hey there i am deciding on what to do to my r32 gts-t rb20 i wanna put a t3/t4 turbo in it but i am thinking should i just put a rb25 and get turbo for that.
if i do put a t3/t4 turbo in my rb20 what other parts do i have to change eg.injectoers,manifold, etc
its a daily and drift car also track in the future...but i dont rely want to spend thousands on an rb25 conversion but is it rely rely worth it?
just wondering what you guys think thanks

I love my R32 with RB25det Neo conversion, nothing better than having another R32 rock next to you only to be flogged.

how much was your conversion? the motor + labour?? i would like to know thanks

Don't worry about the cost TRUST me it's worth every cent.

.......... yeah I 2nd that!! You will never look back once you drop a 25 in!

T3/T4 tells us nothing, it could be one of many T3/T4 combinations. Generally they're outdated and laggy.

Yeah i had a T3/T4 in my cefiro with a rb20det and it was a lag monster. Only good thing about it was when it eventually hit boost. Wasn't good racing in short distances haha.

But i reckon the best idea is the 25. Pick one up cheap and give it a go yourself.

Depends on how many $$$$$ you want to spend.
It was cheaper for me because I jumped on Skylines Australia www.sau.com.au
and they have two or three tutorials on there for dropping the RB25 in an R32.
Read the tutorial, figure out how much you can do yourself, then start talking to shops.
Heaps cheaper if you can mount the motor & gearbox yourself, also cooler piping, fuel lines.
More you can do the cheaper it is. Only problems is the different size yoke on prop shaft and you have to make a custom speedo sender that costs about $100 in parts.

arhh you have all nearly made my mind up lol i wouldn't mind driving someones 32 with a rb25 in it first to see the difference...my uncle does engine swaps so i can save heaps of cash and a rb25 will be $1500?? now i needa take out my first bank loan 2k will do arhhh

Rb20's are boat anchors

get a SR20 instead

RB25s NEO's are also good but make sure you dont skimp on $$$ for the conversion.

meh, if my sr20 blows ill probably go rb25 in the s14, they are so easy to get power from! my mate has a 25 neo making 320hp on 9 pound of boost.

now i want that!

SR20s are just way to expensive to get more than 240 kws out of =[

sr20s are great and good arnt they nearly all drifters have sr20's/ca18 man rb25's must be good then if you said sr20are bad

You are going to get a 2k loan to put a rb25 in your 32...makes me laugh a little. Why people send money modding their cars, when they have none is beyond me. But enough.

Rb25 in a 32 is nice setup. Power of the 33 with the looks of the 32.

I loved the extra 500cc's so much that I am now going for another 500cc's...

so why are the rb20's much worse then the 25's?? is just more power?? or is it more reliable or easy to maintain ??

rb20's are just shit. sure they can be built up to good power, but the amount of power you get out of an rb25 with the same mods would be alot more, plus they rev harder etc.

Yeah planning to but in a rb25 into my s14 aswell once the dough rolls in lol.

I can only talk from experience. A mate at work owns a R32 four door with an RB20det, I own an R32 coupe with a RB25detNeo.
He has spent way more than me maintaining his car and still is having boost leak and over heating problems. He is a sensible driver.
I have spent what I have had to maintain my car and it is as strong as it was at day one.
I have driven both cars and have worked on both cars. I admit there is more information floating around to help with fixing an RB20 but I believe it is heeps easier to work on my RB25.

Just my experiences.

but wouldnt it be better just tp spend 2k on my rb20 rather then 2k on just swapping engines?
injecters, bigger turbo, fuel pump, pfc etc???
i wanna make near 200kw so whats a good turbo for rb20??

well first off, i doubt an rb25 conversion will cost you 2k, i know if i was to swap engines id get the new one rebuilt back to new.

i suppose the best thing for you to do would be to spend the money on the rb20, although in the long run an rb25 will be alot better.

RB20's rev better then 25's...

If you are not going to be chasing more then around 200-220rwkw then stick with the RB20. But if you want more power than that, an RB25 is the best/cheapest option.

The RB25 head flows ~ 30% more and they have a higher staitc compression ratio 9:1 as opposed to the RB20 which is 8.5:1 so the 25 is much better off boost (espically combined with the extra capacity). The 25 will spool a bigger turbo much faster and also give much better midrange power and torque, to the point where on the track a corner you would usually have to take in 2nd and wring the neck out of a 20 you can take in 3rd with a 25 and feed the power on smoother.

