R33 Rb30 Conversion

[Cubes]

The inlet runners/plenum has influence over where the power band resides and from what I've seen does indeed widen the power band nicely.Much more so than leaving the stock inlet and only throwing on a good exhaust manifold, thats providing your not near the stock exh manifolds brick wall simply stop making power limit of 300-320rwkw.

The short runner style plenums also hold power up longer once peak power is made, this is whats important for your requirements use Al.

All though some disagree; seat of the pants a short runner large plenum on the RB30DET even with a stock exh manifold is a very good thing regardless of power being made.

The stock rb inlet manifold and plenum is a damn good thing; their only problem is on the 3ltr its '2-2.5ltr factory tuning' places the power band a little lowish in the rpm for a large GT35r+ turbo.

I remember R33_racer stating he wound his GT3040 out to 8500rpm? He also stated boost was all in by 3300rpm or there abouts?

[Al]

Joel, I have a GReddy plenum, with a Q45 t/b, so inlet should not be a problem. That's why i was questioning only the exhaust manifold.

I am more than happy with a peak power of about 280-300ish, just wanted to know if an ext. manifold would give me more usable rpm and make better average power. If the differance in minimal, i would prefer to stay with the stock ext. manifold.

[munro'sgts-t]

hey guys so im just in the early stages of building a 25/30 hybrid. and im up to page 70 in the thread so bear with me i fmy questions hav been answered, what i would like to no is which part of the head has to be weleded up for the vct is it the little hole just below the larger round gallery in the photo from the pdf doc. if not could someone plz tell me which one it is. and also wear abouts is the oil return line that i need to plum bak into the oil return line from the 25det head? if someone could post up a new link about connecting up the vct via external feed would be great beacause all of the links in the early pages of the thread do not work for somereason. and last of all what sort of power can i push on stock cams with stiffer valve springs? thanx heaps can wait to get started pick up the bottom end friday

[nemini90]

Just thought i would add a few pics of my build

its so close cant wait to see how it goes

[Craved]

Just thought i would add a few pics of my build

its so close cant wait to see how it goes

looks really neat.

couple of questions

what under driven pulleys are they?

what kind of internal baffling is used on that custom PS resevoir tank.

[nemini90]

all pulleys are ross and i only have two bits of flatbar evenly spaced in the tank

the same set up for ps was done to a gtr and worked fine so i hope it will work fine on this

[Craved]

can you put up a diagram of how the flat bar is positioned

in keen to make one of these myself and was always cautious in regards to baffling.

Also note that Silver-gtst had an aftermarket ps resevoir installed on his car, and the system pressurised and caused the seals in the pump to leak (where as the std one is not 100% sealed)

[SirRacer]

im just piecing my setup together now (full ground up rb30 build in a cefiro) and today went to order the pistons as i need to bore my block due to bore wear

acl no longer make the pistons i need.

im wanting to get standard .50. nissan say they dont do them either so want other options do i have for stock pistons with chromoly rings brand wise?

cheers

[Guilt-Toy]

Hey ppls,

A bloke I know who runs on the same dyno as I + one of his mates have RB25/30's in their VLT's. They have been sorting the head oil supply issue's. Both run N1 pumps.

Initially using std restrictors the head was flooding.

2 x 1.1mm restrictors. Initiaily all seemed good until it was noticed they were getting lifter tick when getting off the throttle from a hard run on the dyno.

Off the head came again; 2 x 1.5mm's and all is good but it still does breathe a little. The bloke I know said 1.3mm would 'probably' be ideal.

Bit of a nightmare.

Those who run by Gary's oil restrictor table which states for the hydraulic head to block the rear and run a single 1.5mm restrictor up front. Have you noticed any lifter tick when getting off the throttle from a hard run on the dyno?

Is there a reasonable explaination why 2 seperate motors had the same issue with 2 x 1.1mm restrictors when having 2 1.1 mm restrictors should have more oil flowing in to the head than a single 1.5mm. OR maybe the 1.1mm restrictors reduce pressure within the head too much where as the single 1.5mm provides less flow but more pressure? argg confusing myself.

Never noticed any ticking in mine at all mate.

[munro'sgts-t]

ok so ive just finished reading all 263 pages of posts on this topic and its great lots of great helpfull imformation in hear. i currently am in the early stages of dismatling my rb30 bottom end. the one thing i would like to no is do acl make pistons for the rb30e all i have seen are rb30et pistons on there site and other places but they give a bad cr so i want rb30e pistons some wear on hear i got a part number for acl rb30e pistons ( 6mkry2799 ) this is with moly rings according to the guy who posted it up cnt remeber i no its on hear sumwear. just wondering if any of you have hurd of them im looking to make 300rwkw no more just a nice 300kw would be great from wat ive read i should be able to make this power with these pistons, stock cams,gtr springs,turbo? possibly a gt35r and all the other stuff like ecu n stuff

[R34NRG]

hows it going guys, sorri i dont have much time to read the 260+ pages uve guys have ranted on about, although i read through 9 of them, interesting stuff.

i was very interested in doing this to my r34 gtt, but i hear its a different matter all together? different components different height factors ect ect.

was wondering how much would this sorta setup cost for a r34 GTT, and the power benefits compared to a rebuild of my engine atm.

