GQ RB30/RB25 head/turbo conversion

[MONGREL]

I have searched this and it has been mentioned in many threads but i didn't find any dedicated to it. I have started researching it so thought I'd post up what i've found.

In my opinion the RB30 is a great engine with loads of potential.

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I've made some calls, and can get the head, manifolds, turbo, loom, ECU, air flow meter, coil pack, so basically everthing from te top of an RB25ET.
$1300. Not sure if its a good price or not but a start.

The loom for this is seperate from the loom for the rest of the car.

Dont think i would fit it myself. Any ideas on who would be good to fit it up in syd or wollongng?
Price?

(EDIT)
Some of the info i have found for those interested.
These are all skylines but gives an idea of what could be expected from the mods.
http://www.skylinesaustralia.com/forums ... 04332.html

Detailed conversion
http://users.tpg.com.au/cobra30/twincam.htm

From what i've read, all standard parts from RB25ET can be used s long as your not chasing big power, Apart from turbo (too small)
And as long as manifolds clear in the engine bay, but cant find any info on it being done in a patrol.

Also if not keen on going turbo, just the NA RB25 head, extractors cold air intake should see around 200Kw but might lack in torque for such a heavy truck.

Info on NA RB25 head.
http://www.calaisturbo.com.au/archive/i ... -2082.html

[bogged]

this kind of thing?

http://www.patrol4x4.com/forum/showthread.php?t=37716
http://www.patrol4x4.com/forum/showthre ... ht=RB30det

[B.D.R]

There is also a massive write up about this mod on calaisturbo.com.au

[brad-chevlux]

You most certainly CAN use the stock rb25 turbo. it won't do much past 6000rpm but it will come on very early. Personally if i was to do the conversion in a patrol i would doing every thing i could to use the RB25 turbo on it.

[MONGREL]

There is also a massive write up about this mod on calaisturbo.com.au

Pretty sure that write up is the cobra30 write up, just coppied and pasted.

this kind of thing?

http://www.patrol4x4.com/forum/showthread.php?t=37716
http://www.patrol4x4.com/forum/showthre ... ht=RB30det

Pretty close, but utilising the original bottom end alredy in a GQ, RB30.
No engine number change etc

You most certainly CAN use the stock rb25 turbo. it won't do much past 6000rpm but it will come on very early. Personally if i was to do the conversion in a patrol i would doing every thing i could to use the RB25 turbo on it.

Thats good news.. Are you positve? After reading the cobra30 write up again i think thats where i got that from, but he used an RB20 exhaust manifold and said that turbowas too small.
I did speak to a dude tat makes turbo manifolds today an his opinion was it would be too small, RB25 turbo.

[GAS-747]

IMO the standard turbo is too small for an RB30DET.
Even on a stock RB25 it spools up fairly quickly in my Stagea.
On a 3 litre it would run out of puff as it goes beyond it's efficiency range.
Also keep in mind the ceramic rear on these that like to give up the ghost...

For a Patrol I would recomend a T04E with 57-76 trim & .63-.82 for quick spooling and moderate boost levels.
An even better option would be a GT30. Also if you can keep the VCT do so if not get adjustable cam gears for inlet & exhaust...


BTW I have built an RB30DET with GT3582R, J.D Custom plenum, ETM manifold, 50mm wastegate, forged internals, adjustable cam gears etc etc which was supposed to go into the Stagea but had hassles with the 4wd conversion. It went like a cut cat in a Commodore though...

[brad-chevlux]

IMO the standard turbo is too small for an RB30DET.
Even on a stock RB25 it spools up fairly quickly in my Stagea.
On a 3 litre it would run out of puff as it goes beyond it's efficiency range.
Also keep in mind the ceramic rear on these that like to give up the ghost...

For a Patrol I would recomend a T04E with 57-76 trim & .63-.82 for quick spooling and moderate boost levels.
An even better option would be a GT30. Also if you can keep the VCT do so if not get adjustable cam gears for inlet & exhaust...


BTW I have built an RB30DET with GT3582R, J.D Custom plenum, ETM manifold, 50mm wastegate, forged internals, adjustable cam gears etc etc which was supposed to go into the Stagea but had hassles with the 4wd conversion. It went like a cut cat in a Commodore though...

There is also a massive write up about this mod on calaisturbo.com.au

Pretty sure that write up is the cobra30 write up, just coppied and pasted.

this kind of thing?

http://www.patrol4x4.com/forum/showthread.php?t=37716
http://www.patrol4x4.com/forum/showthre ... ht=RB30det

Pretty close, but utilising the original bottom end alredy in a GQ, RB30.
No engine number change etc

You most certainly CAN use the stock rb25 turbo. it won't do much past 6000rpm but it will come on very early. Personally if i was to do the conversion in a patrol i would doing every thing i could to use the RB25 turbo on it.

Thats good news.. Are you positve? After reading the cobra30 write up again i think thats where i got that from, but he used an RB20 exhaust manifold and said that turbowas too small.
I did speak to a dude tat makes turbo manifolds today an his opinion was it would be too small, RB25 turbo.

The RB25 turbo is too small i your looking for huge power at high revs.
not what would personally want from an engine in a patrol.

I have built a few RB30/25 engines, one of which (we are talking about 3 or 4 years ago here, was a simple engine, the guy had an R33 skyline on which the balancer parted from the crank, he was up for and engine and wanted to go with the RB30 bottom end. back then you couldn't buy off the shelf timing belts like you can now. When we called Gates to ask about it, they sent us a pre production belt for testing. fitted well after removing the idler and fitting two tensioner pulleys.
You couldn't buy ANY off the shelf parts for the conversion at all.

