Rb20 - Rb25 Options For R32 Gtst

[BOOSTA]

Okay I have been a long time member of SAU since the beginning...

I have a dilemma, my old Rb20det has very low oil pressure (21psi hot & cold) and has a miss (sounds like a rev limiter but at 2'000rpm)

I have the car parked up at the moment, as I have been rubbing back the old paint job and getting it ready for a respray (Matt or Satin Black with alot of clear coat over it)

The question I have is..... I have $9000 to have the car sprayed and also running again.

$3000 for the respray (and they are going to fix my leaking sunroof aswell)

$6000 left to play with...... with the money I have left whats a better option? do a Rb25det swap or throw in another Rb20det and throw some mods at it.

I would like to hear from people who have actually spent the money on both options,

Has anyone had a workshop in Brisbane do the conversion? what did it cost?

Thankyou for any options

BOOSTA

[avrahan]

25 for sure, got one in mine and never looked back:D

go for a r33 box too....

let me know what ya do

cheers and good luck

[Cjmartz2k]

I've run the gambet from stock RB20 all the way to over 500hp in my 32. I think the most fun the car ever was had to have been the bolt on stock turbined RB25.

[blockasR32]

look buddy it all depends wat u want out of it ok i kept with the rb 20 i had to change cos had no compression in 1st cylinder. but i like the 20 i think the sound heaps better then the 25 and i didnt have to do all the wiring loom or change anthing else

i nice turbo upgrade, injectors, full exhaust, computer, front mount and coil packs and u will be looking towads the 230rwkw anyway

[R32Abuser]

why not go RB30DET? Sure u have to chase a few parts up, but the 30DET is far superior to both motors for day to day driving on the road. Why not check out the Rb30 thread...its worth a look.

[BOOSTA]

Thanks for the replys....

Yeah the reason for asking for opinions is I really don't know which way to turn, I need a new motor so either way the old Rb20det will be getting replaced with a low k rb20 or rb25. I have a daily driver car so the skyline is my weekend toy,

I'll be buying a proper front cut so whether its a rb20 or rb25 doesnt bother me...

I have thought about a RB30DET but didn't think my budget would cover a proper swap for a rb30det....

I just haven't had any experience with a rb25det swap into the r32 (especially cost wise)

I just want to hear everyones opinion on there choices and why? good points and the bad points!

Theres alot of knowledgable people in these forums so I'm asking to hear all opinions (the budget is $6000),

I have driven afew different skylines and understand the 25 to have much better torque down low but having said that I also love the revy nature of a rb20 aswell.

Thankyou BOOSTA (Pete)

[bubba]

Start with a standard rebuild RB30DET with all the R32 bits on it and put an rb25 turbo (with a vg30 rear housing if you can find one).

I had the good fortune to be offered a prepped block with forgies for a nice price but a standard rebuild would cost similarly. Use an R32 RB25DE head and you can run your standard injectors, afm and ecu, I had mine remapped to run z32 afm and 550cc injectors. Same turbo that was on the 20 (for now) and it makes the same peak power.. just a hell of a lot earlier!

You could easily build a standard motor for around 2k..

My guesstimates:

Complete RB30E - ~$200

RB25DE head - ~$400

Timing belt - ~$100

Water pump - ~$110

Standard oil pump - ?? not sure, my N1 was $410 so lets say $150?

Crank machining - ~$120

Bearings (mains & bigends) - ~$100

Thermostat - ~$50

OEM headgasket - think this was only about $120

That brings us to ~$1350.. Call it $1500 for other little ancillaries and various shit you always end up needing when doing these things

That leaves more than enough for a set of injectors (~$900), z32 afm (~$300 w/ plug), RB25 turbo + VG30 rear housing ($500?), remap tune ($6-800?)

So for approximately $4k you could have a REALLY torquey ~200rwkw which would be ready to bolt a GT30 onto the stock manifold in the future and make some decent numbers

Personally, I have a GT35R waiting to go on mine.

[TTT]

bubba - you seem to be missing Labour.

or the purchase of tools, engine stands, etc etc to "try" to do it yourself

It's NEVER as you first think it will cost.

