RB30DET turbo choices

[Clint32]

the rb30 rods are a lot longer so they need to be much larger in area, but 350rwkw should be fine

[Bl4cK32]

......no worries

[Sydneykid]

the rb30 rods are a lot longer so they need to be much larger in area, but 350rwkw should be fine

Not quite right Clint, the rod length stroke ratio on an RB30 is much higher than an RB26/25. That's why the RB30 block is so much taller than an RB20/25/26 blocks, far taller than would be necessary to accommodate the extra stroke. This means the rods have to withstand much lower side loadings, thus 350 rwkw puts far less strain on an RB30 rod than it does on an RB25/26 rod.

[Steve]

what the?

[Bl4cK32]

So Sydneykid...What sort of powerlevel would be considered a safe "reliable" limit for the rb31?

How far can i get it tuned for everyday driving??

[Sydneykid]

So Sydneykid...What sort of powerlevel would be considered a safe "reliable" limit for the rb31?

 

How far can i get it tuned for everyday driving??

We built our first RB25DE/RB30E about 4 years ago now, it has been running with 475 bhp (as per the engine dyno) without any problems since then. It is completely stock, rods, crank, pistons etc. We just balanced it, o'ringed the block and stuck new standard VL Commondoor rings, bearings, gaskets and seals in it and bolted a used, standard R32 RB25DE top end on it. Last time I saw it it had done over 70,000 k's. The guy that owns it is sensible and doesn't thrash it, it is regularly serviced, oil changes every 5,000 k's etc.

I see no reason why you shouldn't be able to do the same.

[Bl4cK32]

Cheers SK

[Bradyz]

Anyone else pushed the limits of the standard internals?

I currently have an rb30 making 340awkw (with 20psi) but the T66 is begging for more boost. I want to tune it with C16 and up the boost to 25psi, is this a recipe for disaster?

Have already clocked up 35,000kms with no probs but want to get down the 1/4 faster

[Cubes]

If I remember correctly they start to have issues around the 550lb/ft (~700NM) mark.

Fiddle with rev's and max torque to get the power you are after.

Power = Torque x RPM / 5252

Do the math and increase boost as VE & torque begins to drop off to keep it constant.

Lets say 500lb/ft at 7000rpm / 5252 = 666kw at the flywheel... lol if only.

Evil number.. I doubt you would want to push much past 400kw at the flywheel.

[TTT]

what surprises me with al lof this is the ability of the stock nissan cast exhaust manifold to flow so well.

any other turbo car has major problems flowing double it's stock power output.

where as some people are getting way over double the power while still using stock cast exhaust manifolds.

are there any gains to be had by doing and slight port work with a dremel tool on the exhaust manifold ports?

I ask this cause with the VR4 I had, people would get good gains from either doing this to the stock manifold or getting an EVO 3 one which basically has slightly larger ports than the VR4 exhaust manifold.

[fatz]

i have a xr6t on a gtr motor and it cruzes 270 rwkw at 1 bar

when i lunch the bottom end ill replace it with a rb31 that im slowely building now

Sk- how can i imprope the turbo reponse with the current setup and what cams do you recomend for the gtr head

pete

[Sydneykid]

Anyone else pushed the limits of the standard internals?

I currently have an rb30 making 340awkw (with 20psi) but the T66 is begging for more boost.  I want to tune it with C16 and up the boost to 25psi, is this a recipe for disaster?

Have already clocked up 35,000kms with no probs but want to get down the 1/4 faster

You are already past what I consider safe for the standard RB30 internals. Although I know a guy that always uses standard RB30 internals for ~650 bhp and simply pushes them till they blow. When they do eventually die he simply goes and spends another $150 and buys another one. Throws new, standard rings and bearings in it and quick bore hone. He reckons it is cheaper and easier than building a propper bottom end. Not something that I would do, but hey whatever floats your boat......

As for the T66, this is the compressor map...........

As you can see they are quite efficient up to 2.4 bar (35 psi), but you don't get a lot of extra airflow for the extra strain on the engine. They will flow 750 bhp (475 awkw) at 1.5 bar if the top end is capable.

The guy I referred to above has a gun RB26 top end (cams, porting etc) it is only the bottom end that he doesn't worry about. Maybe you should consider that as an alternative.

Hope that helps:cheers:

[Bradyz]

Thanks Sydneykid. I'll just be happy with what I've got for now while I save for forgies.

I only have a standard rb25de head aswell so I'll look into modifying that as well.

Thanks again.

[Cubes]

Thanks Sydneykid. I'll just be happy with what I've got for now while I save for forgies.

I only have a standard rb25de head aswell so I'll look into modifying that as well.

Thanks again.

Forgies as in Forged rods & pistons?..

You will definately need those forged rods.

[Sydneykid]

I shouldn't knock the $150 option too much. I spent ~$5K 3 years ago building a good bottom end that has reliably run 600 - 700 bhp. He spent 3 lots of ~$500 in the same time frame, so he is still ~$3K in front.

Maybe you should do up the top end, to make more power at lower boost. Well that's what he would suggest anyway.

[lwells]

I shouldn't knock the $150 option too much.  I spent ~$5K 3 years ago building a good bottom end that has reliably run 600 - 700 bhp.  He spent 3 lots of ~$500 in the same time frame, so he is still ~$3K in front.

I think it also depends on what the car is used for. If its a daily driver, having the car off the road when something breaks can be expensive (towing, car hire, time, etc) and extremely inconvenient. Most people don't have the time, resources or expertise to pull down their own engines which means they have to pay a workshop. Add to that if its their only car they probably will want it done quickly which adds to the expense.

If its just a second car/dyno queen/whatever then it might be a much more acceptable choice.

LW.

[GTR-Ben]

 Although I know a guy that always uses standard RB30 internals for ~650 bhp and simply pushes them till they blow.  When they do eventually die he simply goes and spends another $150 and buys another one.  Throws new, standard rings and bearings in it and quick bore hone.   He reckons it is cheaper and easier than building a propper bottom end.  Not something that I would do, but hey  whatever floats your boat......

Sounds like my RB30

My GTR head is ported, cams etc. But I have a stock bottom end. I will push it until it blows.. then worry about it.

I have 3 more full bottom ends sitting there ready to go.

I can see I will need a bigger turbo down the road though if I want decent numbers.