Anyway like i said a simple conversion, it ran the stock turbo at 12psi and also used a stock untouched R33 skyline ECU. It was smooth boosted very early and on the dyno made good power and AFRs were very safe.
about 12months after i built it i took a job at different workshop, but up until that time it ran faultlessly. and i still the see the car driving around sometimes.

For a simple effective upgrade to a GQ you just don't need to waste money on all the crap people tell you you need.

RB30 bottom end RB25 top end ALL factory nissan parts and sensible boost will see it running smoothly for years with out hassle.

[AussieJK]

bit expensive, can get a rb26dett head for about that with inlet turbo's etc on it, PM i can point you in right direction I have contacts that can help you out with this

[MONGREL]

PM sent.

Personally not chasing big power. Not to start off with anyways we all know what happens once you stat these things though..

Something that spools up quickly and could hold around 10 psi to 6000rpm would be a good start i think.

[brad-chevlux]

bit expensive, can get a rb26dett head for about that with inlet turbo's etc on it, PM i can point you in right direction I have contacts that can help you out with this

the RB26 head makes it easier, as the water/oil port mismatch you get on the RB25 VCT head isn't a problem.

[MONGREL]

RB25 N/A dosen't have the VCT. The N/A head lines up in regards to water and oil gallery's.
The N/A head needs stronger valve springs.. But has better duration cams than the VCT RB25head.

Some valve springs in the RB25 N/A head (a clean up and reseat of valves while at it $600 been quoted so far) RB25 turbo inlet and exhaust mainfolds along with ECU injectors air flow meter etc.

Sould see an relatively easy and cheap conversion.

What im thinking anyways, open to all opinions though so if you have knowlegde about this or done it without spending 10-15k please add some detailed info.
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EDIT
The RB25 turbo is too small i your looking for huge power at high revs.
not what would personally want from an engine in a patrol.

I have built a few RB30/25 engines, one of which (we are talking about 3 or 4 years ago here, was a simple engine, the guy had an R33 skyline on which the balancer parted from the crank, he was up for and engine and wanted to go with the RB30 bottom end. back then you couldn't buy off the shelf timing belts like you can now. When we called Gates to ask about it, they sent us a pre production belt for testing. fitted well after removing the idler and fitting two tensioner pulleys.
You couldn't buy ANY off the shelf parts for the conversion at all.

Anyway like i said a simple conversion, it ran the stock turbo at 12psi and also used a stock untouched R33 skyline ECU. It was smooth boosted very early and on the dyno made good power and AFRs were very safe.
about 12months after i built it i took a job at different workshop, but up until that time it ran faultlessly. and i still the see the car driving around sometimes.

For a simple effective upgrade to a GQ you just don't need to waste money on all the crap people tell you you need.

RB30 bottom end RB25 top end ALL factory nissan parts and sensible boost will see it running smoothly for years with out hassle.
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Brad, your above post is pretty much what i want. I was going to do away VCT head just to save the hassles that come with them.

[brad-chevlux]

RB25 N/A dosen't have the VCT. The N/A head lines up in regards to water and oil gallery's.
The N/A head needs stronger valve springs.. But has better duration cams than the VCT RB25head.

Some valve springs in the RB25 N/A head (a clean up and reseat of valves while at it $600 been quoted so far) RB25 turbo inlet and exhaust mainfolds along with ECU injectors air flow meter etc.

Sould see an relatively easy and cheap conversion.

What im thinking anyways, open to all opinions though so if you have knowlegde about this or done it without spending 10-15k please add some detailed info.
-------------------------------------------------------------------------------------
EDIT
The RB25 turbo is too small i your looking for huge power at high revs.
not what would personally want from an engine in a patrol.

I have built a few RB30/25 engines, one of which (we are talking about 3 or 4 years ago here, was a simple engine, the guy had an R33 skyline on which the balancer parted from the crank, he was up for and engine and wanted to go with the RB30 bottom end. back then you couldn't buy off the shelf timing belts like you can now. When we called Gates to ask about it, they sent us a pre production belt for testing. fitted well after removing the idler and fitting two tensioner pulleys.
You couldn't buy ANY off the shelf parts for the conversion at all.

Anyway like i said a simple conversion, it ran the stock turbo at 12psi and also used a stock untouched R33 skyline ECU. It was smooth boosted very early and on the dyno made good power and AFRs were very safe.
about 12months after i built it i took a job at different workshop, but up until that time it ran faultlessly. and i still the see the car driving around sometimes.

For a simple effective upgrade to a GQ you just don't need to waste money on all the crap people tell you you need.

RB30 bottom end RB25 top end ALL factory nissan parts and sensible boost will see it running smoothly for years with out hassle.
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Brad, your above post is pretty much what i want. I was going to do away VCT head just to save the hassles that come with them.

you can still use the VCT head. it just needs some welding around the oil/water ports in one corner. you can weld it over and fit an intake cam from an RB20 or N/A RB25 and do away with the VCT. However it is only a mater of drilling and tapping into the side of the head and taking an oil line from a 'T' at the pressure sender to get the VCT going again.

I would just take what ever head/engine you can get and use it, you end up getting the head skimmed anyway, so the welding won't cost much extra. By the time you fit good valves spring to the N/A head, you'll have covered the cost of getting the VCT to work and have change.

[MONGREL]

Bit off topic but wondering if anyone has supercharged one of these carby RB30's before.

A 1ggze with a SU carb maybe?? Deliver better low down torque would think.

Any opinions?