305 is $250 and a 350 is $500.

Sure a 305 can be built into and awesome engine. But it will cost you $1,500 to make it as good as that $500 350..... So what is the God damn point?


You are not saving anything going with a RB20. Rebuild it? Why not just buy the engine that is 10-15 years newer and save the $1,000+ from a basic bitch rebuild. Does anyone even make forged internals for the RB20? Google RB20 forged rods and pistons and all that comes up is RB25/26 stuff.

RB25,

$1000 buys you:
.5 Liter of displacement
Stronger Transmission
Stronger Clutch
Bigger Turbo
Bigger Injectors

SR guys drop $5k to get freaking .2 liters of stroke.

RB20 and SR guys drop $500 to get used bullshit T28s

It will probably cost you a $1,000 to convert to a RB25/300ZX trans.

Injectors will be $100-200

And you'll have to retune it where the RB25 is already tuned for the extra "50hp".

On no planet, in no situation does an RB20 make sense. Even if I had a a stock R32, I'd yank that lump and direct swap a RB25 or convert to a SR20.....

[Croustibat]

I bet 98% of anyone who says its a crappy motor never owned one or even driven one.I say get it,rebuild it since its already needed parts and possably go ahead and replace some parts with forged for a lifetime of 300whp worry free.

I don't need to consume heroin to know it is nasty stuff.

There are better choices than an RB20 in terms of torque, power, money, upgrades, ease of build and parts availability.

I can only see 2 reasons to go RB20:

- you got a working engine and swap kit for free, and will be satisfied with a stock or mildly engine;
- you desperately want an inline 6 engine with "RB" on it, but can't afford an RB25/26.

If you have another one, please post it.

[jaybeatz19]

The answer to your question is quite subjective. I too have looked into the RB20, but depending on what you have already, and what your end goal is, will determine if its worth it to you. Also it depends on how involved you want to be while owning it. If its just 300hp you're wanting to make max and thats the only concern you have for your build, then you may want to consider an RB25 for just the ability to reach that power a bit easier and for less money. But if power isn't the main focus, 300hp can be had overtime, but you'll have to be much more involved.

[Josch]

Bought the car about a year ago and was contemplating which build I would do. At first it was a 2jz since I already had a ge motor I did the NA-t kit on it from Dave h which by the way is great. After looking for transmission options I just kind of lost focus on it because paying 1300 for a used transmission was crazy ( I know these cars are expensive ! Lol) so I started doing a lot of research on putting a Nissan engine in the Datsun and after looking through it more and more I was pretty much set on the rb20 or 25. The fact that these motors come with everything you need to drop it in besides the mounts and a different oil pan made it a lot more better than having to search down the r154 or the cd009 which are pretty hard to come by in Louisiana. After reading what y'all have posted and just lookin more into it I really am set on the 25 and will purchase this Friday. After that I can't wait to get into it and make this car what I want it's just going to be a fun car and something to work on. Thank you guys for the advice and I'll def post pics of the build of anyone's interested.

[mixeds14]

What evryone forgot to post is that while u might want 300hp max, after a while u will get used to it and want more, the 25 will make 300hp with ease like others have said and has potential to make more just incase u decide that 300hp just dont cut it anymore.

[TheRealSy90]

Only thing that worries me with 25's is the bad oil drive gear on the crankshaft and oil pump problems. And to remedy this you have to pull the crank out of the engine to have a different drive gear pressed on. So for someone wanting to just drop in an engine and go, that's not always the best way to go. However some people run 25's with the normal "bad" oil pump stuff and don't have any problems...

[jr_ss]

Only thing that worries me with 25's is the bad oil drive gear on the crankshaft and oil pump problems. And to remedy this you have to pull the crank out of the engine to have a different drive gear pressed on. So for someone wanting to just drop in an engine and go, that's not always the best way to go. However some people run 25's with the normal "bad" oil pump stuff and don't have any problems...

Most of these issue arise at a much higher HP level than what the OP wants. Typically south of 4-450whp isn't a problem. It's the 500hp mark that this condition generally rears its ugly head. Now I'm not saying it doesn't pop up under stock/mildly modified conditions, but less likely too for sure.

[shawn1331]

On no planet, in no situation does an RB20 make sense. Even if I had a a stock R32, I'd yank that lump and direct swap a RB25 or convert to a SR20.....

I have an R32 that I am putting in an RB20. Why? Bc its my daily and it needs to stay reliable. Nothing is more reliable than stock oem parts going into the car they were made for.

Just so you're aware RB25 IS NOT a direct swap. It's fairly easy yes but it requires, mounts, smahing of the tunnel for the tranny, a driveshaft, speedo sorted, and of course wiring plus a couple small things like the exhaust.

