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1JZ vs 2JZ - How do they compare?


Steven Cordiner

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Hi guys,

 

I was wondering how the 1JZ and the 2JZ engines compare in terms of strength. I know the supra 2JZ-GTE lump is incredible when it comes to making power, but whats the 2.5 liter 1JZ like in comparison?

 

Do they share a very similar design just different displacement?

 

Any info would be appreciated!

 

Oh, I'm referring specifically to the 93-97 non VTi engines

 

":: Engine Data for the JZ engines below

 

 

1JZ-GTE

93 – 97

2491cc

8.5:1

280 @ 6200

EFI, Air/Air Twin Parallel Turbo

 

2JZ-GTE

93 – 97

2997cc

8.5:1

280 @ 5600

EFI, Air/Air Twin Sequential Turbo

"

 

 

Thanks

 

Steve

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They are almost the same engine internally... the 1JZ is just as strong. For the 2JZ Toyota basically stroked the 1JZ engine to make it 3 litres. The advantage of this is more torque, but the downside is less willingness to rev and can't rev as high. The turbo system difference you've already mentioned in your blurb above.

 

I have a super rare mk3 manual with 1JZ-GTE :D

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The head on the 1jz appreanlty flows better than the 2jz.

 

i've never seen any figures to prove this, and i'm not really sure why toyota would move on to design a worse flowing head. have you got any data on this? i heard yamaha had a hand in the head design.

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Yes yamaha did have a hand in the top end of the engine it's stamped on the front timing belt cover...and if you go here..and do a search you should find info on the head....

 

http://www.lexus.australia.as/

 

Thats why some people do the 1.5jz cause of the better head design on the 1jz there are a few in Aussieland..i guess thats why a 2jz manifold WON'T fit a 1jz head.

 

And no i dont know why they would alter the design in the head..and like you say go backwards.

 

 

Andy

 

OOPS

Fourm is being updated..try here....

 

http://www.planetsoarer.com/

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There's some info here .......a 1JZ soarer/Mkiii supra is an option i'm considering myself......

What a lengthy read! :blahblah:

 

Some real controversial stuff by Mycroft on why the 1JZ is a better engine than the 2JZ :rtfm:

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I did say allegedly .... :)

 

Yamaha have a relationship with Toyota which extends from the 1967 Toyota 2000 GT (Bond is rescued by a Japanese girl driving a built-for-the-film convertible version in "You Only Live Twice") to the current F1 cars.

 

Yamaha were originally a maker of wind instruments (the Yamaha badge is crossed tuning forks) and presumably acquired an excellent knowledge of gas flow.

 

Toyota_2000GT

Toyota_2000GT.jpg

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garethr - I see you have a soarer TT, thats the particular car thats making me look at what these engines are like :)

 

Is it easy enough to buy aftermarket exhausts, decats etc for the soarer tt in the uk?

 

It's obviously much easier to get stuff for the 2Jz, but .....

 

You can get decats in the UK (but in the end it's just a pipe, so any exhaust fabricator should be able to make one).

 

Dump pipes from Oz.

 

You can make a cold air intake (otherwise known as a BFI -- Big F**** Intake) or buy one.

 

gamer (who posts here and on TIF) and Bedlam (on LSOC) have single conversions.

 

 

There are quite a few cars running decent power with the twin turbo set up, either the original ceramics, hybrids, or aftermarket kits

 

Useful links

LSOC http://www.lexusclub.co.uk/

TIF http://www.toyotaimportsforum.co.uk/

ALSC http://www.alsc.aus.as

Planet Soarer (BFI) http://planetsoarer.com/

mkiiisupra.net http://www.mkiiisupra.net/ (the 1JZ was also used in the MkIII)

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The 2JZ is stronger, with more parts for easy tuning.

 

The head stuff is all crap smoke and mirrors stuff IMHO. Made up by a fool, and believed by those eager to believe. Someone prove me wrong, until then, don't mention it.

 

The 1JZ is VERY nice, but for ease of modification both with and without stock turbos, the 2JZ has it every time. Toyota didn't fcukup and downgrade with the 2JZ, it is not a wonder engine for nothing.

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Syed

 

and believed by those eager to believe

 

chill it out mate..no ones eager on anything everyone in the soarer community knows you and our lad mycroft didnt get on well ;)..but I for one aint eager to believe anyone...but i do wonder why people use the head from a 1jz and put it on the bottom of a 2jz and since you seem to put your "IMHO" accross nice and strong maybe you can let us know why .

 

 

Andy

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Thanks Term, not in a fence mood today ;)

 

Andy,

 

I have NEVER known anybody to remove a 2JZ head and replace with a 1JZ head. I have only known people to replace the 1JZ block with a 2JZ block after breaking them (not at engines fault may I add). If the 1JZ head was the wonder it is proclaimed to be (by someone incapable of telling parallel twins from sequential, lol) why is that?

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Syed

 

Now i wonder why someone would keep the head from a 1jz and stick it onto a 2jz block unless the head from the 2jz was fecked.

 

And yes i know he got that well worng :) but like everyone else we ALL get things worng and i can prob find lots saying your a nut having a BOV on your car like i can find lots that will say yer a nut without a BOV.

 

Andy

PS

And no Syed i aint sticking up for mycroft i know hes a little wacko myself.

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I think it would have been done if the head was superior by now personally, especially in the US, where the drag racers would love more head flow (moot point to the rest of us, as both heads are adequate for anything on the road).

 

Lol, the mycroft stuff is fair enough, the debate is between us, not personal feelings one way or another.

 

Straight question to you: Do you honestly feel the 1JZ head is superior to the 2JZ head?

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Not having looked into the 2jz head... i do know that the heads have to be diff as you cant interchange the manifolds as the ports and studs are a little diff..since i just fitted the supra budget kit to our car..now why would toyota have changed the head config..and why does the 1jz have the yamaha on the cover and not on the 2jz..

 

Asking me if i think the head is better is neither here nor there i am sure i would then find lots saying i was talking crap..which i sometimes do :) but thats an age thing..i also know now that you can have the wastegates altered on a 1jz turbo setup have a 3" exhaust and have no restrictor ring in the exhaust which i wouldnt have believed 2 weeks ago.

 

Andy

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Why would Toyota change the head, probably to best match the sequentials and extra 0.5l. Why would they downgrade it is what I fail to fathom. Made further perplexing by the 2JZs excellent performance (and hence popularity vs the 1JZ).

 

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.

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