R33 Rb30 Conversion

[shanef]

BUT after talking to some builers they all seem to have the same respone... dont do it!

theyre main reason that they dont wona touch it is that the 30s dont handle no where near as much boost as the 25s.

who are these "builders" that you have been talking to? with a properly built engine (you stated your going to put forgies in it and balance it all) there shouldnt be any reason y it wont handle big boost. your only after 400hp, then u dont NEED to go full forged, dont run spastic boost (18psi should be safe over a sustained period) and get someone who knows how to tune the car so it doesnt knock and you will be fine.

im sure R33_racer will post his opinion about your questions, but you have mine and i hope it helps

[Cubes]

i have since got the 30 series2 bottom and r33det head. BUT after talking to some builers they all seem to have the same respone... dont do it!

Don't do it simply isn't good enough.. What is their reasoning? These engine builders only stating 'don't do it' are, as you call it, being a chop.

theyre main reason that they dont wona touch it is that the 30s dont handle no where near as much boost as the 25s. now im getting a bit put off the whole 25/30 idea coz i dont wona be afraid to rev my engine hard.

Since when don't the 30's hold anywhere near as much boost as the 25's? Your source of information is seriously talking out of their arse. Go back and tell them so.

from you guys whats your experiance with reliability with these things? what sort of boost do youse run? what sorta power u making? forged internals? basically is this true or not?

The peak power made is restricted by the head; however average power is up. The turbo spools earlier, gets on full boost earlier and simply pulls harder everywhere in the rev range.

As with all the rb's stock rods and pistons with the 'correct comp ratio' can be pushed to 300rwkw, much over that and you want to look at forged rods, pistons etc.

my plan was to get a responsive and reliable 400rwph... using innovative T04E, turbo back 3", cat back 3.5, fuel reg, arais forged pistons, eagle H beam rods, full balanced and preped bottom end, full preped head with minor port polish and strengthened valve springs.

Your missing one critical part... The full length oil pump crank collar drive.

The early RB's (R32 RB20DET, R32 RB26DETT, R33 RB25DET Series 1) all run a half length oil pump crank collar drive, these are well known as being the weak spot of any early RB.

A good heinz balance, full crank collar, crack test and it won't have issues to 7500rpm UNLESS there is a flaw within a rod that is missed. This is with any motor.

Much over that consistently (track) and I would seriously consider an aftermarket balancer such as an ATI item, as you would do so with any RB.

Regarding high revs and longevity; the higher you rev ANY motor the quicker it will die.

Gibson motorsport back in the days of their R32 GTR in Bathurst limited revs to 7000rpm.

[Sydneykid]

alright, been seriously considering this for some time, ok actually a very long time. mainly because i want my car to piss in the low revs.

i have since got the 30 series2 bottom and r33det head. BUT after talking to some builers they all seem to have the same respone... dont do it!

theyre main reason that they dont wona touch it is that the 30s dont handle no where near as much boost as the 25s. now im getting a bit put off the whole 25/30 idea coz i dont wona be afraid to rev my engine hard.

from you guys whats your experiance with reliability with these things? what sort of boost do youse run? what sorta power u making? forged internals? please help a bruvva out ive already got everything sitting in my shed, just waiting for the some good advice.. basically is this true or not?

my plan was to get a responsive and reliable 400rwph... using innovative T04E, turbo back 3", cat back 3.5, fuel reg, arais forged pistons, eagle H beam rods, full balanced and preped bottom end, full preped head with minor port polish and strengthened valve springs.

(pls dont be a chop and say read the 5000 previous pages)

thanx

I get really sick of hearing this crap, the truth is you if you rev the 3 litre to the same rpm as the 2.5 litre then the 3 litre will make 20% MORE power. Look at it the other way, you can use 20% LESS RPM and make the SAME power.

For example an RB25 that needs 9,000 rpm to make its power target compared to an RB30 that will make the SAME power target at 7,200 rpm.

Higher RPM costs more money, more money to build it , more money in diff and gearbox ratio changes, more money in more frequent rebuilds etc etc.

For the one millionth time boost is IRRELEVANT. Airflow makes horsepower, boost is simply a measure of resistance to airflow. A 3 litre flows 20% more air at the same RPM as a 2.5 litre. That means you CAN have lower boost and make more power.

Try them facts out on your engine builders

cheers

[r33_racer]

HAHA SK basically said the same beans i was going to spill...but he said it better. Except i would have said to go and tell those engine builders that they are wankers!

[AD4M]

just a quik question would anyone happen to have the arp (studs) part numbers for RB26 head bolts and RB30 mains bolts

need to get these asap so i can send my motor off to be machined

cheers

Adam

[r33_racer]

dont hold me to it...but i think they are all the same, main studs that is.

Head studs...well thats another thing.

Umm cant you just ask for head studs for a rb26 head and then main studs for a rb30? Thats what i did and thats what i got, except mine were for rb25 head.

