My Rb25/30

[MNTLRB]

Hi guys,

I'm in the planning/early stages of building my 30det for my R33 and basically looking for a bit of advice before i spend any money on the wrong things. My current plan is:

R31 Rb30e block bored out 20thou oversize, tensioner relocated etc etc..

Arias forged pistons, 9 5 1 compression

Stock conrods (won't be going above 7000rpm so these should be ok, in excellent condition)

ARP race series bearings all round

GTR N1 oil pump with external oil cooler

Rb25DET water pump

R33 RB25DET engine mounts

Head gasket: since i'm using fairly high compression pistons i want a slightly thicker than usual gasket to bring that down a bit, is that correct? and if so, what size etc?

R32 RB25DE head crack tested and so forth, ported valves, aftermarket valve springs, new stem seals etc.

Cams- help! Basically looking for a nice sounding cam setup that is still streetable...was looking at some HKS 256 degree in/ex. Would this do the trick?

Top mount manifold

Turbo- help! Haven't had much sucess here. I'm looking for a street setup (occasional drag/drift use but mostly street) my goal is around 450-500rwhp. I've been told that the Masterpowrt t70 would suit, opinions? I don't want anything that will lag heavily, but still want a decent response.(in case that didn't give it away, my turbo knowledge is fairly lacking...)

38mm wastegate plumbed back to 3inch exhaust and 50mm Tial BOV

600x300x76 Front mount intercooler

RIPS front facing intake plenum

Triple core radiator

External oil cooler-help! what size cooler would you guys recommend?

Fueling- more help required! (sorry)

in tank lift pump- walbro 500hp?

leading to boot mounted surge tank-what size? ie 2 litre?? i have no idea

2x bosch 044 pumps

Injectors....no idea! what would you recommend given my setup?

ECU will be either a Link G4 or Apexi/MicroTech...still deciding between tuners therefore haven't settled on an ecu yet as the 2 tuners specialise differently.

I'm also going to be using a reconditioned RB25DET gearbox with an Exedy button clutch.

As said before, its mainly going to be a streeter, but it needs to be reliable, will end up being my daily driver hopefully, so I want a setup thats performing well within it's limits, not right on the edge.

Sorry I know this sort of stuff has been posted up in the forum heaps before justed wanted advice on this setup especially. I don't have my heart set on any of this stuff especially so don't be shy to tell me if you can spot something wrong!

Thanks heaps in advance guys

Rhys

[Adriano]

My advise would be to do the exact same setup as cubes has, 300rwkw, looks completely stock, plenty enough power for the street. If you want a bit more, fit a bigger exhaust housing and water meth, should be able to see 360rwkw

[MNTLRB]

My advise would be to do the exact same setup as cubes has, 300rwkw, looks completely stock, plenty enough power for the street. If you want a bit more, fit a bigger exhaust housing and water meth, should be able to see 360rwkw

Okay sweet as, sorry i've had a quick look but can't seem to find many details of cubes' setup, where would that be? thanks

[jarrod83]

in terms of not laggy.. what sort of rpm are you expecting full boost? a gt35r should be around 3500-3700 and make around 500rwhp depending on the exhaust housnig, a t04z will be more like 3800-4000 and make over 550rwhp with the right supporting mods

anything over 400rwhp youd definately need a better clutch my last exedy only lasted 3000 kms at 408rwhp

740cc injectors or bigger, depending on final power and fuel

maybe also add ARP head and main studs to your list (probably already on it)

dont see a 3inch exhaust supporting that much power, probably 3.5" or bigger.. maybe a good twin

at that sort of power youd really want to make sure the head flows well so you dont have to run much boost, maybe a light porting?

probably have a look thru the rb30 dyno section for other peoples mods and have a look at what seems to work

hope that helps a bit

Jarrod

[MNTLRB]

in terms of not laggy.. what sort of rpm are you expecting full boost? a gt35r should be around 3500-3700 and make around 500rwhp depending on the exhaust housnig, a t04z will be more like 3800-4000 and make over 550rwhp with the right supporting mods

anything over 400rwhp youd definately need a better clutch my last exedy only lasted 3000 kms at 408rwhp

740cc injectors or bigger, depending on final power and fuel

maybe also add ARP head and main studs to your list (probably already on it)

dont see a 3inch exhaust supporting that much power, probably 3.5" or bigger.. maybe a good twin

at that sort of power youd really want to make sure the head flows well so you dont have to run much boost, maybe a light porting?

probably have a look thru the rb30 dyno section for other peoples mods and have a look at what seems to work

hope that helps a bit

Jarrod

Awesome, thanks for the advice bro. I'm basically looking for something that'll spin up in the same time as the stock turbo on a RB25DET, sorry my turbo knowledge is pretty bad lol. What sort of supporting mods would i need for the t04z?

Head stud kit added to my list

I'll look at possibly getting a larger exhaust, just i already have the 3in. would that really hold back the setup? I also have to keep it under 95decibel to keep it legal but i guess it'd be possible to get resonators/silencers etc put in?

