to port or not to port...wastegate on twins.
#1
I AM A THIEF - READ GOOD GUY / BAD GUY
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Location: Chattanooga, TN
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to port or not to port...wastegate on twins.
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
mods in sig.
Thanks for your help,
Sean
#4
Rotary Freak
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 .
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