I always refer to CEFFIE on here.

he is definitely a one man machine..

does ALOT of shit himself and is very capable.

he built a "budget" rb30det.

set out a plan.,

got everything cheap, did it ALL himself.

it took him twice as long, 2.5 times the money he thought and he is still trying to iron out some things.

The thread started needs to work out what he wants out of this car.

close to 190rwkw can be had from stock motor wit just an RB25 turbo and remap (along with intercooler and exhaust etc..)

that makes a good little, not so laggy street car which could be made to run low 13's (possibly crack a 12.9.. who knows.

that would set him back $1K for wrecker RB20

$350 for rb25 turbo

$300 remap

everything else is ALOT more expensive from there..

RB25 motor and box supply only would be over $2.5K

then you have a stock RB25 in your car.

RB30DET build will require the rb25 gearbox (at least $1K)

as you said $4K to build (minimum)

install - $??

tune - $??

injectors, afm etc etc - $?

decide what you want from this car first.

[Roy]

You could easily build a standard motor for around 2k..

My guesstimates:

Complete RB30E - ~$200

RB25DE head - ~$400

Timing belt - ~$100

Water pump - ~$110

Standard oil pump - ?? not sure, my N1 was $410 so lets say $150?

Crank machining - ~$120

Bearings (mains & bigends) - ~$100

Thermostat - ~$50

OEM headgasket - think this was only about $120

That brings us to ~$1350.. Call it $1500 for other little ancillaries and various shit you always end up needing when doing these things

That leaves more than enough for a set of injectors (~$900), z32 afm (~$300 w/ plug), RB25 turbo + VG30 rear housing ($500?), remap tune ($6-800?)

So for approximately $4k you could have a REALLY torquey ~200rwkw which would be ready to bolt a GT30 onto the stock manifold in the future and make some decent numbers

Personally, I have a GT35R waiting to go on mine.

Im with GTST, check the numbers before starting down a certain path. I cant see anyone selling an RB25DE head for $400, if you are going to do the bottom end rebuild yourself then just be sure you have a clue what you are doing. It woudl be a shame to have to be ripping the motor out after onlt 2,000kms. In the above what is beign doen with pistons? What compression will the thing be running? Drilling and tapping the RB30 block for idlers (inc the cost of idler and tensioner) What are you going to do with the registration when you are now running an engine number that tells the world you have an RB30 in there?

Again, im all for ripping into things yourselves....but not based on what i see as optimistic budgets. Rip an engine out and fluids and air con re-charging will cost you over $300

[bubba]

Ahh yes, I forget not everyone can do a lot themselves

Use standard pistons in the above setup, you're doing a standard bottom end with a freshened up crank.

A CHEAP upgrade, I'm not talking full blown forged everything with crazy stuff, a lot of people get carried away.

GTST, read my post..

as you said $4K to build (minimum)

install - $??

tune - $??

injectors, afm etc etc - $?

I accounted for all of these EXCEPT LABOUR.

Afterall, I said guesstimates, something to entice the person to look further into it.

At the end of the day, talk to your mechanic (assuming you have a reliable mechanic) as he will be the one doing the bulk of the work. RB30's aren't a scary adventure as a lot of people make out, hell we did the conversion in my car in a weekend.

In short, I just can't justify spending 6k on an RB20, each to their own.

Edit: as far as licensing goes, I don't know about other states but my car is registered with an RB30, passed the pits fine no engineering required. Then again I don't have a bigass turbo hanging off the side yet and it all looks stock under the bonnet. IMO that would be the smartest way to do it.

Edited January 13, 2008 by bubba

[BOOSTA]

Hey Guys,

Thankyou for the great replies, Basically with the way police are and not aimming for big hp I think I have afew options, My main problem is I don't have a huge amount of time on my hands... I do have an engine hoist, and more tools the workshop I used to work for (things like a compressor, snapon impact gun, 3/8 air ratchet)...

I'm not after huge power 200-220rwkw on high boost and around 190rwkw on lowish boost for daily driving.

