Originally Posted by
Da55id
After getting the pulley/tune/tcu treatment a month ago I was experiencing lurching on takeoff and wondered what was wrong thinking that perhaps the ecu/tcu was interacting with the wheel spin limiter in a positive feedback loop.
Here's what it turned out to be. The car now has so much torque and the ecu tune has made the throttle so snappy that the g-force on takeoff was pushing me back in the seat and slightly pulling my foot off the gas pedal without my realizing it. Then I would instinctively give it gas because the car had slowed suddenly (of course!) and it would all happen again. So, my car is suffering from newtonian porpoising :-)
The fix was to move the seat down to get my knees lower and below the knee bolster on the bottom of the dash and to brace my body with my left foot before pushing the fungo. Now, we're having FUN!
Has this happened to others out there?
I wont say that I don't buy your conclusion, but the only time I have ever experienced that which you have described is when an electric kool-aid fueled brainstorm inspired a high school buddy and myself to take the factory seating out of his 1955 Olds 88 and replace it with bean-bag chairs (you think hitting the gas was interesting .... you should have seen what happened when you tried to ease on the brakes : )
In these cars, however, with properly secured seats this seems unlikely. I haven't seen it in either of my SLK32s (with a pulley, tune and TCU) nor have I seen it in my SL55 (with pulley tune and upgraded transmission valvebody).
I would lean more towards your original conclusion of the ESP creating this issue (which is why I have it automatically disabled on both of my SLK32s)
Chris