No it does. I wasn't really trying to go higher the D shape is suppose to help with low end power but like you say you cant go lower. Now that I look at the phantom jug the arch is on the top not the bottom. But I still like smooth undisturupted air flow. Since I have to wait for rtv to dry looks like it's time to get some exercise and get some engine degreaser and some cut off wheels for my exuast bolts.