Is there such a thing as...

[JeremyH]

This is the best solution I have seen to get rid of the cruising noise from using a tial bov with a supercharger. Carb foam wrap around.

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


And yeah +1 routing a bov discharge to the exhaust is a horrible idea.

 

[JeremyH]

Hands down the Tial Q flows more air per cycle.
For supercharger guys your going to want a slightly softer spring than idle vac to allow it to open at idle/cruise. 6-8psi spring.




TiAL 50mm Blow off Valve, New Q Version. For use on turbo-charged and super-charged applications (Paxton, Vortec, etc.). The body and all internal components are CNC-machined from 6061 aluminum alloy. It features a large 1.98 in (50.5mm) valve.

- The V-Band design aluminum mounting clamp gives a very clean and unique appearance. The clamp is anodized and uses Stainless Steel hardware for a long lasting, corrosion-free appearance.
- The valve seal utilizes a Viton O-ring that is clamped in place to prevent the possibility of sticking to the seat and pulling out. The valve stem and guide are Teflon-lubricated, hard anodize-coated for wear resistance.
- The Blow Off Valve also comes with our own machined aluminum banjo-type air fitting and bolt, with over sized 10mm hose barb for quick actuator response. The actuator has a high temp silicone Nomex-reinforced diaphragm for long life.
- An aluminum or mild steel weld base mounting flange is furnished with each unit. Stainless Steel is available at an additional cost. The use of 6061 aluminum allows the housing to be anodized with a selection of colors.
- Through countless hours of R&D we were able to make the same size valve flow a staggering 60% more than the original design - that means 60% more air is blown off per cycle! This is the highest flowing BOV on the market.

 

[tjm73]

Until someone can tell me why it's a bad idea, it remains viable in my mind. If it is indeed bad for actual reasons as experienced by people that have tried it, I would concede my opinion. But I can't see a reason why it's "bad".

 

[TheKurgan]

Until someone can tell me why it's a bad idea, it remains viable in my mind. If it is indeed bad for actual reasons as experienced by people that have tried it, I would concede my opinion. But I can't see a reason why it's "bad".

If the noise bothers you that much then it could be done sure. But really if it's bothering you that bad then it's just better to go with a bypass. Also the heat would probably transfer up to the BOV which might damage the unit.

 

[JeremyH]

When would routing exhaust gas to the intake or vice versa ever be good? lol

Beside when in boost the exhaust is pressurized as well so exhuast would work its way back to the valve and likely force it open/restrict flow. Not to mention at part throttle/cruise the valve is open and exhaust gas is going ot get pulled into the intake.

No good could come of this.

 

[KenB]

Until someone can tell me why it's a bad idea, it remains viable in my mind. If it is indeed bad for actual reasons as experienced by people that have tried it, I would concede my opinion. But I can't see a reason why it's "bad".

What these guys have said is very good feedback. I would be worried about it getting hot and also the direction of flow under certain circumstances.

I think your best best is to build a muffler off the BOV. That's what I'm doing. It will be down in my fender.

 

[Sky Render]

When would routing exhaust gas to the intake or vice versa ever be good? lol

Beside when in boost the exhaust is pressurized as well so exhuast would work its way back to the valve and likely force it open/restrict flow. Not to mention at part throttle/cruise the valve is open and exhaust gas is going ot get pulled into the intake.

No good could come of this.

This is why it is a bad idea. BOV's are made to seal from one side, not both. You'd end up with EGR through the air intake!

 

[tjm73]

When would routing exhaust gas to the intake or vice versa ever be good? lol

Beside when in boost the exhaust is pressurized as well so exhaust would work its way back to the valve and likely force it open/restrict flow. Not to mention at part throttle/cruise the valve is open and exhaust gas is going ot get pulled into the intake.

No good could come of this.

