I searched, Trust me. RB25 vs sr20, Different questions... - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Seanbonham · 06-29-2010, 03:49 PM

I have read through the bazillion or so threads addressing this debate but i have a few other questions and none of the other threads really answered my query.

First, i can't even really find a post addressing this, but it seems that a lot of the motors coming from japan have been beaten to hell in terms of never having their oil changed. Is an rb25det LESS likely to have these problems/treatment than an sr20det cause it's a nicer car?

Anyway,

This fall i get a check for 10k on the button. I'm planning on swapping something into a 240sx, professionally, not myself (cause well, i'm not that good yet and i want AC)

Here is my goal/dilemma

It's a DD, so i need it to start, and ideally keep starting for at least...idk a year, preferably 2.

I want to hit low 12s in the 1/4 mile so that's at a minimum,

310+whp from the RB25det

or

290+whp from a RED TOP s13 SR20det (ideally 300, cause that's the magic number)

Here are my concerns/questions.

Redtop SR20det CONS/concerns:

290whp i know isn't pushing it for the sr20det stock internals IF you got a slightly bigger turbo, injectors, etc. you'd still be pushing out probably 14-17 (guessing) lbs of boost to reach that....that's a lot to ask for an engine to run everyday. IS that a lot?

SR20DET PROS:
Cheap parts, common, etc. shit we all know, ALSO, the s13 swap is simple enough that after i had it professionally done and all the parts in place, i'm more then capable of swapping in a new block if i blow it....so that's kind of nice.

RB25DET Cons/concerns:
Little bit more invasive a swap...that's a big engine, going to have to cut the fire wall etc...If something did break in the rb25, that's harder to find, harder to fix, more expensive. Not so confident i could swap in an rb25...probably could manage i guess....but still a more expensive motor. Biggest concern is really that... If i got an rb25 and something broke...i may be a whole shit more out of luck than if i had the s13. However, if the rb25 is a lot less likely to break...that's kind of worth the risk.

RB25det Pros:
It's a skyline..(had to say it), More importantly, it's a lot closer to that goal of 320 then the redtop is. You could probably put 300rwhp down with just a few bolt ons and stockish boost. Some have argued it's more reliable. Is it?

The most important thing here is reliability! That's what i want most.

Here's the place where i'd be getting the swap done, this is literally all they do pretty much. Both swaps would be the stage 2 for either, take a look at the parts list etc., and tell me what you guys think i should do for my goals.

roboticnissan · 06-29-2010, 04:16 PM

Where are you getting your information that the rb25det is 300pounds heavier than the sr20 I'm sure that's way off.

Just looked it up and rb25det is 150pounds heavier than an SR. And it only effects the cars weight shift by 90 pounds.

corbin · 06-29-2010, 04:22 PM

KA-T is better than both, visit KA-T.org - The Home of 1000+ whp/7 sec Turbo KA's and check out the flat, powerful torque curves on the dyno and see the video section for them in action. People make 300+ whp and even more torque on 12 psi all day long with a moderate sized turbo.

KA's also cheaper and more reliable (with the proper tuning) than a poorly maintained Japanese SR20 that hasn't been rebuilt. Really the only good thing about SR20's is all the fan boys that will be sucking your weiner and the rev limit. Other than that its a peaky motor that lacks torque. The only reason Nissan had it succeed the CA18DET is because it was cheaper to produce.

The fastest KA-T's are in the 7 second range. They have more displacement, a stronger block, more torque, and better gear ratios than SR20's.

YouTube - [email protected] @ 15psi VS C6 z06 boltons
Street car KA-T vs. 550WHP Z06... Z06 gets beat and its not even a close race.

seRu13 · 06-29-2010, 04:36 PM

Quote:

Originally Posted by corbin

KA-T is better than both, visit KA-T.org - The Home of 1000+ whp/7 sec Turbo KA's and check out the flat, powerful torque curves on the dyno and see the video section for them in action. People make 300+ whp and even more torque on 12 psi all day long with a moderate sized turbo.

KA's also cheaper and more reliable (with the proper tuning) than a poorly maintained Japanese SR20 that hasn't been rebuilt. Really the only good thing about SR20's is all the fan boys that will be sucking your weiner and the rev limit. Other than that its a peaky motor that lacks torque.

The fastest KA-T's are in the 7 second range. They have more displacement, a stronger block, more torque, and better gear ratios than SR20's.

YouTube - [email protected] @ 15psi VS C6 z06 boltons
Street car KA-T vs. 550WHP Z06... Z06 gets beat and its not even a close race.

