stock wastegate porting, overboost vs less lag myths
 

So I'm doing the full non-seq set up on my twins at the moment and I've got to that stage of wastegate porting. Now I'm just trying to uderstand the logic of this.

Am I correct in assuming that ( the porting) is done out to the size of the WG door to help bleed off more exhaust to help control overboosting at high RPM /boost levels ( maybe above max stock psi) ?
If so, is the trade off with a larger WG port more lag?

The reason I ask this is that I've seen various threads stating that with the stock ECU you wont really run higher ( than stock) boost levels therefore you dont ned to port the WG in the non-seq setup, but there are also others who say you do.
At this stage I have closed the door and done the old spray paint thing to get the trace of the door size to port to. I've read that you need to port out to 3.18cm to get to the correct door size, so far I have used a dremel and got the port size to 2.8cm and I dont really want to go any further until I dispell ( or confirm) these myths of porting sizing and performance related pros / cons.

My theory would be that if it some say you need to port out to 3.18 ( even on stock ECU) and some say you dont have to at all, and the larger WG=more lag is true then i would be best to leave my WG at its current port sizing of 2.8 ( stock port size is 2.56 ) to achieve an acceptable level of overboost control with minimal turbo lag.


your thoughts

Your source of info for this stuff is like the blind leading the blind. Porting it won't effect lag. Porting is to bleed off the better breathing mods you will do. If you have no restriction, setting the boost controler to 10psi won't be effective w/ stock WG port. Understand?

Porting the wastegate will not affect lag, because it remains closed until boost reaches the level your system is set at.

With the stock wg door open the hole to 1.24 inches.If you remove the door and replace it with the prespool door that is 1/10 inch bigger than the wg door ,you can open the hole even bigger .Or you can make a bigger door on the lathe and go way bigger .My port is open to 1.38 inches with the supresized BNR twins .