javx2

anyone used the msd 5462 btm? used with factory hei ingitions? need to raise initial timing to 14 or 15 degrees, without putting advance through the roof. supercharger needs more timing to stay running going in and out of gear. i'm told this works great. any better ideas? thanks , john

cobra marty

I have one for sale. See Swap Shop.

RLW

Run locked timing at 30 degrees.

z.zuperboat

Whats the trick to run it locked with the factory stuff ?

z.zuperboat

Ttt

RLW

Z,
Your answer is below.

http://www.offshoreonly.com/forums/s...ghlight=timing

Post #15

articfriends

iTrader: (1)

When I first modified my boat I bought the same msd box (btm). The idea is simple,you build a low compression blower motor that runs on high octane gas -it needs signifigantly more timing at idle and when not under boost to run clean. You can set your base timing to 16 or 18 degrees,total timing to 36 or 38 if you want that much then when your motor goes into boost it pulls the timing back anywhere from 0 or 1 degree per pound of boost to 3 psi per pound of boost.Its a proven fact that innercooled blower motors make 20-40 more hp under boost from each 2 degrees of timing until you reach detonation. For short runs you could set btm to not pull out any boost referenced timing, for a longer sustained run you can dial timing back a little more and if you had to fill up with 89 octane when you really needed 92 you could pull more out yet. The beauty is you could do it from the helm in 2 seconds with the control knob. Just keep in mind if you pull too much timing out under boost you can send exhaust temps skyrocketing too. I unplugged mine from the msd box and no longer use it because it is redundant with my efi program that already pulls timing out,Smitty

NOMOGOFAST

Ran mine locked @30 degrees and pulled timing out 1 degree per lb of boost. Be very careful, friend of mine destroyed his fresh 572 w/ 1471 in one long pass, he forgot to check the dial which was under the hatch. He basically was running no timing w/ 16lbs of boost Needless to say two pistons and a couple of valves were lit up. Need some timing a WOT.