alternate pop-off valve?

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May 1, 2003 | 06:08 PM

zpeedracer25

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From: Tongie, Kansas

alternate pop-off valve?

Ok all you ZX turbo guys...I've got an L28ET in my 1977 280 and am looking to find a different pop off valve for preserving my engine from extreme overboosting. I'm not finding much out there as far as a direct bolt on replacement that is adjustable. What are you guys using?
Thanks all,

May 2, 2003 | 03:28 AM

jerms280

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both trust and HKS have them

May 2, 2003 | 07:32 AM

Lockjaw

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I am using the plug that goes in the 300ZX NA intake manifold.
No pop off for me. HAHA

MSA also has an adjustable pop-off valve.

May 3, 2003 | 07:29 PM

lifegrddude

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From: San Diego

I have an HKS adjustable one. Got it used though. It's the red spring version good to 18PSI. If you look in my sig at my imagestation folder I have pics of the popoff valve and the huge crescent wrench I used to pull that stupid thing off with. lol

May 3, 2003 | 10:07 PM

zpeedracer25

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From: Tongie, Kansas

Thanks for the info everyone. Now of all the ones out there which one is the best as far as function, adjustability, and ease of installation?
Gary

May 4, 2003 | 11:20 AM

lifegrddude

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I don't have any experience with the Greddy unit, but the HKS one bolts right in. The install is as easy as it gets. Just remove the old and plop on the new one! Then, take it for a road test and adjust the tension until it doesn't vent at whatever psi you're using. Mine is set to go off at 13psi. I usually only 9-10, so I have a 3 psi cushion in case of spike. On a low note though, the HKS ones are sorta getting hard to find, a search engine might turn up results, the Greddy one is relatively new. www.morepowerracing.com has them in stock and they have free shipping on anything that isn't oversized (aka requiring freight).
John 82ZXT

May 4, 2003 | 09:36 PM

jtmny1999

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I pluged my pop off valve with a 1 inch plug that i got from home depot am boosting 12 psi with octane booster so far so good

May 5, 2003 | 10:10 AM

zpeedracer25

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From: Tongie, Kansas

Thanks for the info Life!

I tried the plug for a while and it worked fine until my manual boost controller failed and I way way way overboosted. I'm lucky that I didn't break anything.

May 5, 2003 | 10:29 AM

lifegrddude

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No problem, here's another site for pop off valves, dunno if they still carry them or not. I happened to find this while doing some research. http://www.importstylez.com They list different springs and stuff too, hopefully they still carry the valves since HKS did discontinue making them. As for overboosting, yeah that sucks, when I was first trying to set my controller I overboosted to 14psi, but thankfully nothing happened. I have since set my popoff valve to 13 psi and my boost is at 10 psi or so I think, whatever .8 BAR is.