cburglb34

ok so i did stall at first then once my car wouldnt move i look at the bov and its open....i throw on the extra spring that came with it and put it on low with two springs......................worked perfect car ran like stock never attempted to bog......but i guess this only works with stock injectors?

johnhawkins

iTrader: (1)

I have two ebay bov...the HKS knock off and the type rs one. I swap them in and out depending on how I feel. LOL. I have never had any stalling issues or idle problems at ALL. But I run my setup different than most.


Throttle Body------MAF Sensor-----BOV------Intercooler-----Turbo

I run the MAF like SP Racing. In between the throttle body and the BOV.

cburglb34

oh so u use a blow thro setup...i was going to run it like that but was affraid to expose boost to the maf

cburglb34

i think alot of people before spending money to recirculate should check to see if the bov VALVE is actually really shut they may look shut as mine did but still suck air....and is a major boost leak...the valve has to actually look like is going into the charge pipe for it to be really shut and to do that i ran two springs and a soft setting and tada no leaks no recirculation....NO STALL

johnhawkins

iTrader: (1)

Awesome - You posted on the other thread right???? What happened to your turbo???

Obike

There is no point to running a BOV other than for the noise... running a BPV (recirculates back into the intake) is the REAL solution. When you vent to atmosphere you've just removed all work the turbo has done to compress air...

If you had two identical cars, with the same tune, with the same driver doing EXACTLY the same thing between both runs... the BPV setup will be faster.

cburglb34

it was cheap and the exhaust wheel snapped off the shaft

SoFloTC

iTrader: (3)

thats weird. why do all the big turbo supras, rx-7's, evos etc etc run a BOV venting then?

TheFantasticG

For the noise... stock on all turbo supras is recirculated.

gompka

iTrader: (5)

When you recirculate it goes back into the intake side of the turbo and has to be re compressed to be turned into boost so how do you figure this is any faster? Either way you have to re compress the air that was blown off whether you blow off to atmosphere or back into intake side of turbo.

Ace83

iTrader: (6)

nice to hear it works!

Obike

When you recirculate it is not recompressing it over and over again (otherwise you would get a massive boost spike). The reason why a lot of the big turbo vehicles run a BOV setup is for two primary reasons... the first is for noise and the second is plumbing. Why is it all F/I vehicles, from the factory, run BPVs regardless of HP? Two reasons... efficiency and emissions.

One reason why a lot of tuners change the BPV out from what the factory used is longevity... the OEMs didn't design their diaphragms or pistons to take more pressure and CFM than stock. That's why an aftermarket exists for BPVs/BOVs. We have a Porsche 997T where I work that, with only chip and exhaust, is able to make 650whp and 700ft-lbs... guess what system it runs? OEM BPV. Most of the serious big-F/I vehicles I know run recirculating setups, including the Audi R10 TDI.

gompka

iTrader: (5)

I was referring to the setup with the supercharged tc. The bov is on the charged pipe and blows off back into the inlet of the supercharger... so yes the air is uncompressed when you blow it off and recompressed again after entering the supercharger. The guy who posted above me said that a bpv doesn't "loose" boost when it blows off, what i'm trying to explain is that it does, when you blow off with a bov or bpv it is still lost boost that you can't get back.

TheFantasticG

Where's that quote of the guy saying the bpv doesn't "loose" boost when it blows off?

When the BPV/BOV blows off, it's releasing compressed air. True, it isn't the same psi that's right out the compressor side of the turbo. If it wasn't compressed, we wouldn't get that ultra cool bov noise.

Obike

The supercharger setup on the tC is not a BOV, it's a BPV. It provides an outlet to vacuum for the compressed air, making sure that the compressed air doesn't hit the throttle body and cause compressor surge (damaging the compressor in the process).

The air is still compressed, and when it vents back into the intake there is still a vacuum towards the throttle body causing the air to circulate back through the compressor (the only pressure difference here is from volume differences). If you measured the pressure in-between the compressor to the diverter valve, and between the diverter valve (after being circulated back into the intake) and to the compressor the system would still be pressurised at those points.

Pressure likes to distribute evenly, becoming uniform. Because of this the pressure will always go towards the largest vacuum source... no pressure is lost back through the filter until the vacuum source has reached the same pressure as the charged air. At that point the only way for it to escape through the intake is to have a higher pressure than atmospheric pressure.

cburglb34

dude give it up bov and bpv are the freaking same, u dont get more power out of either, the bov releases compressed air just like a bpv, the bpv releases compressed air into a intake(not compressed air.....its actually a giant vaccum ..) so you my friend fail with your completely horrible theory

Obike

It's not theory, it's fact... governed by fluid dynamics. The entire engine generates one very large vacuum, it's how fuel and air get into the engine. If you don't want to believe me, fine. You'll learn different when you take any basic physics course.

Ace83

iTrader: (6)

both actually share pretty much same function but slightly different.. they both relieve pressure from extra boost when the throttle plate closes.. a BOV vents to atmosphere, so it is not recirculated to the intake.. the BPV goes back to the intake and will be sucked again to the s/c compressor as needed.. a BOV in the turbo becomes a BPV when you recirc it.. so nobody is wrong, both of you are just looking at a different perspective