To Rb30 Or Not?

[Simon-S14]

ahhh choke central!

im just a little worried that i might choke my 3071R as it has a GCG cast OP6 housing .7AR... dunno.. should be ok.. `

[Simon-S14]

another thing that im worried about is the CR of the stock pistons... ive read that its around the 8.2:1 mark... should i be concerned or is it a moot point?

[SirRacer]

Use a power steering bracket from an rb20de or e engine and they bolt up perfectly.

In my opinion with the rb30 is that everything seems to slowly require upgrading to suit everything else, eg gearbox & clutch due to torque. Other than that its a good choice for good power.

[Simon-S14]

yeah ive already got everything to support the power, injectors, turbo, exhaust, box, clutch, etc etc

[Guilt-Toy]

you should use ACL race series bearings, my first rb30det spun a bearing and i used nissan bearings.

the rods and pistson will be ok for 320rwkw, just tune them rich. ARP rod bolts are a must!!

[madaz R33]

excellent thread to those of us considering the build,(i am) interesting to see some peoples opinions on forged pistons in the RB30. Guilt toy, what would u say u spent on ure build up from start to finish? is it possible to introduce nitrous into this equasion without sounding stupid and blowing finances absolutley out of the water?

[acsplit]

Ask Chris Easton .....

18 months of drift practice an DA Stock r31 rb30 bottomend and stock head. XR6 turbo with ext gate.

275 rwkw all day long... and she loves it

[rev210]

Yep. Nitrous is easy. Supporting systems for the extra horsepower and therefore fuel required to handle and you're done. It's very cheap horsepower relatively speaking.

You could add 100hp or 400hp depending on what the motor is built to take.

[N1GTR]

thanks guys, yeah i have read through the RB30 thread, theres some 400 very informative pages but it makes finding what you want to know very hard lol. very impressive power figures being made too.

Wrong thread, read this one:

http://www.skylinesaustralia.com/forums/in...t&p=1920659

Its probably not a big deal in the grand scheme of costs, but all too many of these RB30 rebulds do not seem to allow for changes to engine mounts etc to clear strut braces.

Bin the strut brace

Its probably not a big deal in the grand scheme of costs, but all too many of these RB30 rebulds do not seem to allow for changes to engine mounts etc to clear strut braces. Power steering and other belts (dependign on model of car its being transplanted into. The cost of new intercooler pipes and dump pipes. Cost of re-charging/gassing air-con. Change to water and oil lines around manifolds. Cost of dyno time to re-tune the engine. And the big one, bother to change the engine number with the local registration...who' ears prick up when they read RB30

All for doing it, just do the numbers. Im a negative bastard when i look at these things, the real cost of these conversions is always higher then what ppl start out thinking

I agree on the costs point, but they arent all that bad, its just that $50 here, and $100 there adds up fast

another thing that im worried about is the CR of the stock pistons... ive read that its around the 8.2:1 mark... should i be concerned or is it a moot point?

My RB2630 has 8.5 CR, 1mm headgasket

[bubba]

Wiseco forgies, 8.5:1, standard rods, new standard headgasket. Oh and I'm using NDC bearings (jap brand).

[Guilt-Toy]

from start to finish i would have to say that i have spent over 25grand in the last 5 years fixing f**k ups rebuilding engines etc etc

Here are some of the costs i can think of that i have spent

forged bottom end, $5000

turbo & manifolds setup $4,500

injectors computer fuel system etc $3000

ahhh man im gettin depressed now. anyone want to buy my car? cheap

excellent thread to those of us considering the build,(i am) interesting to see some peoples opinions on forged pistons in the RB30. Guilt toy, what would u say u spent on ure build up from start to finish? is it possible to introduce nitrous into this equasion without sounding stupid and blowing finances absolutley out of the water?

[R34NRG]

from start to finish i would have to say that i have spent over 25grand in the last 5 years fixing f**k ups rebuilding engines etc etc

Here are some of the costs i can think of that i have spent

forged bottom end, $5000

turbo & manifolds setup $4,500

injectors computer fuel system etc $3000

ahhh man im gettin depressed now. anyone want to buy my car? cheap

i hear u buddy, i took the plunge about 3 months ago and in parts alone its costing me about 14k.

the worse thing is its not even a gtr

but i highly recommend anyone wanting to take up the rb30 journey look at this.

learnt alot from it.

but this stuff properly is common sense to some of the guru's out there.

Edited December 3, 2008 by Cubes

[aquariuz6]

Hi guys,

I am actually very curious into why this rb30 journey would cost thousands unless ofcourse you go forged this, aftermarket that.

Let me get this straight.

If you already have a R33 and only after a street car that will never see track nor never see revs past 7,000 rpm,

isn't it possible to just use the rb25det head you have and stick an rb30 bottom end on and then thats mainly it?

