Rb30/26Head Or A Rb28 Stroker

[R31Nismoid]

They are far better balanced than a GTR

A 280awkw EVO will easily keep pace with a 330-340rwkw GTR. Friend of mine has said EVO - they are light for a 4WD car.

The GTR is only faster due to extra RPM really but the EVO comes on boost almost as early with a turbo upgrade. That's saying something for a 2ltr vs a 2.6ltr - all in the head/variable timing etc.

Each to their own - i give credit where it's due and a EVO9 is the best platform at the 40k marker IMO if you wanna go fast without spending big coin as all you need power wise is to flash the stock ECU/injectors/exhaust/turbo/cooler piping and thats about it. Cheaper than a GTR would be to get to 340, 8 years newer etc. Also the bonus of the funky ECU business for yaw/diff control etc. Better brakes, tough gearbox list goes on.

Still prefer the RB scream @ 8,000 but if i was in the 40k region and wanted to go fast for under 50k without that nagging risk of rebuild - it'd be a pretty easy decision of the newer/stronger car.

[bubba]

I also give credit where credit is due, evo's just aren't my thing

If I wanted a newish car and to go fast and had a budget of 40-50k.. I'd probably be going for an LSx commonwhore with an exhaust, cam and tune.

[Trozzle]

I also give credit where credit is due, evo's just aren't my thing

If I wanted a newish car and to go fast and had a budget of 40-50k.. I'd probably be going for an LSx commonwhore with an exhaust, cam and tune.

Sorry but when deciding the "better" car, a straight line or dyno figure isn't what language we speak.

[gtr fan]

I agree with Nismoid that if I was looking for a car right now, its very hard to go past the EVO 9. They are pretty damn impressive.

But the 9 is a different kettle of fish to the evo 6.

[Nee-san]

A heavy car with an engine a bit too small in std form to make it a nice street car . Nissans sollution was to fit lowish gearing and a peaky engine because the only way to make the power was at higher revs . They had an agenda , they wanted to develop a homologation special and sized the engine to fit in a desirable weight class which is fine for the stripped out race cars . Not so good when you throw in air con/fast glass/sound deadening/sound system/and 101 other things to make a road car habitable .

Sorry people but you can't escape the fact that RB26's lack low down punch in a tonne and a half of GTR Skyline and the only practicle solutions are to 1)alter the state of tune to put the torque where its most usefull or 2) build in more cubes of which an RB30 short is the easiest route .

These cars are not true all wheel drives because they drive their front differentials with basically a motorbike clutch - not a center differential like most AWDs do . When you have a center diff , particularly with some sort of side to side "differential limiting devise" you can limit the differentiation and make them drive the front and rear diffs all the time and when necessary at different speeds .

It's not difficult to understand where Nissans engineers , back in the late 1980's , wanted to have a RWD based car with RWD handling characteristics and throw in a bit of front drive when the rear contact patches weren't quite enough .

BUT they started with a car that already a bit front heavy and proceeded to fit a transfer case/front drivshafts/front differential/half shafts/live front hubs and it got a lot heavier - and forward in the car .

Now weight is the enemy of performance because it pulls the power to weight ratio in the wrong direction , when you can't increase the engines capacity you have to increase the existing ones state of tune and then it loses that nice torquey drive it sedately feel . Not a problem in a race car but no one drives those on the street , they drive the porked out version with the number plates .

This is the reason why I think people are talking up 707160-9/GTSS turbos , they work better than factory ones and you can still impoove other things like heads cams exhausta etc and not lose anything nice but gain it . Sure it may not allow you to have 20 pounds of boost at 8000 revs but it gives you the all important torque down where its needed most between say 3 and 6.5 . I think people need to lose the idea that a lot of boost and a lot of revs is pig heaven , it may be dramatic but its a tiresome pain in the ass to live with unless driven flat out - like race cars aim to . You see cars on the street over done , cranky cammy no guts under 4000 with atrocious driving manners and horrific fuel consumption . Not surprisingly cops love them because they're easy prey and while you may out run them you won't outrun radio waves .

This probably sounds negative and not the right place to find fault with here ar SAu . The fact is that all these cars are what they are and its often impossible to iron out limitations the manufacturer built in - no matter how much money you throw at them .

