Jump to content
SAU Community

Recommended Posts

Hey guys my name is Craig :rant: .

I'm building the RB30dohc

Was wondering what inlet plenum would be best suited 4 this setup other then goin custom ?

Even turb setup, injectors manifold etc pls

96 R33 RB25 head.

Edited by HR31DRFT
Link to comment
https://www.sau.com.au/forums/topic/175812-my-rb30dohc-build/
Share on other sites

You dont say which "DOHC" ?

Easiest would be to go with the orig std setup, but as someone who has built a custom Intake plenum I would say it may not be worth the expense for the gain in performance.

I was never able to quantify the results from mine unfortunately as I fitted it with many other mods at the same time, but I dont think it made much diference except in looks and presentation.

Though it did enhance the FMIC fitting with no unesessary longer I/C pipes etc.

Definitely look at a R26 head and its std plenum.

Rb25 head for ~$1000 + ~$700-900 for a decent plenum.

That 2k can go a long way in buying a good rb26dett head and its std plenum and better factory cams.

Got this 25de head 4 $400

Was gona go 26 but found it hard 2 get complete. Covers etc this stuff can be a bitch 2 get in parts.

I dont mind goin the greddy plenum, 10k has been put aside 4 the engine build, already have block + head, rods, N1 water + oil pump.

N still have 10k hehe, i kind of like keeping 10k in my bank 4 as long as i can :rant:

I was gonna go Borneo setup, but alot of custom work what will be a headf*k.

I only want around 300-350 atw but 4 a while :rant:

As turboX said which head are you using?? RB25, 20, 26?

turboX your plenum looks pretty intersting any links to the build??

Just follow the link on my sig below and go to my website listed at the bottom -there's about three pages on it.

Got this 25de head 4 $400

now somoene please correct me if im wrong..

By using a DE head.. you will have NA compression.. So.. about 10:1.

Because your going turbo.. you will have an turbo engine with a 10:1 comp ratio.. so.. you wont be able top push alot of boost though it.. engine longitivity will be greatly sacraficed.. and chances are.. your going to blow your head (hahaha)

Does the engine get its comp ratio via the head or the pistons/cylinders?

just a passing thought.. :dry:

Car is fully decked out in suspension love.

Kaaz 2way hehe fun times.

Its actually 300-350 hp not kw

Car is awesome now, dont need anymore power from the rb20 but i want 2 build a engine.

RB30dohc POWER

This bitch is gonna be sick.

now somoene please correct me if im wrong..

By using a DE head.. you will have NA compression.. So.. about 10:1.

Because your going turbo.. you will have an turbo engine with a 10:1 comp ratio.. so.. you wont be able top push alot of boost though it.. engine longitivity will be greatly sacraficed.. and chances are.. your going to blow your head (hahaha)

Does the engine get its comp ratio via the head or the pistons/cylinders?

just a passing thought.. :dry:

Lumpy is building the engine, i'll leave that up 2 him.

Compresion ratio's will be adjusted 4 optimum performance, but like i said thats 4 the gurus...

I dont like talkin about stuff i dont have a full quid on.

Lumpy is building the engine, i'll leave that up 2 him.

Compresion ratio's will be adjusted 4 optimum performance, but like i said thats 4 the gurus...

I dont like talkin about stuff i dont have a full quid on.

Nice answere.. should tell that to the people that like to talk shit..

Keep us updated!..

be fantastic to see how she runs!..

Good luck and keep the details comming!

now somoene please correct me if im wrong..

By using a DE head.. you will have NA compression.. So.. about 10:1.

Because your going turbo.. you will have an turbo engine with a 10:1 comp ratio.. so.. you wont be able top push alot of boost though it.. engine longitivity will be greatly sacraficed.. and chances are.. your going to blow your head (hahaha)

Does the engine get its comp ratio via the head or the pistons/cylinders?

just a passing thought.. :dry:

NA head is fine; it won't affect comp ratio as that is achieved by the domed pistons the N/A motor uses.

Drop the head on a N/A RB30E bottom end and you will end up with around the usual 8.2-8.3:1 comp ratio.

