Will this kill my 904 ?
An other idea could be some type of damper on.the throttle to just ease the hit
That's kindof what I was thinking.
I've rigged up a few things for my junk; a two-stage throttle was one such. Nothing complicated. Just a light return spring on the first part of travel, then a heavier one on the latter part, with an adjustable sliding stop to change the cut-in point.The springs were chosen to make the cut-in point obvious.
I used coat-hanger wire bent into an elongated S shape with one long leg, and a wire clamp from the lawnmower dealer;real simple. Drilled a hole in the throttle return-spring anchor for the long-leg.Took about 10 minutes to build and set. Don't know if it would work on my high-rise AirGap as originally built, but it worked on other intakes. Pretty sure I could make it work on the AG if I wanted to.
I used it for a couple of purposes on different cars. On my DD the early part was set to stop the throttle opening to just achieve 62 mph as a poorman's cruise control. I just laid my foot on the pedal and eventually it got there, great for fuel mileage. A little heavier foot got into the second spring for passing and such. I think on the DD it has over 400,000 kilometers on it and still works.
I'm still not a racer tho.