2jz Bottom End 1jz Head

[benny c]

I'm using a gte mate. Thought about the ge for a little while, but seeing as I'd have to change the pistons (and as such replace all the bottom end bearings) the gte was the better choice pricewise, especially when it only has 35,000km on the clock

Only drama is that after being stuffed around by the first engine builder, the budget has almost gone, so I will have to be content with the stock 1j ct12a's for the time being. I have a garret en-route, but that is still a few months away.

[EldarO]

let us know what RPM they start making positive boost from with the 3ltr block

[Liau.Bdar]

EldarO, for which gear do you want to know the RPM that they start making boost? I'm running the 3ltr with the stock turbos here, I don't have a boost gauge in the car but I'm running the JZX81 instrument panel which indicates 'turbo' in hte middle of the panel when you start making boost.

[whatthe?]

So, those in the know here may be able to answer this, what happens with the whole 1.5J thing when you try and throw a 1J VVTi head into the mix?

Hypothetically, if a certain person already had a VVTi 1J in their car would they need a VVTi 2J block to firstly fit the block in the car with the same engine mounts and secondly, to fit the head to said block?

Enquiring minds want to know....

[benny c]

The lads doing my head work seem to think that it can't be done. I think it may have something to do with the fact that the vvti engines (i think) are rather different all together internally. Toyota list 2 completely different head gaskets for the vvti vs non vvti, leading me to believe that the galleries are in totally different positions.

My mate that takes care of my radiators also thinks that vvti is more of a hinderance when chasing big power (I'm just going from what I've been told, not knowing too much about the vvti). He has built several off tap 7M's (pushing 360rwkw) and was even considering attempting to graft vvti system onto one for shits and giggles, then he sobered up and scrapped the idea!

So you're pumping out near 300rwkw with a vvti 1J hey? What did you need to do to get up there? Does the vvti need some kind of interceptor at all? From what the lads in the soarer club tell me it gets difficult when you start pushing over 260 in a vvti. I might end up building one for a friend at some stage so I'm keen to hear what you have done!

[whatthe?]

Motec ECU and big ass turbo. The cams become a restriction at about this point but 1200 bucks to HKS will solve that

The head gaskets being so differnt would kind of confirm my fears, although it'd be interesting to see a comparison between 2J VVTi and 1J VVTi. A VVTi 2J bottom end shouldnt be too hard to source (albeit in N/A form from an IS300)

[EldarO]

EldarO, for which gear do you want to know the RPM that they start making boost? I'm running the 3ltr with the stock turbos here, I don't have a boost gauge in the car but I'm running the JZX81 instrument panel which indicates 'turbo' in hte middle of the panel when you start making boost.

well, in second through to fifth im making positive boost by about 2K RPM, bit less.

would be insane with the bigger capacity block!

[HKS_TRD]

My mate that takes care of my radiators also thinks that vvti is more of a hinderance when chasing big power (I'm just going from what I've been told, not knowing too much about the vvti). He has built several off tap 7M's (pushing 360rwkw) and was even considering attempting to graft vvti system onto one for shits and giggles, then he sobered up and scrapped the idea!

Whose 7Ms are these you refer to?

[benny c]

The blokes name is Mark, seen him in the supra club? Almost finished building the engine, just awaiting a few miscelanious items like fittings and hoses, etc. Only issue now is that the chassis is still a good few months away. After it comes back from being sandblasted and painted, he's conned me into making a custom wiring loom for it! Yay, I can't wait (yes, there is sarcasm there )

Just had a look at the pics of yours, that looks very tidy, nice work!

[brett_celicacoupe]

anyone run OEM 1JZ ECU on the 1.5JZ?? something ive been wondering

i reckon you could get away with it by using 550cc us 2j injectors.

1JZ vs 2JZ is a 20% VE increase.

390cc vs 440cc is a 12% increase so it might not be totally safe. 8% not enough fuel?
390cc vs 550cc is a 40% increase so there might be 20% too much fuel?

[benny c]

I'll be using the 440's in mine. They came out in the stock jdm 2j so I don't really see any dramas with them. I highly doubt that the stock 1j ecu will cope well with them, that is why I am now pondering if I will go a safc or an emange, either of the two will run the injectors to the best of their ability for the application at hand.

[HKS_TRD]

The blokes name is Mark, seen him in the supra club? Almost finished building the engine, just awaiting a few miscelanious items like fittings and hoses, etc. Only issue now is that the chassis is still a good few months away. After it comes back from being sandblasted and painted, he's conned me into making a custom wiring loom for it! Yay, I can't wait (yes, there is sarcasm there )

Just had a look at the pics of yours, that looks very tidy, nice work!

Not sure I know of this guy, he has an MA-70 I presume? What color. I don't turn up to many Supra club events, but sounds like he has one tuff car, wouldnt mind seeing it. What turbo and ECU is he going to be running?

[Liau.Bdar]

I'm using the 440cc's of a JDM 2JZ with the stock ECU and have been running this setup since early June. I've yet to get it on a dyno to check if the mixture is ok but assuming that a 1JZ on stock injectors run rich I'm 'hoping' that with the stock ECU and 440 injectors the car is still running rich albeit leaner than before (using brett_celicacoupe's calculation), we'll know for certain when a dyno run is done.

On the injectors, I've come across information saying that the 1JZ injectors are either 370/380 and the JDM 2JZ are 430/440.

EldarO, was raining tonight so didn't get a chance to do the boost experiment.

[benny c]

His missus has a GA70 supra, he has a white MZ20 soarer. lol, he doesn't even show up to many supra club events either, he reckons they don't like non-supras that much. Wether that is because he has a soarer, or his 20 year old car is making more power than 90% of the jza80's there remains to be seen!

btw, OEM 1J injectors are 380cc and 2J injectors are 440cc.

[Soarer21]

So, those in the know here may be able to answer this, what happens with the whole 1.5J thing when you try and throw a 1J VVTi head into the mix?

Hypothetically, if a certain person already had a VVTi 1J in their car would they need a VVTi 2J block to firstly fit the block in the car with the same engine mounts and secondly, to fit the head to said block?

Enquiring minds want to know....

To make a VVTi 1.5J you need the VVTi 2JZ block. Seen them done in Japan.
Also, the engine mounting point on the drivers side of the 2J VVTi is different to all other J series engines. Passengers side is same though.