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Rb30det Or Rb20det?


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when you say dead stock, I am assuming as it was when it left the factory but with many many km's on it.

so.

turbo back exhaust - $600 (xforce)

air filter - $50 (Piper Cross Panel filter)

FMIC - $500 (Just jap generic hybrid style)

boost controller - $300 (some Electronic one second hand)

fuel pump - $300 (bosch something or other)

GTR injectors and resistor pack - $300

Z32 AFM - $250 (used or about 350 new I think)

PFC and controller - $1400

tune - $500

so far it's cost you

$4200 and you still have stock turbo so you're limited to about 170rwkw on 14 or so psi boost.

that is going about it cheap too..

you could ad an RB25 turbo with the $800 you got left... would be another $400 so you got $400 left and have about 190rwkw.

so that is what I meant by $5K on an RB20 won't get you far.

but you have rb30 block, head, gearbox already.

if you did it cheap and just got a set of NA pistons, neaw rings, bearings, gasket kit, weld that vvt crap up, you still have a decent wack of cash left.

a GT30 internally gated 500hp turbo will see that engine produce your 280rwkw you want with lowish boost (14-17psi or so).

youd still need ECU - PFC = $1400

and tune - $500

and injectors, pump afm exhaust blah blah blah..

so all the things I listed above for the rb20, you'll need for the 30 as well.

but it will produce bigger numbers for sure.

and forget the KW output, the torque figures are even more impressive.

have a read through the rb30 dyno thread sticky at the top of this section.

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i had rb20 with about 210rwkw and was in your position.

i didnt know weather to build a rb30 or do more to rb20. but i didnt like the lag my 20 had and i thought if i try get more power out of it, it will only get worse.

so now im in the middle of building rb26/30.

for a rb30 280kw i fairly easy to get and when you want more power the rb30 will handle it(aslong as you build it strong from the start) were rb20 wont go to much further than 280 unless you spend sh#t loads on stroking it and getting alot of head work to get them to flow.

so i say build rb30 put some good forged pistons in it, and you will be laughing

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I will quickly add up my kinda cheap RB25/30DET conversion, its not quite finnished.

Not including the block and head which I pretty much got for free:

ACL Race rebuild kit, came with cast pistons, rings bearings gaskets etc, about $400 trade price at repco.

I got the head rebuilt and modified for VCT plus the block drilled for the extra tensioner that was about, the block bored and honed surfaces decked I think it was around $1300

550CC injectors $300 (pretty sure theyre out of a 95on VG30DETT)

We put the motor together ourselfs.

I am going to need a custom exhaust and I am going 3.5" (its going in a VL) I got a quote for $1000. I am going to use a cheap hyrbid cooler 600x300x76, Should cost around $600 with plumbing. JD plenum $600

I am getting near new GT35/40 .82ex and 38mm Tial gate for $1650

6Boost manifold $1200.

R33S1 Loom $50, Wolf3DV4 skyline plugin $650

Thats about $7700 theyre. You wouldnt need a JD plenum and 6boost manifld, or the $1000 exhaust, so I reckon you could almost do a 30DET for $5000 if you can do a lot of it yourself or with your mates and your conservative, use 2nd hand parts If all I had was 5k and thats it I wouldnt try as you can see I got some good deals, but im sure u can get a bit more cash, my cars been off the road for nearly a year now!

Anyway I hope its some indication.

If I have missed anything let me know and I will update it.

Cheers Eddie

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how many kw's can a stock N/A rb30 bottom end hold? in that case i can easy sell the rb30et bottom end and pick up a compelet N/A rb30 so i dont have to buy pistions etc..

i have been reading around people have just bolted up N/A rb30 bottom end to a rb25 running everything stock but only a high flow turbo and they are getin close to 200rwkw's.

if thats the case ill just balance the bottom end and do a mild port to the head and get better value springs. GT30 500hp turbo 555cc nismo injetors. 040 fuel pump with that should push over the 200kw easy

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This wil be interesting to see some of these hybrid RB thingies go into an R32...my thinking is even with the lag of my old RB20 when i get the boost into it i think its supidly quick, adn doesnt wheelspin everywhere.

