gorpobr

Just to clarify, POV/Pop Off/ Relief Valve is a boost controller valve that make the same function of the wastegate bu instead of bypass the exhaust air, it throws the pressurized air from the turbocharger to the atmosphere to control the boost, different from a blowOff valve.

There are some blowoff that could be used as a POV, do you know which ones?

Very few people use this kind off valve, so I need to know who are using and what brand is?

Thanks!


Modified by gorpobr at 6:09 AM 2/5/2007

DJ_SaNdOz

Do you mean the saftey valves that I believe NASCAR used to run? The ones that prevent overboost by opening at a specified PSI to bleed off excess air?

BB6-213

I know that greddy makes a pop off valve because I used to have one.

jameelrose

when was nascar turbo charged? do u mean formula one?

AWDstylez

The GReddy Type S has a port on the bottom of the diaphram that goes to the compressor outlet (or any pre-throttle reference point) and is supposed to be used to quicken response. If you ran the line for that bottom port to the intake manifold instead and left the top port VTA, then it would act just like a wastegate. You would just have to hope that the adjustment screw would tighten down enough to let you run the boost you want.

Why do you want regulate boost from the intake side and why do you want to use a BOV? Most people just use regular wastegates off the intake plenum or a charge pipe.

DJ_SaNdOz

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jameelrose &raquo;</TD></TR><TR><TD CLASS="quote">when was nascar turbo charged? do u mean formula one?</TD></TR></TABLE>

I think you're right; my bad

MiraiZ

Champcars still use pop off valves...yes they do function similarly to wastegates

BTW...might wan to take a look at the HKS racing BOV's design...looks like it could be easily modified into a POV

gorpobr

Yeah, it is the safety valve.

But I am going to use as a primary valve to control the boost. So I can use a BOV like a POV, just changing the point of get the pressure, before or after the TB.

Bailhatch

i tuned a toyota that had a greddy type R bov/POV and no WG at all. it actually controlled boost pretty well. just sucks spinning the turbo for no reason...IAts were ok though

BlueSi2k

wouldn't this have a negative effect on the performance of the turbo? overspinning it and increasing iats...

gorpobr

This setup make the turbo run all the time at WOT at maximum RPM, doesn't matter what boost you use, different from a wastegate. But this setup boost quickly from zero and between shift gears.

jameelrose

most modern day ems have map sensor regulated boost cut, so they arent as important as in the past.

the reason why champ car still uses em, is to prevent cheating. they are handed out right before the race and collected immediately after for inspection. so even if a team was to up the boost through their ems, the regulated pop off valve would prevent it.