My turbo MX-5
#81
Usually, this. ^
The rule of thumb is to keep at least a millimeter of flat, untouched edging to keep a seal. There are different ways to "knife edge", by removing material either on one side at a 20 - 30 degrees, or both sides at an even 45 degree, or even "rounding" the square edging.
Edit: and by looking at yours, dont touch the front edge, its the sealing point.
M3 tuners do this, from what ive seen thats why I asked. Its not for power, but throttle response.
The rule of thumb is to keep at least a millimeter of flat, untouched edging to keep a seal. There are different ways to "knife edge", by removing material either on one side at a 20 - 30 degrees, or both sides at an even 45 degree, or even "rounding" the square edging.
Edit: and by looking at yours, dont touch the front edge, its the sealing point.
M3 tuners do this, from what ive seen thats why I asked. Its not for power, but throttle response.