Jump to content
SAU Community

Recommended Posts

Hi all,

Just a little advice in terms of what cams would be worth running in the 25/30 build i have just started.

The head is a R33 RB25, and the intention is to disable the VCT and run adjustable cam gears. What cams would be a good option, or are the stock RB25 cams okay.

The current RB25 motor gives a little over 235kW ATW, and have saved my new SARD 850cc injectors to go in the new hybrid block.

Other parts will include:

CP forged pistons 9.0:1

1.4mm Head gasket

Forged pistons - make undecided

Adjustable cam gears

T04z or GT 3540 undecided

SARD 850cc injec

Thanks

Link to comment
https://www.sau.com.au/forums/topic/243692-poncams-or-larger-for-rb2530/
Share on other sites

Hi all,

Just a little advice in terms of what cams would be worth running in the 25/30 build i have just started.

The head is a R33 RB25, and the intention is to disable the VCT and run adjustable cam gears. What cams would be a good option, or are the stock RB25 cams okay.

The current RB25 motor gives a little over 235kW ATW, and have saved my new SARD 850cc injectors to go in the new hybrid block.

Other parts will include:

CP forged pistons 9.0:1

1.4mm Head gasket

Forged pistons - make undecided

Adjustable cam gears

T04z or GT 3540 undecided

SARD 850cc injec

Thanks

anyone got an opinion?

I'd match the cams to the turbo.

GT35r/T04z you really want to start looking at cams with decent lift (9mm+) with a mid 260 duration to make full use of the turbo on pump fuel.

Ideally for street gt35r/t04z a mid 260duration and 10-11mm lift but thats not easily achievable with the hydraulic head. :cheers:

Go beyond 9mm lift and there are issues with getting valve springs that can physically fit and do the job without coil bind problems.

A good bet is to get the stock head and springs measured up so you have a known base to work from. There are good, useable cams and springs available to suit RB25 heads, but you'd likely need a 26 head if you want to be able to use some serious cams easily.

Neo = solid followers.

Grab some suitable springs from performance springs and shove in a set of cams with decent lift. Decent lift and they make power so much easier on less boost with pump fuel and you don't need to ring its neck by running long duration cams to try and make the power. 8000rpm is really all you need with peak power sitting just over 7000rpm and holding nicely to 8k.

on the subject of higher lift with a neo head

has anyone worked around the issue that Spool found with any lift over 9.xx mm lift, and exposed oil galleries (if my memory serves me correctly)?

intererest to know this aswell because if my cams are choking then will need to upgrade to something bigger. And 8k rpm is plenty for me.

as far as i know

the crank bent on the dyno while increasing its rev limit

and it runs a ross balancer

most of the workshops here dun wanna know about the 26/30 (yay wa)

they either suggest a stroker or stick to the 2.6 and rev it a bit more

Im planning on

CP pistons

Spool rods

Cometic headgasket

Acl shells

crank collar

arp headstuds undecided 11mm or 12mm

arp main studs

N1 oil pump

4wd adaptor plate

ati balancer

will/wont this rev safely?

either that or i might just buy an engine from proengines/lewis engines

Edited by R32 Driver

The workshops don't want to know of the 26/30 because they have no experience with them.. :P

The cranks simply do not bend they break oil pumps so possibly a build issue due to lack of experience with the rb30's.

Speak to Rajab racing and a few of the other workshops (inc. proengines) that build serious RB's they know how to get them to hold together at high rpm. i.e grub screw the crank.

There are a few tricks to be performed its not just a matter of giving the rb30 a refresh and a good balancer then hope for the best.

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

    • Yeah well per the video it took 15s for the stock unit to start up....even if I give it a few seconds discount for starting that is at least 12 sec before you get a reverse camera if you are trying to leave a park.  The android unit is way faster, but 2016 for the stock unit is a long time ago in consumer electronics
    • Yea that’s why I said ima test them with multimeter and see the reads.
    • Only at idle. Isn’t a problem when rev it seems.
    • @Haggerty This seems silly to ask, but are you confident in your ability to tune the Haltech?  
    • Next on the to-do list was an oil and filter change. Nothing exciting to add here except the oil filter is in a really stupid place (facing the engine mount/subframe/steering rack). GReddy do a relocation kit which puts it towards the gearbox, I would have preferred towards the front but there's obviously a lot more stuff there. Something I'll have to look at for the next service perhaps. First time using Valvoline oil, although I can't see it being any different to most other brands Nice... The oil filter location... At least the subframe wont rust any time soon I picked up a genuine fuel filter, this is part of the fuel pump assembly inside the fuel tank. Access can be found underneath the rear seat, you'll see this triangular cover Remove the 3x plastic 10mm nuts and lift the cover up, pushing the rubber grommet through The yellow fuel line clips push out in opposite directions, remove these completely. The two moulded fuel lines can now pull upwards to disconnect, along with the wire electrical plug. There's 8x 8mm bolts that secure the black retaining ring. The fuel pump assembly is now ready to lift out. Be mindful of the fuel hose on the side, the hose clamp on mine was catching the hose preventing it from lifting up The fuel pump/filter has an upper and lower section held on by 4 pressure clips. These did take a little bit of force, it sounded like the plastic tabs were going to break but they didn't (don't worry!) The lower section helps mount the fuel pump, there's a circular rubber gasket/grommet/seal thing on the bottom where the sock is. Undo the hose clip on the short fuel hose on the side to disconnect it from the 3 way distribution pipe to be able to lift the upper half away. Don't forget to unplug the fuel pump too! There's a few rubber O rings that will need transferring to the new filter housing, I show these in the video at the bottom of this write up. Reassembly is the reverse Here's a photo of the new filter installed, you'll be able to see where the tabs are more clearing against the yellow OEM plastic Once the assembly is re-installed, I turned the engine over a few times to help build up fuel pressure. I did panic when the car stopped turning over but I could hear the fuel pump making a noise. It eventually started and has been fine since. Found my 'lucky' coin underneath the rear seat too The Youtube video can be seen here: https://www.youtube.com/watch?v=uLJ65pmQt44&t=6s
×
×
  • Create New...