Gotta say I agree with him^^^^

but between SR and RB ive seen more DD's with SR's and i mean 4+ years of DD. RB cars are usually weekend cars or track cars. but RBs are capable of a lot more power and torque. IMO the weight an RB adds is worth all the extra torque.

rb25_s13*CHUKI · 06-29-2010, 04:43 PM

Quote:

Originally Posted by corbin

KA-T is better than both, visit KA-T.org - The Home of 1000+ whp/7 sec Turbo KA's and check out the flat, powerful torque curves on the dyno and see the video section for them in action. People make 300+ whp and even more torque on 12 psi all day long with a moderate sized turbo.

KA's also cheaper and more reliable (with the proper tuning) than a poorly maintained Japanese SR20 that hasn't been rebuilt. Really the only good thing about SR20's is all the fan boys that will be sucking your weiner and the rev limit. Other than that its a peaky motor that lacks torque. The only reason Nissan had it succeed the CA18DET is because it was cheaper to produce.

The fastest KA-T's are in the 7 second range. They have more displacement, a stronger block, more torque, and better gear ratios than SR20's.

YouTube - [email protected] @ 15psi VS C6 z06 boltons
Street car KA-T vs. 550WHP Z06... Z06 gets beat and its not even a close race.

Funny cause sr20's are also In the 7's

rb25_s13*CHUKI · 06-29-2010, 04:55 PM

I'd say go with the sr20, If mitsubishi can run 6.8's with their 4g63 and nissan can run 7.2 with their sr20. 2jz's and rb's have trouble getting In that range with a frame car and not a rail car.

Shit 13b rotary's run 6.8's.

YouTube - RX7 6 second drag run

YouTube - 6 second Mitsubishi Eclipse

YouTube - Import DPS Nissan 240SX Ka-T 7.87 @ 174MPH

^^^ all that 2.4 and can't even run faster than the sr's or 4g63's. Like I've always said Ka's are nice but just not what people think they are.

YouTube - Brent rau vs. mazworx s15

rb25_s13*CHUKI · 06-29-2010, 04:57 PM

Quote:

Originally Posted by corbin

KA-T is better than both, visit KA-T.org - The Home of 1000+ whp/7 sec Turbo KA's and check out the flat, powerful torque curves on the dyno and see the video section for them in action. People make 300+ whp and even more torque on 12 psi all day long with a moderate sized turbo.

KA's also cheaper and more reliable (with the proper tuning) than a poorly maintained Japanese SR20 that hasn't been rebuilt. Really the only good thing about SR20's is all the fan boys that will be sucking your weiner and the rev limit. Other than that its a peaky motor that lacks torque. The only reason Nissan had it succeed the CA18DET is because it was cheaper to produce.

The fastest KA-T's are in the 7 second range. They have more displacement, a stronger block, more torque, and better gear ratios than SR20's.

YouTube - [email protected] @ 15psi VS C6 z06 boltons
Street car KA-T vs. 550WHP Z06... Z06 gets beat and its not even a close race.

Ka turbo can go to sleep now. This Is a rb and sr argument. Ka's have been shut down In every aspect.

S13 curtis · 06-29-2010, 05:30 PM

Quote:

Originally Posted by corbin

KA-T is better than both, visit KA-T.org - The Home of 1000+ whp/7 sec Turbo KA's and check out the flat, powerful torque curves on the dyno and see the video section for them in action. People make 300+ whp and even more torque on 12 psi all day long with a moderate sized turbo.

KA's also cheaper and more reliable (with the proper tuning) than a poorly maintained Japanese SR20 that hasn't been rebuilt. Really the only good thing about SR20's is all the fan boys that will be sucking your weiner and the rev limit. Other than that its a peaky motor that lacks torque. The only reason Nissan had it succeed the CA18DET is because it was cheaper to produce.

The fastest KA-T's are in the 7 second range. They have more displacement, a stronger block, more torque, and better gear ratios than SR20's.

YouTube - [email protected] @ 15psi VS C6 z06 boltons
Street car KA-T vs. 550WHP Z06... Z06 gets beat and its not even a close race.

And thats exactly why An SR has the 2nd spot on the board! Second to a boosted LS7 and faster then all the KA's on their own board, and not to mention they had the #1 spot on this board for a while!

www.ka-t.org ::

corbin · 06-29-2010, 06:48 PM

Quote:

Originally Posted by S13 curtis

And thats exactly why An SR has the 2nd spot on the board! Second to a boosted LS7 and faster then all the KA's on their own board, and not to mention they had the #1 spot on this board for a while!

www.ka-t.org ::

Er, the SR is fourth and a KA is third, almost half a second quicker.