If you are going to keep the RB20 then go for a HKS2530 and a PFC + Z32 AFM and grab a rising rate fuel reg and you will see over 300rwhp (225kw)

thanks very helpfull i think i will just do up my rb20...with the HKS 2530 i havent seen any of these turbo's selling on forums how much are they worth? i saw on a video a r32 rb20 had a HKS 2535 is that any dfferent?

yeah got the hks 2530 for sure great turbs got one on my rb20 laurel

its interesting the RB25 v SR debate

it seems alot of people with SR's are keen to put a 25 in... yet i own an Rb and love the fact SRs can get some kick ass power very easily (S15s etc)

ok so its runs good with the normal mods fmic,exhaust etc no laggg?? how much power have u gotten??

'JayRad Posted May 19 2008, 10:52 AM


You've got to kidding me right? Most good 25's go for 2g easily, then he has to add on labour costs if he pays a shop to do it. Plus money for all the things that go under the "extra expenditures" heading, that always come along with these sort of conversions.

The hks 2510-30 are very good turbos for 20's, A few people i know that run them get very good response and power (easily get around the 200-220rwkw) Ive got a T3//T4 (whatever the fuk that means..)on my rb20 and i dont get Boost till after 5000rpm!! Hence why im now changing my entire setup.

its a realy good matched turbo for rb20's yeah ive got fmic exhaust havnt had it dynoed but my mate had a r31 with 300hp and i stay with that so probly round 280hp, but i would definently get a hks one not any other brand

so whats the difference if i get a 2525 and 2530 ?? or is it just later models or something?

The difference say between the 2510-2530 is in there sizes and power ratings. 2530 is rated higher than the 2510, but with the bigger turbo comes more lag.. But they are still very responsive turbos. Best bet is to talk with a workshop about what turbo is best suited to your needs.

2530 will max out the power an RB20 can take on stock internals.
Should be full boosting on it by like 4000rpm too.

ok so the hks 2510 will be perfect for rb20, i will adventuly get bigger injectors,PFC, fuel pump etc so should e looking at some serious power...

RB25 with stock turbo will make your 200rwkw if you give it a bar of boost, and exhaust, a cooler, and a ecu. And will be hell responsive.

Or find yourself a good high flowed RB25 turbo, but that on RB25 and with the above mods 250rwkw isnt out of reach...

RB20 is a slug off boost and we all know it, but i love how they rev.
i went with a TR43 on my RB20.
has slight more lag than a 25/30 but can reach higher power. i'm making 210rwkw on 15PSI with stock ecu maps (timing, boost and tps adjustments, no remap). the turbo is capable of 20PSI so there is a lot more potential once i tune.

Go the Rb25 for sure. I love mine!! They have heaps more torque than RB20's, and are driveable on and off boost. You won't get muhc more than 200rwkw on a 2510, they are tiny, but as said above, a stock turbo on an rb25 can make that power. Mine has a stock tubo on 9psi and makes 185rwkw on a really rich tune, and it's hell responsive and torquey.....
Rb20 with big turbo - laggy and torquless.

Hi there R32 DRFT4,

So you want around 200kw? The cheapest and easiest option would be to replace your 20 turbo with a R34 GTT neo turbo. Bolt straight in, no modification to oil/water lines and gives very good response. Just add a good fuel pump, walbro 550hp is good and cheap. Don't really need to worry about a fuel pressure reg. Run an Apexi Super AFC and get it tuned to smooth out the flat spots. So 25 neo turbos go for around $400, walbro 550hp are around $160, SAFC II second hand around $200-$220, tuning from $110/hr. Will only take around 45 minutes to tune SAFC. Run 12-14psi and if you have a good engine you should be seeing around 200kw.

I'm not saying RB25 conversion is not a good option. By all means it is an awesome option with so much more power potential however the costs involved is a lot more than you realise. And besides, if you go to the trouble of putting a RB25 engine in then ideally you should run a RB25 gearbox. There is a little modification to do this such as custom mount and need a 33 tailshaft or just the yoke. RB20 gearbox is ok, but you'd run it behind a RB25 knowing that it will wear out one day. RB25 box is very strong. A good RB25 half cut around $3800-$4500 plus your extra stuff i.e. mounts, yoke, clutch, mod plates ect so you'd budget $5000. More if you then wanted to modify it. And don't forget the wiring. This is doing the work by yourself. Go to a workshop and be charged a buttload.