The Ultimate Rb.

[FineLine]

We,ve seen some mighty impressive builds over the years on these forums but to my mind I dont think we've seen how good it can get yet.

In conversation with my builder and tuner the other day I came up with what I believe would be the formula to creating an RB with the power and torque characteristics of a wild big block V8.

A nitto 3.2 (or other) stroker kit for the bottom end to give max cubes for better torque and response crowned with a well prepped head with all the hardware to rev comfortably around the 8000 rpm mark fitted with a hks variable cam system To again improve response and midrange without sacrificing top end power.

I like the idea of the quick spool valve currently being debated in the forced induction area. This mod along with the extra cubes and the variable cam arrangement should see an engine capable of carrying a rather large turbo in the vicinity of a T51R with the ability to show reasonably early boost numbers And some very impressive midrange power and torque figures.

Turbo size and make would be discretional, I only used the garret to give an indication of size and I would probably look further afield for the right turbo for the job. I believe garret are going to be left behind in the next year or so as the new generation of turbos start to show their wares.

Has anybody built an engine incorporating all these features and if so, what was the result.

I may build it myself some time in the future. Ireckon it would really kick arse and take names.

Thoughts and ideas Peeps ?

[GTScotT]

There are a couple items I would like to bring to light, considering the extent of your suggested build, you could ditch the HKS Vcam setup.

Costs involved in prepping a RB26 head would be close or equal to that of an RB25 head, which has native VCT. No need for expensive Vcam setups. The advantage of the Vcam is applying it to your existing big budget build. In this case with custom manifolds on both hot and cold side the RB25 head would be at no disadvantage to the RB26 head.

Secondly I would like to note that the quick spool valve is still under heavy scruitiny and a conventional TS setup would be the safer bet.

[zebra]

Mine would be (given infinate moniez) would be a Bullet cylinder heads Billet alloy block with a 90mm bore and a custom Billet crank/rods giving something like 3.6L, with a CNC ported RB26 head, custom cams, big titanium valves, Twin GT-RS turbos with 11:1 comp and running on E85, and of course Dry sumped...and if we are going a billet block, might as well have a nascar style billet sump with pump incorporated into the pan

ala this

[Deano 1]

Mine would be (given infinate moniez) would be a Bullet cylinder heads Billet alloy block with a 90mm bore and a custom Billet crank/rods giving something like 3.6L, with a CNC ported RB26 head, custom cams, big titanium valves, Twin GT-RS turbos with 11:1 comp and running on E85, and of course Dry sumped...and if we are going a billet block, might as well have a nascar style billet sump with pump incorporated into the pan

ala this

put it all into a GTR and the first launch you do the alloy block will spilt in half.....

[zebra]

put it all into a GTR and the first launch you do the alloy block will spilt in half.....

Rated at something like 2000hp, so if a thin wall cast iron block doesnt, than a billet alloy one wont.

[FineLine]

There are a couple items I would like to bring to light, considering the extent of your suggested build, you could ditch the HKS Vcam setup.

Costs involved in prepping a RB26 head would be close or equal to that of an RB25 head, which has native VCT. No need for expensive Vcam setups. The advantage of the Vcam is applying it to your existing big budget build. In this case with custom manifolds on both hot and cold side the RB25 head would be at no disadvantage to the RB26 head.

Secondly I would like to note that the quick spool valve is still under heavy scruitiny and a conventional TS setup would be the safer bet.

I'm not going to debate the merits or otherwise of the quick spool valve here, there is a thread on it already, Suffice to say I like the idea but to each his own.

You are correct in your 25 v 26 head comparison though,. There is farkall difference between the 2 other than bolt patterns and the vct setup. The neo head would be the way to fly as it already is solid operation.

The build isnt about making 2000 hp but I believe an RB could be built to make 700 plus hp and still be a real torque response monster if all the technology available was applied.

Interesting to hear others ideas. Obviously I am not the only person thinking along these lines.

[jarrod83]

It does sound like it would be a mean setup.. but a big turbo is always going to feel like a big turbo and not a responsive v8

I have a rb30 with a gt35r and its pretty damn responsive, but it really cant compete with v8 torque anything under 3200 rpm even tho its making 12psi of boost there, it just doesnt make the torque/hp until the turbo really gets going at 3500+... theres also that slight delay before you come onto boost when you put your foot down even when your high up in the rpm.

Jarrod

[rob82]

Stop pissing around with old technology and buy an FG XR6T engine put a TO4Z on it and throw it into you skyline!!! Raise the comp to 11:1 and e85 you'll have around 850rwhp and 1500N.m of driveline assholing torque!

I've made 740rwhp (around 1200N.m) on a BA with a T04Z @26psi on e85 with a comp of 8.6:1 and variable cam timing that isn't independant. Boost came in very strong with 26psi@3500rpm reving to 6400rpm - peak power around 5800rpm however. You add 11:1 comp, independantly variable cams(FG) and a better intake manifold(FG) on the same setup I would think that the above figures wouldn't be out of the question. With a boost threshold of about 2800 and peak power around 6000rpm and a slightly more workable torque curve.

[tridentt150v]

your final setup would depend on whether you are making a road or track unit, you can see this in the answers already.