Besides, that SR is bored out to 2.4 liters. Such an extreme modification is hardly a fair comparison. Bore a KA out to 2.8 liters and see what happens.

S13 curtis · 06-29-2010, 08:20 PM

Quote:

Originally Posted by corbin

Er, the SR is fourth and a KA is third, almost half a second quicker.

Besides, that SR is bored out to 2.4 liters. Such an extreme modification is hardly a fair comparison. Bore a KA out to 2.8 liters and see what happens.

lol how immature, your a 1 uper thats forsure... bitching about a 2.4L SR shitting on KA's then about Boreing a KA to 2.8?!?!?! GTFO bro.

rb25_s13*CHUKI · 06-29-2010, 10:52 PM

Quote:

Originally Posted by corbin

Er, the SR is fourth and a KA is third, almost half a second quicker.

Besides, that SR is bored out to 2.4 liters. Such an extreme modification is hardly a fair comparison. Bore a KA out to 2.8 liters and see what happens.

It's actually a 2.2 liter. mazworx buddy maxworx.

8Nismo9 · 07-01-2010, 06:57 PM

Quote:

Originally Posted by corbin

Er, the SR is fourth and a KA is third, almost half a second quicker.

Besides, that SR is bored out to 2.4 liters. Such an extreme modification is hardly a fair comparison. Bore a KA out to 2.8 liters and see what happens.

2.6 to be correct,crower stoker kit my friend.

To the OP,if you thinking of SR then i don't see why not thinking of the KA

s13silvia123 · 06-29-2010, 07:36 PM

Quote:

Originally Posted by corbin

KA-T is better than both, visit KA-T.org - The Home of 1000+ whp/7 sec Turbo KA's and check out the flat, powerful torque curves on the dyno and see the video section for them in action. People make 300+ whp and even more torque on 12 psi all day long with a moderate sized turbo.

KA's also cheaper and more reliable (with the proper tuning) than a poorly maintained Japanese SR20 that hasn't been rebuilt. Really the only good thing about SR20's is all the fan boys that will be sucking your weiner and the rev limit. Other than that its a peaky motor that lacks torque. The only reason Nissan had it succeed the CA18DET is because it was cheaper to produce.

The fastest KA-T's are in the 7 second range. They have more displacement, a stronger block, more torque, and better gear ratios than SR20's.

YouTube - [email protected] @ 15psi VS C6 z06 boltons
Street car KA-T vs. 550WHP Z06... Z06 gets beat and its not even a close race.

LOL youre 19 and you still dont know jack. youre one of those fanboys who jumped into the 240 scene since fast and the furious came out. grow some balls before you talk kid

jspaeth · 07-01-2010, 06:24 PM

Quote:

Originally Posted by corbin

The fastest KA-T's are in the 7 second range. They have more displacement, a stronger block, more torque, and better gear ratios than SR20's.

What? Last time I checked, an SR and KA tranny had the same gear ratios.....someone please correct me if I am wrong....

jamanrr · 07-01-2010, 06:52 PM

Quote:

Originally Posted by jspaeth

What? Last time I checked, an SR and KA tranny had the same gear ratios.....someone please correct me if I am wrong....

they are the same except for 5th gear it is lower in USDM KA powered 240s than the SR20 counterpart.

Sileighty_85 · 06-29-2010, 04:32 PM

Dude all your info on these engines and swap information is wrong.

Too much for me to wanna correct and type out.

We have an SR and RB FAQ thread you need to read through and SEARCH harder
Look through build threads and questions ppl ask.

Seanbonham · 06-29-2010, 04:52 PM

Quote:

Originally Posted by Sileighty_85

Dude all your info on these engines and swap information is wrong.

Too much for me to wanna correct and type out.

We have an SR and RB FAQ thread you need to read through and SEARCH harder
Look through build threads and questions ppl ask.

Have you ever thought that maybe i got all this information from the copious amount of terribly answered threads out there?

I'll tell you something else, there is always some guy like you who claims to "know all the answers" but doesn't want to take the time to explain.

If instead of wasting a post with your "i know, but i'm not going to expalin" and adding yet another 1 to the thousands. Why don't you just answer and keep it in the copy paste file, to answer later for other people who ask the same question, and EVENTUALLY all the posts people come across will have solid information and no one will ask anymore?

Hell bookmark this post and send the next guy here so you start cutting down on the bad info, instead of adding to it.

