# TurboXS H-34 installation on a '87 Z31



## asleepz (Feb 24, 2004)

Parts and Supply

1 - TurboXS H-34 BOV - Ebay $146.99 (price includes shipping)
1 - 1 1/4" piece of radiator pipe. As long as the pipe has at least 5"of straight line. Curves are fine as long as you still have around 5" of straight hose.
1 - 1 1/4" Steel pipe barb
1 - 1/4 Fuel Line
1 - 1/4 vacume line T
2 - Hose clamps that will close to at least an inch or less
1 - Dose of patients

*Step 1* 
If at all possible this is easier and better looking if you get rid of your AC components. The bracket will be used later on a different step. If your not up to it well you will have to install it in a different way. The way the Blow-Off Valve is mounted (which will now be abbreviated to BOV throught the rest of the time) it will not sit. You will have to mount it in a different position.

*Step 2*
Decide and mark around the pipe barb of where you want to install the BOV. This is where I installed mine. Use a permanent marker to mark around the pipe barb to mark the hole on the pipe. Running 3 to 4 inches below the top of the shock tower running parallel with it.










*Step 3*
Disasemble the intake assembly

here









To get off the rubber hose running from post MAF to your downpipe to the intake of the turbo you have to take 4 screws off under the MAF. 10MM if I remember correctly.




























*Step 4*
Take the pipe that connects to the post turbo outlet and into the throttle body and clean it up a bit. Make sure that your marks of where you want the pipe barb welded to stay.

*Step 5 - This step is only if you are going to be fitting/welding yourself*
Take your pipe and cut the hole where you marked so that the pipe barb fits nicely inside and at the angle that you want it. You can use a cutting torch but I found out quickly that the metal is a bit thin and you might make a hole through the other side, but that is repairable by just putting a spot weld over it. I suggest using a Dremel or Rotozip.

*Step 6*
Go weld it or get it fitted and welded on. If you are taking it somewhere to get it done make sure you show them the angle it needs to be at otherwise it will be off center and basically look like crap.

*Step 6 - This step is only needed if you welded it yourself or they didn't grind and clean it up after the company welded it*
Grind it with either a sand paper head on a grinder or a fine stone and after that touch it up with a wire brush head. Don't go crazy and make holes in it but try to smooth things out a bit.

*Step 7 - This step is optional but suggested*
Paint the pipe. Where you welded on the inside it is likely if it gets moisture on it, it may rust. Prep and paint the outside of the pipe with a high temperature engine enamel. Priming is not needed but may be done if you feel the need, but make sure to use a high temp primer.

*Step 8*
Put your intake back together. You will probably need to replace some hoses since most of them have never been taken off. You'll find that they fit more loosely than they did when you took them off.

*Step 9*
Get the radiator tubing and cut any curves off if there are any and make it a straight piece.

*Step 10*
Get the TurboXS H-34 BOV and put all 6 packing washers in it if you are going to be running open atmosphere, and install the hose adaptor. (I needed 7)

*Step 11*
Fit the tubing where it fits both the pipe barb and hose adaptor well and make sure you have almost no space in between the two. I have about a 1/4" gap so they don't hit each other. This way it will have good support and almost no chance of the hose expanding. Also this way you don't need to make a bracket to hold the BOV up.










*Step 12*
The vacume nipple on the BOV is 1/4" there is a 1/4" exsiting vacume line running close to the BOV. It runs up across the valve cover and is larger than all of the others. Cut it about 3" from the end and install the T fitting










*Step 13*
Get your 1/4 fuel line or which ever type of hose you got and hook it up to the top of the BOV on the nipple and the T fitting. If you got the same line that I did and you don't have an AC but still have the bracket on there the hose slips right into the stop two little dips where bolts went. This also gives support to the end of the BOV giving it more support.










*Step 14*
Alright now almost done. Crank the engine. If it idles rough or idles then dies you have a vacume leak somewhere. You need to check all the hoses you disconnected to make sure that they are all properly installed.

*Step 15*
Take the car for a test drive and make sure to run full boost a couple times to make sure the BOV isn't letting out pressure before you hit full boost and while you are hitting full boost as this may make your turbo work harder than normal and make your car run rich.

*Known Problems*
You have now installed the TurboXS H-34 BOV. If you are running open atmosphere and running at low speeds and making boost it will vent it and the engine will bog down a little bit and threaten to die, fortuneatly on mine it doesn't but I may be one of the lucky few out there that don't absolutely need to recirculate. If you car dies at low speeds after it lets out boost please post a thread in here and I will continue the write up to recirculate.