Yes you need to do some modifications like vct. Doesn't the fmic pipes match in the end?

You could use rb30, 26 and 25 headgasket.

Can't you use stock rb25det inelt manifolds, plenum and exhaust manifold?

I know I am missing a few things but you know the drill. Just have to make sure that all stock parts are in good condition.

What exactly stock items from rb30, 25, 26 that can't you use. I think most of the parts you can use OEM.

If its just basically for street and don't want overboard power Isn't this possible?

I am actually curious to why some guys suggest not to do this for only street purposes. So you don't really need to go forged this and that right?

Isn't that where the big dollars are?

[Simon-S14]

you can do everything you mentioned, I know of a few people who have got 100 dollar bottom ends from wreakers, slapped a twincam head on it and then realed off insane power figures.. since your retaining the 25 head then yes everything will still bolt on as per standard.

In short this is what im doing, but with a fresh bottom end.

[Chris_A31]

A lot of the time the bores need machining and honing again, bearings and rings need replacing. The block needs a few modifications and a decent oil pump fitted. Also the crank needs work, oil pump drive needs upgrading... etc. The head.. you really should upgrade the valve springs to avoid them dancing at high rpm. It using the standard bottom end components then the rev limit should be around 7000 to be safe. I've heard the rb25 inlet manifold doesn't fit.

I have read a fair bit of the "R33 RB30 Conversion" thread and can see things do add up quickly, but I can't see it getting towards 25k, I feel sorry for that guy. If you aim for roughly 300rwkw then it shouldn't cost much at all, seeing you can use the stock items. If its just for a street car then that power is more than enough, if for the track then you have to accept track work is expensive..

[Simon-S14]

love_hate: i assume your talking about the r32 25de head there, as the 33 25det head ythat i plan on running wont need the valve springs upgading, and i can run the manifold no worries.

can someone shed some light onto the oil drive mod. how do you go about it?

[The Mafia]

I've heard the rb25 inlet manifold doesn't fit.

Why wouldn't it? If you're trying to bolt it onto the block, it won't fit.

The only reason it wouldn't is because its too high (deck height is higher), but get $250 ebay greddy copy and you're in business.

[Chris_A31]

yeah im guessing the deck height.. as its the standard item for the head anyway, thats probably the only reason..

I'm going to run one of these china copy plenums..

[Sydneykid]

All very good and well....but me and many others will see far higher costs doing this.

That's why I contribute, to show that some things are possible

Cheap china inlet manifods that need their flanges machined

Still cheaper than buying aftermarket side feed injectors.

new cool pipes, throttle cables, plus other mods to fit all costs hundres of dollars by workshops.

Knowledge is king, once you know what has to be done you don't get scammed as easily.

If you are an R32 owner going RB30 you dont have all the gear off the front of the RB25 for belts etc.

But you need and RB25 head, that's why I suggested buying a complete RB25DE then selling off the bits you don't need.

The power steering brakcet needs to be modified

I have never ever had to modify a power steering bracket, maybe I have just been lucky.

none of it is overly difficult in isolation but unless you are a budding DIY guy i sense too many people make out as though this is an easy anc cheap conversion

.Exactly that's why the RB30 guide exists, to help inexperienced guys do a little bit of the DIY. If you don't try, you never learn.

Things like having enough flex in pipes to me is a receipe for popping cooler hoses for the rest of time

It's not that much flex, less than 10 degrees at the compressor outlet. On one car I used a slightly longer silicone joiner where the pipe from the compressor outlet goes through the inner guard. No flex at all then.

you having the smarts to get thigns to work and what other can expect as a result are a little different

. I know what you mean, what's looks easy to one person looks impossible to another.

Especiually gettting a car through rego...re-stamping blocks isnt exactly a done thing

All new blocks come without engine numbers, so stamping is in fact very, very common. Our Pajero tow car (long since replaced) had a new block fitted under warranty, no engine number until we stamped it with the old numbers.

Cheers

Gary

[Sydneykid]

from start to finish i would have to say that i have spent over 25grand in the lasst 5 years fixing f**k ups rebuilding engines etc etc Here are some of the costs i can think of that i have spent

forged bottom end, $5000

If you had built an RB25 or RB26 forged bottom end it would have cost more

turbo & manifolds setup $4,500

You would have had to spend that money regardless of whether you used an RB25 or RB30 bottom end

injectors computer fuel system etc $3000

They are directly related to power outputnot whether you chose an RB25 or RB30 bottom end to makwe that target.

ahhh man im gettin depressed now. anyone want to buy my car?

So you can spend the same or more on another? You've got the bug and it's hard to shake, trust me I know.

Cheers

Gary