[AD4M]

the guys at my local parts place luv it when i have model numbers thats all

last time i asked them for something for my 32 it took 4 trys hahaha

[shanef]

not sure about aftermarket studs/bolts, but for my head the engine builder (if you want a name just ask) said that rb25 headbolts were the ones that fitted the rb26/30 combo

[r33_racer]

umm ok name please

I think rb25 head studs are 11mm and rb26 are 12mm. Sure someone else can verify this.

[Scooby]

rocket have purpose made 25/26/30 head studs

[FORZA-MOTORSPORT]

HAHA SK basically said the same beans i was going to spill...but he said it better. Except i would have said to go and tell those engine builders that they are wankers!

Likewise Seriously those guys have no idea!

[shanef]

umm ok name please

I think rb25 head studs are 11mm and rb26 are 12mm. Sure someone else can verify this.

John Hill from JHH Engineering

[r33_racer]

John Hill from JHH Engineering

Where abouts are they? In the switch somewhere? or in brisbane?

We used a bloke at enogerra to do the machining for us Hagen Cylinder Head Reconditioning.

Yeh i dunno about some engine builders and their thoughts. They dont know so they assume, or they do know and are either lazy or have their own preference so they spill shit to make you think otherwise. Our tuner likes rb25s for whatever reason and didnt want us to do the conversion, but we did and it makes more power everywhere! First one they have seen and i think they were suprised at the results

My opinion is 30 hybrids pwn all! If you dont like it you know where to shove it

[shanef]

He's in slacks creek, right across the road from accurate suspension. He's known to build some of the toughest motors around. When i dropped my motor off he was working on a V8 engine that came out of a drag car, and when i went and picked my engine up he was just starting on a twin turbo conversion on a VQ35 (or what ever it is lol) so he know's what he's doing. He also does his own balancing in-house among other things.

I will definately be going back to him when i need the engine rebuilt again.

I just cant wait to get this adapter plate so i can get the engine back in and fired up!

[r33_racer]

I just cant wait to get this adapter plate so i can get the engine back in and fired up!

I bet. It shall be awesome.

[humz]

alright, been seriously considering this for some time, ok actually a very long time. mainly because i want my car to piss in the low revs.

i have since got the 30 series2 bottom and r33det head. BUT after talking to some builers they all seem to have the same respone... dont do it!

theyre main reason that they dont wona touch it is that the 30s dont handle no where near as much boost as the 25s. now im getting a bit put off the whole 25/30 idea coz i dont wona be afraid to rev my engine hard.

from you guys whats your experiance with reliability with these things? what sort of boost do youse run? what sorta power u making? forged internals? please help a bruvva out ive already got everything sitting in my shed, just waiting for the some good advice.. basically is this true or not?

my plan was to get a responsive and reliable 400rwph... using innovative T04E, turbo back 3", cat back 3.5, fuel reg, arais forged pistons, eagle H beam rods, full balanced and preped bottom end, full preped head with minor port polish and strengthened valve springs.

(pls dont be a chop and say read the 5000 previous pages)

thanx

ok guys some good enlightening info thanx,

so no one can say theyre are ne reliability issues with the 30, so basically you guys are saying the 30 is just as reliable as the 25 as long as youve done precautions such as good tuning and strengthened internals.

how bout comparing both engines in their factory form.. would they have the exact strength fundamentally?

i guess u can buy a crank collar from any good jap distributer, anyone selling one, what they worth??

also bought the bottom end rebuild kit today, should be sending the block away for acid bath, decking ect by friday, just waiting for cash for rods and pistons.

btw the builders really credible, its applied engineering in welshpool perth. i guess he might not know his rb30s well, or just really picky!

i think i might go ahead with it, and yee see what happens... you never never know, if never never go!

[humz]

SYDNEYKID

"For the one millionth time boost is IRRELEVANT. Airflow makes horsepower, boost is simply a measure of resistance to airflow. A 3 litre flows 20% more air at the same RPM as a 2.5 litre. That means you CAN have lower boost and make more power"

so whats the secret to creating max air flow?

port match n polish the head... ne thing else?

[r33_racer]

camshaft selection and valve size are two to look at.

[SLIMVLT]

its like bowing through2 straws.

1 is from maccas the other 1 is the small 1 u get from kfc.

you will get more presure with the small 1 than the big 1

but alot more air flow with the big 1.

no diferent with your head manifold ect.

the boost presure u get is a mesure of restriction, reduce the restriction reduce the boost and get more power.

[Cubes]

how bout comparing both engines in their factory form.. would they have the exact strength fundamentally?

In theory the rb30 should be stronger as it has a longer rod and better rod to stroke ratio, as a result there is less rod sideload.

Here in Adelaide one bloke pushed his stock rb30 bottom end to 370 something rwkw, another I know of I think on this board was pushing 340 ish rwkw and another in adelaide pushing 312rwkw on his $50 300,000km rb30.

As with all RB's the trick is to keep rev's in check.