R33 Rb30 Conversion

[shanef]

So, are people actually going to answer the question, not give bullshit responses?

How exactly can you fit the RB25/30 into the R33 GTS-t WITH a strut brace fitted, and NO, I'm not putting on a new plenum.

Well if u actually were half smart, or even quarter smart, or had any brain at all, ud realise by now that all the info u need is in this thread, or in the pdf.

but because im not a c**t, ur only other option is to lower the engine by modifying the mounts

[dano4127]

I have heard along the way that rb20 mounts can be used and will lower it

can anyone confirm?

PS: GET A NEW PLENUM

Edited January 15, 2008 by dano4127

[GTRgeoff]

What Shane said. You will have to fab up lower mounts.

My setup still just touches at the front. So I'll be using the soft mallet to create clearance when some new engine covers go in. The primary reason I went 26/30 was to have the lower plenum as well as 6 throttle for the racetrack.

Also my machining including a head skim cost $1400 including full balance, fitting slugs, crank deplug and clean and full check then tapped and grub screwed. I used forged rods so no prep of those. It came cleaned ready to give a final wipe and assemble.

[HR31DRFT]

Hey man i went same setup as you, rb30/26, but my block cost me like $2300 had 2 re-line bore and all what u metioned, using Mahle forgies, spool rods, 7ltr sump, tomei oil pump h/v.

Any pointers about this setup, just finished block work...

[Maddo]

its cost me 482 dollars to get my block preped still ahvent got it balanced as yet the preping of the block includes, acid diped/cleaned, crank machined, re-bored and honed and the edition of some new welsh plugs sending my stuff away now to get balanced and sending my head away for a rebuild cant wait till i can finally start it up

[GT-RZ]

what machining did you get done to the crank?

isn't it nitrided?

i think the conversion to 1/2" studs is a very good idea if your going for a bigger turbo too. imo.

Edited January 15, 2008 by GT-RZ

[Adriano]

I think all this talk about a 1/2 in conversion is a bit of a concern. Firstly is is to M12, not 1/2 in. Secondly, you have to have a switched on engineer do the job on a mill, as its easy to stuff up. A lot of builders dont worry, as the ARP RB25 head studs are able to withstand a lot of cylinder pressure. I upgraded mine to rb26 arp head studs(M12 x 1.75), and am now regretting it. In hindsight, i think its really only necessary once you are looking at getting close to 1000hp

[[200]]

Duncan Foster Engineering?

Why would you regret doing that?

[Crans]

Will a rb20det ecu be able to run a 25/30 with a s2 rb25 head on it?

[dano4127]

dont think so mate will be a lot easier to source another ECU

[Crans]

i got a pfc to use with it but wanted to stay with stock ecu.

I will use it else where then

[dmac_25]

Will a rb20det ecu be able to run a 25/30 with a s2 rb25 head on it?

You would be if it was a s1 head but no vct

[GT-RZ]

I think all this talk about a 1/2 in conversion is a bit of a concern. Firstly is is to M12, not 1/2 in. Secondly, you have to have a switched on engineer do the job on a mill, as its easy to stuff up. A lot of builders dont worry, as the ARP RB25 head studs are able to withstand a lot of cylinder pressure. I upgraded mine to rb26 arp head studs(M12 x 1.75), and am now regretting it. In hindsight, i think its really only necessary once you are looking at getting close to 1000hp

1/2 is just a general term, not sure you can buy imperial studs anymore anyway.

i work with a mill almost every day. i don't see why it's a big job? infact id go as far to say it's an easy job. although i am interested to why you regret doing it?

[MBS206]

Well if u actually were half smart, or even quarter smart, or had any brain at all, ud realise by now that all the info u need is in this thread, or in the pdf.

but because im not a c**t, ur only other option is to lower the engine by modifying the mounts

If you go through, and search for it, you'll find that it doesn't actually state HOW to lower it.

Everyone claims to "lower" the motor 15mm on the drivers side, 12mm on the passenger.

But, they don't say how or WHERE these measurements are from.

Is that nock 15mm off the bottom of the mount?

Is it make the engine physically sit 15mm lower (Which removing 15mm square off the bottom of the mount won't do)

How exactly is it meant to be done?

At the moment, after measuring a few things, I'm just going to remove the strut brace.

[Dahtone Racing]

ive seen spacers used between the chassis and engine cross member

[Guilt-Toy]

PM if you want to know how i did it mate. but yeah. spacers is what got me outta trouble

[Adriano]

1/2 is just a general term, not sure you can buy imperial studs anymore anyway.

i work with a mill almost every day. i don't see why it's a big job? infact id go as far to say it's an easy job. although i am interested to why you regret doing it?

There are certainly more imperial stuff made than metric, I had a machine shop do mine with a mill, and the results are bloody ordinary. Unfortunately the size ifference between the two threads isnt a great deal, which can easily result in the thread not cutting cleanly. I just think for the ordinary person, the added expense, and the risk of damaged threads make it unnecessary when rb25 ARP studs do the job fine.

[Crans]

What would I have to change on the series 2 head for my rb20ecu to work?

Coil packs, resistor pack for injectors CAS?

Also what plenums are people using to get it to fit under an r32 bonnet?

[bubba]

There would also be things like water temp sensors etc which would need to be swapped for the RB20 items.

I'm using the standard intake manifold for now, am building a custom out of a GTR plenum. If you are using a 25DET head then you have the option of Greddy/copy plenums, I don't have that luxury

Bonnet currently rubs slightly on the very forward corner of the standard intake plenum and barely on the timing belt cover. No modified engine mounts or anything like that.

[dano4127]

There would also be things like water temp sensors etc which would need to be swapped for the RB20 items.

do these types of things interchange?

I am going to try and run R32 RB25DE head with my R33 Power FC im guessing I need to change these sensors too? the coil packs will be fine wont they?

so far I have worked out i will also need to change some ecu pins around as the R32 had a different firing order

Edited January 17, 2008 by dano4127