Safe PSI?

[lilrussian]

Well this might be a stupid question....But I was wondering, How much PSI can you run on a stock RB20DET Block?

In other words, How much PSI can the stock block handle and how much HP will it be running around?

This might be a stupid question...but I'm just trying to see what engine to swap into my s14

Thanks to all the info!

[Yellow4g63]

Yup it was a stupid question. You need to be more specific about it. Stock Turbo? Stock injectors? Bigger turbo, Bigger injectors ect ect. All Stock 12psi to 14psi modded who knows.

[SullivanRacing06]

be more specific on what your goal is...

a stock set up youll have 200-230

450-550, z32 maf, walbro 255, tune, larger turbo, fmic 300+

the end result is in your tune and your pocket

[lilrussian]

Okay more specific!

I am thinking of buying an RB20DET or an SR20DET...but that's a diff story, that's why I'm doing research on the RB

My question is, let's say I got a bigger turbo, injectors, fuel pump, and all supporting mods...But the block, pistons, the head, is bone stock!What is safe PSI? I'm just wondering...Cause I wanna run around 400hp +/- and I'm doing research to see if I would be better off with the RB20 or the SR20!

Thanks for any kind of info I get!

[sololock]

do some more research dont go rb20 if you want that much HP. Let me guess you just got a 240 and saw rb20 and sr20s on youtube?

[lilrussian]

Yup, I got a 240 pretty recentlyBut my friend has a 1990 s13 with an RB20DET...

And why are you saying to not go with an RB20 for 400hp?

[virus77]

25 swaps are getting so cheap these days its really not worth the difference in price to get the 20 IMO.

You get .5L displacementway stronger transway more aftermarket supportmore power out the boxbetter response to modsthe list goes on....

save your pennies and start with a 25 as a base, my $.02

[lilrussian]

Yea I was considering the RB25Thanks for the info!

And I have a SR20 vs. RB20 battle going on in my head...But the RB25 is the next level where I will have to save up money...But would I ever regret the rb25 in any way?\

And where are decent places with good rep to buy RB's and all these import engines?Cause I heard the "ebay" importers lie about their mileage and sometimes come bad

Thanks for all the info so far!

[virus77]

sr20s a good choice too. I had one in my s14 for about 4-5 years, great little motor if you take care of them.

Again I see no real reason to go RB20. If you want a 2 litre go with the SR. Its lighter, more aftermarket, generally newer, same trans(internally), way easier to swap, etc...

sr or 25... forget the 20

[lilrussian]

Makes Sense....Just you can't beat a 6 cylinder haha

But so far, I'm leaning toward an RB25....Price for a black top SR are around 1,750-1,850..An RB25 is around 2,200-2,400So I guess it's the other 2 cylinders that your paying for haha

Oh and quick question out of the blue...Whats the difference between a RB25DET and a RB25DET Neo?...same thing or different?

Thanks!

[virus77]

Neos came in R34 skylines so they are naturally going to be newer motors. They also have the crank snout oil drive issue fixed, solid lifters, higher lift cams, slightly bigger turbine, rb26 rods and a variable VTC system. A lot of nice changes actually. If you can save up and get the NEO I personally would, the best base motor to start with of the bunch you mentioned.

Look around man for a good deal, I got my motorset for under 2 grand, good deals pop up all the time.

[lilrussian]

Neos came in R34 skylines so they are naturally going to be newer motors. They also have the crank snout oil drive issue fixed, solid lifters, higher lift cams, slightly bigger turbine, rb26 rods and a variable VTC system. A lot of nice changes actually. If you can save up and get the NEO I personally would, the best base motor to start with of the bunch you mentioned.

Look around man for a good deal, I got my motorset for under 2 grand, good deals pop up all the time.

Oh so that is what a NEO is! O.O

I found some for cheaper than a normal rb25.......So I guess if I get a neo it will be a good thing? lol

Thanks!

[WhatsADSM]

sr20s a good choice too. I had one in my s14 for about 4-5 years, great little motor if you take care of them.

