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What?

555
Can you give a little more info on the 924 recirculating valve?

Well...I can try...

My friend has a 924 turbo, and we were looking in his shop manual and it shows the recirc. valve that is a 931 (924 Turbo) only part I think, maybe used on the 951 (944 turbo). Anyway...my memory is foggy, but the valve releases the blownoff air into the turbo in some fashion too keep the impeller spinning...

It's pretty neat and def. noticable when driving the car, as it really doesn't have any turbo lag between gears...

Sorry I can't give more insight...

Our stock blowoff valves release the blown off air into the compressor inlet.

yeah all valves relive the pressure but recircs just dont leave the system open, so theirs no air leak. aptmo valves create an air leak. if your woried than get a txs recirc valve and wrx adapter if you are using a wrx top mount. its like 30 bucks

The original by pass valve is appropriatly tapped into the fmic.

I was curious about the Porsche approach

When I go to the bigger turbo it might need a bigger valve.

Tks.

vrg3 wrote:Why are you guys saying it will help keep the turbo spooled?

I should be more clear... What i meant to say was that it will help keep the turbo spooled as opposed to no blow-off valve.

This thread confuses the hell out of me, and there are so many damn contradicting posts!!!

I've got a few questions for all of you who have contributed to this thread:

1. What is this pressure differential?? If the BOV is letting air out when you let off the throttle completely, it keeps the turbo from building up pressure and stalling. Right?

2. How does using a Atmo-venting BOV mess with your MAF??? They way I understood was that when you let off the gas and the BOV starts letting out air, your car will run rich for a second. I don't see how making that air recirculate into the intake of the turbo could possible make any difference. Is there something I'm not taking into consideration???

3. (this isnt a question) I don't think any BOV helps you turbo spool faster, they only prevent the turbo from stalling.

I'm also trying to understand how the BOV can leak when idling. Is it because during idle there is a vacuum just like when you let off the gas? I wonder how having my IAC unplugged will mess with things if I get a BOV

would a BOV be the end of the world on an auto tranny cus i like many love the sound. Almost got an SRT-4 just for it

OK.

The stock recirculating valve DOES help keep the turbo spooled between shifts. It was very noticable to me when I installed my TMIC and switched over to an atmospheric BOV.

With the stock valve venting back into the compressor inlet, getting back onto acceleration from a shift was smooth and quick. The turbo stayed partially spooled.

With the atmospheric BOV, after a shift it was quite obvious that the turbo had some work to do to get back up to speed. The smoothness of acceleration coming back on was gone; and there was noticably more lag after a shift. Not to mention that I had idle problems after letting off the gas on boost.

edit: the idle problems were due to my GReddy Type S BOV not being hooked up in the most optimal way possible; but before I could figure out what that was, I got me an HKS SSQV valve which never leaks at idle and is guaranteed to hold insane boost pressures, like 50 psi +. Leaking at idle is mainly due to the BOV opening from a pressure differential between the intake tract and manifold, and then not closing properly and leaking instead until you give it some throttle and it sees enough vaccuum to close fully.

BOV's are only useful on autotragics when you let off the gas quickly under boost. Which you'd probably be doing more and more often to hear the valve, and which will similarly make other motorists think you have a manual But it wouldn't hurt the car in any way.

1. The pressure differential across the turbo's compressor. With a recirculating valve, the pressure is equalized very well, even when the pressure upstream of the compressor is below atmospheric.

2. If the air recirculates, it doesn't leave the system until the engine ingests it, which means all the air seen by the sensor still gets burned by the engine with the fuel metered for it.

3. Not true. See #1. Like Chris says.

hi guy i have a tmic wrx 06 and im planning to get td04

i have already the injector and the jesc maf

i dont have the bov adapter i think!

i never see it on my car unless its really well hide
but this only on engine with intercooler?

i have a legacy 94 sedan turbo

and i found GFB Stealth FX for 120$ right aound my place sound a good price but, if i have one i may not need it.

im planning to use revtronix chip stage 2

around 16 psi

your tough?