I know where your at , I spent for the times lots of money trying to re engineer cars and it just runs you broke . I have three cars and they are very different and span from 25 to 11 yrs old , the GTS25T is 14 yrs old and the only Nissan and 2wd/RWD . The old 86 Subie L Series RX Turbo I had converted to AWD which was a quantam leap , but it made 120 Hp std and weighted 1070 Kg . Its possibly 140 hp/1060kg now and its at a point where throwing money at it is pointless . I had big ideas for the R33 but it can spin the wheels with mild mods so why push further .

I only drive on the street so what happens out 120 odd clicks is irrelevant - provided they can cruise nicely at that speed . To get the almighty rush up to 120 from rest is difficult because it forces you to try harder to make usable torque down low and get good traction at the same time . Suddenly you don't need a 4 inch exhaust or a billiard table sized intercooler , the turbo can be a similar configuration to the original one and the engine can be almost as smooth as a fresh factory one . You can afford to buy fuel AND food AND have a social life and not attract much attention from the whallopers though a lot of that depends on how you drive on the street - in anything .

I don't mind GTRs but unless really really rich I wouuldn't own one , I ended up with an Evo VI GSR and its the best Jap performance I could find out of the box in its 99-2000 era . Its a lot of car and because its rock stock factory standard , ok light Enkei wheels , I know the base line and know what can be gotten out of these cars for nothing like 10-30K .

This time around I don't aim to lose anything down low Mitsy built into these cars and to do this going from 206 to 240 odd at all four shouldn't be too hard . It weighs 1360 std and lost 10 of unsprung weight in just wheels .

At the end of the day I reckon you should buy the car that most suits you needs in std trim because the last mods are easiest and cheapest .

Your call , A .

Good Point disco,

But don't lose sight of the fact that:

32 GT-R 1.79CC/KG

Evo VI 1.46CC/KG

It's true Nissan did not develop the best platform for a comfortable road car, but that was not their aim, people have to reevaluate their expectations in terms of power, performance and street-ability and realise that after a certain threshold these things become mutually exclusive.

Further, the sort of base differences between they way world rally went (power restriction) and group A had a big hand in making the Evo such a lovely road car as it changed the vehicle dynamic towards something which is alot nicer to be punted A -B, now I get around the problem this way.

Drive a Corolla to work and to the shops and I drive my GT-R only when I want.

Cheers,

Mitch.

Edited March 8, 2011 by Nee-san

[bubba]

Sorry but when deciding the "better" car, a straight line or dyno figure isn't what language we speak.

I didn't say "better", I said if fast and comfortable was all the mattered then that is what the choice would be.

Don't treat me like a v8 driving, VB swilling bogan.

I love my Nissans and won't be straying from the marque anytime soon.

[PaulosECR33]

v8 commodores arent that fast, they are heavy... they make good power pretty cheap but they are boring and common and a lot o them seem to all have the same mods.. i have one, with all the common mods lol.. good daily..

at least with jap cars in general there is a chance for everyone to have something a little more unique..

[discopotato03]

A 6 is a bit smaller and lighter than a 9 for the same engine capacity . So the story goes Ralliart developed the versions 4/5/6 and Mitsubishi Heavy Industries developed the CE etc Lancers afterwards - not the other way around .

Mitsy was obviously keen to win the Group A based world rally championships which they did consecutively in 98 99 and 2000 . The 6 was the last of the true homologation specials because with the WRC or World Rally Car class cars the racers had more freedoms to alter things like suspension location points etc and the manufacturers could stick with what better suited production line processes with the 7-10 models .

The updates to the 9 or MiVec 4G63T are not hard to graft into any 4 or later Evolution Lancer , mechanically its mostly in the VCT head which bolts on and takes the same manifolds pattern wise . Actually the turbo is slightly different in that the cartridge is slightly bigger and the compressor housing and diffuser section is also a bit bigger . Both can be fitted though if you really want to , I guess its not unlike putting an R33 0r 34 VCT head on an R32 RB25 block only the VCT actuator line is external on MiVec engines and the passages line up .

I don't think the AYC rear diff is any great advantage and I'd rather have had the lighter less complex RS mechanical LSD , that shaves another 15 kilos off too .

Just on weight the RS version of the 6 is fully 100 kilos lighter than a GSR like mine but you get no stereo aircon or fast glass , the glass in them in thinner and lighter too . The 6RS and 6TME versions got titanium aluminide turbines which are a third lighter than the usual inconel ones and some had a slightly smaller compressor too . Still cranked out the same 206 Kw on 11 pounds of boost but the torque peak was at 2750 revs rather than the GSR's 3000 . This sounds low but you have to remember that the rally classes demanded from memory 32-34mm turbo restrictors and the works cars cranked out ~ 650 Nm of torque and the drivers were changing up at under 5500 revs .