For those 2 reasons is why I decided to stick the cheap, reliable RB20 in that revs higher and free-r than an sr or 25.

Have you ever been in an RB20 car or driven one? They drive amazing bc they rev high. Ppl hate them bc there is an RB25/6. If there was an SR25 people would hate the SR20, kinda like how everyone hates on the CA18...

OP
If you want to go ahead with the RB20 there are many benefits to it as opposed to a 25.

Do yourself a favor if you decide for more power and use Holset turbos almost religiously. They're cheap and for what ever reason seem to spool up quite fast on the 20. Theres a few RB20's rolling around with 400whp using hx30 turbos that make full boost by 4500rpm.

Not saying the RB25 isn't any good. I just think the 20 gets a bad rap for no reason. It's a very capable motor and is for a different crowd. If you like revving high go for the 20, if you want something easy to make power get the 25. At 300hp though you'd be better off with an RB20 using a 25 turbo for $150 and a couple bolt ons. You'll get there with the stock injectors and maf but you will be close to the limit o the injectors at 300hp

[Corbic]

If you want a high-revving engine, swap a K24.

The RB20 is junk and none of your arguments disprove that.

Stock OEM parts? That are 30 years old?

Anyway, there is a reason the SR is a popular swap into the R32.

http://i195.photobucket.com/albums/z52/JDM32/PA220321.jpg

http://csgarage.files.wordpress.com/2012/12/img_3256-edit-2.jpg

[Croustibat]

Have you ever been in an RB20 car or driven one? They drive amazing bc they rev high. Ppl hate them bc there is an RB25/6. If there was an SR25 people would hate the SR20, kinda like how everyone hates on the CA18...

Theres a few RB20's rolling around with 400whp using hx30 turbos that make full boost by 4500rpm.

Not saying the RB25 isn't any good. I just think the 20 gets a bad rap for no reason. It's a very capable motor and is for a different crowd. If you like revving high go for the 20, if you want something easy to make power get the 25. At 300hp though you'd be better off with an RB20 using a 25 turbo for $150 and a couple bolt ons. You'll get there with the stock injectors and maf but you will be close to the limit o the injectors at 300hp

I removed a ton of crap from your post and just left this crap to answer it.

I don't know who hates the CA. Maybe US people, aka the guys that don't have them ?
We got them in Europe, in our stock S13; they are cheap, reliable (yes, despite what the usual dorifto kids can say, when maintained properly they last for ages), tons of aftermarket support, rev high and make power, unlike the RB20.

You can get 300hp out of them and keep the internals stock, just need a *bolton* SR20 turbo, that will hit full boost at 3000. And it will rev at 7500+rpm in stock form, like mine still does after years of trackdays and 160K+ miles.

If you can wait a bit, i think my tuner should finish the latest evolution from his this week. Since the last time he got around 600WHP @ 8500rpm out of it, with a broken turbo (no nitrous, no meth, just e85 and 40+psi of boost that went down to 30 at high revs due to the turbo dying), i'd say it is going to be quite amazing.

Now 400whp, full boost by 4500rpm. First, that really is a crappy spool. Second neither the transmission nor the internals can hold that. The only possible way to get 400Whp without blowing your gearbox and sending your rods through the block is to use a cheating dyno. BTW good luck finding someone to tune it.

An SR20 will do 100 more HPs with its full boost at 3500 rpm with a gt2867r. slap a smaller or EFR turbo instead and you will get your full boost at 3000 with slightly less power. It will still rev to 7000rpm, will rev faster, be lighter and stronger. Of course as it has a similar gearbox it will also self destuct once you go around 300-400whp with sticky tyres.


The RB20 gets a bad rap because as stated before, there are better alternatives that make more power, more torque, more revs and are more reliable, with way more aftermarket support, all that for cheaper and less hassle.

There is a reason you can't find aftermarket parts for this engine: it is crap and there are no market for them.

[Corbic]

I removed a ton of crap from your post and just left this crap to answer it.



I don't know who hates the CA. Maybe US people, aka the guys that don't have them ?

.


CA18DET isn't hated in the US, it's just so old and so rare that it's not worth the time. I can go on Craigslist and find SR parts all day long.

CA was generally considered a better design and I recall many people said Nissan moved away from it because the SR was more affordable to produce.

Either way, last CA18 was built in 1991, SR20 was what, 2001.

[96red240sx]

Love these type of posts. It always brings out the spirited posters. They are always so enlightening. Much like who we should vote for in the 2016 election. You never really know what might pop out...LoL.

