Dump/Blow off valve on 4AGZE how???

[MartG]

ae86 Wrote:Use a open filterbox and hear the screaming sound of the charger

[Lauren]

ae86 Wrote:He only like the sound of PFFFFFFFFFFFFFFFFFFFFSSSSSSSSSS
BOV on a4agze is not done.
Use a open filterbox and hear the screaming sound of the charger

Amen to that.

[Erik_dk]

yeah but you can get the charger sound and a bov sound also... in tha same time:-) and i have seen alot of 4agze there have difficult to idle whit front mount ic.. when yoiu have modified the throtle body you can have fine idle all the time..

[ae86]

the problem with de fmic is that your hose sucks together.
Because the trottle body coms first than the SC, fmic and inlet.
The inlet vacuum sucks everthing together.
You must bypass the SC in idle , than you have no problem.

[NoHachi]

Quote:Pressure isn't an issue on the SC because the SC is not before the throttle body. In fact a GZE is more responsive when the ABV is taken out of the equation. From your reasoning you would need a BOV on an NA.

If you think that is my reasoning, then you're not trying to understand what I'm saying. The supercharger is spinning, it its still creating a pressure differential over itself even if the throttle is shut. It pulls a vacuum between the compressor inlet and the throttlebody and creates a higher pressure at the intake manifold (if it is pumping more air then the engine). Compressor surge happens, its just a fact..whether or not it is a problem depends on the application.

You get a lot of surge with a normal compressor setup during part throttle cruising. Toyota added the clutch for that problem, so less of a need for a by pass valve.

Anyway, don't take my word for it. Check the specs for the bigger SC brothers in the GZE superchargers Eaton family..MP45 MP60 they all have em and I dont mean a ABV. Corkey Bells book on superchargers has a nice bit on it too.

I'll take your word for it that it isn't a very big problem on the GZE. Just stating that having one of these can make sense on an SC.

[ae86]

There is no pressure between the SC and intake when the trottle is close, only vacuum.
When you close the trottle, instanly there is only vacuum.
When you have part trottle and the SC clutch is NOT on, the SC spins also up during the air coming in the engine.

[NoHachi]

There is a pressure differential between the SC inlet and outlet. The outlet can still have neg.pressure but it will be XX bar less neg.pressure then inlet.

[Lauren]

NoHachi Wrote:If you think that is my reasoning, then you're not trying to understand what I'm saying. The supercharger is spinning, it its still creating a pressure differential over itself even if the throttle is shut. It pulls a vacuum between the compressor inlet and the throttlebody and creates a higher pressure at the intake manifold (if it is pumping more air then the engine). Compressor surge happens, its just a fact..whether or not it is a problem depends on the application.

You get a lot of surge with a normal compressor setup during part throttle cruising. Toyota added the clutch for that problem, so less of a need for a by pass valve.

Anyway, don't take my word for it. Check the specs for the bigger SC brothers in the GZE superchargers Eaton family..MP45 MP60 they all have em and I dont mean a ABV. Corkey Bells book on superchargers has a nice bit on it too.

I'll take your word for it that it isn't a very big problem on the GZE. Just stating that having one of these can make sense on an SC.

Okay fair comment. I understand what you are saying and yep can see that there will be a pressure differential when coming off the throttle.

I've got both of the corky bell books (supercharging and turbocharging).

I guess what i was saying was that in practice its a non-issue. Taking the ABV out of the equation does mean that when you click the SC on it does so more abruptly, but thats not really an issue in itself. I did some 30K miles plus in an MR2 SC with a big pulley and no ABV at trackdays all over the UK, including a few euro trips to Spa.