I've always used motorsavers before, bu now I've heards of the end caps poping off, and due to the desighn really the only part of the filter that air goes thru is the end, as the rest of it is prefilterd. you will notice every time you clean a motor saver the end cap/foam is very dirty compared to the rest of the filter, making it the main part of your filter. a dual stage 1/8 scale buggy type filter would be best.