The versions 7-9 made more power and torque but the peaks rose 500 revs in the road cars which is a lot in the world of production turbocharging . I'd say the 9 got MiVec because they were getting reasonably heavy and they couldn't go to 2.5L like Subaru has in the later Rexes , variable inlet cam timing would allow them to reduce the valve overlap at low revs and increase it at high revs giving more linear power delivery in a 220 Kw two litre four .

I know of one slightly later Evo thats cranking out 250 at the wheels and the unopened engine is 90% std externally too . Fuel exhaust the hot side intercooler pipe and a flash tune on apple cider .

They could port the head/use a better exhaust manifold/fit aftermarket cams but the things already a weapon and so much of it is factory . It drives like a std car and goes beserk from where a factory car comes on boost when flattened .

I reckon the big difference engine characteristics wise between a twin scroll 4G63T and an RB26 is that the 4G will come on boost earlier and pull harder sooner . All 6s got the largest 10.5 cm twin scroll turbine housing so they don't choke on the hot side .

Anyway I also forgot to mention I got my almost immaculate GSR6 with 12 months rego for 16.5K which is a lot less than the 40K for a 9 .

Anyhow we all like what we like and I reckon I got good bang for buck , cheers A .

[TristantheBaker]

Found an RB30 which runs well for $250...

Now I need to decide if I want the RB26 head from the car once I buy it, or ..an RB25 head..

Either way I'm prepared to do the work.

Can anybody recommend me a good thread regarding which conversion is better?..

Or a pros and cons list?..

I imagine the 25 head would be good with the VVT and all except the 26 would have a bigger combustion chamber...

Ah the decisions..

[NickR33]

You see cars on the street over done , cranky cammy no guts under 4000 with atrocious driving manners and horrific fuel consumption .

I didn't know you were from my area Disco, when did you see me? lol

seriously though, its a fine balance... you are over stating the cost and piggishness of a tuned GTR on the street... sure if your running a T88 or something on a stock capacity then yeah fine its going to be a painful drive

modern cars are easier and easier to drive and drive quickly... most are super quick from 0-100km/h and do so with little fuss... cleverly modded 90's jap cars can do just as well with sensible mods

however, that's not the point... I don't want an easy car to drive... I don't want a car that is really quick to the speed limit but feels flat when your really pushing... I want a car that takes skill to drive and on the rare occasion when the road opens up it thrills you... it sticks its hand down your pants and slaps you in the face... and when you get out your hands are shaking just a little bit

I don't want to race traffic, I couldn't care less if the guy in the X5 get's in front of me at the lights... I know if I really wanted to I could smash him but unlike when I was younger I no longer feel the need to prove it

also lag is only an issue if your not in the right gear... like those stupid tests Clarkson does when he sits in top gear and hits the gas at like 60km/h... use the gear stick, its what its there for

[Nee-san]

Look in the RB30 subsection at the top of the forced induction performance forum.

Put the 26 head on it.

[wolverine]

it sticks its hand down your pants and slaps you in the face...

That is an image that I am going to carry with me for the rest of the day. I am just not sure what is grabbing me and what is slapping me.

[PaulosECR33]

26 heads have solid lifters

25 heads i have HEARD have bigger ports... dont quote me on the ports though

[Harey]

26 heads have solid lifters

25 heads i have HEARD have bigger ports... dont quote me on the ports though

25 neos have solid lifters too

[PaulosECR33]

25 neos have solid lifters too

ah yeh. my mistake

[dorifticon]

If you have the room in your engine bay for the adapter plate, (and the $$) I reckon a 6-throttle rb26 intake mated to a VCT-rb25 head, bolted to a rb30 block would be a wicked setup.

ah yeh. my mistake

[US05LW]

rb30/26 the way to gooo !

[ohno1]

since everyone's just dribbling shit in this thread anyway..

anyone aware that nismo produce a rotating assembly that'll do 2771cc capacity on a 26?

http://www.nismo.co.jp/en/products/competition/engine/rb26dett.html

crank is ~300,000yen which is about 3800$aud

[TiTAN]

it was probably developed for use in the Z-tune engine

[robincooper]

since everyone's just dribbling shit in this thread anyway..

anyone aware that nismo produce a rotating assembly that'll do 2771cc capacity on a 26?

http://www.nismo.co....e/rb26dett.html

crank is ~300,000yen which is about 3800$aud

Love the look of that intake collector!