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

[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.