"The BIG BOV thread" (Where all bov question threads get merged)

[Rogan]

if you were to wire/weld the OE wastegate flapper shut, and add an EWG of equal pressure settings, then no 'tuning' is required. An EWG's principle is the same as the stock flapper style, only it's more accurate, 99% of the time, it's quite a bit larger, and tends to control boost levels with greater accuracy. It doesn't do anything other than let exhaust gasses out, pre-exhaust turbine, to control turbine wheel speed.

[Donkey]

Hey everyone, i'm sure these questions have already been asked and i'm sorry if i'm repeating a question, but i didn't want to read through the 500+ pages to find it.

Or you could have just read the BOV FAQ's.............

[Donkey]

if you were to wire/weld the OE wastegate flapper shut, and add an EWG of equal pressure settings, then no 'tuning' is required. An EWG's principle is the same as the stock flapper style, only it's more accurate, 99% of the time, it's quite a bit larger, and tends to control boost levels with greater accuracy. It doesn't do anything other than let exhaust gasses out, pre-exhaust turbine, to control turbine wheel speed.

Actually I thought the same as you until recently. From what I have been reading EWG's require less timing (3-4°) due to the fact they allow engine VE to go up. Also they shift the load targets through out the RPM range (kinda like installing an MBC). This has to do with the ability to relieve large amounts of exhaust gas pressure quickly due to the size of the EWG and the fact it has no resistance behind it. Also because its only opening at higher loads/rpms less exhaust is going through the turbine making it more efficent. Custom tuning is definately recommended as both fueling and timing areas will need to be monitored and tweaked.

[Rogan]

GTFO, Ron! ??? I can see where you're coming from.


I stand corrected.

[benson156]

what?

You should get a protune.

[nxwrx]

i have a 2011 wrx and I installed a type S bov.And after driving around for a little while it will want to stall out coming off the throttle.Any one know what to do?

[Rogan]

Yeh. Take the type s off, put the stock unit back on, and RTFM

[nxwrx]

so there is no way to make it work huh? what if i take out the plug?

[Donkey]

so there is no way to make it work huh? what if i take out the plug?

Brilliant..............and taking out the plug will do what? If you do not understand how they work or have the ability to read the installation instructions then don't install them. Stick with stock. The valve needs to be adjusted.

[nxwrx]

Brilliant..............and taking out the plug will do what? If you do not understand how they work or have the ability to read the installation instructions then don't install them. Stick with stock. The valve needs to be adjusted.

it is adjusted and I read the instructions.it only wants to stall out after driving about 20+ miles. I have read in here that the stock one opens from time to time.. thanks for the help..

[suzuki23]

hey guys sorry if this was brought up in the thread, but i was wondering how the newer 08+ wrx or sti guys like the forge recirc? thanks

[Impreza2.0]

Before this turns into offense and defense, that type S valve is NOT made for "close to stock" modded EJ engines... at all. I tried one. It created a rich/lean air/fuel ratio that made stalling and bucking and not one GOOD effect.

Replace it with an RS (If you are a die-hard GReddy fan), or go back to stock... or get a bypass valve from someone who makes good pieces.

Forge, for instance, makes a valve FOR OUR CARS. It's fully recirculating, meaning there's no "whoosh" sound, it's just capable of holding boost pressures that your stock turbo can't create. If you are upgrading your turbo, and you are going with some uprotated beast, the vent-to-atmosphere valve you have might work well with the right tune. Until you have replaced your entire exhaust system from the manifold through the turbo, to the back bumper, you really won't benefit from a bigger turbo anyway.

There is no benefit to just dumping the valve pressure into the outside air. It's loss of boost you are having when that happens, and who wants that? Loss of engine performance for a neat-o sound effect is pretty cheesy, and makes Subaru owners look like idiots.

If you go back to the beginning and read this whole thread, you will know enough about this valve system to know you really don't need anything more than the stock piece, and if you want a nicer looking valve, that you need to go for a stock replacement bypass valve... not a blow off valve.

As for pulling the plug out of that hose... don't do it. You go one way or the other with a VTA valve, and you aren't going to be able to mod it to make the valve push air into the pipe. You need a valve made to do that by design.