Again I see no real reason to go RB20. If you want a 2 litre go with the SR. Its lighter, more aftermarket, generally newer, same trans(internally), way easier to swap, etc...

sr or 25... forget the 20

^^ I'm with him. (Keeping in mind I have also owned a 20).

Nothing wrong with an RB20, it just isn't a very cost effective way to go in my mind, especially when considering the SR20. Only reason I got the RB20 at the time was to be different.

The RB25 on the other hand is a great bang for the buck.

[eh?]

Well if this RB20 is good it's not a bad buy. http://cgi.ebay.com/ebaymotors...33675It's actually the price an RB20 should be.

[Sil240]

Keep in mind 10 Psi from a T25 is not the same as 10 psi from a T70. The pressure will be the same br the volume will be different.

If you got the $ go for the 25.More parts available for it.

[lilrussian]

^^ I'm with him. (Keeping in mind I have also owned a 20).

Nothing wrong with an RB20, it just isn't a very cost effective way to go in my mind, especially when considering the SR20. Only reason I got the RB20 at the time was to be different.

The RB25 on the other hand is a great bang for the buck.

Well The RB20 is much cheaper than the SR20's...RB20 = 1,100 - 1,300SR20 = 1,750 - 1,850So the RB is cheaper.

But the swap problems you run into with RB's they say is just too much to work with...so ehh...

Are you running an RB25?If so, how much did you dish out for what you have now, and how much power?And is it reliable?

Thanks

[lilrussian]

Keep in mind 10 Psi from a T25 is not the same as 10 psi from a T70. The pressure will be the same br the volume will be different.

If you got the $ go for the 25.More parts available for it.

Hmm, very interesting..I never really looked into the difference on turbo's...

So how will more volume affect the car?

Thanks

[Yellow4g63]

Well The RB20 is much cheaper than the SR20's...RB20 = 1,100 - 1,300SR20 = 1,750 - 1,850So the RB is cheaper.

But the swap problems you run into with RB's they say is just too much to work with...so ehh...

Are you running an RB25?If so, how much did you dish out for what you have now, and how much power?And is it reliable?

Thanks

The RB really isn't cheaper, RB's are never cheap. You might get the motor cheaper but mods are going to cost more vs the SR20. Cams cost more, valve springs cost more, injectors.

[lilrussian]

The RB really isn't cheaper, RB's are never cheap. You might get the motor cheaper but mods are going to cost more vs the SR20. Cams cost more, valve springs cost more, injectors.

Yes Agreed!But buying it stock, It's cheaper!My current KA24DE is running like a champ, so if I buy an RB/SR/Rb25 it's gonna stand around getting upgraded slowly until my KA dies or blows...so Overall price is what I need..I'm 18 and I still don't have a job...so it's gonna be hard!But hey, gotta plan ahead right?

Thanks

[crazyandevil05]

well, if the stock ka is doing ok, maybe check on putting some boost to that. or have you checked an ls1?

[Sil240]

Go Ka-t if your motor is good.If you don't want any downtime, buy a spare block build it then swap it in.

The difference depends on he Turbo. Google how to read a compressor map.That should help you out some.

[90240sxca18]

That is an ignorant question. PSI varies on every turbo....saying a RB20 can handle 21 psi means absolutely nothing, because that is talking about the amount of air coming fomr the turbo...where each turbo is different in size.

What I am trying to get at, is that 14 psi on a stock RB20 turbo can net you....230whp...

While 14 psi on a larger turbo...such as a GT3071R can net you 350whp....bigger turbo, so while the turbo is spooling at 14 psi, it is technically moving more air then a smaller turbo at 14 psi...due to biger wheels and housings....so there is no answer to how much psi a motor can handle, I could say 31 psi, and you could find a turbo that is tiny and will spool to 31 psi...and only make 300whp...while you get a larger turbo and spool 31 psi and can make 700whp and blow ur motor...make since? So a RB20 with a head gasket and head studs should hold....450whp.....but depending on the health of your motor it may not be very reliable.

