Getting compressor surge only when recirculating

2007 Mustang GT Paxton Blow Thru A2A cooled setup, trying to quiet down my BOV was the initial goal.

Swapped a Tial style 50mm BOV to the newer Tial QRJ.

Product link:
http://www.tialsport.com/index.php/tial-products/bovs/140-tialbvqrj

Running it fully atmospheric this is louder than the 50mm and also a different sound but loud and annoying none the less on both setups at fully atmo.

So I tried to recirculate the QRJ and used a 1.5" radiator hose to the inlet intake tube and during normal driving it's fine but any boost higher than 3-5 PSI I get compressor surge. Or at least that's what it sounds like.

As soon I unplug the hose from the BOV I get a clean blow off every time.

Where is the restriction coming from?

The BOV is mounted before it enters the intercooler core with a 50mm V-Band and the outlet of the BOV is 1.5" Straight to 1.5" hose and doesn't taper anywhere.

If you're surging the restriction is at the BOV. Doesn't matter how much air you dump back into the intake tube as long as it's post-MAF, pre-blower inlet. The only other thing I can think of is the new bypass valve is not responding fast enough when you left off the fun pedal. Like it's operating, but it's late. May want to contact the manufacturer and ask if they are preset (like the ATI BOV/BPV come) or if they need/can be adjusted.

Was re-reading your post. You're set up for blow thru but returning the air to the inlet. I assume your MAF is after the Bypass?

Yes MAF is after the BOV and intercooler right before it enters the TB.

Not sure on the surge. But did you try the carb foam trick to quiet the regular 50mm.

http://www.s197forum.com/forum/showthread.php?t=58379&highlight=bov+foam

I have tried it actually, but I got funny idling issues so took it off.

The noise of the Tial doesn't bother me. I'm glad the noise pisses off other people. Having said that, why don't you just get a bypass setup instead of trying to turn a BOV into a bypass ?

The Tial QRJ is a BPV that can be used as a BOV. Tial designed it to be a BPV first.

Hmm, odd. Okay back to the bpv, when you say you unplug it are you unplugging the hose at the valve or from the intake tube? Does it do it if you just run the hose to no where? No need to recirc really since its not metered air that's causing the issue. Maybe make a silencer. Run the hose to foot long pvc pipe with a cap on one end and drill a bunch of holes in it, spray paint it black and hide it somewhere etc. lol

I'm using a 1.5" flexible radiator hose. When I'm "unplugging it" I'm disconnecting it from the BPV port. I just lay down and undo the clamp and pull it off.

I haven't tried with keeping the hose attached and unplugging it from the intake pipe.

I run about a foot of hose off my BPV and then have a K&N breather on the end of it and it muffles the sound pretty good. You can hear enough to know it's working but it is half as loud as it was without the hose and breather.

is it possible you have a hose collapsing?
I use the wrong hose, oil got onto it and soften up hose enough to cause issues.

RED09GT said:

I run about a foot of hose off my BPV and then have a K&N breather on the end of it and it muffles the sound pretty good. You can hear enough to know it's working but it is half as loud as it was without the hose and breather.

Click to expand...

What type of BPV are you using?

06monera96 said:

is it possible you have a hose collapsing?
I use the wrong hose, oil got onto it and soften up hose enough to cause issues.

Click to expand...

Which hose, the Radiator hose? The radiator hose has metal coils in to give it flexibility so it can't collapse. The vaccum hose on the BPV is a 1/4" fuel pressure hose and don't think those collapse either.

x3 on the silencer/muffler idea, I think it's the fastest route to solving your problem. The silencer could literally be as long or whatever as you needed it to be to do the job, you could even run it to a small engine muffler, lol.

o2sys said:

What type of BPV are you using?

Click to expand...

It is an OEM Mitsubishi one that powerhouse included with their turbo kits, it does the job.

Does airflow prefer a smooth passage way?

If the outlet of the recirculating hose is ribbed as opposed to a smooth inside would that impact air flow coming out of it???

I'm using this hose and maybe the bends and turns plus the ribbed inside is restricting?



I also tried this filter only and the filter flows too much and doesn't do anything as far as sound suppression. But it doesn't surge with the filter alone.