an accurate measurement of boost. I ran boost jets for years. I temporarily spliced in an accurate aftermarket boost gauge (through the driver window) so I knew exactly how much boost I was pushing when I sized my boost jets. Then I "upgraded" to a MANUAL boost controller that a lot of folks here would call trash but it worked well for me. I like simplicity. Either way you have to invest dollars into either a boost gauge or moer $$$ for an EBC. Never mind, just get an EBC. Point is, you have to have an accurate measure of your boost, one way or another.