no blow off

[nosdsm3]

Hi guys. Here is my problem when I am driving my car I can hear my blow off working. Yet if I just rev the engine while sitting still it dose not is this normal?

 

[ricktb]

My car does the same. Something about the engine load to spool the turbo and build boost

 

[wickedz]

you need to drive the car to put a load on the bov to vent right. You need to load the turbo because sitting still you dont build boost

 

[rstare]

If you look at your boost gauge while just revving your engine, you will see it won't actually go into boost. As others have mentioned, this is because you need a load in order for the turbo to create boost. Apparently there isn't enough pressure differential while revving to open the BOV, which is normal. Mine doesn't actually open either.
If you just flick the throttle open and closed really quick while looking at the BOV, you'll be able to see it move a little bit.

 

[GRAVEDIGGER]

From my experience if you rev the engine up and slam the throttle closed you should and will get the bov to vent. Even though you are not putting a load on the engine and aren't building boost you are still creating enough airflow to make the bov vent when you close the throttle immediately. It may not be as loud as it is when it opens under boost pressure, but it will open. Maybe I'm wrong as every setup is different, but every dsm I've owned would do it.

 

[nosdsm3]

If I rev it from the engine bay I still dont notice anything.

 

[Evo_This]

What bov are you running? Are it to vent you're goin to have to rev it kinda high like 3500-4000 + rpm

 

[TurboATM]

From my experience if you rev the engine up and slam the throttle closed you should and will get the bov to vent. Even though you are not putting a load on the engine and aren't building boost you are still creating enough airflow to make the bov vent when you close the throttle immediately. It may not be as loud as it is when it opens under boost pressure, but it will open. Maybe I'm wrong as every setup is different, but every dsm I've owned would do it.

siting still and revving will build some boost, yes...But is alot less psi than while driving. you hear the bov ALOT more at 15 psi than at >1...

If you have a vented BOV, then you will hear it...like the SRT4 with their bov plate thing

 

[steve]

From my experience if you rev the engine up and slam the throttle closed you should and will get the bov to vent.

Sounds like an adjustable BOV that set too soft. The BOV shouldn't open unless there is pressure above atmospheric in the intake that needs to be vented. You don't want the BOV to open under just manifold vacuum and suck air in.

It should be adjusted to open when you've made boost and closed the throttle but not just by reving and closing the throttle unless your trying out for the latest edition of F&F.

 

[david-b]

My BOV opens at idle when revving, but obviously it will never build boost while not moving (due to lack of a load). It's a 1G BOV so no adjusting. It doesn't make a sound though with no load. Love that BOV!

 

[jrohner]

I have my BOV crushed as much as possible, and it vents a lot of air just revving it up a little in neutral. You just might not be able to hear it since there's not much pressure there.

 

[nosdsm3]

I am only at about 6 psi right now, and you can hear the BOV under load I just thought it always did it. I have a HKS SSQV blow off valve. I'm running a high compression set up so this motor wont be pushed to hard. After it gets broken in a bit then maybe 9 psi. Its just my toy not a dd but I want to get some miles on it.

Thanks for settling this for me guys.

 

[TalonESIT]

At 6 psi, like everyone has stated, you won't hear your BOV when letting off from an idle rev. If you were boosting higher, like 12+, you should be able to hear it a bit. Again, depending on the BOV you own.