[Adriano]

To avoid filling up the thread with more posts from people who cant be bothered reading the whole thing, a neo rb30 is exactlt the same as an rb25/30 except you use vl turbo pistons. Resulting compression ratio to be exact can only be determined by trial assembly. Putting an rb30 bottom end will not give you more power, just heaps more torque basically, and allow you to spool up a bigger turbo earlier

[R34NRG]

To avoid filling up the thread with more posts from people who cant be bothered reading the whole thing, a neo rb30 is exactlt the same as an rb25/30 except you use vl turbo pistons. Resulting compression ratio to be exact can only be determined by trial assembly. Putting an rb30 bottom end will not give you more power, just heaps more torque basically, and allow you to spool up a bigger turbo earlier

it might not give me more power but putting a rb30 block will allow my car to run more power.

the only reason im considering this is that a rb30 block will allow me to achieve 300+rwkw with no problems, as aposed to doing a full rebuild on my current engine

so i guess my main questions are, will the rb30 block allow me 300+rwkw without shittn itself, and how much does this sorta setup cost?

im assuming no more then 8g? thats excluding basic things like ECU, clutch, boost controller ect

Edited May 14, 2007 by anDru

[R31Nismoid]

Im cracking down on this thread, if people keep asking mindless questions because they are too lazy to read

You post will just be removed as im cleaning this thread up slowly and dont need more crap by the time im done

[Al]

andru: If you are suggesting on slapping a std rb30 bottom end to your neo head, then you're better off building the rb25 with strong internals. The rb30 bottom end does not add strength to an engine, it fact it's probably more prone to blowing, only quality components used in the build make the engine stronger.

I have calculated my build to cost somewhere in the region of about $10K.

[Cubes]

Al,

The stock rb30 bottom ends are like any other rb bottom end.. Rev it hard 7.5k+ and you will eventually have oil pump problems.

Darren, Sky30 and a few others are pushing well over 300rwkw on stock bottom ends.

Darren's was making 470rwkw on a stock bottom end + hypereutectic pistons and ran a 9sec 1/4 before an alt failure resulting in a lean out breaking pistons.

Sky30's is still pushing 370rwkw on his 300,000km' old RB30.

So in short.. No they are not prone to blowing compared to the rb25. If anything its the opposite due to their more boost and pump friendly static comp ratio and better rod:stroke ratio.

They don't need as many rev's to make the same power + the better rod:stroke ratio which is good for rod sideloading; so stock vs stock the rb30 bottom end will always hold more power reliably.

As with any RB (apart from r33 s2 and r34) if you want to rev it hard you will need to sort out its oil pump drive.

[r33_racer]

i love it when you see those great numbers on such old and tired bottom ends....and how they keep on doing it with no dramas. Until something gives and it all breaks...which sux. But then again you see motors fully built up and they still blow....haha i know of a few

[R34NRG]

Al,

So in short.. No they are not prone to blowing compared to the rb25. If anything its the opposite due to their more boost and pump friendly static comp ratio and better rod:stroke ratio.

and dont forget the massive amount of extra torque u get aswell.

i proberly have to get a quote from a actual shop later because i cant decide on building up the rb25 or adding a rb30 bottom end.

im sorta leaning to the rb30 side because its not that more exspensive (say 1-2k more?) and id proberly be able to produce more torque and it should withstand over 300+rwkw.

if any of u guys can give me some pointers that be great!!!

atm im just trying to see how much rb30 blocks are, forgies ect ect are for both sides of each project.

im hoping they dont go over 9g.

[Cubes]

For you R33 GTST blokes building up an rb30det should cost near the same as building up your rb25.

The only additional costs are running the vct oil feed line and blocking off the heads std vct oil feed. Of which in total should only cost a couple hundred max.

If you run a plenum; no need to drop the motor.... If you don't well... $70-$100 for an engineering shop to lower the engine mounts.

So in total to build the rb30 over an rb25 were looking at ~$300 more and maybe for you r33 s2 owners another 300-400 for the oil pump drive collar which pulls the additional cost up to around $600-$800 there abouts.

Its not all that much considering the streetability you gain with a large turbo. For example rb30det's, rb25det's on the dyno I run on; the rb30det running a gt35r .82 in the low rpm range doesn't give anything away poiwer wise to an rb25det running its stock turbo all tuned up and pushing ~200rwkw at the wheels. Thats quite impressive when you consider the gt35r .82 has the capability to push a shade under 400rwkw.

[GTRgeoff]

Let's see, for my 26/30 in the 25t

26 Head complete with inlet and injectors - 1500

cam gears, 200 or whatever brad at spoolup is charging

Block - 60

pistons and rods - 1090

machining - 1400 including bearings

turbos - steelies from the GTR to make way for sliding highflows so free but say 1500

braided lines - 400 but donated from the RB25DETT

gaskets - say 200 as I use silicone blue mostly

build, install and fire up - free in 5 days for a poor broken cripple (me)

so $6350 but then there is tuning so allowing $10K with tuning (no more than $1K and less at a good MOTEC tuner like SelectMaz) and a workshop to do the work is fair enough, but less if you are using a donor head from a 25 and not needing to muck with twin turbos.

Still been too crook to get the cam gears in and run it away for final tune so no number yet, just running it as a na with 160rwkw.