[Chernobyl]

This car will be a street driven fun weekend car. I am not looking to push over 300 to the wheels I would say 300 to the wheels would be the Max I would go ( I'm not looking to make a rocket).

You will need a turbo, injector, and ecu upgrade to get to 300whp on an RB20. RB26 injectors are an easy and cheap swap (needs a resistor box) and will get you to those numbers. Not sure if the bolt-on RB25 turbo will get you quite there. Probably close, but not quite.

So my question is just getting the rb20det worth it? I've found one for 450 that just needs new rods and Pistons. Or should I deck out the money to buy from a online company for a complete "working" engine for 1400 shipped. Or should I shell out the extra money and go with the rb25 ( roughly 2200 shipped).

$800 is totally worth it for the extra displacement and ease of getting to 300whp. This is coming from an RB20 owner.

Also is the rb20det ecu able to be reprogrammed with a chip? I had a z32 and there was tons of off the shelf ecu chips for larger injectors and single and dual intake set ups.

Yes you can socket and chip the RB20DET ecu cheaply and easily just like the Z32 you're familiar with. This doesn't seem to be nearly as common with the RB25 ECU (correct me if I'm wrong someone).

[TougeSR20Kid]

RB20 is a crappy engine. It was the cheap entry level inline 6 from nissan, and it shows.

You want inline 6 sound only ? The rb20 is a good choice. You want decent power, reliability and torque ? An SR20 will do it better. Want even more torque and the L6 sound ? Go rb25.

Don't waste your time on the rb20.

So many crack rocks smoked by this guy.
WHO IN THE FUCK ACTUALLY THINKS SR20 IS GOOD???
I'm sorry I've had 4 of them everything from mild to wild and they are good but once you try and get real power out of them all they do is break, like f*cking continously. I've since swapped to RB20 and have had it running just fine for like 3 years? The problem with this swap like all others are the people that run them. People who buy this motor are often cheapskates because it is so much cheaper than most other swaps. SO you have a bunch of cheap people buying a 20 y.o. motor and not doing anything to it or fixing it properly because... you guessed it they are broke dicks... This is why you hear so many stories about them being unreliable or always breaking, because the people that typically own them don't take good care of them cus they cant afford to. We used to see the same thing with KA-t back in the day when the people that took the time to do it right had great success while most (the broke dicks that couldn't afford SR) were having nothing but issues. //// rant and on to information

SO like I said I've been driving my RB20 swapped s13 for about 3 years, for about 2 years of that it was my daily and my weekend drift/touge fun car. The motor has only failed me 2 times once was the ecu (got water on it) and the other was an injector (direct replacement with ka single cam, fixed same day).
This leads me to my next point, parts availability: There are now a lot of people with these swaps stateside so parts are less scarce than they were. You can also get a lot of parts by cross referencing to other ones that will work (Like my ignitor chip, its off of a 300zx). The only real problem I've had finding a part is the TPS, that seems to be an RB20 only part, which you can buy from raw brokerage used or modify a j30 one i believe? Not sure but there is one that is similar and just requires some dremeling to work. The point I'm trying to get across is that as long as you are resourceful its not difficult. But if you are like most of the current generation of car enthusiasts that would give up the second you cant just call up Napa or Oriellys for instant fixing then yeah this motor is not for you.

The reason why I personally have the 20? I bought a car with the swap already done for a really good deal. Hasn't made sense to get rid of it yet. The plan was originally to go 25 once this motor goes out. That was 3 years ago, and they've been really hard three years and its taken the abuse. I have driven all three motors and I gotta say that out of them I like the revvability of the 20 the most. I heard someone say that they don't have a high redline? You are correct, the laurel and cefiro ones do not, but the skyline one's, which mine is, do. As far as the power issue. 300 is just fine and still reliable with this motor. I'm running around 280 with no problems and my buddy is running 320 or 330 also with no problems.

[shawn1331]

There is absolutely nothing wrong with RB20s if you're not going crazy with them. Theyre reliable as hell and make pretty good power up to around 400whp, at which point they run out of steam like an sr tends to without serious modifications.

I stand by my comment that RB20's are hated on mainly bc there is an RB25. In Canada where we have had skylines for longer there are a ton of guys modifying and running around with the RB20 still in the car and drifting it for the last 9 years or so.

I never said it was the best "bang for your buck" swap but if you have an R32 that you're not going overboard with and want something bolt in, reliable and still make decent numbers then leave the 20 in, like what me and countless other R32 owners do. Theres nothing wrong with them, but if you're doing a swap into a drift car or want crazy power by all means do a 25.