Rb30det/tt Vs 2jz

[Cubes]

Power to weight ratio mate, that's why he's running them times.

That's why i want to compare engines as is, not engines in the cars. The engine might be stock, but everything else also counts towards 1/4 mile times, i.e suspension setup, weight etc. In the end of the day that gives f*ck all of a comparison.

But regardless.... 144mph compared to 134mph is a hell of a difference.

Unique Autosports 300zx which is of similiar weight to the Supra ran a 10.79 @ 139.4mph with 456rwkw.

[GTR-026tt]

I guess we have to Email Top secret and ask him why he put a Rb26 in his Supra!

[Alf]

Dont forget there are 3.4L stroker kits available for the 2J.

[NYTSKY]

Reading this makes me want to put a 2j in my 33

[nizmo_freek]

Dont forget there are 3.4L stroker kits available for the 2J.

Someone in the U.K is said to be making a 3.3ltr rb30 as we speak

[Warpspeed]

The thing that makes the 2Jz superior is the crankshaft design and the extra capacity, and only that.

RB30 was available for Nissan to use in the GTR if they had wanted to. Why do you suppose they only used the RB30 bottom end on the low revving Australian "taxi" engine.

Nissan could have built a twelve counterweight forged crank, and built a factory RB30DETT for the GTR easily enough, but they chose not to. The RB26DETT is a much better balanced overall design for a high revving endurance race engine. Its competition success and reliability speaks for itself.

While hot rodders can certainly extract big power from an RB30DETT combination, it would never stand up to something like a full Bathurst race, or the Le Mans 24 hour race.

Very big difference between a 1/4 mile back yard hot rod engine, and a serious professional long distance endurance race engine. Why do you suppose there are no long stroke Formula One engines ? Given a choice, big bore short stroke is a better lower stressed package.

The biggest weakness of the RB30 is its long throw spindly uncounterweighted crank, and the torsional vibrations it produces. The shorter throw RB25 and RB26 cranks are far stiffer because of more main/big end journal overlap.

So yeah, the RB30DETT makes a great street and drag race engine, just don't confuse it with a thoroughbred professional race engine.

The 2JZ is a better long stroke DOHC design simply because it was originally designed for high performance, the SOHC two valve RB30E and the later RB30ET were not.

Edited February 17, 2007 by Warpspeed

[Cubes]

That being said The GTR at bathurst during the early 90's were limited to 7000rpm so they could make the distance safely.

[foznice]

I thought the 2.6litre bottom end was used as it was the maximum capacity allowed as per the rules in some Japanese racing league? Thats only from what I've read here so it could be total BS too.

[Roy]

If Nissan had gone for any bigger displacement they would have been classified differently, and i recall it would have meant an increase in minimum weight for homologation...look at the old 3.0L Supra. It raced in Grp A but was a dog because of the minimum homolgated weight it was forced to run because of its engine displacement yet only rwd. Hell even Holden de-stroked the 308 to 304 for exactly the same reason

Wanting to run 4wd the car was going to be heavy for the class (Based on cc) it wanted to run in...so accepting the weight of the 4wd system they bumped up displacement to suit the class where it would be more suitable.

So saying Nissan didnt chose 3L for any other reason then homologation to Grp A...well i believe is wrong. Ditto LeMans, hell they stroked the 2.6 to 2.8L so that they could get maxmum displacement as per their class. Again they would have probably loved to go 3L but the regs would not allow it to run in the desired class

[Roy]

Can someone comment on what sort of valvetrane is used in the 2JZ, solid, hydraulic?

[Cubes]

Solid.

They are a better designed motor. Just a pitty they are heavy arsed and have old school design interiors.

[Roy]

Id rather the RB26 plenum and throttle bodies

[psybic]

wrong

Please have a search, it has been debated before and proven (flow numbers and all) to be a load of crap that the 1jz head is better than the 2jz head

Pretty much

Thank God someone said it.

This has been a bad debate. I was expecting something better from this forum. All this my mate this and my mate that.