I also had to add one more packing washer to keep the BOV fully shut at idle. You can stick your finger in the BOV while idleing and see if it is open and another symptom is a lower idle.




























Thank you very much for reading my write up on "TurboXS H-34 installation on a '87 300ZX" Please post any questions or comments.


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## 0341TODD (Nov 15, 2003)

Very clever man!

How is it working at full boost and do you have any leaks? I was originally going to do that with a cheapo bov that I had but I figured just doing one with a flange would be a little more reliable.


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## asleepz (Feb 24, 2004)

I've yet to have a problem with it besides at idle I needed one more washer to equal 7 I was pulling too much vacume or something but it was slightly cracked open and that was enough to make it not idle real well. But since I've added the 7th washer all is good. No leaking under full boost and has a real nice sound to it.

Before when I would shift at full boost it would start back up at about 2 PSI and go back to full boost. Now when shifting it backs off to about 7PSI and comes back up.


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## Spongerider (Nov 18, 2002)

You might want to change that white plastic T connector because mine became brittle and it cracked. It took me awhile to find that leak. 

BTW, nice write up! :cheers:


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## asleepz (Feb 24, 2004)

I got some metal tubing around here I'll fabricated it out of that. Thanks for the comment.


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## asleepz (Feb 24, 2004)

Just wanted to update... Still no problems with the BOV and it still works perfectly. I coat the cylinder down with oil just about every oil change to keep the seal good.


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## Nismotune86 (Jul 23, 2005)

*The Ruber hose.*

Why do you have to take off the rubber hose running from post MAF to your downpipe to the intake of the turbo ?


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## asleepz (Feb 24, 2004)

You've lost me there, if I have a picture depicting what you are saying repost it, if not try once again.


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## Xorti7 (Dec 27, 2004)

asleepz said:


> You've lost me there, if I have a picture depicting what you are saying repost it, if not try once again.


I think he's asking why do you have to remove all of the intake before the turbo. Why can't you just remove the turbo-throttle body pipe and leave the rest on.


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## asleepz (Feb 24, 2004)

Because if everything is put together properly you cannot access the post turbo to throttle body screw that holds the pipe on. I had to take off the 90 degree bend metal tube that went from post MAF to pre-turbo to get it off.


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## Aceman85Turbo (Feb 22, 2004)

asleepz said:


> Because if everything is put together properly you cannot access the post turbo to throttle body screw that holds the pipe on. I had to take off the 90 degree bend metal tube that went from post MAF to pre-turbo to get it off.


that screw is never tight, and the screws that hold the pipe to the bracket that comes from the block is what holds that turbo to tb pipe.

you do not need to remove the intake piping to the turbo

good write up though.


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## Zen31ZR (Mar 24, 2004)

Aceman85Turbo said:


> you do not need to remove the intake piping to the turbo


Sure you do, if you want to remove the rubber portion from between that pipe to the TB pipe without ripping it, especially if it's old. Had to do that on my car, twice. I'd like to know how you'd plan to do it, then. And a good explanation with some pics, please.


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## Aceman85Turbo (Feb 22, 2004)

Zen31ZR said:


> Sure you do, if you want to remove the rubber portion from between that pipe to the TB pipe without ripping it, especially if it's old. Had to do that on my car, twice. I'd like to know how you'd plan to do it, then. And a good explanation with some pics, please.



what are you talking about, there is a hose clamp at the throttle body, one or 2 10mm's that attatch the turbo-tb pipe to its bracket from the engine, 2 air hoses, one to the air regulator, one to the idle valve, and it slides off.

the 10mm at the turbo on the turbo to tb pipe is never tight, not on any engine ive ever worked on.

there is no need to remove intake piping before the turbo.


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## asleepz (Feb 24, 2004)

Maybe you've just worked on POS Z's... Mine was tight.


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## Zen31ZR (Mar 24, 2004)

asleepz said:


> Maybe you've just worked on POS Z's... Mine was tight.


Yeah, really, all my hoses and clamps were super tight on mine too. And the rubber section of the post-turbo to TB pipe cracked when I removed it, so it had been on there for a very long time....


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## OK85ZX (Jul 18, 2004)

Good writeup, very thorough, keep it up.


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## asleepz (Feb 24, 2004)

Thanks, whenever I can get into my clutch expect a write up similar. And intercooler and paint and anything and everything else on this thing.


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