Seanbonham · 06-29-2010, 04:33 PM

Edited and changed, the source i had for the weight on the rb25 i realized now also included a few extra things. 150lbs is about right. So only really 15 more whp, which isnt even worth mentioning.

drift freaq · 06-29-2010, 04:34 PM

Quote:

Originally Posted by Seanbonham

I have read through the bazillion or so threads addressing this debate but i have a few other questions and none of the other threads really answered my query.

First, i can't even really find a post addressing this, but it seems that a lot of the motors coming from japan have been beaten to hell in terms of never having their oil changed. Is an rb25det LESS likely to have these problems/treatment than an sr20det cause it's a nicer car?

Anyway,

This fall i get a check for 10k on the button. I'm planning on swapping something into a 240sx, professionally, not myself (cause well, i'm not that good yet and i want AC)

Here is my goal/dilemma

It's a DD, so i need it to start, and ideally keep starting for at least...idk a year, preferably 2.

I want to hit low 12s in the 1/4 mile so that's at a minimum,

320+whp from the RB25det

or

290+whp from a RED TOP s13 SR20det (ideally 300, cause that's the magic number)

Here are my concerns/questions.

Redtop SR20det CONS/concerns:

290whp i know isn't pushing it for the sr20det stock internals IF you got a slightly bigger turbo, injectors, etc. you'd still be pushing out probably 14-17 (guessing) lbs of boost to reach that....that's a lot to ask for an engine to run everyday. IS that a lot?

SR20DET PROS:
Cheap parts, common, etc. shit we all know, ALSO, the s13 swap is simple enough that after i had it professionally done and all the parts in place, i'm more then capable of swapping in a new block if i blow it....so that's kind of nice.

RB25DET Cons/concerns:
Little bit more invasive a swap...that's a big engine, going to have to cut the fire wall etc...If something did break in the rb25, that's harder to find, harder to fix, more expensive. Not so confident i could swap in an rb25...probably could manage i guess....but still a more expensive motor. Biggest concern is really that... If i got an rb25 and something broke...i may be a whole shit more out of luck than if i had the s13. However, if the rb25 is a lot less likely to break...that's kind of worth the risk. Also 300lbs weight difference means it has to make about 30 more rwhp then the sr20det needs to.

RB25det Pros:
It's a skyline..(had to say it), More importantly, it's a lot closer to that goal of 320 then the redtop is. You could probably put 300rwhp down with just a few bolt ons and stockish boost. Some have argued it's more reliable. Is it?

The most important thing here is reliability! That's what i want most.

Here's the place where i'd be getting the swap done, this is literally all they do pretty much. Both swaps would be the stage 2 for either, take a look at the parts list etc., and tell me what you guys think i should do for my goals.

Ok I do not know who is feeding you information or where you are getting it from, most it sounds like hearsay.

First off to get the HP numbers you are after on the SR you will have to with a bigger turbo, That usually means upgraded injectors and quite possibly a upgraded maf which means a ecu tune .

So on top of the price of purchasing a SR which is actually not much cheaper than the cost of a RB . You will spend $500-700 more on a bigger turbo, $250-400 more on injectors, $70 for a maf, $350 for a tuned ecu.

Now with the RB25DET you do not have to cut your firewall. In fact there are several install kits out there for around $500. Oh and with just a slight turbo upgrade you can see 300whp at 11lbs without even touching your injectors or maf. Though a tuned ECU does help.
Downside is keeping it cool.

Honestly neither engine should break in this HP range they are designed for boost from the factory and as long as you have your air fuel ratio right they will work fine.

The question you should be asking yourself is what am I after? Fast quarter mile times mean nothing.
Do you want more torque? Do you want linear power? The RB will have more torque and be a much more linear power band engine.

The SR will be more like a 2 stroke motorcycle , not a lot till hits boost and then snap your neck. Less torque as well some people like one some like the other.

I also do not see a parts list lol. Also all this Stage 1 stage 2 crap that is marketing. Build for what you are boosting to and correct your air fuel accordingly so you don't blow shit up.

Its the same on any turbo engine.

Seanbonham · 06-29-2010, 04:44 PM

The parts list is massive, you have to click the stage 2 link....

As for the upgraded parts, i'm well aware? I'm pretty sure i acknowledged in my post the additional needs for larger turbo, injectors, standalone ecu..etc..?

As for being fed bad information. I agree 100%. I've read about 1000 posts, and they all for the most part say what sounds like BS, and are half of them are 5 years old.

Thus why i am bothering everyone here today, trying to get the facts straight.

Your info was helpful, i've been sort of leaning towards the rb25det, but i do live in texas, it'd be nice to have AC in 100 degrees and not overheat my engine. I suppose that's all doable though? Not exactly sure... Are the RB25's generally in better condition than the sr20s when they're imported over? That may be a stupid question. But again, my information only comes from other peoples posts thus far.

