what if you don't use!!
11-08-2003, 11:32 AM
#4
3.0 BAR
Join Date: Apr 2003
Posts: 11,058
Re:what if you don't use!!
here ya go........ "An Explanation of Compressor Surge:
The turbine in a turbocharger in its ideal mode is spinning at a very high rate and therefore generating lots of pressurized air that is fed into the OPEN (wide open throttle) intake manifold which translates into more power, but what happens when you take your foot off the gas when shifting between gears? The turbine in the turbo is still spinning at a high rate but now you've taken your foot off the gas and the intake manifold is CLOSED. Now the turbine spinning at a high rate and is trying to push out all this compressed air but since the manifold is closed, that compressed air has nowhere to go. What happens next is that the turbine slows down because of this pressure build-up between the compressor and the intake manifold. Since the pressurized air can't go forward into the engine it heads the wrong way back towards the turbo where it slows the turbine down (compressor surge). After you shift gears and you step on the gas again you want to have the turbine spinning fast so that its producing boost but since you took your foot off the gas and caused compressor surge, it slowed down, so you have to wait for the turbine to "spool up" (spin fast) again. This delay waiting for turbines to spool up is what causes some of the performance degradation that were trying to avoid."
The turbine in a turbocharger in its ideal mode is spinning at a very high rate and therefore generating lots of pressurized air that is fed into the OPEN (wide open throttle) intake manifold which translates into more power, but what happens when you take your foot off the gas when shifting between gears? The turbine in the turbo is still spinning at a high rate but now you've taken your foot off the gas and the intake manifold is CLOSED. Now the turbine spinning at a high rate and is trying to push out all this compressed air but since the manifold is closed, that compressed air has nowhere to go. What happens next is that the turbine slows down because of this pressure build-up between the compressor and the intake manifold. Since the pressurized air can't go forward into the engine it heads the wrong way back towards the turbo where it slows the turbine down (compressor surge). After you shift gears and you step on the gas again you want to have the turbine spinning fast so that its producing boost but since you took your foot off the gas and caused compressor surge, it slowed down, so you have to wait for the turbine to "spool up" (spin fast) again. This delay waiting for turbines to spool up is what causes some of the performance degradation that were trying to avoid."
11-08-2003, 03:45 PM
#5
Administrator
Join Date: Dec 2002
Posts: 13,991
Re:what if you don't use!!
You dont need one, lots of factory cars dont use them, and only if your running incredibly high pressures will it ever hurt the turbo. The noise it makes without one "compressor surge" is more of an annoience than anything.
jeff
jeff
11-09-2003, 02:19 PM
#8
1.5 BAR
Join Date: Jan 2003
Posts: 1,115
Re:what if you don't use!!
Sooner or later the thrust bearing will fail, but who knows how long it will last. My best friends has a BUICK GN that runs 18-30psi and he has never had a BOV ( even from the factory ), but his car is an automatic so that changes things a little.
11-09-2003, 05:44 PM
#9
Guest
Posts: n/a
Re:what if you don't use!!
Sooner or later the thrust bearing will fail, but who knows how long it will last. My best friends has a BUICK GN that runs 18-30psi and he has never had a BOV ( even from the factory ), but his car is an automatic so that changes things a little.
11-09-2003, 09:25 PM
#10
0.5 BAR
Join Date: Jun 2003
Posts: 88
Re:what if you don't use!!
Well, to explain why Buick Grand Nationals don't have BOVs is because with an automatic, you don't have to let off the gas to shift, so the air doesn't build up until you actually let off the gas pedal. My friend with a GN told me that he just lets off the gas a little slower when boosting so he doesn't build up pressure behind the throttle plate.