Thanks heaps man

[jangles]

try looking at this http://www.skylinesaustralia.com/forums/26...ml&hl=huddy

should do what youre after

[MNTLRB]

Sweet, thanks for that man

After having read thru some more of the dyno posts I'm thinking of using a t04z, what sort of supporting mods would i need to run one of these?

[jangles]

the TO4Z is never going to spool as quick as you mentioned in an earlier post, its more of a turbo for 400+ rwkw.

a GT35 would even suit a bit better,

with the 25 head, depending on condition, it is known to have valve float issues at the 350+rwkw mark.

make sure you get a good quality manifold to match the turbo also.

depending on what power figure you think you want, base your turbo selection around that,but be clear of what you want as the TO4Z is a larger turbo

[MNTLRB]

Yeah, I've basically realised I'm not gonna make my power goals (450-500rwhp) with a turbo that spools as quick as the std 25DET one does...If achieving 500hp means a bit of lag I can put up with that lol. Do you think the t04z would be a good choice? How many psi would i have to run it at to be getting 500hp? And would a 39mm wastegate be big enough or should I be looking larger?

Also any help/advice with cam choice would be awesome if you have any ideas...

Thanks heaps

Rhys

[jangles]

id be going with a GT35 or equivalant for that sort of power level, the TO4Z is probably oversized for it.

probably around 22psi with thre GT35? depends on the tune and specs of turbo

plenty of threads on here giving examples. around 50mm gate would be required for good boost control.

im no expert so a cant really recommend anything, but id go with the biggest drop in cams you can get if not doing any head modifications

Edited April 25, 2010 by jangles

[bubba]

General rule of thumb.. more boost = smaller gate, less boost = bigger gate (as you need to bypass more exhaust gasses)

So, if you were going for a bigger turbo but only wanted to run 500rwhp you would need a big gate, if you went for 500rwhp with a GT35 then you wouldn't need as big a gate as you would be running a fair bit of boost (~25psi) to get there.

[MNTLRB]

Okay sweet, so a GT35 at bout 22-25 psi would get me ~500rwhp? I'd be needing at least 800cc injectors for that would that be correct?

In terms of head work i'm basically looking at a full recon, light porting, and some upgraded cams.

Also one other thing I wanted to check, the engine is going in my 33 but i'm using a 32 head, i should therefore use the 32 loom so that the plugs match up? I've been told the 32 and 33 looms are slightly different, is this the case?

[jangles]

800cc should be plenty sufficient,

a mate of mine ran a 26 with a RB20 loom, not much of a difference.

a GT35 would suit that power goal perfectly i think

[MNTLRB]

Awesome thanks man sounds like I have my turbo choice

Any ideas what size head gasket I should use?

[jangles]

just use a new stock headgasket, Rob from RIPS reckons they are good for 700hp

or buy one of the new gasket kits so you have everything you need!or a cometic gasket.

any of them will suit, depends on how much you want to spend!

1.2mm would be a good thickness for it, to suit the bore obviously

Edited April 28, 2010 by jangles

[MNTLRB]

just use a new stock headgasket, Rob from RIPS reckons they are good for 700hp

or buy one of the new gasket kits so you have everything you need!or a cometic gasket.

1.2mm would be a good thickness for it, to suit the bore obviously

Awesome okay i was just a little unsure of the thickness, cos i'd been told that a thicker one would be better as i'm using quite high comp pistons

Haha 700hp is a little past my power range so that should be all good lol\

Any other handy hints you wanna pass on? what kinda car & engine do you have? I'm guessing RB30 given how much you know about em lol

[jangles]

a thicker one will be good if you want to bring the compression ratio down,but why use such high comp piston just to bring it down with a 1.8mm gasket?

id seriously recommend some rods, for an extra 600ish youll be safe, as now ull have a 350-400kw engine with stock rods, i dont see it lasting, no matter what rpm you keep it too,its rather cheap piece of mind in my opinion.

I have a cefiro, and an ever changing RB30 build started off similar to yours, now its ending up similar to some of the other active users on here.just the addiction.

I dont know much, ive got most/all of my info off here, so just ask away if you have any Q's and cant find em

Edited April 28, 2010 by jangles

[MNTLRB]

Just out of curiousity, what sort of cost are forged conrods? I know it'll be slightly different here in nz, but what sorta price do you guys pay in oz? I haven't found any on kiwi sights, gonna ask my parts guy next time i'm in there tho...which will be picking up my pistons next wed then the block work can start! yay! lol can't wait for the 30 goodness haha

[TiTAN]

http://www.spoolimports.com/content/SPOOLRB30CONRODS.asp

[The Bogan]

What are you using the car for, I only ask this as Im unhappy with my outcome, I would rather more response than to a turbo that comes on late and hard, my set up is more suited to drag but I wanted track. The spool time is crap, its like waiting-waiting-waiting-wheel spin.