Simple question: Can the stock dump valve (MY98) be vented to air?

 

Yes

 

But why would you want to?

 

I have recently installed a Hybrid FMIC. When the dump valve opens, after decreasing throttle input, I get a strange "surging" acceleration when I reapply throttle.
My theory is that the increased amount of air returned by the dump valve (due to the FMIC piping) upsets the air flow meter. If my theory holds true, the problem will disappear when venting the return to atmosphere

 

Just get rid of the dump valve completely, depending on the turbo you are running......

 

I guess self destruction is imminent if you combine a VF29 with no dump valve?

 

I assume you had the car mapped when you fitted the FMIC?

 

Sure. Or rather, I do it myself. Have FC Datalogit with wideband and EGT. DIY knock cans.

 

If you are running a stock recirc DV then it must be used as such and not run as a VTA.
I assume you are still running your MAF? That is another reason for continuing to run recirc.
You could try plugging the spiggot for the DV connection on the hard pipe close to the throttle body.
If you are running a VF29 I would not operate without a dump valve as that will greatly shorten its life.