Okay more specific!

I am thinking of buying an RB20DET or an SR20DET...but that's a diff story, that's why I'm doing research on the RB

My question is, let's say I got a bigger turbo, injectors, fuel pump, and all supporting mods...But the block, pistons, the head, is bone stock!What is safe PSI? I'm just wondering...Cause I wanna run around 400hp +/- and I'm doing research to see if I would be better off with the RB20 or the SR20!

Thanks for any kind of info I get!

[lilrussian]

Okay then here's a question for you guys!What do I have to do on a KA to make it around 400hp....Is it gonna cost more than an SR20 with mods, or is it about the same to boost a KA? and reliability?...Well I guess reliability all matters on how much money you put into the parts, but stillLike the 4G engines suffer from crank walk...

I like my torque on the KA...so turboing it should be niceBut I would still want to swap out something into it

And I'm not a big fan of LS1/7...well I'm not an american engine fan, I like to have a turbo and a spool! ^_^

Thanks!

[Sil240]

I'd check the ka forum. If I had to guess.

T3 /STEVE 50 TRIM550 - 650 Injectors Z32 MafNistune, flash, chip etc...metal HG Head studs I'd rebuild the motor for reliability forged pistons and new rings Bearings, valvetrain refresh

[lilrussian]

Hmm....How much is that going to run me? lol

I'm just thinking that I'm going to swap an engine, if I were to What to getCause If I get an SR20 and make it 400hp +/-Or an RB25 400hp +/-Or a KA24DE 400hp +/-

What would they all run me?That's kinda what I need to do my research on!

[jers15]

Just to add on to your question. I have a S14 with a RB25DET Gen 1 with 400HP. Still running the stock turbo and injectors. Upgraded radiator, intercooler, engine oil cooler and raised boost to 14PSI. I have not seen any problems yet. The RB25det conversion is not cheap though.

Engine- 2400Mounts- 500Drive shaft- 400Intercooler- 800Radiator- 450plus miscellaneous parts, blow off valve, gauges, battery moved to rear ( won't fit up front), Q45 Trottle body, clutch, flywheel and the list goes on. Final cost for me was just over $7000. After that the car has had no problems. Did all the work myself. Good luck on the wiring. It takes a little bit, but it is fairly easy.

[Sil240]

I haven't done the.math on the Injectors nor have I researched the 25 Turbo.

But I highly. Doubt you have 400 hpProbably 300, but not 400.

The Turbo will run out of steam and become inefficient and you will go beyond 80% Injectors duty cycle

[lilrussian]

Just to add on to your question. I have a S14 with a RB25DET Gen 1 with 400HP. Still running the stock turbo and injectors. Upgraded radiator, intercooler, engine oil cooler and raised boost to 14PSI. I have not seen any problems yet. The RB25det conversion is not cheap though.

Engine- 2400Mounts- 500Drive shaft- 400Intercooler- 800Radiator- 450plus miscellaneous parts, blow off valve, gauges, battery moved to rear ( won't fit up front), Q45 Trottle body, clutch, flywheel and the list goes on. Final cost for me was just over $7000. After that the car has had no problems. Did all the work myself. Good luck on the wiring. It takes a little bit, but it is fairly easy.

Yes I was going to do all the work myself too!And my friend and me have went through a messed up wiring harness for his RB20...not fun but it runs now!

But Yes, That's why a SR20 or turboing my KA would be more realistic!Thanks for that info jers15

I haven't done the.math on the Injectors nor have I researched the 25 Turbo.But I highly. Doubt you have 400 hpProbably 300, but not 400.

The Turbo will run out of steam and become inefficient and you will go beyond 80% Injectors duty cycle.

Actually The rb25 has a T28 Turbo if I'm not mistakenAnd the injectors are 370cc...I'm sure they can handle around 400

[90240sxca18]

No.

The injectors, and the turbo will not make 400whp...

They can make 300.

Maybe 320whp maxing out the turbo...but he does not make 400 wheel stock.. its impossible, unless he is running nitrous.