GM Metric Suspension. What am I feeling
I am racing a homebuilt IMCA GM Metric Stock car with a name brand rear end. I've had some success winning 2 out of 10 races this year. As all racers, I am looking for a certain feel and hopefully more speed. I started the year with a 150lb LR spring, 200RR and 100 lbs of bite with me in the car. The feel was great on starts and the car felt stable and took off well, but had to really pedal it in the center of the corner, and once the car was back under me, had really good drive again. As the tracks have dried out, I went higher in bite number, up to 140 only to lose feeling of being "on the track". Seemed as though it made the center-off worse and would feel like instant traction, but felt like the lr would "give up" even quicker and the RR just over drove it. I went down in the RR spring rate to a 175 and def helped tighten that center off feeling, but still need to pedal it. I have a modified background and been following the trends of soft LR springs so I gave that a whirl. I used a 125 with same 140lb bite number (6" of preload at installed height). With this spring it felt like the instant traction wasn't there and lazy/sagged on lr on entry. I didn't have to pedal it as much as the 150 and liked the feel there, but it seems like the car doesn't take off straight (I'd describe it as spinny/squirrley) on the starts. Almost like the RR is dominate to start, then LR..like its climbing between each tire. This last weekend I tossed a 200 LR spring in there and stayed with that 140lbs of bite. The initial traction on starts was back, but the mid-corner pedaling is back and felt like traction ran out even quicker than the 150lbs spring. So my question is what am I feeling? The higher preloaded LR should provide more dynamic bite vs. the others, but is it too soft on starts? Old adage that "stiffer spring gets the weight"? Does that still hold true even when preloaded to same installed load as stiffer rate? Is it the static bite number that is causing this to feel "off the track"? Other ideas? 2"offset around the car with a 4" RR. 53% Left and 54% rear. 7 5/8 ride height across the rear per the rear end builder giving top links 13 deg down hill to the chassis at ride height. Consistently 1-3/4 to 2" travel on RR and LR has been spring dependent..I am all for trial and error and I have found a way to win with it now, but need someone to bounce thoughts off of to avoid wasting a night on R&D.Bananahammack00