1JZ vs 2JZ - How do they compare?

[bedlam]

Ah you see we are finding more Q's now than answer Syed....why this and why that now why wont Mr T come on here and enlighten us all and explain why he had Yamaha do something to the 1jz and not to the 2jz..why would someone put a 2jz block onto a 1jz head unless like i say the 2jz head was bust..why am i saying why all the time..

 

And yes it is nice to see that there IS an alternative to them AHEM! hybrids..and a GOOD alternative as well.. i just wish someone would get back to me .

 

andy

[Syed Shah]

The reason to fit the 2JZ block to the 1JZ head: When you break a 1JZ block, it is a lot cheaper to buy a new 2JZ block instead.

 

Yes, that vid definately made it look like a good alternative. What size turbo is it? Get back to you? You looking at doing another single Soarer?

[bedlam]

Yes but if i own a scrappy you aint getting any block unless the head is knacked ..i dont know any breaker that would split a good engine..

 

Anyway i dont think anyone has won this one if it was a contest to find out if the 1jz is a better head than the 2jz since no one knows for SURE if that is the case..and no one said it was DEFF a better head well somone once did but he aint here..

 

And the turbo is the same as Terrys the T61 and yes there is a queue forming which wants the kit it has transformed the car completely..much more controlled power on it and more linear.

 

Andy

[Syed Shah]

No, I mean Toyota price. A new 2JZ shortblock is 2k USD from Toyota, an appealing option to those who have broken a 1JZ block.

 

Yup, your right, we still have no definative answer, but I am fine with that, we can all believe whatever we want to believe. Sure the truth (eirther way) will out in time.

 

Queue forming indeed! I will certainly be on it when the stockers blow (same witht he Supra). T61 sounds like an ideal road car turbo, definately looked good in the vid lag-wise. More linear? Compared to hybrids or stockers? Stockers feel perfect in that respect to me.

[bedlam]

Well the T61 is based on the garret but it aint a garret..and linear i mean the pwoer delivery compared to hybrids..we had our hybridfs up at 400+..and it did nothing for the 1st 60feet then all hell broke loose..but once it neared the end of a 1/4 it was petering out..this is very diff..launch is very diff have to launch this at 2,600 compared to 2,200 on the hybrids due to the hybrdis bing more efficent at lower boost levels..but we could never stay with a oem turbo'd car with hybrids now we can, as you saw in the vid.

 

Andy

[Guest ChrisB__1]

I read about your budget kit on LSOC, sounds very good. Nice to know a single is more affordable now when the stockers blow, certainly more appealing than hybrids.

 

Are you so sure? I'm the one who runs no restrictor in the exhaust. I'm the one.

 

Turbo Technics might have their workflow "dynamics" but they know their shit. Powerhouse still use them and they're happy.

 

Chris.

_________

jzz30 '92

UK

[bedlam]

Someone just mentioned turbo technics i will now ignore this thread completly

 

 

Andy

[Syed Shah]

Are you so sure? I'm the one who runs no restrictor in the exhaust. I'm the one.

 

Turbo Technics might have their workflow "dynamics" but they know their shit. Powerhouse still use them and they're happy.

 

Chris.

_________

jzz30 '92

UK

 

Single is more appealing to me than hybrids. But hybrids can obviously still be appealing to you. They do have upsides (insurances for one). It depends on your goals.

[Steven Cordiner]

Wow ... didnt intend for this thread to take a leap to one engine vs another lol (although the title may look that way )

 

The heads are likely to be different. The 1jz I now know is a short stroke engine designed from factory to make peak hp at a higher rpm than the 2jz. Its not a matter of better or worse, they're just designed with a different aim.

 

At the end of the day, if you take any head and throw the cash at it it generally matters little which one you use.

 

Oh, back onto the big single talk. Is that big single kits for a soarer?

[Gamer]

Oh, back onto the big single talk. Is that big single kits for a soarer?

 

 

Correct, Bedlam should be able to fill you in on the details ...

[Chris Wilson]

Until someone shows me proper flow bench figures for both heads, and chamber volumes et cetera i have yet to see anything other than "X is better than Y" posted re the 2 heads, and that makes it impossible to form an unbiased opinion. For a road car the 2J engine has it as the extra torque from the longer stroke is what 99% of road cars need. For a competition engine I'd favour the shorter stroke engine *IN A LIGHT CHASSIS*

 

Both are inerior to the RB26 engine, as they have single throttle bodies and a stock RB26 head and manifolds flows better than a stock 2JZ-GTE head and manifolds.

[garethr]

I don't think there's any doubt about the Yamaha connection, but I'd love to find out how many of the 1JZ myths are true

 

1) Is the head better than a 2JZ?

2) Do they have forged pistons?

3) Is the crank made from exceptionally high-grade steel?

4) Because of the above, will the stock 1JZ take more power than a stock Skyline RB25DET?

 

and here's another question.... would it be possible to persuade one of the budget single kits to fit the N/A 2JZ-GE in a 3-litre Soarer?

