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Spent the past weekend at New Jersey Motorsports Park on the Lightning circuit. This is one of my favorite tracks in the Northeast and the main track I use when testing / comparing any changes to the car. No new changes to the suspension have been done since Thompson, but I have removed the JB4 tune from the car to bring it back to stock HP levels. The reason for removing the tune is that the 10 modification points in NASA TT are better used for Hoosier R6 tires. Although I still ran this weekend on the Bridgestone RE-11's, I wanted to get a baseline here on street tires without the tune. The result.... about 3 seconds a lap faster then when I was at Lightning a few months ago (though a lot of the time difference is driver improvement).
I also finally had the chance to get the Z4 on the scales. Total weight with myself, full safety gear and a full tank of gas was 3,465lbs. Which translates to a total of a 21lb weight reduction from stock with all the modifications done. I do need to corner balance the car though, with the current corner weights the car has a 47/53 front/rear weight distribution (which is the same as factory) and I'd like to bring this closer to 49/51. The weights also show that there is a little reverse wedge in the cross weight at 48% which is actually pretty far off from the 50% it should be at. Left turns currently feel a little less stable than right turns (possibly because most tracks I drive have more right hand turns, but I'd still like to get the cars balance closer to ideal.
Finally, not related to the suspension, I've recently been in contact with the folks over at Hawk Performance. They have a new line of brake pads coming out called "Street/Race" which are based on the DTC-30 race compound but with silica added to help reduce the noise and dust. I will be switching to these pads for testing at Watkins Glen on the Z4 in September. I have also confirmed that Hawk will be making a new pad for those of us who have the Z4 35is rear rotors and calipers installed. The new pad shape number will be HB751 and will become available in October. This will be a big improvement over running the HB669 pad with the larger 35is rear brakes.
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