The stock wastegate is not big enough to prevent boost creep, especially for the
1986-1988 Zenki turbos. Boost creep is the uncontrolled rise in boost usually
caused by a freer flowing exhaust system. By porting the wastegate passages,
we allow the stock wastegate to have better control over boost creep.
We have two different wastegate porting pages in the How-To sections. Please
click on the links below...