R33 Rb30 Conversion

[Adriano]

Just use your rb25 loom, and change the injector plugs. Fit the rb25 water temp sensor, thats it(unless you need the resistor pack)

[Maddo]

GT-RZ i got the crank machined to suit my new rods and no its not nitrided i think the crank will be ok as its the same as the vl turbo one and wont be revving past 7 grand anyway so at the moment i have spent $5500

Complete RB30ET engine rebuilt kit

ACL MLS Headgasket 1mm

CP Forged 20 thou oversized flattop pistons to suit RB30DET build

Precision H-Beam Rods

Apexi Power FC

T3/T4 Turbo

Walbro fuel pump

Sard Fuel Pressure regulator

I need a few more things for it to be complete, balancing, injectors, head re-built, throttle body, plenum, clutch, flywheel, new engine mounts other ones are stuffed lol and thats all i can think of at the moment

[bubba]

do these types of things interchange?

I am going to try and run R32 RB25DE head with my R33 Power FC im guessing I need to change these sensors too? the coil packs will be fine wont they?

so far I have worked out i will also need to change some ecu pins around as the R32 had a different firing order

Pretty sure they are interchangable, my head came with a brown water temp sensor (which I believe is the same as RB25DET's), different resistance so the ecu ran in cold start all the time. Swapped it with a yellow sensor of an RB26 plenum (the old RB20 one that I snapped was yellow) and it works fine.

I wasn't aware that RB25DET's had a different firing order.. thought it was just reversed injector pinouts or something on the ecu..

Yours is s2 yeah? you'll need to keep your s2 coils if keeping the powerfc. If you were to change to a 20 ecu you'd need 20/26/25s1 coils to suit.

Have you considered injectors yet? 25DE plenum is practically identical to a 20DET plenum (slightly larger ports though) and as such run the same injector style as RB20's meaning your 25DET items won't bolt up.

IMO in a 33 you'd be better off using the 25DET head, for me in a 32 the 25DE was a major benefit as it all worked straight away and everything was in the same spot

[dano4127]

My R33 is a S1 (94 model) have got S1 JJR Coils

Im going to go after-market Injectors anyway so I will just get top feed high impedance when I order em

I want to keep the R32 RB25DE head for a number of reasons:

Get to keep the RIPS Plenum

Dont have to pull apart a ready built motor

No VCT

[bubba]

Sounds like a plan

[MBS206]

Have you considered injectors yet? 25DE plenum is practically identical to a 20DET plenum (slightly larger ports though) and as such run the same injector style as RB20's meaning your 25DET items won't bolt up.

So a set of SARD 550CC injectors for an RB25DET, won't fit an RB25DE from an R32 head?

[Dahtone Racing]

No, RB25DET use side feed injectors and RB25DE from R32 use top feed

[R34NRG]

hows it going guys another update on my setup. im trying to source a RB26 head to put onto my rb30. the reason because that i can sell my rb25 as a whole and get some money back.

i was wondering apart from rocker covers,centre cover,front cover,intake plenum,,idle control motor. would i be missing anything to run the motor?

ill be getting new cams so thats not a worry. i hear stuff about a wiring loom? do i need those?

sorry guys wen it comes to engines i know f*k all lol.

[Dabro]

heard this term a lot and have limited my own 26/30 to 7k rpm with an ATI balancer BUT have yet to see or hear firm evidence of someone who has trashed an RB30 and can conclusively trace the cause to harmonics. not saying it an't so but can anyone provide evidence?

Scooby,

Harmonics will break a crank or could possibly cause early failure of the big end bearings after periods of sustained operation or extremely high load like in a drag or higher reving track car.

The main limitation of the RB30 with revs will not be a harmincs problem but an physical overload issue caused by the longer stroke and higher piston speeds of the RB30 bottom end.

How many people do you know who have actually broken a crank in a nissan? or any late model engine for that matter. much more likely you know ten who have thrown a rod out the side of a block!! generally this is due to a catastrophic failure due to overload I,E huge H.P or over reving, especially during a downchange through the gears.

Do some numbers on the difference in intertial loads and piston speeds with RB25/26 versus RB30 and you will quickly get the idea.

The end result of this is not a harmonics problem but a damn good reason to put a decent set of pistons and rods (read stronger) in if you want to rev it.

Anyway back to your original comment, I have built a RB30DET for a friend that has a 7000rpm limit (Rb25 harmonic balancer fitted) and is a daily driver. Considering that even if driven fairly hard it will only see the limiter a dozen or so times a week for short bursts there is no reason for it not to live a long and happily thrashed life. Harmonic problems in any stucture are only an issue when the frequncy remains CONSTANT! at a level which provides an amplitude which is detrimental to the structure, either continous or increasing due to it matching the natural resonance of the structure. This on a street car almost never happens as we are constantly changing gears and the engine speed changes with it. Also the engineers who design the crankshafts deliberatelly position the natural resonate frequency out of the normal operating range of the engine.

7000rpm and higher limiters for the RB30 are certainly not out of the question for a street driven engine, Just remeber what your driving when trying to decide how long to hold that third gear pull onto the freeway and you might want to lower it to be safe for track days if using more than 7000.

Dabro

[MBS206]

No, RB25DET use side feed injectors and RB25DE from R32 use top feed

Possible to change whole fuel rail from the 25DET to the 25DE (R32 25DE that is)

Edit: No, it is not possible to do a direct swap. Found out today.

