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Can someone tell me what this part is for? Someone duct taped it.


kevboost7
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I had a old Blitz BOV on my old boat, it leaked "alot" under boost

It was replaced with a Turbosmart one if I recall correctly and the Blitz one went in the bin

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On 6/28/2023 at 3:57 PM, Duncan said:

Yep....but it is so much better than not being able to have it at all.

If someone wants to start 3d printing them I'll take 3

You don't have one at all on your car?

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Yeah the rally car is off the road until our local motorsport body decide what changes they are going to make to cage regulations, and the one currently on it is cracked after a crash. I do have a lead on one nearby though :)

 

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  • 1 month later...
On 6/28/2023 at 11:38 PM, The Bogan said:

I had a old Blitz BOV on my old boat, it leaked "alot" under boost

It was replaced with a Turbosmart one if I recall correctly and the Blitz one went in the bin

What do you mean it leaked under boost? How can you tell? 

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52 minutes ago, kevboost7 said:

What do you mean it leaked under boost? How can you tell? 

I had a smoke/pressure test done at Unigroup engineering years ago

https://gfb.com.au/tech/tech-articles/15-smoke-testing-boost-leaks/

That was at least 15 years ago though, my memory ain't what it use to be

I just remember them saying that the Blitz valves were junk and had a bad habit of leaking

 

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  • 9 months later...
On 6/25/2023 at 8:34 PM, GTSBoy said:

Well, a big chamber at whatever pressure the turbo inlet duct is at, which can be anywhere from atmospheric to a moderate level of suction. Remember, you do not want low pressure between your air filter and your turbo because that is stretching out the air available for the turbo to ingest. Any lower pressure than atmospheric at the turbo inlet works against the pressure ratio that the turbo is able to create. PR2 when you start at 14.7 psi is >29 psi (absolute), which is a whole 14.7 psi of boost. PR2 when you start at only 13 psi is suddenly only 26 psi (absolute). Subtract the 14.7 psi of the outside air from that and you only have 11.3 psi of boost.

What is PR2?

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On 6/26/2023 at 5:45 PM, Duncan said:

So, your Blitz blow off valves release air to atmosphere (you can see the trumpet shape) who maximum duck noises. If you are happy with the how the car runs then no need to change anything, but they can cause stalling when returning to idle for example because air that went past the AFM never makes it to the engine.

Same goes, if there is nothing wrong with how it runs you could leave the BOV return in place and taped off, but I think it is trouble (or future trouble). The correct way to cap it off is a proper rubber or silicone cap with a hose clamp right back where it joins the intake and remove everything else.

Correct, the factory BOVs have outlets that connect to that pipe and send air back to the inlet when they pop open, so no metered air is lost. 

Again, in the factory setup the cam cover breathers are connected to the inlet near the airbox. As the engine gets tired it will breathe more and more oil back into the intake, which is meant to be sucked into the engine and burned. In practice, over the years, some will collect at the low points in the intake and your BOV is one of those points. Since it looks like your front bar might be off, it would be worth disconnecting at least one side of the lowest intercooler pipes and seeing how much oil has pooled there

Revisiting this thread again x2... 1 year later. This car has been an ongoing project between life. But, I never removed the re-circ pipe. I know, shame on me. But since then, i took it to get tuned and only making about 280hp (lame) and i'm chasing a boost issue where the car wont boost past 7-8psi. Mac valve installed. Haltech Platinum pro with the map sensor. 

This is the first time i've tackled the turbo side of things, but i have that side somewhat taken apart to chase the waste gate vacuum lines. And noticed this stupid pipe again. I'm peicing together the puzzle and @GTSBoy mentioned that it was a big vaccuum chamber and said a bunch of car math stuff that I couldn't quite follow the car math (im trying). You guys think this would be the culprit? between rotting vacuum hoses? 

i'm making a DIY boost leak tester this weekend. 

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Posted (edited)
12 minutes ago, kevboost7 said:

What is PR2?

Pressure Ratio = 2. ie, 1 bar of boost (assuming 1 bat absolute pressure at the compressor inlet).

This is relevant because compressor maps do not have "boost" up the y-axis. They have pressure ratio.

Edited by GTSBoy
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7 minutes ago, kevboost7 said:

Revisiting this thread again x2... 1 year later. This car has been an ongoing project between life. But, I never removed the re-circ pipe. I know, shame on me. But since then, i took it to get tuned and only making about 280hp (lame) and i'm chasing a boost issue where the car wont boost past 7-8psi. Mac valve installed. Haltech Platinum pro with the map sensor. 

This is the first time i've tackled the turbo side of things, but i have that side somewhat taken apart to chase the waste gate vacuum lines. And noticed this stupid pipe again. I'm peicing together the puzzle and @GTSBoy mentioned that it was a big vaccuum chamber and said a bunch of car math stuff that I couldn't quite follow the car math (im trying). You guys think this would be the culprit? between rotting vacuum hoses? 

i'm making a DIY boost leak tester this weekend. 

I do not think that the return pipe could be the cause of your particular troubles, unless perchance it is leaking in a lot of unfiltered and unmetered air (assuming your ECU is still using AFMs). And then it could be very bad, but it shouldn't prevent you making boost. Blow then engine up from running lean? Sure. But it would make boost.

You really needed to disconnect this thing from the turbo inlets and close those inlet ports off a year ago, and you should do it now.

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Doing it this weekend. For sure this time. Thank you forum gods. 

And im running map sensor now with the haltech. Still have the AFMs attached to the mushroom dome shaped air filter things

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Is there a best practice on how to cap this? Its a 1.5 inch hole. I couldn't find standard sized caps, except some thin walled vinyl caps to fit the hole. Is there where you guys would cap it at? (circled in red) image.thumb.png.0069815bfb1346ba9626638271ea8e83.png

 

or would you cap it off the hose that attaches to this. As the re-circ pipe comes up from the intercooler and has a bunch more twists of connections and hardpipe that seperates into a soft rubber pipe to each turbo. 

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1 hour ago, GTSBoy said:

Right. Of course i knew the turbo inlet is sucking air. Just testing you. 

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On 6/13/2024 at 10:31 AM, GTSBoy said:

Shhh... Muricans don't understand the idea of metric so can't find half the stuff we have for modifying JDM cars 😛

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