:. Racing .:. RMCBMW CCA #5
Results: Here
Light!
After taking some time away from the car to help myself reduce my "fed up" factor, stepping back into the car with renewed enthusiasm was fantastic.
| Newly installed were my shortened shocks, so I could go back to running 0 front droop and some
nice preload (14 turns was all I could get by hand), and some 250/400# springs. After talking extensively with Tommy Saunders and Stuart Lumkin at the Topeka Divisional, I was able to determine that my 400# springs (480# wheel rate), were roughly 3 times stiffer than they were running. So, I dumped down to the softest springs I had that would still keep the roughly .60-.65 ratio.
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Result? WOW. The car finally had the grip I was looking for. Neutral-state turnaround behavior was OUTSTANDING, and the bumps hardly existed at all. With the large front preload, the front-end responded excellent (what slalom), but was not slidy or scary at all to drive. Lots of grip, and the car really "took a set" nicely.
Extra gearing from the 14/50 sprocketing doubtless helped as well, although I'd still like another tooth or two reduction on the front sprocket ot really get into the meat of the 2nd gear powerband most of the time.
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With the 250# springs and no front rollbar, there was enough roll to scrape the sides of the splitter pretty significantly, despite being at the highest ride height I could (about 2.5"), and having nearly an inch of preload on the springs. I also set the bump at 6/6, and had almost zero issue with bump compliance, even in the bumpy northwestern portion of the lot. I may need to back that down to 4/4 or 5/5, but if the 350# springs go into the rear, the extra bump may be just right. I ran the tires at 12psi and 14psi. |
| So, to prevent this, I think I need to reinstall the front swaybar, and see if that reduces roll enough to keep the nose off the ground. If so, then I can try moving to a 200/350# combo, and see if that improves grip, or if it is too soft for good performance. If the 250# spring turns out to be the minimum for the front, then I can either bump the rear springrate, or see if it's finally time to hook up the rear swaybar again, to get that last bit of neutral handling back in.
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roll!
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I had FTD today, and was able to outrun both Jeff and Evan, despite Jeff's huge new front wing and splitter contraption. The car is definitely working well! It would have been enough for 948 points, which would have been a new high for me in the car.
I guess this proves that AutoX setups really are a lot different from road racing setups!
For Next Time
For next time, it's more steps in the same direction. Adding the front swaybar to see if I can keep the front roll in check. Then, seeing if I can go 1 step softer on springrate to 200/350, and see how that behaves. I don't want to go stiffer on front spring, since that'd require a 300/500 combo, and the 500# rear spring would definitely start having bump-compliance issues again. So, I would like for 250/400 to be the new max for solo, maybe 250/450, but assuming the bar keeps roll in check, 200/350, 200/400, or 250/400 may be where I end up before the aerodynamic changes start coming into play. After seeing how soft I can go on the front, with or without the bar, and if it works, the rest will be tuning the rear spring and bar to get the last of the balance I can out of the car.
Aside from suspension, the next tweaks are to gear down as much as possible, and finally, to start reducing the weight of the car, and moving it forward as much as possible, to help that on-throttle behavior.
NEW CHANGES:
- Zero Droop
- 250/400 springs
- 14/50 sprocket
Media:
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