The only real comparison would be stress testing in a controlled environment. Even then, you'd need a good number of test engines from each manufacturer.

I doubt any one is going to line up 10 RB30with RB26head, and 10 2JZGTE's, then give those cars the same turbos and supporting mods. Then put them in the same car and run then tune them the same ( that would be hard to do... ) then stress test them and post the data.

These engines are often in different cars, with different turbos, with different exhaust and fuel setups with different ECU's. One of them isn't even from the factory, so rarely found in even close to the same setup as another just like it.

Whats the point of the question? If you want an engine in you skyline, put an RB, simply because it fits.

If its for a Supra, leave the 2JZ, because it fits.

Obviously both engines are capable of plenty of power with $$$ thrown at them.

Myth busters can help us out perhaps...

[Warpspeed]

Yes and no.

Engineering is all about calculating stress and fatigue limits, and staying within known and reasonable bounds.

The guys that design and build bridges and high rise buildings do not build whole bridges or buildings and then test them to destruction !!

There is a lot you can tell by just calculation, or these days computer simulation. Crankshaft resonances and harmonic damper (balance) design is not a hit or miss affair. Neither is the correct sizing or placement of counterweights just guessed at.

No need to place an engine on a dyno and flog it to death for hundreds of hours, although the big car manufacturers still regularly do this as routine with their new designs.

I doubt if any aircraft flown today is actually stressed to the point where the wings rip off, just to see what speed that actually is. Engineering has come a long way over the last few hundred years.

Yet drag racers will build and run an engine on the strip until it breaks. Then try again. "If you ain't bustin stuff on the strip, you just ain't tryin hard enuff".

But most of these guys are not real engineers, and would you trust these blokes to design a passenger aircraft in which your family would fly?

[slip]

You can compare motors all day, but you have to come back to reality as well.

Even if the 2J is a better thing if you just want to slap a big single on there with minimal internal prep - is it worth going through the hassle of putting one in a skyline?

Probably not. But that depends on the level of the build, the budget, and time available. LS1+TT R34 drift car that has been built was a full house thing, whereas most of the time the $$ used for a conversion like that would be better spent on current equipment/support systems etc.

2J's aren't cheap either.

You need to look at all the factors in a situation like this.

[The Mafia]

Think about it - to get a RB26 \ 30 to have as much power as a 2jz as safely as a 2jz, you'd need to spend $10,000 to $15,000.

Easier to buy a 2jz for around $4k - $5k? And standard.. will run up to 500rwkw..

....

[Fitzpatrick Speed Works]

Threads like this make me laugh. Always good value and plenty of input from a bunch of people with little to no use for the real facts, with the real facts provided by the people who actually know what they are talking about ignored, and the useless comments like the one above argued till the cows come home.

[The Mafia]

and the useless comments like the one above argued till the cows come home.

no need to be a jerk. Its comments like yours that ruin discussions thinking you know all and that your shit doesn't stink?

Tell me where you've seen a standard RB26 head, and a Standard RB30 bottom make over 400rwkw?

Not a chance.

My best mate, not a guy that I barely know, a guy that I hang out with all the time, visited his car on the dyno, raced beside him down the strip, and uploaded his videos onto youtube for him has a stock motored Supra making 450rwkw. no aftermarket cams, nothing. Head hasn't NEVER been taken off. Compression test revealed the engine being within 5% of a new motor, and it runs 10's in a car that weighs a lot more than a skyline or VL turbo.

we are looking way too much into this - a guy wants a cheapish reliable motor to make big power and the 2jz wins in that regard hands down.

He's got a choice - spend well over $10,000 on a RB26\30 or spend less than that for a motor that can do the same, standard setup.

[fEkuaR]

^^ agreed the debate is to what has more potential and with standard set ups the 2jz is without a doubt the best option when it comes to bang for buck.

[TSL]

The main problem with these sorts of topics is the original question is not defined clearly enough and then everyone comes up with hypotheticals to suit their argument.