Be good to see some of these cars with way more torque and 50rwkws more then me everywhere in the power range...i suspect they will be crazy fast cars which can only ever be used at the track. Keep in mind that a GT3 POrsche only has about 240rwkws at best :(

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Personally it sounds like too much screwing around and you wont know how reliable it will all be in the end... sell the RB30 bottom, RB25 head and even your RB20... that should get you some cash about $3500 + your $5000 = $8500...

Buy yourself an RB26DETT with loom and harness from SSS Automotive for about $6000... FMIC $500... PFC $1000... Fuel pump $300... You said you had the RB25 Gearbox which you can use and slap it all in!

Regards,

Sarkis

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how many kw's can a stock N/A rb30 bottom end hold? in that case i can easy sell the rb30et bottom end and pick up a compelet N/A rb30 so i dont have to buy pistions etc..

i have been reading around people have just bolted up N/A rb30 bottom end to a rb25 running everything stock but only a high flow turbo and they are getin close to 200rwkw's.

if thats the case ill just balance the bottom end and do a mild port to the head and get better value springs. GT30 500hp turbo 555cc nismo injetors. 040 fuel pump with that should push over the 200kw easy

My engine that made 312rwkw was a completely stock n/a bottom end with 300,000kms before the conversion. I had this engine in the car for 2 years and is still a good motor, tunning is very important.

When i had a high-flow turbo on the engine it made ~240rwkw.

So sell your rb30et bottom end and buy a RB30 n/a motor, bolt the rb25 head.....

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Personally it sounds like too much screwing around and you wont know how reliable it will all be in the end... sell the RB30 bottom, RB25 head and even your RB20... that should get you some cash about $3500 + your $5000 = $8500...

Buy yourself an RB26DETT with loom and harness from SSS Automotive for about $6000... FMIC $500... PFC $1000... Fuel pump $300... You said you had the RB25 Gearbox which you can use and slap it all in!

Regards,

Sarkis

i dont agree with it being to much screwing around,and it would be reliable if its done right, but that is another great option for him to do, if all you want is a bit more power and be able to use it as a daily driver i would go rb26 too, it will make great power with out to many mods

but must admit it will be easier then building 25/30

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I will quickly add up my kinda cheap RB25/30DET conversion, its not quite finnished.

Not including the block and head which I pretty much got for free:

ACL Race rebuild kit, came with cast pistons, rings bearings gaskets etc, about $400 trade price at repco.

I

I dont think the pistons you have got are the race series as the race series are the forged ones. If you do indeed have the rb30 forged pistons your compression is going to be very very low from what ive been told. (Friend of mine works at repco and id get the same discount so ive been doing lots of research.)

Im not to certain your bearings and gaskets are included in that price, i think thats bullshit. My rings were around 150 trade, gasket set 200 trade and pistons were going to be 550. Thats staff discount also not trade so cost + GST

Edited by SirRacer
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Here is a brief breakdown of mine, I did a decent amount of the work myself as well which kept costs down by a grand or two I imagine.

R33 RB25DET Head (injectors/turbo/manifolds) ~ $900

RB30E bottom end ~ $150

Full rebuild with CP forged pistons ~ $4000

R33 Loom/various sensors ~ $600

Wiring, tidying up and tuning at a workshop ~ $1500

PowerFC: $927

So there's about 8 grand, and there's probably a decent amount of misc. parts I've not added in.

Take a grand or so off if you don't use the forged pistons...

Edited by platinum
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i can get the engine together and running with no problems. my mate has 3 N/A rb30's sitting at home and will give me one for free. but i want it to be reliable and not much screwing around under the bonnet 24/7.

i was thinking of buying a Rb25det compelet engine package for $2500 but with that money i could reco the engine and slam sum forged pistons in.

but with petrol prices goin up these dayz. i duno if it will be a good idea to run a 3L as a daily driver. im at the crossroads i think i have to put a vote poll up or sum thing for

Rb20det - $5000 engine work, already in car and less head Fu<ks!

or

Rb25det - compelet engine package, drop tune and drive?

or

hybrid RB25/30 - with $5000 engine work, about 1month of off road and tune

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I would almost say due to the effortless torque, and if you do a lot of city driving, the fuel economy difference would be negligable, if not better with the 3L - of course, totally depending on how its driven. :(

But I'd say if you're worried about saving a couple of dollars per tank of petrol, maybe sell the modified skyline and buy an excel. :(

Edited by platinum
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The RB30 does suck a little more IF you are stuck in to it constantly as it comes on boost and starts hauling off idle vs the rb20's 3000rpm+.