I would argue that with the exhaust under pressure, the exhaust exiting the system it would draw the BOV pressure out faster. This is exactly what happens with crankcase venting systems in race cars. For the pressure to reverse flow and flow back to the BOV, there would need to be a severe restriction in the exhaust system. A fast moving charge of of gas is not likely to reverse flow, especially under pressure. It is more likely to create a draw (vacuum) from that smaller BOV discharge tube aiding it in it's discharge roll.

At part throttle, a simple one way valve would prevent back flow if it actually proved to occurred.

 

[tjm73]

I think your best best is to build a muffler off the BOV. That's what I'm doing. It will be down in my fender.

A great option that had not occurred to me.

 

[FalconGTHO]

I would argue that with the exhaust under pressure, the exhaust exiting the system it would draw the BOV pressure out faster. This is exactly what happens with crankcase venting systems in race cars. For the pressure to reverse flow and flow back to the BOV, there would need to be a severe restriction in the exhaust system. A fast moving charge of of gas is not likely to reverse flow, especially under pressure. It is more likely to create a draw (vacuum) from that smaller BOV discharge tube aiding it in it's discharge roll..

Youre thinking too hard about this and trying to solve a problem that doesnt really exist. Have you SEEN a centri setup in person WITH a BOV? Have you seen the packaging involved and I dont mean just from the top?

If I had known this was going to be a point of debate I wouldve taken pics of the assembly. On Tres setup the BOV location requires a nearly impossible path to fab a discharge pipe back to the exhaust. Its just needless, extra labor and cost and regardless of that just one more thing to add underhood heat as the tube would heat up via conduction due to being attached to the header/mainifold as well as being exposed to hot exhaust.

Theres no need anyway. The sound is the sound and thats just part of having a car built and set up for drag racing.

 

[tjm73]

Youre thinking too hard about this and trying to solve a problem that doesnt really exist.

It sounded like someone didn't like the sound of the large BOV, so I offered a possible solution that was poo-poo'd without any explaination. I challenged that. That's all.

I'd bet no matter the "packaging constraints", I could design a build my idea for very little money. But I digress. Back to your original question....

 

[Sky Render]

It sounded like someone didn't like the sound of the large BOV, so I offered a possible solution that was poo-poo'd without any explaination. I challenged that. That's all.

I'd bet no matter the "packaging constraints", I could design a build my idea for very little money. But I digress. Back to your original question....

Then do it, and let us know how those exhaust gasses entering your air intake work out for you.

Remember, bypass/blow-off valves are PARTIALLY OPEN AT IDLE AND UNDER VACUUM, as has been said multiple times before. But go ahead, don't let us stop you from your uber-cool blow-off-exhaust valve.

 

[TheKurgan]

Dude you're obsessing. Not only is it not practical, but hazardous tying in compressed oxygen with hot ass exhaust fumes and piping. Let it gooooo.

Also I don't know if you've ever seen someone hit the rev limiter on a SC'd car but it shoots flames out the pipes lol. Just think.

 

[s8v4o]

Until someone can tell me why it's a bad idea, it remains viable in my mind. If it is indeed bad for actual reasons as experienced by people that have tried it, I would concede my opinion. But I can't see a reason why it's "bad".

That would require a pretty long tube for starters which may affect the BOV's performance. Also most people reroute the air back into the intake tract post MAF but pre intercooler. This way the MAF metered air is already accounted for and won't cause driveability issues with it just vanishing. This is more important in a draw thru setup instead of blow thru. Another possible problem with your setup is carbon buildup from the exhaust might be a problem for the BOV and it's diaphragm. Also most people reroute bypass valves and not blow off valves. It would require much more effort to reroute a BOV due to its shape then a bypass valve which often has a place for a hose to clamp onto. Also when routed back into the intake tract it will muffle the sound. So while it could be done I think there are better options. It's nice to think outside the box though as it often gives more options for the seemingly mundane and gives often fresh ideas that people "in the know" won't think of because of traditional ideas and thoughts.