Any one use Summit Racing Springs? Need feedback

They are real close in price to the QA1's that I have so, I dont know it they are just summits knock off version. where are these springs going (front/rear). 450 spring rate seems really high. 9" seems pretty short too but, I only have coilovers in the front. Is this for a drag car or road course? Mine on the front were for a drag set up and were 14" 150's some say you should use 12" though.

I only have them up front as my car is more of a drag/street car. My first set of coils were 200's 12" they felt just like stock 20 year old springs to me. Those where from granatelli & they called the 200's their "drag" setup. The problem I had was that they were to stiff & too short. I say too short because I had to lower the perch all the way down to get the ride hight I wanted but, when the suspension was extended, (jacked up or launching) the spring would no longer touch the strut tower. You could flop the spring around by hand. I went to QA1 14" 150's next. Those worked perfect until I dropped 200 lbs off the front end. Now I have the adjustment all the way down again & it still rides too high. That is why Im going with 14" 95's I havent tried them out yet though. If you want stock ride hight up front, you might want to go with your 450's but probably 9 or 10" like you planed instead of 12". that way with the short springs you will be able to go lower than stock ride hight.