2JZ conversion experts - your insight please!

[pwpanas]

Originally Posted by Johnny A

Hey people, thought i'd sign up as I have no knowledge of Jap motors.

I am a Vauxhall man (already got the flame suit on!) and have been offered a Toyota Aristo with the 2JZ lump in it

The car isn't perfect by any means but is ripe for a donor as the mechanicals are fine, I would like to remove the 2JZ and install it into my Vauxhall Carlton (can anyone say 'sleeper'?).

Baiscally the carlton handles and drives superbly but in my opinion the 3.0 24v it has already is underpowered and the 2JZ is far superior in every which way I think of!

As I have no knowledge of jap cars or engines I was wondering if the experts would mind filling in some gaps for me.

1: First off I hate auto's, so I would want to convert the 2JZ to manual. As it's going into a carlton a custom prop and mounts is a given, but what box do I need and how much will it set me back?? Anything else I would be made aware of?

2: Wiring, I am pretty good with electrics but I still hate doing it! On a Vauxhall the engine has it's own independant loom which onto joins to the chassis loom for power and instrumentation readouts. Is this the case for the 2JZ or is the loom fully integrated??

2a: I hear the 2JZ's ECU isn't mappable and is best off being replaced for big power, if the loom IS fully integrated would you recommend I jump straight to aftermarket programmable management??

3: Tuning!! Its a JDM import so it's got the ceramic turbos. Currently its got an exhaust, filter and a fuel cut defenser. Rolling roaded at just shy of 400bhp. How much punishment will the turbo's take before needing to be replaced??

I think that covers the basics, I hope you guys can help.

If there is anything else I should know about these engines or the conversion itself just let me know

I'll assume your Aristo is a TT (not sure if the Aristo came in an n/a or not).

1: Especially if you're going to upgrade that 2jz-gte (bigger turbo(s), etc.), you'll need a Getrag V160, which came stock in the Toyota Supra Turbo. You'll also need to switch from an auto ecu to a 6spd ecu...since the auto ecu will be trying to control the gear switching and will likely throw error codes if it doesn't see an auto tranny.


2: The oem Toyota Supra Turbo wiring loom is separate from the engine. It connects at the sensors and the coil packs. I'm pretty sure the Aristo loom is the same way.


2a: The oem 2jz-gte ecu is not mappable. I need to know your power goals if you need an ecu recommendation.

3: If you keep the oem turbos at oem boost levels, they'll last for years. If you decide to run race fuel and increase to ~22psi, they probably won't last more than a year or so (about 10K-20K miles).

[Johnny A]

yeah sorry it is a 2JZ-GTE TT lump.

So the V160 manual box is what I need, does the manual really have it's own ECU?? can't see why it would!!!!

It's already running just shy of 400bhp from less than 1 bar of boost, will know more once I go to see it this sunday.

I have a Go-tech programmable ECU (a universal one, not 2JZ specific) which I am tempted to use. I think 400bhp would be good for a while, but you know what it's like - you get bored and want more! No more than 600bhp though.

[pwpanas]

Originally Posted by Johnny A

yeah sorry it is a 2JZ-GTE TT lump.

So the V160 manual box is what I need, does the manual really have it's own ECU?? can't see why it would!!!!

It's already running just shy of 400bhp from less than 1 bar of boost, will know more once I go to see it this sunday.

I have a Go-tech programmable ECU (a universal one, not 2JZ specific) which I am tempted to use. I think 400bhp would be good for a while, but you know what it's like - you get bored and want more! No more than 600bhp though.

No, the V160 is not shifted by the ecu, but the auto tranny is. Since I didn't know what you were starting with, an auto->6spd swap generally requires an ecu change because the ecu no longer shifts the transmission.

For 600bhp the oem 2jz-ecu Mkiv Supra Turbo ecu would work just fine.

[Johnny A]

Will the engine ecu have any issues once I take away the auto box's ecu?? On the vauxhalls it's simply a case of earthing a pin on the engine ecu to tell it the gearbox is manual.

I'm glad to hear the factory ecu will be happy with 600bhp, if we ignore the obvious turbo, exhaust and intercooler upgrades what else would be required to achieve 600bhp? The engine already has a fuel cut defencer (hks).

[pwpanas]

Originally Posted by Johnny A

Will the engine ecu have any issues once I take away the auto box's ecu?? On the vauxhalls it's simply a case of earthing a pin on the engine ecu to tell it the gearbox is manual.

I'm glad to hear the factory ecu will be happy with 600bhp, if we ignore the obvious turbo, exhaust and intercooler upgrades what else would be required to achieve 600bhp? The engine already has a fuel cut defencer (hks).

Again, you'll need to swap out the auto ecu for a 6spd ecu. They are two different Toyota part numbers.

For 600rwhp, you'll first need to decide what kind of fuel you want to run (pump gas alone won't work):
- pump gas with a heavy shot of methanol?
- race fuel (104+ motor octane)
- E85?
- any other ideas?

[Johnny A]

We have 99ron pump gas here is the UK But to be honest I plan to run this all the time anyways as it's a JDM import. If that's not enough I could put a little methanol in there too, I am a fan of water/meth injection.

I am still confused as to why a manual gearbox has it's own ECU though

[pwpanas]

Originally Posted by Johnny A

We have 99ron pump gas here is the UK But to be honest I plan to run this all the time anyways as it's a JDM import. If that's not enough I could put a little methanol in there too, I am a fan of water/meth injection.

RON is not MON. You need to find out the MON of that 99RON gas...I'd guess that it's about 89MON. This is only good for about 16psi of boost, max, using the oem Mkiv ecu. In other words, yes, you'll definitely need to supplement with methanol injection to make 400+rwhp. To make 600rwhp, you'll need a very heavy shot of methanol - the biggest kit you can find should do the trick.

Originally Posted by Johnny A

...I am still confused as to why a manual gearbox has it's own ECU though

Sigh. The manual gearbox does not have its own ECU. There's a different ECU for the MKIV Supra Turbo depending upon which transmission it has. Hypothetically speaking, if you already owned an Mkiv Supra Turbo with an auto tranny and you decided to convert it to a 6spd, you'd have to swap out the primary ECU. Make sense?

To make 600rwhp+, you'll need an aftermarket fuel controller (eg. an A'PEXI AFC Neo), and a small-medium single turbo kit (eg. 57+mm inducer). The oem twins can't make 600rwhp. Be sure you're running Toyota's 550cc injectors (your j-spec 2jz-gte probably came with 440s, so you'll have to swap them out). Together with the meth kit, you'll have enough fuel for 600rwhp, but just barely. For additional safety, I'd recommend an aftermarket fuel pressure regulator, and bump it up to about 50psi base.