D4 Racing coilovers FRONT SPRING RATE: 12.1 kg/mm REAR SPRING RATE: 7.2 kg/mm
From www.justjap.com

http://www.justjap.com/parts_nsuspension.htm

I was wondering if anyone has any experience with these? ride quality? hows the handleing? Street or track use? Drifting?

 

And it`s G4 Racing not D4. My bad

 

Never thought I'd say this but.....the rear spring are too SOFT, as compared to the fronts. 10/7 would be much better than 12/7. Other than that, who knows, I've never heard of them. I would stick with Tein Flex in that price range.