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Questions regarding my 1JZ swap.


pedrosixfour

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I've changed the title to reflect my obvious lack of knowledge and need for assistance!

 

If the mods feel this is no longer MKIV specific then please feel free to move to a different section at your discretion.

 

Hey folks,

 

Just about to bolt the stock 1JZ turbos back on to the engine along with the dump pipes I got for it.

 

I was just wondering if there was anything of note about the turbos.

 

I have it on very poor authority that they may have steel turbines fitted.

 

Is there any way to identify such an upgrade, is there a chance that the retaining nuts are coded in some way? ie one type of nut to hold on ceramic turbines, a different type of nut for steel.

 

Any input would be appreciated as I have a 1.2 bar restrictor ring to fit to the system but I may reduce that to a 1 or 1.1 bar restrictor if these are definitely ceramic and then play with my boost controller to eke out the last pound or two that ceramics can safely run on.

 

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Regards,

Damien.

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Edited by pedrosixfour (see edit history)
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Thank you for all the confirmations lads.

 

I'm happy once I know where I stand, rather than pushing ceramics beyond their comfort zone and having a very short but vey costly inaugural track day!

 

With regards to the magnet test I was considering this myself but while trying to identify my own I read somewhere that despite the desired units being classed as steel turbines they're not necessarily ferrous.(?)

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Next question!

 

I'm running a stock 1JZ BOV.

 

However I am missing the one way valve which ensures the BOV remains closed under boost.

 

Now we use a pretty decent alloy cased non-return valve in the garage on diesel engined machines to stop leak backs in the fuel systems and such.

 

Can I use this one way valve as a substitute for Toyota's version of one or is there more to Toyota's than just restricting air flow in a certain direction?

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if its the same as the one on the mr2 it's an awkward 70% one way valve, or so they say :) same setup on both, although on my mr2 mine fell apart on removal recently, it's made no affect whatsoever.

I do have a spare 1jz bov and valve if you can't find one, toyota wanted £38 +vat for the valve when i enquired a month or so ago :(

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if its the same as the one on the mr2 it's an awkward 70% one way valve, or so they say :) same setup on both, although on my mr2 mine fell apart on removal recently, it's made no affect whatsoever.

I do have a spare 1jz bov and valve if you can't find one, toyota wanted £38 +vat for the valve when i enquired a month or so ago :(

 

Those sneaky little engineers!

 

I have the BOV sorted mate, would you be willing to split? Is the valve in good order?

 

I also need the pipe that feeds the surplus boost to the BOV from the turbos, would you have one of those in good order too?

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I think you may find no valve at all is needed as you benefit from boost on the diaphragm to help keep it shut with boost on the other side of the valve. Just try it first.

 

Chris, thats exactly what I was mulling over in my head while I was out in the truck.

 

The valve and any kind of input to that side of the diaphragm would seem counter productive if positive pressure and/or negative pressure to the primary side of the daphragm is all that is needed to operate the BOV properly.

 

I'm going to try it without any valve or pipework to that side of the diaphragm and see how she fares.

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Here is a picture of a stock 1JZ BOV just in case we are not visualising the same item at all!

 

#1 Line should have the one way valve in it, which it appears is actually a two way valve with a restriction to the flow in one direction. If you blow into this line the BOV opens.

 

#2 line is straight into the main chamber of the diaphragm. If you suck on this line the BOV opens. Both line one and line two are fed by the same line via a T piece, coming from the intake manifold.

 

#3 is where the excess boosted air enters the BOV

 

#4 is where the excess boost is fed back into the intake system.

 

image

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  • 2 years later...

I hope returning to this thread and adding a new question is alright, didn't see much reason to start a whole new thread.

 

Anyway NEW QUESTION!!

 

Can anyone confirm that a JDM 1JZ-GTE engine lifted from an early 1990's Toyota Soarer does NOT have an EGR valve of any sort?

 

I was thinking about blanking the one I thought would be on the engine, then I went to look for it and I'm at a loss to find the bloody thing.

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