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Overboost valve query

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KiloooNL
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Overboost valve query

Post by KiloooNL »

Hey guys,

A long while back as I was browsing thru either this forum, the yahoo archives or nissanexa forums, I came across a post that mentioned somewhere that either an old Nissan Pathfinder or Patrol uses an overboost valve with the same thread size as the N12 one on the intake mani.

From memory this stock valve was set to open at ~12psi (or was it 15?). However I have searched endlessly to find this post again as I didn't bookmark it (silly me :roll:) without any luck... does anyone know anything about this? As I am drawing closer to doing my mods this valve is particularly appealing to me for the safety factor in the event of a boost related failure.

I ran around my local 'pick-a-part' (u-pull-it) to try to locate a Patrol or Pathfinder but unfortunately they didn't have any cars at the time.

Any info would be appreciated!
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N12turbo_DK2300
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Post by N12turbo_DK2300 »

Hi
Just got me interested in the overboost valve questions (which has been on my mind for some time), and made me search (and read) the hell of of this forum. Thanks for making me spend my afternoon in here ;)

I found this thread, where some guy talks about a valve from a Terano 2:
http://forum.n12turbo.com/viewtopic.php ... =overboost

I have a question on the same area (sorry... not intending to overtake your thread), is a just want to keep my engine more or less stock, the turbo might be slightly bigger. Should I try to adjust my wastegate to open at 0.5/0.6 bar, or just let it boost the hell out of it, letting the overboost vavle save me?

Previous owner(s) been fiddling with different parts, but know this specific turbo (it is a CZ something something) is standard put to 0.9 bar on the wastegate, but has not idea with is it as now.
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photoglossy
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Post by photoglossy »

Overboost valve should be used as a last backup, definitely don't use it as a boost controller.

Don't run your turbo without the wastegate, it will operate way out of its efficiency range, producing too much heat (hot air is bad air), and possibly cause detonation.

Moral of the story, if you want to keep the overboost on there thats fine, but have proper control of turbo pressure also (bleed valve for instance)
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KiloooNL
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Post by KiloooNL »

N12turbo_DK2300 wrote:Hi
Just got me interested in the overboost valve questions (which has been on my mind for some time), and made me search (and read) the hell of of this forum. Thanks for making me spend my afternoon in here ;)

I found this thread, where some guy talks about a valve from a Terano 2:
http://forum.n12turbo.com/viewtopic.php ... =overboost
Thanks!!! That was the thread I reckon. For some reason I was thinking Pathfinder or Patrol.
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