Rb30dett Build Questions

[jackrabbit]

Hey guys,

Long time lurker but have just opened an account so as to ask for some advice on a few things in my upcoming build i have been piecing together for some time.

It is a 3 litre rb30dett build

I am using the head and intake off of a r32 gtr and a built rb30 bottom end

The specs when finished should look something like this, bearing in mind there are still a few things needing to be purchased.

Rb26dett head, stock refurbished w upg valve springs and stock cams, 20 thou shaved off head face, rear oil drain back mod performed.

Rb30 block, decked 30 thou, deburred and painted block walls, extensive oiling mods performed.

Cp pistons with head mods and gasket choice 9.6 to 1 cr achieved.

Spool rods w upg rod bolts

Arp main and head studs, block prepped for 12mm rb26 head studs

Cometic gasket

Stock intake assembly rebuilt

600x300x120 garrett core intercooler

Id2000 injs

Twin 044 pumps

Nismo fuel reg

Stock r32 gtr exhuast manifold match ported with minor head exhuast port clean up performed too, ceramic coated.

Trust t517z turbos

Hard intake piping kit

Running rwd only with built box

Running on e85

Haven't purchased an engine management system yet as still deciding and will collaborate what my chosen tuner will be able to work best with.

I would love on final tune of 25 to 30 psi be able to see 450rwkw with very very strong midrange and no more than 8000rpm

Does this seem achievable to you guys?

My main concerns are with wether or not the turbos will flow the amount of air required to produce the power goals i have.

Now i know full well that it is jusy a number and my main priority is the delivery of the power and area under the curve.

I have chosen to try and push the stock cams as the shorted duration will allow me to achieve a much higher dynamic compression ratio for more power throughout the midrange and early in the powerband. I have upgraded the valve springs to reduce valve float but i can not imagine the rb26 head and valvetrain in good working order even with stock cams having any problems revving to 8000 rpm.

I would love some opinions of the more experinced gtr guys here as this is newish territory for me.

Previously a v8 guy and a mild rb25 with 300kw was the most i have delved into the rb world myself so now its time to step things up a bit.

Thanks in advance and looking forward to being more active in the community, may even start a build thread when the assembly starts.

[KiwiRS4T]

Your goals should be easily achievable but don't know enough about the turbos you list - some would argue for a modern single turbo. If its a street car get some more modern fuel pumps - the 044s will be as noisy as.

[GTRPSI]

Key point when your in pieces is to fit a long nose oil pump drive collar, get a good oil pump, deepen the sump to increase capacity as much as possible and extend the oil pickup tube.

The rest looks about right.

I also cannot comment on the turbos.....

Rear oil drainback is not needed any more, these days people are just putting breathers above the oil level in the sump and venting it to a catch can.

[jackrabbit]

My fabrication skills are pretty reasonable, so a larger capacity baffled sump definitely wouldn't be out of the question.

As far as not needing the head return and just using a catch can, isnt that somewhat of a bandaid solution? If the oil is not pooling in the head and is flowing back to the sump quickly there should be minimal oil blow back yes? Or am i over complicating haha?

And any suggestions on a modern fuel pump solution to support 500kw on e85 ?

[GTRPSI]

Oil pools in the head because blow by is going up while oil is trying to return, the oil cannot get back down again.

The oil return was never a return, it was another channel for blowby to go up and equalize crankcase and head pressure.

You may as well have run a line to the top of the cam covers and achived the same results.

Now people simply vent the crankcase pressure straight out of the bottom end into a catch can to avoid it trying to go up into the head.

Read the last 10-12 pages of the oil control thread.....

Dont forget to run a smaller than standard block restrictor. Info is in the first page or 2 of the oil control thread.

[luke gtr]

Get arp rb25 head studs.

No need to drill and tap the stud locations.

The 25 studs are the right length for the 26 head, and the right size for the 30 block.

The studs only clamp, the 2 collars locate.

Have the 25 studs in my combo.

Was pushing 450rwkw on 98.

Often spun to 8-9k.

[jackrabbit]

Thanks for the info guys, read the oil control thread and it was very informative.

I have print the thread and give to my engine builder to read.

Is there any benefit to using the rb26 studs as opposed to the rb25 studs ? My engine builder is family so any thing that is labour only intensive is free. If for no extra cost wouldn't it be worthwile ?

And yes restrictors will be installed as recommended.

Any opinions on the turbos ? And how they will perform

[luke gtr]

There is a for/against debate on the larger studs.

Have heard they can weaken the block due to less material, but obviously stronger studs.

Dont have any actual proof.

But, as I said, I ran 25 studs without problems, and will be reinstalling when reassembling.

[r32-25t]

I used 25 studs in mine cause heard to many horror stories of cracking block due to reduced material and stronger stud combo

[KiwiRS4T]

Skimmed through the RB30 thread - seems No-one has chosen your turbos! If you have already bought them then with the right tune etc you might crack 400kw or better (maybe someone who actually still has some will let you know) but if you haven't bought them yet there are probably better choices - even in bolt on twins.

BTW you will need minimum 3.5 or preferably 4in exhaust all the way through.

[jackrabbit]

Yeah im struggling to find much info om these turbos attop a 3 litre engine.

I can always pass them along and buy another set of turbos.

What would be the best turbocharger for a trade off between response and power >8000 rpm.

And yeah 4inch mandrel bent system was planned with one high flow box muffler from hooker headers, they sap minimal hp

[breaker1845]

I don't think those turbos will do the job for 450kw, probably just under. You're better off getting a bigger set of twins if you want or go with a single turbo.

Are you wanting to peak at 450kw and be at max efficiency on the turbo or do you want something that can pull 500kw plus and have more breathing room? As there are a few low and high mount twin setups that can do that.

Plenty of singles that can do that too, just need to do some research and find your optimal choice.

[XKLABA]

Those turbos are TD05H-16G and with the 10cm rear housing will happily pass 400kw but i think will struggle to see 450, you can get Kando Billet TD05H-18G with 9 blade turbine wheel CHRAs that will still be pretty responsive on the 3.0 and happily pass 450kw

I have a similar setup except Type R poncams and am debating between the TD05H-18Gs and TD06SL2-20Gs for mine to replace the GT-RSs, would really like a set of EFR6758s as factory mount bolt on, they would be the ultimate bolt on for. 3.0

[luke gtr]

Give me time(probably over a year ) and I should have new results from my next setup.

Going to t618z's.

[jackrabbit]

Those turbos are TD05H-16G and with the 10cm rear housing will happily pass 400kw but i think will struggle to see 450, you can get Kando Billet TD05H-18G with 9 blade turbine wheel CHRAs that will still be pretty responsive on the 3.0 and happily pass 450kw

I have a similar setup except Type R poncams and am debating between the TD05H-18Gs and TD06SL2-20Gs for mine to replace the GT-RSs, would really like a set of EFR6758s as factory mount bolt on, they would be the ultimate bolt on for. 3.0

Thanks heaps for the information here, and yes i love the efr turbos but my wallet and budget hates them haha

Just spoke with hypergear as far as hybrid stock turbo arrangements go and they have a t28 based billet wheel chra that they can incorporate into stock housing with stock positioning that he tells me will be more than capable of the 450kw goal i have set and the utilization of stock mounting position etc is a massive plus to me.

[KiwiRS4T]

Go with the Hypergear! At least you can be sure of good back-up. Make sure you get the right oil and or water supply set up for the turbos.

[XKLABA]

Can't go wrong with Hypergear stuff, Stao knows his work