I've got an opportunity to Borrow a KB Blower from one of my "L" buddies while he gets his new motor built.He also has an assortment of pulleys for it.
My question is...
I have an 8lb lower on my HD and get a true 12lbs Boost on an Autometer gauge [Running Dynatech L/T's and hi-flow cats]Making pretty good power,Dyno's Sat. @ 406RWHP / 536 RWTQ with a very safe 10.7 A/F Max.
I've been told not to exceed 15lbs of boost on a stock bottom end.
With the KB Which upper pulley will get me there?
I WAS thinking of getting a re-burn to maximize my current set-up.Should I leave it alone to run the KB with an overly Rich A/F??
Thanks for any help!

 

I initially had a 9" - 6lb lower and a 3.20" - 2lb upper and with the stock exhaust I was pulling 17 lbs of boost. When I switched the long tubes and high flow cats I lost one pound, settling at 16lbs.

I think you should be o.k. with a 4lb lower, 2lb upper and that should keep you around 14 with your new exhaust.

Personally I would have your tuner review your burn, the KB really changes the ball game. And by the way I have stock lower and no problems todate.

Good Luck!

D-Day

 

Keep in mind that an HD outweighs an L by some 500lbs. This extra weight puts an increased amount of stress on the reciprocating assembly....connecting rods to be more specific. I would keep the boost levels at or below 14psi at the MOST to be on the safe side. A 2lb lower and 3.25'" upper should put you between 13 and 14 psig. Just my .02. Have fun!

Later,
Rob