Anyone else have things to add? Could use more info. More information the better.

Slidin' Sam · 06-29-2010, 04:38 PM

Any motor your gonna get from Japan has probably been beaten pretty hard. Also, Japanese motors are not as low mileage as you would expect. I have had 4 Silvia's now and all of them were at/around 100,000km min. when I got them.

As far as reliabilty, either one can be very reliable.

RB25 definately has a better transmission, but is less common and more expensive in the states (from what I have heard, but I live in Japan).

RB's sound cool, IMO.

SR's are more fun, IMO. They have a quick spool and good powerband.

Either motor can handle abuse fairly well, as long as you maintain it.

.9-1bar is ok for daily boost on both motors.

It all comes down to personal preference IMO.

Seanbonham · 06-29-2010, 04:47 PM

[quote=Slidin' Sam;3518579]Any motor your gonna get from Japan has probably been beaten pretty hard. Also, Japanese motors are not as low mileage as you would expect. I have had 4 Silvia's now and all of them were at/around 100,000km min. when I got them.
[quote=Slidin' Sam;3518579]

That's the thing though, I wonder if because Skylines are better cars even in japan, if the owners maybe beat on them less haha, or at least change the damn oil on time. You live there, any ideas if that may be true?

drift freaq · 06-29-2010, 04:55 PM

Quote:

Originally Posted by Slidin' Sam

Any motor your gonna get from Japan has probably been beaten pretty hard. Also, Japanese motors are not as low mileage as you would expect. I have had 4 Silvia's now and all of them were at/around 100,000km min. when I got them.

As far as reliabilty, either one can be very reliable.

RB25 definately has a better transmission, but is less common and more expensive in the states (from what I have heard, but I live in Japan).

RB's sound cool, IMO.

SR's are more fun, IMO. They have a quick spool and good powerband.

Either motor can handle abuse fairly well, as long as you maintain it.

.9-1bar is ok for daily boost on both motors.

It all comes down to personal preference IMO.

Honestly right now I would say your bets are higher on a a low mileage RB over here.
The days of low mileage SR's are indeed coming to an end. Though you have to realize something. 100,000k is still on 62 thousand miles. That is still low mileage . Plus fact is you have been buying running cars that have not been crashed so of course the mileage will be higher. LOL

As far as it being beat on you can inspect a clip and tell immediately if the engine was beat on or not just by how stock the clip is. For one thing. The other thing you can do is a cylinder leak down test and compression test, you can also inspect the turbo.

The RB is less likely to be beat on as well because it has enough power stock and its coming out of a GTST which like I said before is not exactly the performance model version of the car.

RB's can spool damn fast with the right turbo. I know my GT2530 on my RB spooled instantly and my friends with SR's were shock by the way the car pulled like mad.

Either way indeed both engines are fun.

Just because you are in Japan it does not mean you know anything about the engines imported over here. Unless you work for an exporter over there you really have no idea what we get here as you are over there.

To the OP if you are living in Texas then forgot about stage builds and think about cooling, of course depending on where you are in Texas the humidity could play in your favor as 100 degree temps with high humidity are much more forgiving on a Turbo engine than 100 degree temps with no humidity i.e. wet heat vs dry heat.

Though with a RB in your car cooling cooling cooling cannot be stressed more.

Seanbonham · 06-30-2010, 12:21 AM

Quote:

Originally Posted by drift freaq

Honestly right now I would say your bets are higher on a a low mileage RB over here.
The days of low mileage SR's are indeed coming to an end. Though you have to realize something. 100,000k is still on 62 thousand miles. That is still low mileage . Plus fact is you have been buying running cars that have not been crashed so of course the mileage will be higher. LOL

As far as it being beat on you can inspect a clip and tell immediately if the engine was beat on or not just by how stock the clip is. For one thing. The other thing you can do is a cylinder leak down test and compression test, you can also inspect the turbo.

The RB is less likely to be beat on as well because it has enough power stock and its coming out of a GTST which like I said before is not exactly the performance model version of the car.

RB's can spool damn fast with the right turbo. I know my GT2530 on my RB spooled instantly and my friends with SR's were shock by the way the car pulled like mad.

Either way indeed both engines are fun.

Just because you are in Japan it does not mean you know anything about the engines imported over here. Unless you work for an exporter over there you really have no idea what we get here as you are over there.