I just want a abit of grunt but nothing crazy as the car will be used for daily driving and also wanting to keep the attention off me aswell. It will get maybe a few track days, maybe a run down the strip and to the skid pan.... But also drivable enough that the missus can have a drive aswell.

I just wanted opinions on people who have done various swaps to see what differences they made, how the car drives and cost of the swaps from there eyes.

I think im leaning towards either an RB20det swap with a low km engine and a few performance touches or a stock Rb25det...

I just don't know which one i want yet as either engine is fantastic to drive.

Cheers Pete (BOOSTA)

Edited January 14, 2008 by BOOSTA

[R32Abuser]

well here are my costs so far that iv calc'd

RB30E ~ 150 (sell hed for 50) ~ 100

RB25DE head ~ 650-1000 depending on whether you have to get an RB25DE complete or not.

Now from here you can just bolt these two together, and you will havea RB30DET...How reliable-i dont know depends on the engine before hand. But Sky30 did this and made ~ 300RWKW and it held together fine. So if you aiming for 200RWKW i wouldnt bother wiht freshening up the bottom end as it should hold together at these power levels. For turbo choice you could just use a Rb25DET Neo turbo which should make around the 200RWKW mark with absolutely no lag. Gearbox-the 20det one would hold for a while, but as cubes did, the additional torque stripped his 3rd gear. So factor about 1000 for a 25 gearbox.

At the end of the day, for mayb 2500 you will have an engine setup that will do the work day in day out. It will be an unbeliveably torquey motor and a good daily. Far better than any 25 or 20 will give you. if you went down the 25 path, you still have an engine in there which wasnt in the car to begin with, you still have to get a 25 box, and you still have the same glitches any engine change will bring. Stay with the 20 and you will have an engine which lacks response, and all round has less potential.

Its up to you but i highly recommend the 30.

[BOOSTA]

R32Abuser,

Thankyou for the informed response its great to see answers like yours as it gives me serious food for thoughts on what to do with the engine of choice.

I always thought the Rb30 route was a $6000k + job but i am very wrong. What ecu did you use with the Rb30/25?

Cheers BOOSTA

[bubba]

Remapped 32 ecu is running my 30.

[BOOSTA]

bubba, how long did the conversion take you to do?

I have to make sure if I do a bigger swap that I can legally get the relevant mod plates for it aswell...

[KISIN]

bubba, how long did the conversion take you to do?

I have to make sure if I do a bigger swap that I can legally get the relevant mod plates for it aswell...

Im not so sure you can get the RB30 to be legal in a R32 ? (sum1 with experience/knowledge please confirm).

Also, whatever HEAD you use, use that matching ECU.

Im gathering parts for my rb30dett build (26/30 twin turbz). Got 80% of the parts (including 25 box). cant wait for it to be finished, but like mentioned before, it will ALWAYS take longer then you planed !

Good luck !

Edited January 30, 2008 by KISIN

[bubba]

Conversion took a weekend from start to finish, Saturday lunchtime with a concert Saturday night, back into it Sunday and drove it home about 3am Monday morning..

Mine is registered with the RB30, don't know how easy it is in other states.

[SEX-DR.]

Im in the process of starting a engine swap and this thread is inspiring me to forget the 25, and go with a 30 setup, in my r32!!

Im guessing the potential of the 30 is significantly higher than the 25, and if im there i may as well go all out,

like mentioned earlier, im replacing the original motor, might as well have the potential there for future perfomance gains.

thanx guys...for making me wanna spend more money...lol

great thread, ill be keepin an eye on this one.

Cheers

Peter

[KISIN]

Im in the process of starting a engine swap and this thread is inspiring me to forget the 25, and go with a 30 setup, in my r32!!

Im guessing the potential of the 30 is significantly higher than the 25, and if im there i may as well go all out,

like mentioned earlier, im replacing the original motor, might as well have the potential there for future perfomance gains.

thanx guys...for making me wanna spend more money...lol

great thread, ill be keepin an eye on this one.

Cheers

Peter

your wallet hates this thread

[Jmaac]

Go Rb26dett, no fiddling then and you'll have enuough left over to get someone to fit it