Edited January 21, 2008 by MBS206

[Dahtone Racing]

im making a conversion fuel rail for a customer at the moment

[R32Abuser]

I was after a RB25DE but now it looks as its easier to find a RB26 head for my 30 than an R32 Non VCT RB25DE. Whats the go with this and sensors/injectors etc etc. I have read the ENTIRE thread and am a little unsure.

To my knowledge i will need (providing i use a aftermarket comp etc e.g. PFC) all new sensors...or wat can i utilise from my rb20?

Any help will be greatly appreciated.

[shanef]

youll need to make sure u use the correct injectors to suit the chosen power fc

im not sure on the sensor side of things though sorry

[R32Abuser]

cheers, yeh i figured i would need the GTR injectors....anybody else know regarding the sensor side of things? what about AFM/Throttle bodies can i use a single one (read 32 AFM) or whats the go? am i better off biting the bullet and just getting a R32 RB25DE?

[Adriano]

YOu can use any throttle body(single or multiple) any AFM, use the appropriate water temp sensor for the PFC, and use any early CAS(rb20.25 mitsubishi type,or 26) Use the appropriate O2 sensor for the PFC. You can use a single AFM on a RB26 PFC, but multiple AFM's on a rb25 PFC is a bit tricky. IMO the rb26 PFC is the way to go, as its far cheaper than the rest., although you may need to fit an injector resister pack if you have low impedence injectors.

[dano4127]

damn that is good information mate!

Im running the R32 RB25DE head with the R33 RB25DET Power FC

[Sydneykid]

Scooby,

Harmonics will break a crank or could possibly cause early failure of the big end bearings after periods of sustained operation or extremely high load like in a drag or higher reving track car.

The main limitation of the RB30 with revs will not be a harmincs problem but an physical overload issue caused by the longer stroke and higher piston speeds of the RB30 bottom end.

How many people do you know who have actually broken a crank in a nissan? or any late model engine for that matter. much more likely you know ten who have thrown a rod out the side of a block!! generally this is due to a catastrophic failure due to overload I,E huge H.P or over reving, especially during a downchange through the gears.

Do some numbers on the difference in intertial loads and piston speeds with RB25/26 versus RB30 and you will quickly get the idea.

The end result of this is not a harmonics problem but a damn good reason to put a decent set of pistons and rods (read stronger) in if you want to rev it.

Anyway back to your original comment, I have built a RB30DET for a friend that has a 7000rpm limit (Rb25 harmonic balancer fitted) and is a daily driver. Considering that even if driven fairly hard it will only see the limiter a dozen or so times a week for short bursts there is no reason for it not to live a long and happily thrashed life. Harmonic problems in any stucture are only an issue when the frequncy remains CONSTANT! at a level which provides an amplitude which is detrimental to the structure, either continous or increasing due to it matching the natural resonance of the structure. This on a street car almost never happens as we are constantly changing gears and the engine speed changes with it. Also the engineers who design the crankshafts deliberatelly position the natural resonate frequency out of the normal operating range of the engine.

7000rpm and higher limiters for the RB30 are certainly not out of the question for a street driven engine, Just remeber what your driving when trying to decide how long to hold that third gear pull onto the freeway and you might want to lower it to be safe for track days if using more than 7000.

Dabro

Some randomn things to add;

RB30E/RB30ET's were designed around a 6,250 rpm rev limit

Every 500 rpm increase in the rpm results in around a doubling of the force exerted on the crank, bearings, rods and pistons.

RB30's have a far superior rod length / stroke ratio than any other RB, this means less side force on the bores, rods and pistons.

This helps to ofset the often quoted higher piston speed argument

By far the most RB engine failures I have seen are due to oil control issues, then it's daylight, then some more daylight, then overheating.

If you rev an RB30DET/TT effeciently to 7,500 rpm thne you will be making over 750 bhp, so the first question you have to answer is "is my power target over 750 bhp". If it isn't, then why would you want to rev it to 7,500 rpm inefficiently, much smarter to simply change up a gear and take advantage of the faster acceleration.

The reason why I have an RB30 is so I DON'T have to rev it to make enough power, hence it lasts longer and costs less to build and to maintain.

Cheers

Gary

[Sydneykid]

YOu can use any throttle body(single or multiple) any AFM, use the appropriate water temp sensor for the PFC, and use any early CAS(rb20.25 mitsubishi type,or 26) Use the appropriate O2 sensor for the PFC. You can use a single AFM on a RB26 PFC, but multiple AFM's on a rb25 PFC is a bit tricky. IMO the rb26 PFC is the way to go, as its far cheaper than the rest., although you may need to fit an injector resister pack if you have low impedence injectors.

RB26's run low impedance (~3 ohm) injectors, RB20/25's run high impedance (~14 ohm) injectors.

Cheers

Gary

[HR31DRFT]

Nail on the head !

Low rev drift yee ha!

[Scooby]

Some randomn things to add;

RB30E/RB30ET's were designed around a 6,250 rpm rev limit

If you rev an RB30DET/TT effeciently to 7,500 rpm thne you will be making over 750 bhp, so the first question you have to answer is "is my power target over 750 bhp". If it isn't, then why would you want to rev it to 7,500 rpm inefficiently, much smarter to simply change up a gear and take advantage of the faster acceleration.

were they designed around a 6250 limit or is that the limit imposed on them due to longevity requirements, vehicle performance envelope etc and hence where holden put the redline on the tach?

i could probably second guess, but what's 'efficient' revving?

cheers