To the OP if you are living in Texas then forgot about stage builds and think about cooling, of course depending on where you are in Texas the humidity could play in your favor as 100 degree temps with high humidity are much more forgiving on a Turbo engine than 100 degree temps with no humidity i.e. wet heat vs dry heat.

Though with a RB in your car cooling cooling cooling cannot be stressed more.

Drift,i'm sure i can search and find this out, but i figured it might be nice to get a free knowledge ride...do you know of what cooling stuff i need to keep my rb25 nice and cool? What fans fit, etc.

drift freaq · 07-01-2010, 07:03 PM

Quote:

Originally Posted by Seanbonham

Drift,i'm sure i can search and find this out, but i figured it might be nice to get a free knowledge ride...do you know of what cooling stuff i need to keep my rb25 nice and cool? What fans fit, etc.

Preferably you run want to run dual FAL fans on a s14 you can actually sandwich them in between the motor and radiator while using a s14 radiator. You can run the S14 radiator in the s13 to try and do that as well.

If you go aftermarket radiator then you either run dual pushers or a push pull setup. Also especially on a s13 you need to maximize air flow.
The the stock zenki/chuki/Kouki fronts barely pass enough air when running a FMIC and the engine.

Either a Silvia front or S15 front will definitely improve the air flow, or a modified zenki/chuki/kouki front.

When I say modified, I mean heavily ducted for extra air flow with cutouts. You also want to seal the underside of the car with a underpanel.

From the lip of the front bumper back to your oil pan. As well as run a cooling panel up top. Its all about air flow and control of it.

chituntang · 06-29-2010, 05:19 PM

1. People drives nice cars without basic car knowledge all over the world, not just in Japan. So yes, it is possible to get a shitty engine (SR, RB or any JDM engine), especially when it is used.

2. It is hard to blow either RB or SR, assuming everything is done right. And it is not more difficult to work on RB than SR. There are some SR parts that are interchangeable between FWD and RWD, but it if you do break something, especially when you modify it (RB or SR), you will have to either pay top dollar for a shop to special order it, or wait for your internet order.

3. 300whp is doable on stock RB's, but SR can be there with a turbo upgrade. But neither will hit low 12's with that kind of horsepower.

Seanbonham · 06-29-2010, 06:14 PM

Quote:

Originally Posted by chituntang

1.
3. 300whp is doable on stock RB's, but SR can be there with a turbo upgrade. But neither will hit low 12's with that kind of horsepower.

Are you kidding? Just a turbo upgrade for an SR is not going to net you 300whp....Sure you need an upgraded turbo, along with injectors, ecu, z32 maf, etc., pretty much all the things already listed in this thread.

And i beg to differ on the 1/4 times.

Choku_Dorian · 06-29-2010, 06:33 PM

Over build your motor for the amount of HP you want.

I built my motor too make close to and hold 450whp relatively reliably. My SR has lasted like 4+ years making 350whp on low boost(16lbs). I have never raised the boost, no need.

I also stay out of boost when I DD it, but it takes major rape on the track. Still strong.

Edit: Besides appropriate supporting mods the most important for reliability is your tune.

Choku_Dorian · 06-29-2010, 06:47 PM

double edit:

Quote:

Originally Posted by Seanbonham

Are you kidding? Just a turbo upgrade for an SR is not going to net you 300whp....

just a FYI, buddy of mine put down 295hp, 305tq stock s14turbo, just maf and 480's. It's all in the tune.

Seanbonham · 06-29-2010, 07:42 PM

Quote:

Originally Posted by Choku_Dorian

double edit:

just a FYI, buddy of mine put down 295hp, 305tq stock s14turbo, just maf and 480's. It's all in the tune.

I know. I agree. my point was that he said just upgrade the turbo for 300whp?

Which is stupid...you'll just blow your engine .

Maf and 480 injectors sure, but not just a bigger turbo without injectors or anything.

06-29-2010, 04:16 PM	#2
roboticnissan Nissanaholic! Join Date: Mar 2007 Location: SOCAL/NORCAL Age: 32 Posts: 1,867 Trader Rating: (12) Feedback Score: 12 reviews	Where are you getting your information that the rb25det is 300pounds heavier than the sr20 I'm sure that's way off. Just looked it up and rb25det is 150pounds heavier than an SR. And it only effects the cars weight shift by 90 pounds. __________________