The N/A bottom end with the SOHC head achieves a 9:1 comp ratio; the DOHC lowers the comp from 9:1 to 8.2-8.3:1 because its combustion chamber is larger.

Yeh not rushing anything !!!

Building the engine in 2 parts...

Bottom 1st

All little bits like crank collar etc are goin 2 be used.

Using Mahle racing pistons

Head 2nd

Porting polishing work but really not much is required but doing anyway cuz i'm there u no.

Comp ratio's will be worked out so they are exact for fuel i'm using and what i'm doing with it.

But yeh havnt looked into it yet, just read and fully undestood the RB30dohc build guide.

As all says, a really good builder is assy the engine so i'm not gonna loose sleep over ratio's

I will blow the project out a couple of months if it takes, 2 get things exact or as close as poss.

No dead lines

Then paint :dry: lol

Thanks guys i appreciate the feedback

P.s i work at Coventry's so alot of gear is from here cutting costs big time.

U gotta cut at least 1 corner hey.

Yeh not rushing anything !!!

Building the engine in 2 parts...

Bottom 1st

All little bits like crank collar etc are goin 2 be used.

Using Mahle racing pistons

Head 2nd

Porting polishing work but really not much is required but doing anyway cuz i'm there u no.

Comp ratio's will be worked out so they are exact for fuel i'm using and what i'm doing with it.

But yeh havnt looked into it yet, just read and fully undestood the RB30dohc build guide.

As all says, a really good builder is assy the engine so i'm not gonna loose sleep over ratio's

I will blow the project out a couple of months if it takes, 2 get things exact or as close as poss.

No dead lines

Then paint :rolleyes: lol

Thanks guys i appreciate the feedback

P.s i work at Coventry's so alot of gear is from here cutting costs big time.

U gotta cut at least 1 corner hey.

a light polish is the way to go, ive seen more gains from mates who have done a mild polish than a major polish when aiming for lower hp.

i got most of my rebuild parts from coventry for my rebuild through my mate when he used to work there. it was probably the cheapest rebuild in history lol (just a std rebuld). i got pretty much everything but the rings from them.

goodluck with the build mate.

Thanks dude,

Head is gettin a light polish, we all need a polish every now n then :rolleyes:

Will be a great package.

Will keep ya's posted.

Goin 26 head now thanks Richard :D

POWER TIME :D

Edited by HR31DRFT

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Need to see other side of PCB in that area...ie; I don't see any thru-hole mounting, just soldered vias (smd zeners in SOT23 have 3 legs but only 2 are used, as reflected by PCB tracks)
    • 4 to 5 is fine. It will be slow, but that's better than blowing turbos. I don't have a PS pump idle up solenoid on my car, because... I think when we put the Neo in we retained my R32 lines. But.... From inspecton of the R34 vacuum hose diagram, you can see that the solenoid needs to be connected to the turbo inlet as source of clean air) and the plenum (as source of vacuum - which is the place for the air to flow to to cause the idle to increase). So 3 to 1 is VERY WRONG. 3 should go to either the turbo inlet, or the plenum. Follow the other hose from the PS solenoid and if it goes to the plenum, then your 3 goes to 2 2 would also serve as a bleed port for a boost solenoid.
    • Pull them out and pull more apart. You can't do shit with them still bolted to the floor of the car.
    • Yes it is. ZD1 is on the other side of the board. Where ZD1 is marked is clearly opposite a 2 pin device. Our 3 pin device here is not a ZD.
    • Alright, a little update on this... I called Fulcrum, who used to be the distributor in Australia. No Bueno, they don't service them anymore.  Called shock works, who don't service them but offered to dyno the shocks for performance, and suggested DNA in Sydney might service them.  Called DNA, who also do not service them and basically said they try to steer customers away from tein for this exact reason these days- there is just no support for them anymore apparently.  Both SW and DNA said they are a not necessarily a bad product, but they just don't service the brand or know anyone who does service the brand anymore.  So... I could keep calling around but at this point I think I'll probably just spring for the shockworks product, unless anyone here knows anything.  Cheers 🍻 
×
×
  • Create New...