I'm using a TurboXS 50/50 BPV and it's pretty perfect. I get even shift RPMs, and no leakage. It will also retain pressure in excess of 50PSI! Fast valve reaction also. It's pretty darned good. It isn't as loud as most blow off type valves, but I wasn't interested in loudness, just performance and tuneablity. You might like the 50/50 type, especially the ones which offer a dial to adjust how far towards atmospheric the release is set. This means you can dial in the right air/fuel ratio, while still getting some sound (in case you use the sound of your car to determine shift points). Really the sound is a handicap in a race situation, everyone knows when you are about to shift. Big disadvantage. I'm also running 18psi... I destroyed 3 valves (cheap eBay junk valves) learning this stuff. It is easy to overdo it, but on a stock setup, any valve will work "OK", but the stock or near-identical-to-stock works best. Forge - makes one that is nearly identical in every way to our stock valve, except that it is billet, polished, and far superior materials in construction. There's a million good valves, and a million bad ones. Don't get put off by making a mistake and buying one that isn't working. Sell it and get one that works.

[nxwrx]

Before this turns into offense and defense, that type S valve is NOT made for "close to stock" modded EJ engines... at all. I tried one. It created a rich/lean air/fuel ratio that made stalling and bucking and not one GOOD effect.

Replace it with an RS (If you are a die-hard GReddy fan), or go back to stock... or get a bypass valve from someone who makes good pieces.

Forge, for instance, makes a valve FOR OUR CARS. It's fully recirculating, meaning there's no "whoosh" sound, it's just capable of holding boost pressures that your stock turbo can't create. If you are upgrading your turbo, and you are going with some uprotated beast, the vent-to-atmosphere valve you have might work well with the right tune. Until you have replaced your entire exhaust system from the manifold through the turbo, to the back bumper, you really won't benefit from a bigger turbo anyway.

There is no benefit to just dumping the valve pressure into the outside air. It's loss of boost you are having when that happens, and who wants that? Loss of engine performance for a neat-o sound effect is pretty cheesy, and makes Subaru owners look like idiots.

If you go back to the beginning and read this whole thread, you will know enough about this valve system to know you really don't need anything more than the stock piece, and if you want a nicer looking valve, that you need to go for a stock replacement bypass valve... not a blow off valve.

As for pulling the plug out of that hose... don't do it. You go one way or the other with a VTA valve, and you aren't going to be able to mod it to make the valve push air into the pipe. You need a valve made to do that by design.

I'm using a TurboXS 50/50 BPV and it's pretty perfect. I get even shift RPMs, and no leakage. It will also retain pressure in excess of 50PSI! Fast valve reaction also. It's pretty darned good. It isn't as loud as most blow off type valves, but I wasn't interested in loudness, just performance and tuneablity. You might like the 50/50 type, especially the ones which offer a dial to adjust how far towards atmospheric the release is set. This means you can dial in the right air/fuel ratio, while still getting some sound (in case you use the sound of your car to determine shift points). Really the sound is a handicap in a race situation, everyone knows when you are about to shift. Big disadvantage. I'm also running 18psi... I destroyed 3 valves (cheap eBay junk valves) learning this stuff. It is easy to overdo it, but on a stock setup, any valve will work "OK", but the stock or near-identical-to-stock works best. Forge - makes one that is nearly identical in every way to our stock valve, except that it is billet, polished, and far superior materials in construction. There's a million good valves, and a million bad ones. Don't get put off by making a mistake and buying one that isn't working. Sell it and get one that works.

Thanks.I got the type s because its one of the best sounds out there and not to many ppl have it around me.But my wife drives it to and i can let it stall out on here like that so I going to have to look into the 50/50. Which one would you recommend if I like the pssh sound?

[Impreza2.0]

Forge Motorsports Hybrid Valve (pssh sound here) or Bypass valve (no sound on bypass valve)
Greddy RS for WRX and STi (silent valve also)
Go Fast Bits (GFB) Hybrid or 50/50 Valve (pssh sound)
TurboXS Hybrid RFL (what I've got, loud pssh sound!)

These work correctly on your application. Some require adjustment. All can be made to allow for smooth rpm changes between shifts (will cure your problem).
Non of them are under $200. Unless you get a killer deal...

make sure you get a new gasket!! very important!

[Sinister]

I recommend the stock bpv and just get a short ram intake...