06-29-2010, 04:55 PM	#6
rb25_s13*CHUKI Post Whore! Join Date: Mar 2007 Location: Cali Age: 32 Posts: 2,759 Trader Rating: (16) Feedback Score: 16 reviews	I'd say go with the sr20, If mitsubishi can run 6.8's with their 4g63 and nissan can run 7.2 with their sr20. 2jz's and rb's have trouble getting In that range with a frame car and not a rail car. Shit 13b rotary's run 6.8's. YouTube - RX7 6 second drag run YouTube - 6 second Mitsubishi Eclipse YouTube - Import DPS Nissan 240SX Ka-T 7.87 @ 174MPH ^^^ all that 2.4 and can't even run faster than the sr's or 4g63's. Like I've always said Ka's are nice but just not what people think they are. YouTube - Brent rau vs. mazworx s15 __________________ Obliterate

06-29-2010, 04:32 PM	#16
Sileighty_85 Post Whore! Join Date: Dec 2006 Location: Misawa, Japan Posts: 6,815 Trader Rating: (8) Feedback Score: 8 reviews	Dude all your info on these engines and swap information is wrong. Too much for me to wanna correct and type out. We have an SR and RB FAQ thread you need to read through and SEARCH harder Look through build threads and questions ppl ask. __________________ 後輪駆動車１番 1989 Built SR GT2871R -363whp 1998 S14 W/RB25- 250ish (For Now) 1986 SR86 - 200ish 1990 R32 GTR - 320hp Don't Buy Engines from JDM-Online http://zilvia.net/f/businesses/207457-jdm-online.html Don't Buy XS-Power or SSAC Shit

06-29-2010, 04:38 PM	#21
Slidin' Sam Zilvia Addict Join Date: Jul 2009 Location: Japan Posts: 729 Trader Rating: (9) Feedback Score: 9 reviews	Any motor your gonna get from Japan has probably been beaten pretty hard. Also, Japanese motors are not as low mileage as you would expect. I have had 4 Silvia's now and all of them were at/around 100,000km min. when I got them. As far as reliabilty, either one can be very reliable. RB25 definately has a better transmission, but is less common and more expensive in the states (from what I have heard, but I live in Japan). RB's sound cool, IMO. SR's are more fun, IMO. They have a quick spool and good powerband. Either motor can handle abuse fairly well, as long as you maintain it. .9-1bar is ok for daily boost on both motors. It all comes down to personal preference IMO. __________________

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06-29-2010, 03:49 PM	#1
Seanbonham Join Date: Jun 2010 Location: Texas Posts: 16 Trader Rating: (0) Feedback Score: 0 reviews	I searched, Trust me. RB25 vs sr20, Different questions... I have read through the bazillion or so threads addressing this debate but i have a few other questions and none of the other threads really answered my query. First, i can't even really find a post addressing this, but it seems that a lot of the motors coming from japan have been beaten to hell in terms of never having their oil changed. Is an rb25det LESS likely to have these problems/treatment than an sr20det cause it's a nicer car? Anyway, This fall i get a check for 10k on the button. I'm planning on swapping something into a 240sx, professionally, not myself (cause well, i'm not that good yet and i want AC) Here is my goal/dilemma It's a DD, so i need it to start, and ideally keep starting for at least...idk a year, preferably 2. I want to hit low 12s in the 1/4 mile so that's at a minimum, 310+whp from the RB25det or 290+whp from a RED TOP s13 SR20det (ideally 300, cause that's the magic number) Here are my concerns/questions. Redtop SR20det CONS/concerns: 290whp i know isn't pushing it for the sr20det stock internals IF you got a slightly bigger turbo, injectors, etc. you'd still be pushing out probably 14-17 (guessing) lbs of boost to reach that....that's a lot to ask for an engine to run everyday. IS that a lot? SR20DET PROS: Cheap parts, common, etc. shit we all know, ALSO, the s13 swap is simple enough that after i had it professionally done and all the parts in place, i'm more then capable of swapping in a new block if i blow it....so that's kind of nice. RB25DET Cons/concerns: Little bit more invasive a swap...that's a big engine, going to have to cut the fire wall etc...If something did break in the rb25, that's harder to find, harder to fix, more expensive. Not so confident i could swap in an rb25...probably could manage i guess....but still a more expensive motor. Biggest concern is really that... If i got an rb25 and something broke...i may be a whole shit more out of luck than if i had the s13. However, if the rb25 is a lot less likely to break...that's kind of worth the risk. RB25det Pros: It's a skyline..(had to say it), More importantly, it's a lot closer to that goal of 320 then the redtop is. You could probably put 300rwhp down with just a few bolt ons and stockish boost. Some have argued it's more reliable. Is it? The most important thing here is reliability! That's what i want most. Here's the place where i'd be getting the swap done, this is literally all they do pretty much. Both swaps would be the stage 2 for either, take a look at the parts list etc., and tell me what you guys think i should do for my goals. Last edited by Seanbonham; 06-29-2010 at 04:32 PM.. Reason: Better information.

