MKIV turbo's

[Big rob]

Hey guys,
I've got an option to buy a set of MKIV turbos including manifold and all the shit that makes it work for very little. I was wondering what people would think about putting htem on a 1g. It sounds good but I think they are cermamic turbines, would this cause any problems

Cheers

[Draven]

They are ceramic (unless you get US spec turbos). You're going to have to make up a new manifold anyway, so why not go something a little newer, put a GT single on it or something? remember the jza80 turbo design is 13+ years old now - even if the turbos are nearly new.

[30psi 4agte]

The ceramic wheels will limit you to running 14 psi max or risk failure

[Norbie]

Please stop propagating myths. Practically everyone on supraforums.com.au runs way more than 14psi and you don't see turbos blowing up every other day. I've been running up to 19psi through mine for the last 3 years, and others have pushed in further.

As for the original question, you could do it but it wouldn't be very cost effective when you consider how much you'll have to spend on pipe work to make them fit. Also remember the 2JZ turbos are designed to work as part of the sequential turbo system, which means only one of the turbos has a wastegate. This will cause major headaches unless you want to spend even more money getting the #2 turbo modified to accept a wastegate.

I have a feeling it would be a laggy bitch too. My 2JZ only gets full boost at 4000rpm when sequential mode is disabled. Imagine what it would be like with only 2 litres of engine spooling them up instead of 3!

[JustCallMeOrlando]

I'm with the rest of them. Those turbos would 1) be a problem due to only one of them having a wastegate and 2) would be laggy as f**k if you did get them on.

Your cheapest option would be a single GT or KKR turbo on a Y-pipe manifold that bolts onto the factory manifolds, ala emp.

[ed]

The ceramic wheels will limit you to running 14 psi max or risk failure

plus...

since when is failure rated on boost? its shaft rpm that determin failure, which on a smaller capacity engine correlates to higher flow/boost...

...even if it were a 'fact'

[Big rob]

ok so you reakon lagy as. I thought they would be spool automatic on sequential mode even on a 2lt. Considering i can get all the goodies for like next nothing, and when i mean next to nothing i mean it. Um yeah i thought that failure was related to flow of air. Like they can supprot approximatly this amount of air to make this much horsepower, over that they could fail.
When are you making full bost in sequnetial mode norbie? Why arnt you running sequential mode?

[Norbie]

I am running sequential mode at the moment, mostly because true-twin mode makes the car twice as loud and I got sick of it. Full boost still happens at about 4000rpm in sequential mode but the difference is you have 5-10psi from 1500-4000rpm, so it has ridiculous torque up to 4000 then a sudden rush of power after 4000.

The sequential system is controlled by the ECU so forget about making it work on anything except a 2JZ. And that's why the 2JZ turbo setup can be bought for next to nothing - it's practically useless if you don't have a 2JZ already.

[30psi 4agte]

[QUOTE=Norbie]Please stop propagating myths. Practically everyone on supraforums.com.au runs way more than 14psi and you don't see turbos blowing up every other day. I've been running up to 19psi through mine for the last 3 years, and others have pushed in further.

Propagating Myths? I dont no about that one ! I have worked with turbos for 7 years and have seen my fair share of ceramic turbine failures!!!!!!!



since when is failure rated on boost? its shaft rpm that determin failure, which on a smaller capacity engine correlates to higher flow/boost...


OK ED !!
If you want to get tech you are right but if you want to generate boost you will need to increase shaft speed .
To get 14 psi you will be spining the turbo close to 100 000 rpm mabe higher ( can check a flow map if you like) and in this range the turbine can become unstable and fail due to the centrifual forces acting upon it.

Ed Not too many people understand compressor maps so i tried to make it as simple as possible


All im am saying is that if Big Rob wants to run over 14 psi he should be aware that running this sort of boost with the turbo he has in question has a possibility of failure at this level.

[Big rob]

ahh fair enoguh i thought it was some vacuume actuattor. Acutally is it like a pressure switch thing. Like once it reaches a cetain manifold pressure, it switches an acuator? I really dont know much about the system, do you know of any good reading on the net about it?

Cheers norbie

Oh 30psi, not to be a smart arse, but since we are all bing ll techincal there is no such thing as centrifugal forces. Thats a description that was made up by people to describe a reaction force felt in circular motion. THe actuall force that causes failure is called 'centripetal force'.

[Norbie]

Propagating Myths? I dont no about that one ! I have worked with turbos for 7 years and have seen my fair share of ceramic turbine failures!!!!!!!

No doubt you have, but not all ceramic turbos are created alike. Pushing a 1JZ past 1 bar is asking for trouble, but the experience of a large group of 2JZ owners suggests the 2JZ turbos are far more robust. My personal experience backs this up; 3 years of daily-driven high boosting goodness and the turbos show no sign of giving up.

To put it simply, some ceramic turbos are weak but others are not. Conversely, some steel turbos (eg 1G-GTE) are known to fail at high boost levels also.

[Big rob]

I've been doing a bit of reading into this MKIV turbo stuff and am i correct saying that the 6 odd valves used to control the setup is all solenoids switched by the ECU which is dependent on manifold pressure and revs. No lets just say i did go ahead with this, I think i could control this with either 2 jaycar voltage swithc circuts(dodgier) , and i have a freind who can program PIC's. Now using inputs from the revs and a map sensor i think all i need to do is work out what pressure the 2nd turbo kicks in and what revs it needs to switch the solenoids. Yeha anyone know what the car isusing the revs for, like how they determined why it was approximatly 4k?

Not really even a question is it

[Norbie]

In theory it's entirely possible to do what you describe. In practice, the amount of time and stuffing around to make it work properly means it will never actually happen. There's a very good reason you never see aftermarket sequential turbo setups anywhere, ever. Unlike Toyota, the average home enthusiast doesn't have access to an engineering lab and an entire team of engineers to make stuff like this fly.

[Big rob]

Yeah i kinda got over it after doing more research on it. The turbo manifold is the main reason for dropping the idea. It just doesnt look like something you would want to modify. I actually thoguht it would be fun having to get all the electronics to work and all but in the end i was going for something that was just pretty damn old in design. Ohwell looks like i'll be going for the orriginal plan, garrett GT32 or similar.

Cheers for your help

[stradlater]

You got a 1g... Just a get a big turbo like mine.. Then you'll have lots of fun..