[bedlam]

Steven

 

No it was a kit for the supra i had altered And may be on sale at another date for the Soarer..but i am now lacking a response from certain parties.. I have a walkthrough for the fitting of the kit but if the kit for the Soarer sees the light of day who knows.

 

I do have to add the alterations to the supra kit is not something that could have been done in the street ..but it wasnt rocket science :0.

 

Andy

[bedlam]

gareth

 

 

would it be possible to persuade one of the budget single kits to fit the N/A 2JZ-GE in a 3-litre Soarer?

 

I couldn't see a market for the kit with the 3Ltr Soarer over here as they are very rare models over here maybe in the states yes but not here.

 

For the TT yes lots of sales out there, and it has now been done.

 

Andy

[Chris Wilson]

I don't think there's any doubt about the Yamaha connection, but I'd love to find out how many of the 1JZ myths are true

 

1) Is the head better than a 2JZ?

2) Do they have forged pistons?

3) Is the crank made from exceptionally high-grade steel?

4) Because of the above, will the stock 1JZ take more power than a stock Skyline RB25DET?

 

and here's another question.... would it be possible to persuade one of the budget single kits to fit the N/A 2JZ-GE in a 3-litre Soarer?

 

1) Better for what? A 2.5 bottom end? Parallel twin turbos? Low speed torque? High RPM power? With stock cam duration and lift, or with other cams? Better boat anchor...? Not specific enough a question to be answerable, even given flow bench data.

 

2) No

 

3) Nothing special, normal cast crank

 

4) RB25DET is boost limited by its very high static compression ratio, what compression is a stock 1JZ TT?

[Gamer]

what compression is a stock 1JZ TT?

 

 

Displacement, cc 2491

Engine model toyota 1jz-gte injector size-380cc

Max.power (Net), kw(PS)/rpm 280 ps (205.94 kw) / 6200 rpm

Max.torque(Net), N*m(kg*m)/rpm 37.0 kg*m (362.85 N*m) / 4800 rpm

Power density 5.57

Engine type Serial 6 cylinder DOHC24 valve IC twin turbo

Fuel system EFI (electronic fuel injection)

Turbocharger Twin Turbo with intercooler

Fuel type Unleaded premium gasoline

LEV system (Low emission vehicle) No

Compression ratio 8.5

Bore, mm 86

Stroke, mm 71.5

[Chris Wilson]

9.00 to 1 on RB25DET, so the 1JZ should take some more boost before det on normal pump fuel becomes a problem. Both are competent engines. I have a GENUINE as in engine dyno 500 BHP on pump fuel RB25DET engine here. Hydraulic cams, dropped CR (8.4 to 1), medium size single remote W/G turbo, stock bottom end save for decent rod bolts, bigger injectors, Power FC, been totally reliable, ran very low 11.00 seconds at some drag run last year in a stock full weight R33GTS-t shell on normal (cheap) road tyres. Was amazed the engine wasn't more modded internally.

[Gamer]

Sounds like a nice set-up

[JohnA]

I've managed to read the Mycroft 'paper' up until he advocated the use of Slick50.

I could pretend I didn't see the odd typo and misuse of apostrophes, but when it came to Slick50 I drew the line. Someone has to be clueless if they advocate the use of this product (and there are no commercial interests involved)

 

Sorry Mycroft, but my Zero or Hero score currently stands:

Hero - zero

Zero - one

[garethr]

Those were just some of the assertions I've seen on various forums. I'm sure there must be more, and I'm sure that every "enthusiast's" car has a similar collection of myths and half-truths.

 

As long as it goes, and I know that if I want to I can create some extra horsepower for "bench racing", that'll do me

[Guest ChrisB__1]

hey guys.. I have some airfield videos with audio of what a Soarer can do to a 100 with just simply an exhaust on CT12a turbos with larger wastegates to control the boost to 1 bar. Please note that this run included wheelspin in 1st (hence the strange gearchange to 2nd) and was not with a stalled autobox start.. just counted (video frames) from when the rev counter moved a muscle right up to the top.. 11 and half seconds to 101mph from standstill. This is a conservative figure of course due to the slow off the line start.

 

http://www.planetgt4.com/0_100_2nd.mpg

 

Let me know what you think.

[Syed Shah]

Better then the RB25? Don't know. But the 1JZ is more than competiton for the Skyline GTS-Ts and GTTs, changed the views of a few skyline owners.

[Bobbeh]

Good vid. Now lets see some of yours and less of Knight Riders motor

[Guest ChrisB__1]

oh.. was reading up on the mkiv site over in NZ:

 

http://mkiv.supras.org.nz/articles/speed12_2.htm

 

There's a tuner who's done an 8 second GTR who discusses the 1JZ head and flow characteristics.. 2nd page.

 

Another one for the mixer eh?

[Miguel]

Just another for the mixer . Do you not think that the reason that the soarer guys keep the 1jz head and swap it on to a 2jz bottom end is because they want to retain the stock turbo workings and manifolds of the 1jz??????? They would not be able to to this if they used the 2jz head as the manifold stud paterns are all in a different place . And that it has nothing to do with flow/ being better .....Its just that its easier work to do this than convert its over to 2jz running gear!