speedricer05

i recently installed a turboxs boost controller on my 83' 280ZX and i was planning on bumping the boost up to 9psi. The problem now is that my pop-off valve pops off around 8. I've heard of people using washers or something to make them pop off later, but I wasn't exactly clear on how they did it...does anyone know how? pleeeeeeeeeeeeeaaaaaaaaaaaaase!!!

L0ki

take out the pop off vavle and screw in a plug ... no more problems

Rusty Datsun x 3

speedricer05

Really? That's it? Ok...Well...Where can I get a plug for it...and what effect will that have on the motor. Isn't the pop off there to protect that? Or is it one of those things that is just there...but never is never really used?

L0ki

Yeah just get one of those brass fittings with a hex bolt head on the top to fit the hole and take the vavle out and stick it in ... plumbing shop may have something !? The pop off valve is just there if you shut the throttle and there is over XXpsi left in the plenum .. rearly used

Rusty Datsun x 3

speedricer05

cool...thanks for your help man

Ben

That's not what it's there for. Its an overboost valve, designed to vent boost if you have a wastegate failure & prevent you from destroying your engine.

It's one of those pieces of equipment that you hope that you never end up using (like an airbag). Apparently some of the turbo-diesel Hiluxes have a valve the same physical size that doesn't open until 15psi. Worth a look at, since it gives you the factory-style protection while running higher boost (assuming the rest of the system is up to it). I'm not sure how common they are in EFI cars these days, as most run electronic boost control & will shut down the engine in an overboost situation. So a mechanical safety mechanism isn't needed. My aftermarket EFI computer will drop my wastegate duty cycle to 5% if my engine overboosts(>10psi), and my gate is set to 4psi.

A lot of people plug them up, but the Hilux thing is a possible alternative.

Ben
Adelaide
Sth Australia
IZCC#1902
240Z L31ETT
L28ET MR30 Skyline
FJ20ET DR30 Skyline RS-X

L0ki

yeah whats right ben .. how stupid of me ....it didnt sound quite right when i read it after i posted...

Rusty Datsun x 3

speedricer05

thanks for the help...i never could find a plug to fit the metric sized hole...apparently nobody down here in the south uses metric stuff...so i did what any dumb kid would do...i welded the pop off valve shut...but...i do have another, and i'm working on modifying it...i don't need to be blowing up my poor little z car

speedricer05

ok..now i feel like a really dumb kid...i was reading that web page, and found another guy that welded his shut...now i got a question...what's the difference betweent welding it shut, and capping it off? isn't it the same thing? but...now that i saw that...i've turned my boost back to 6psi and i'm working on shimming up my spare one...