[74goldtarga]

I ran my 951 at the racetrack this weekend in a PCA DE. I have run this same car at the same track many times without a problem. Background on the car - it has 134,000 miles with about one-third of the last 10k being track miles - I haven't touched the engine other than timing belt and water pump (and tune-ups/oil changes) since I have owned it. The engine has Weltmeister chips, wastegate shims and a Lindsey Boost Enhancer.

Here's what happened - I drove the car to the track - 140 miles no problems. In the first session I'm going down the main straight shifting through the gears with full-throttle applied after shifts and running to redline. In 4th gear at like 3K rpm and the dash boost gauge reading 2bar the engine stops pulling - it doesn't buck, the rpm stays stable but my foot is to the floor and there's no acceleration. If I lift the throttle the boost falls off (obviously) and I can then floor it again and it will accelerate to redline like normal. This happened multiple times in a long sweeper where I short shift to 4th (so I don't have to shift mid corner) and then feather in the gas mid-corner, at corner exit I put my foot to the floor - usually this is where the car would basically stop accelerating. This happened multiple times on the main straight as well, sometimes I would have to lift off the throttle a couple of times.

My mechanic thinks it might be a throttle switch, doesn't sound like the clutch because the rpms stayed stable. What do YOU think?