RANT ON -- Having been a drag racer since the late 60's, competing in countless NHRA and IHRA events, setting NHRA records, and only recently having discovered the pleasures of autocross, track days and road racing, I would like to respectfully request that y'all stop talking about a DRAG RACE in the CHALLENGE. THERE IS NO DRAG RACE IN THE CHALLENGE. There is a 1/4 mile ELAPSED TIME RUN in the challenge. There is NO RACE. A drag race is a competition between two cars from a standing start for a specified distance and whoever gets there first wins. (Yeah, I know, breakouts and all that E36 M3, let's not go there). The vast majority of the skill in drag racing is the start and the finish; properly staging, cutting a light, hitting your shift points and taking just enough stripe to win. In handicap racing it also depends mightily on choosing the right dial-in. None of that comes into play in this challenge thing. It's not drag racing, so stop calling it that. -- RANT OFF
For the OP's question, from a technical ET perspective, you want the suspension set up to provide the as much weight transfer on the initial movement of the car as is needed to provide necessary loading of the drive tires such that they don't loose traction, i.e. spin. On a low powered car, you don't need a lot of weight transfer with decent tires. On a high powered car with a great suspension designed for a standing start launch, it is what is needed, and no more. On a high powered car with a lousy suspension you need a lot of weight transfer, even with good tires. Watch a "pro-stock" car launch. It doesn't do a ridiculous wheel stand. It just barely pulls the front wheels off the ground, which means, obviously, that the weight of the car is being handled by the rear tires. The multi-link suspension is set up just right to direct all available energy to planting the rear tires. Putting the front of the car 4 feet in the air is wasted energy in that case. Watch an older "stock" or "super stock" car launch and it is completely different. Older high powered cars do crazy high wheelies because they are saddled with old, obsolete or structurally compromised rear suspensions. Standing the car up on the rear tires is the best way to increase the rear tire loading in that situation. You can't tune a leaf spring and shackles to work like a multi-link suspension. Newer cars, like "factory stock" (which are anything but stock) have much better (i.e. modern) designed suspensions and, even though they are far, far faster than the "old" cars, they launch much more like a tube chassis, purpose built "pro-stock" car. Small, low wheelies, even on a 9" slick (which is tiny in the drag race world).
For the OP's situation, with a fair amount of power in a light car, he will need as much weight transfer as he can get to keep from spinning the tires, and he needs good tires first and foremost. If treated like an "old" drag race car, he wants a low friction front suspension with virtually no rebound damping, literally none. I have known guys that actually drill a hole in the shock and drain all the oil out of them because the rules say you have to have a shock, but they don't really do anything. The car is going to bounce though, and you have to be ready for it. That is where the "90/10" shocks came in way back in the dark ages. Very little rebound but tight compression to dampen the motion when the car comes back down. They still bounce, but not as bad. Most people just run double adjustables these days that have very light rebound settings and are velocity sensitive. Before the urethane and Del-alum days some guys used to loosen the pivot bolts for the front suspension arms so that they would rotate more easily and not have to deflect the rubber bushings. There was some scary E36 M3 stuff going on at the local drag strip. The OP also wants as much weight as possible off the front end, dinky front wheels and tires, battery in the back, maximize the weight at the rear of the car. Take the sway bar off. He has an automatic with a torque converter and the converter is going to be the determining factor in how hard the car hits the rear tires on launch. If it is a street converter with a low stall speed, he isn't going to hit the tires very hard unless he is making massive torque at 2500 RPM, and won't need as much traction, thus less weight transfer, as it would with a high stall speed converter. I assume that he will not have a trans-brake, which could hit pretty hard even with a low stall speed. A high stall speed converter would give better ET results, but will generate a lot of heat in a road course type of application, probably not the best thing to do for the "challenge". He can control the hit to some degree by experimenting with launch RPM, i.e. how much RPM he puts against the converter while on the brakes at the start. He can only go to the stall speed, of course, but the amount of "power braking" at the starting line can make a big difference in how hard the tires are hit and it is highly dependent on the car itself. You just have to experiment to see what works best. A lot of people think power braking to the stall speed gives the best launch, but many times "flashing" the converter from a lower RPM lets the converter torque multiplication work to your advantage provided you have enough traction to hold the power.
There is another HUGE factor that is completely unknown is track prep. Starting line prep is everything to a high powered, small tire drag car. Where are the ET sessions going to take place and how well is the starting line going to be prepared and maintained? If it is prepped to a competition level expected by the small tire drag race community then the traction worries drop drastically. If it isn't, well, then who knows what to expect.
