My opinion here. The longer the wheelbase (Lever) the lighter the front needs to be. The more horsepower the heavier it needs to be. Bottom line it it is a balancing job to get it right and if there is too much up front car will not work. IMHO.
My car is 225 inches with 760 Hp, 1730 with 389 up front. Did not work very good. So I am moving weight and making other major changes. I believe on my car it needs to carry front tires out a ways to keep rear tires planted. Right now it pops them up drops them back down and unloads rear tires. Also I am thinking on this car a stiff sidewall tire may help this chassis work better. My goal is to get it to hook good on any track. Now 300 does not sound like much weight and it is not but look at how long the chassis is and that works like a long lever.
I think on my car with my horsepower it really needs to be around 300 LBS up front. Once I get it right then probably 10 LBS over front wheels would make a difference.
Do you even know what the static weight is up front? Where is battery located? Fuel cell? How big is it? With a 225 inch car I would shoot for 300-320 up front as a starting point.
Nobody can answer how much weight to add if we do not know what the static weight is.