Drive it around normally with the odd squirt and I average around 11L/100km's. Drive it really nice and it WILL nudge the same as my rb20det was getting. ~10.5L/100km's.

All my driving is local short trip 60km/h stuff to uni/shops and back, no peak hour and no open road.

The worse I have seen after a shade over 1/4 tank on the dyno and a lot of hard driving that followed was 380km's to a tank ~50l.

My fuel economy did go to the crap for a little while there.

I replaced the o2 sensor. No difference.

Replaced injectors. Problem solved. + had a little tune that picked up a little better fuel economy again. :(

There's still more left in it with regards to economy tuning, as soon as I get my hands on a wideband I will be tuning up to around 3psi with an afr of 14.7:1 vs the current 12:1 once it sees any boost.

So I may pick up a little again.

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This wil be interesting to see some of these hybrid RB thingies go into an R32...my thinking is even with the lag of my old RB20 when i get the boost into it i think its supidly quick, adn doesnt wheelspin everywhere.

Be good to see some of these cars with way more torque and 50rwkws more then me everywhere in the power range...i suspect they will be crazy fast cars which can only ever be used at the track. Keep in mind that a GT3 POrsche only has about 240rwkws at best :(

I suspect people that talk abou their cars wheelspinning tend to try to drive the accelerator pedal through the firewall and wonder why they cant get the power down.

How many people jump on a Yamaha R1 and wrench the throttle then complain the bike doenst handle?

I can safely rev my 3lt out to 6500-7 and stay off boost yet control the wheelspin. If i do its my fault due to the suspension setup and the crapola tyres im running.

Everyone forgets u NEED a turbo to suit this motor. A stupid highflow is fun, but a gt30 or bigger is needed minimal. It aint fun wheelspinning @ 1500rpm off the lights. This costs like 2k before u even got the motor in.

Add extras like gaskets, oil, coolant, etc and it adds like 2k onto the end budget. Typical with this shit is that stuff comes up. Expect that u WILL blow the gearbox as it simply wont handle the torque (cubes mashed 1 with 176rwkw). Subframe mounts, suspension etc all take a beating with extra power, so dont expect to try to pull a a budget 280rwkw anyday. It aint happening.

Buy a 2535 for the 2Lt and be happy....unless u want to spend 10k +. The motor and head are the cheap bits to buy for the 3lt conversion...

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Interesting reading here guys.

I also have a r32 gtst and am in desperate need of more power, yeah the rb20's are not very torquey motors 3 people in the car up a hill you lose so much power!

I was gonna convert to a rb25det neo but for a bit more $ i was told to got the rb25/30 optoin.

Ok i am new to this but from what i have read on these forums this is what i think i need.

*RB30DE BLOCK (this i send off to get honed, bored & decked) Where can I get this done??(Im am in Adelaide)

*RB30DE REBUILD KIT (rings, bearings & gaskets) - this part i can do myself right? Do the bearings need to be presed in? I have all other tools.

*RB25DE or RB30DE N/A pistons?????? Or is it worth getting proper forged ones, if so how much$$ ??

*RB25DE HEAD. R33 OR R34 WHAT SERIES? Should i get this reconed aswell?Valve seats??

Cams??Cam gears?? Springs?? (Which ones will i need??)

*TURBO MANIFOLD OR N/A?? (Are they the same??)

*CUSTOM EXHAUST MANIFOLD

*WHICH TURBO

*R33 GEARBOX

*R33 WIRING LOOM

Other stuff I have or can get easily: PFC, FMIC, Z32 AFM, Bosch 044, etc....

Also what compression will I have with that combo, as this will determine which turbo I choose and boost levels??

I am planning on gathering these parts and building the motor over the next year or so, I would do it now but have to save and do it gradually.

Thanks guys :(

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what would the best and cheapest way to do the hybrid RB25/30?

i know the R32 came out the the non turbo Rb25de would that be Direct blot up to a RB30e bottom end? And I know that the rb25de will work on the rb20’s loom and I wont have to change any sensors etc..

I was looking at the RB30 thread and its amazing how much kw’s these guys get on a stockish engine.

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