06-29-2010, 04:22 PM	#3
corbin Zilvia Member Join Date: May 2009 Location: Spring, TX Age: 30 Posts: 207 Trader Rating: (0) Feedback Score: 0 reviews	KA-T is better than both, visit KA-T.org - The Home of 1000+ whp/7 sec Turbo KA's and check out the flat, powerful torque curves on the dyno and see the video section for them in action. People make 300+ whp and even more torque on 12 psi all day long with a moderate sized turbo. KA's also cheaper and more reliable (with the proper tuning) than a poorly maintained Japanese SR20 that hasn't been rebuilt. Really the only good thing about SR20's is all the fan boys that will be sucking your weiner and the rev limit. Other than that its a peaky motor that lacks torque. The only reason Nissan had it succeed the CA18DET is because it was cheaper to produce. The fastest KA-T's are in the 7 second range. They have more displacement, a stronger block, more torque, and better gear ratios than SR20's. YouTube - [email protected] @ 15psi VS C6 z06 boltons Street car KA-T vs. 550WHP Z06... Z06 gets beat and its not even a close race.

06-29-2010, 04:33 PM	#18
Seanbonham Join Date: Jun 2010 Location: Texas Posts: 16 Trader Rating: (0) Feedback Score: 0 reviews	Edited and changed, the source i had for the weight on the rb25 i realized now also included a few extra things. 150lbs is about right. So only really 15 more whp, which isnt even worth mentioning.

06-29-2010, 04:44 PM	#20
Seanbonham Join Date: Jun 2010 Location: Texas Posts: 16 Trader Rating: (0) Feedback Score: 0 reviews	The parts list is massive, you have to click the stage 2 link.... As for the upgraded parts, i'm well aware? I'm pretty sure i acknowledged in my post the additional needs for larger turbo, injectors, standalone ecu..etc..? As for being fed bad information. I agree 100%. I've read about 1000 posts, and they all for the most part say what sounds like BS, and are half of them are 5 years old. Thus why i am bothering everyone here today, trying to get the facts straight. Your info was helpful, i've been sort of leaning towards the rb25det, but i do live in texas, it'd be nice to have AC in 100 degrees and not overheat my engine. I suppose that's all doable though? Not exactly sure... Are the RB25's generally in better condition than the sr20s when they're imported over? That may be a stupid question. But again, my information only comes from other peoples posts thus far. Anyone else have things to add? Could use more info. More information the better.

06-29-2010, 04:47 PM	#22
Seanbonham Join Date: Jun 2010 Location: Texas Posts: 16 Trader Rating: (0) Feedback Score: 0 reviews	[quote=Slidin' Sam;3518579]Any motor your gonna get from Japan has probably been beaten pretty hard. Also, Japanese motors are not as low mileage as you would expect. I have had 4 Silvia's now and all of them were at/around 100,000km min. when I got them. [quote=Slidin' Sam;3518579] That's the thing though, I wonder if because Skylines are better cars even in japan, if the owners maybe beat on them less haha, or at least change the damn oil on time. You live there, any ideas if that may be true?

06-29-2010, 05:19 PM	#26
chituntang Zilvia Junkie Join Date: Sep 2005 Location: ATL Age: 35 Posts: 505 Trader Rating: (13) Feedback Score: 13 reviews	1. People drives nice cars without basic car knowledge all over the world, not just in Japan. So yes, it is possible to get a shitty engine (SR, RB or any JDM engine), especially when it is used. 2. It is hard to blow either RB or SR, assuming everything is done right. And it is not more difficult to work on RB than SR. There are some SR parts that are interchangeable between FWD and RWD, but it if you do break something, especially when you modify it (RB or SR), you will have to either pay top dollar for a shop to special order it, or wait for your internet order. 3. 300whp is doable on stock RB's, but SR can be there with a turbo upgrade. But neither will hit low 12's with that kind of horsepower.

06-29-2010, 06:33 PM	#28
Choku_Dorian Zilvia Member Join Date: Mar 2008 Location: WADE County Age: 34 Posts: 179 Trader Rating: (1) Feedback Score: 1 reviews	Over build your motor for the amount of HP you want. I built my motor too make close to and hold 450whp relatively reliably. My SR has lasted like 4+ years making 350whp on low boost(16lbs). I have never raised the boost, no need. I also stay out of boost when I DD it, but it takes major rape on the track. Still strong. Edit: Besides appropriate supporting mods the most important for reliability is your tune.