BOV Question

[T66]

Guys, will my turbo go to wrack and ruin when I remove the BOV? Boosting 8psi.

[beyondloadedSE]

If you remove the BOV, you wont be boosting at all and your car will run like absolute junk, now that youve got a huge intake leak.

[beef_bourito]

if you seal the intake when you remove it you run the risk of hurting your turbocharger. why do you want to remove it anyways?

[UncleBob]

at 8psi, you won't hurt anything.

BOV's are most effective on high-boost engines. Low boost over many many many miles, will see a very slight change in turbo longevity without a BOV, but its decimals. Look at all the stock turbo cars that didn't come with BOV's over the last 20 years, and had turbo's live 100+K miles.

[beyondloadedSE]

Originally Posted by UncleBob

at 8psi, you won't hurt anything.

BOV's are most effective on high-boost engines. Low boost over many many many miles, will see a very slight change in turbo longevity without a BOV, but its decimals. Look at all the stock turbo cars that didn't come with BOV's over the last 20 years, and had turbo's live 100+K miles.

thats because they used bypass valves instead. Seriously, not running a BOV or bypass valve is bad news.

[beef_bourito]

just a question, why do you want to remove your BOV?

[534BC]

Originally Posted by T66

Guys, will my turbo go to wrack and ruin when I remove the BOV? Boosting 8psi.

It depends on the application, if it is sized such that will overboost without a valave then that is exactly what will happen. I imagine that is true if it has a bov on it and will hurt engine before hurting turbo most probably.

[beef_bourito]

what you're thinking of is a wastegate. a wastegate opens to let out exhaust gases so you don't overboost. a bov (blow off valve) vents boost from the intake into the atmosphere so that the turbo isn't hurt when the throttle valve closes because that sends a pressure wave back at the turbo and it can surge.

[534BC]

Originally Posted by beef_bourito

what you're thinking of is a wastegate. a wastegate opens to let out exhaust gases so you don't overboost. a bov (blow off valve) vents boost from the intake into the atmosphere so that the turbo isn't hurt when the throttle valve closes because that sends a pressure wave back at the turbo and it can surge.

Ok, I got it. My mistake. We used to use that also to control max boost also. What would a typical set point be for a 10 pound system?

[beyondloadedSE]

Originally Posted by 534BC

Ok, I got it. My mistake. We used to use that also to control max boost also. What would a typical set point be for a 10 pound system?

a 10 lb spring.

[Black Lotus]

Originally Posted by 534BC

What would a typical set point be for a 10 pound system?

Try adjusting it so it just cracks open at maybe, 6 PSI.
That's just a starting point, so watch out for under/overboost.

[534BC]

I'll rephrase question. If I want to push 10 pounds of boost what should the setpoint or cracking pressure of a bov be?

If the cracking point of a bov is below the amount of boost then we are losing pressure, that sounds typical of some of the small diameter valves I used in the past. It makes for slower boost building.

If I understand what the bov is for (keeping the high pressure from backing up into turbine during shifts or during quick throttle letoff) then it would seem to set the blow off point at some setting higher than the highest boost attained.

How does that sound?

[Polygon]

The problem there is that you're trying to do two completely different jobs with one type of shift valve. You should do it right with a wastegate and a possibly a boost controller.

Anyhow, at any PSI you can damage the turbo’s bearings if you remove the BOV. The intake charge will move back into the compressor blades causing them to shudder and damage the bearing. Granted the lower the PSI the less damage you can cause. However, at high boost you can break off compressor blades. At lower boost, like 8 PSI, you're causing damage to the bearings.

Leave it on.

[Schister66]

Originally Posted by Polygon

Leave it on.

I couldn't agree more....compressor surge isnt a good thing and if its severe enough, it could slow spool time slightly