ok. so I finally got everything ironed out on my car and once I put my midpipe on I get overboost after about 5K on the 2nd turbo (obviously). my primary boost is rock solid...right to 11 psi and then the transition is excellent 11-9/10-11...but once I hit about 5 grand it starts to creep pretty bad...I havent seen it stop, but I have only let it creep to 14 psi in hopes that it would back off...nope. I am looking at porting the wastegate. And upon inspection of my spare set of twins (practice), I noticed that there is a plate on the back side of the secondary wastegate. I have an extra gasket on my spare set of twins that I can put on. I am thinking that the wastegate plunger might be restricted by the rear plate. of course this is fine on a stock/ slightly modded car where back pressure is present since the wastegate doesnt need to bypass as much axhaust. I would like to avoid porting the wastegate if I can. Is it a bad idea to try before porting the wastegate?

mods in sig.

Thanks for your help,
Sean

 

already off first page...TTT

 

up, up , and away. I really need some help. Thanks guys.

 

You can releave the spot where the back of the wastegate hits for more travel but the travel is limited by the stroke of the diaphram and rod . So you do need to port the wastegate .IF you have a spare set pull the prespool door out of the spare and put it in the wastegate position of the good set .The prespool door is 1/10 inch bigger than the wastegate door and you can port the hole bigger for more control .