When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Forge is physically bigger and comes with several springs. Forge doesn't have the cooling fins. Both are very good.
I've read complaints about the lube on the Forge messing up but I don't know. I never saw any trouble with either of them. This was one of two installed on an S4. The other one was purple. The pair were replaced with a matching set of Forges when the car went stage 3 in case the other springs were needed.