increasing stealth downhaul purchase

anyone got any sketches , photos on how to increase the purchase on the standard JP stealth set up , looking to get to 16 :1 and lead out to traprings , any one beefed up main purchase ? i'm running 7:1 , just thinking of the wimps in the f18s and the super easy purchase sytems they have , this ease of adjustment has seemingly sped them up .

I'm running 16:1. My boat came with a 8:1 originally, lead to the sidestays. I doubled the purchase by adding a two dyneema lines from the boom attachment up to the tack and down to the blocks originally attached to the main.

It works, but space is tight: the length of the line need to be calibrated carefully if you want enough travel down, and the blocks occasionally catch up on the boom. Sorry, no pics...

Can you make it internal?

I have 12:1 internal on the Blade.

rather not , my mast is watertight at present dont want to muck about with it , think i know what your getting at pepin sketch would be good to see if i'm thinking same , though i cant see how it ends 16 :1 , but if it works who cares ! think scooby put up a picture many moons ago ?

Here a pic of what my 8:1 downhaul looked like before I started mucking with it. Not exactly the same blocks, but the layout is the same. The system in this pic (out of the Murrays catalog) uses one back plate for all the blocks at the bottom, mine has two separate ronstan swivels and the bottom block simply screwed to the mast base.

Keep in mind that somewhere in between the top and the bottom the boom connects to the mast.

I added two lines from the boom gooseneck, to a shackle with two ears attached to the sail tack and down to each of the blocks.

take a look at this thread on the F16 forum: http://www.catsailor.com/forums/ubbthreads.php?ubb=showflat&Number=146087

Starting here: http://www.catsailor.com/forums/ubbthreads.php?ubb=showflat&Number=146080#Post146080

What you cannot see is that the blue D12 has a bobble on the bit that come up from the base of the mast and the D12 that goes around the block on the sail has a loop in it (to go over the bobble). Works like a dream; releases well.

"simples " and a cheap easy upgrade too , many thanks , mod will be done ,when I max out down haul cleats struggle to hold , plus easy adjustment may see me being less lazy and adjusting more often , as a fat big lad i could pull on no troub , but ease of adjust will have many more advantages.