: Atmospheric BOV for T-7?????
So I understand that the T-7 air mgt. system won`t take an atmospheric BOV very well, since it needs to recirculate the spent air. :roll:
There has to be someone out there that has gotten this to work! :o
Feel free to jump in and tell me how you did it,(if it worked) and pics as well!
23-09-04, 08:37 PM
nope no one has gotten it to work. unless u like staring at a check engine light and not having your car run right
23-09-04, 09:02 PM
if you're looking for that blowoff sound, you can replace your intake box with a free flowing cone filter. That was pretty much my first mod on my car, and you can definitely hear the turbo more and the blow off noise is also much louder.
23-09-04, 09:33 PM
This has come up time and again. I pricey idea, that may or may not work is the GoFastBits Adjustable Dump Valve. It was designed with ECU's that need air to recirculate to maintain proper Air/Fuel ratios. The Adjustable valve is just that, it adjusts how much air gets vented to the atmosphere, and how much recirculates. You can play with it to find out what balance keeps your ECU happy and still makes noise. I think the valve is about $200
If any BOV will work it will be the gofastbits hybrid BOV.
It's got a pre-loaded vent, and recirculates a good portion of the air it's letting off.
I know they work on the mitsubishi metered air setups, And I would have faith in one for the saab.
but I'd be Certain to ask *THEM* if they have experience with their valves on T7 Cars
here ya go!
*THIS* looks like it may be better, because you can change the returned/dumped ratio!
looks a little pricey, though
24-09-04, 01:53 PM
this may sound silly, but is there any measurable performace gain to a BOV vs BPV, or is it mostly just the sound everyone is after?
To me, it would make sense to keep the air in there and recirculate so you don't have to build boost up from scratch each shift. I also understand the temp of the recirculated air is warmer than fresh air. But is it warmer enough to make THAT big of a difference, hence you want to dump it for fresh air?
24-09-04, 02:26 PM
I just sent gofastbits an email regarding those 2 BOV's. I'll post their response when it comes.
24-09-04, 03:16 PM
There's no notable increase in performance from a BOV on a T7 car equipped with the Viggen's Bosch bypass valve unless you're going past the 22 psi that valve should be able to handle.
I spend a lot of time on Scooby boards and at NASIOC I hear nothing but complaints/falures regarding the GFB BOV. However, the "WORX" BOV seems to be reliable, and I believe it works under the same principle.
Just google WORX BOV and you should be able to find a site.
T7 shouldn't be damaged by the BOV, but the CEL could get annoying real quick. T7 would be fooled if the valve were open during a multiplicative adaption window, but the same would be true of the stock valve ... because of that there is a solenoid that keeps any BOV or BPV shut during those windows. Otherwise, T7 should be even more resilient to BOV's than Scooby's as the Saab ECU also uses a MAP system during quick load changes, whereas the WRX/STi does not.
But eh, IMHO a BOV is best avoided until it's necessary because of a significant increase in turbocharger size, or required because of a modified arrangement in your engine bay.
28-09-04, 07:45 AM
"To date, there has not been a car that will not work with the Hybrid or the Stealth FX, even the particularly sensitive Audi and VW engines. Both valves allow the recirculation bias to be adjusted (the Stealth more so than the Hybrid), as well as the spring pre-load. If your car is using a factory Bosch-style diverter, either valve should drop in its place when fitted with 25mm hose adaptors, which can be purchased at the same time as the valve.
now, just find A state-side GFB vendor...
Most are subaru dealerships.
19-10-04, 03:39 AM
Here is another valve that should work as well.
Turbo XS Racing Bypass Valve H-25:
The Racing Bypass Valve Type 25 was specifically designed to replace the 1 inch (25mm) Bosch Bypass Valve used in most Volkswagen and Audi applications. The Bosch valve is prone to failure in stock application and not adequate for holding boost in "chipped" 1.8T equipped vehicles. The RBV-25 spring tension is adjustable, making it ideal for your modified vehicle.
This valve is not loud compared to an atmosphere BOV.
Has anyone ever tried a Turbo XS valve on their T7 car?