I'm also not so certain that you need Neo heads, plenty of VCT 25's that rev it up these days, I think the prep is the answer, after that it starts to level out [unless you are building a dedicated all out racer, then the need for VCT is a moot point]

Has anyone explored using a 370Z motor in an RB based skyline, might make a good base???

[FineLine]

Stop pissing around with old technology and buy an FG XR6T engine put a TO4Z on it and throw it into you skyline!!! Raise the comp to 11:1 and e85 you'll have around 850rwhp and 1500N.m of driveline assholing torque!

I've made 740rwhp (around 1200N.m) on a BA with a T04Z @26psi on e85 with a comp of 8.6:1 and variable cam timing that isn't independant. Boost came in very strong with 26psi@3500rpm reving to 6400rpm - peak power around 5800rpm however. You add 11:1 comp, independantly variable cams(FG) and a better intake manifold(FG) on the same setup I would think that the above figures wouldn't be out of the question. With a boost threshold of about 2800 and peak power around 6000rpm and a slightly more workable torque curve.

If i were going to go to that trouble I would throw the ford engine in the harbour and grab the nissan 4.8 with a brian crower stroker kit.

Neither of them address the thread topic however.

Its about RB engines, You know, the ones that actually bolt in to skylines.

[Roy]

Interested to see the figures of a well prepp'd RB6 head vs anything that has come out the last 5 years. I suspect the ultimate RB will be ribbish compared to what the VQ etc heads can flow these days

[FineLine]

I've no doubt they would flow more Roy but the RB head should never be under estimated in terms of its ability move air.

The trend around here atm is to lay off the mega port jobs in favor of more refined work in the chamber and a minor port tidy up to keep the velocity high for better spool.The guy that did my head sat me down and turned my ideas upside down by steering me away from major porting and a few other things.

He compared the fabled yamaha designed 2J head to the rb and highlighted the fact that the ports are already larger in the RB.

Just do the right touchups in a few spots and some secret squirrel shit in the chamber and the Rb head will flow all I ever need without sacrificing air speed.

Heads are not a limiting factor in building a tuff rb engine.

[Roy]

Engine efficiency etc has come a long way the past 20years and an RB26 head will get the job done...but my money would be on a VQ25 with the right bolt ons giving it a hell of a run for its money

[FineLine]

Engine efficiency etc has come a long way the past 20years and an RB26 head will get the job done...but my money would be on a VQ25 with the right bolt ons giving it a hell of a run for its money

I'm not argueing with you Roy, i agree completely but, Until such time as I can bolt a pair of VQ heads on to an Rb block They remain out of the running in the quest for the best RB donk.

[Roy]

LOL...ok. Ultimate RB in my eyes really depends on what car you are putting it in. What yo uhave spelt out would be a good thing in a GTR...if its were a rwd platform I would be focussing on making the turbo as small as you really need and throw bigger housings on it so that the thing doesnt ramp hard onto boost and has a flatter torque curve

[FineLine]

Agreed, It would require an awd setup to utilise the type of power torque setup I envisage.

Oh for an unlimited budget to be able to experiment with this type of stuff.

[Nee-san]

I've no doubt they would flow more Roy but the RB head should never be under estimated in terms of its ability move air.

The trend around here atm is to lay off the mega port jobs in favor of more refined work in the chamber and a minor port tidy up to keep the velocity high for better spool.The guy that did my head sat me down and turned my ideas upside down by steering me away from major porting and a few other things.

He compared the fabled yamaha designed 2J head to the rb and highlighted the fact that the ports are already larger in the RB.

Just do the right touchups in a few spots and some secret squirrel shit in the chamber and the Rb head will flow all I ever need without sacrificing air speed.

Heads are not a limiting factor in building a tuff rb engine.

I think alot of people will be surprised to find that due to the enormous scrutiny placed upon the emissions of vehicles today that alot of the great engines being designed currently are being strangled and held back from completely realising the potential that knew technologies can afford.

In contrast, we must also note that 99.99% of all technology used in ICE's currently and in the future was and has been developed 50+ years ago and not primarily in the automotive sector....

I'll also add that there is actually no black magic with how various heads perform, in the end it all comes down to how big your holes are and the various architectural geometries of the valve train.

PSS.

We all know that the ultimate combo for the JZ engines is to have a 1J head on a 2j bottom end this sort of disproves the notion that the JZ engine is the be all and end all of I6's, and for comparisons people should really be looking at output/displacement which is where you start to see alot of the bigger engines (BARRA etc) fall down in comparison.

Anyone can make more power given an infinite supply of cubic displacement but that's not how it rolls in the real world peeps

[Roy]

How do the front diffs, shafts etc go (gearbox and rear end) go when you throw all that torque at them? I think the 3.2L, 3.4L bottom ends getting around must go close to being drivetrain killers?!?!?!?

[r33_racer]

I guess we wont find that out until someone does it and pushes it to the limit and finds what breaks. But safe to say if it does and you got lots of money you can always fix the weak link/s.

[NYTSKY]

There is an RB being built at the moment that will be a first in the world!

Cant say too much but what i can say that it has been engineered and built here in Australia.

But if had a billion dollars i would have the bottom end made from titanium