Sorry to post a link to another site, but there is a nice thread on NLOC about running a pulley up to a certain size without a chip on a Lightning. I was curious if anyone did this yet on a 2002+ HD and what were the results?

-Mark

Link to NLOC thread

 

From what I've heard...you shouldn't run higher than 4 extra PSI without chipping your beast. Personally...I wouldn't add any boost without chipping and checking my A/F ratios. But that's just me.

 

Truckin magazine had an article on running 20PSI without a chip! They said the Air/fuel numbers were a very safe 10.3.

 

I'm sure you are more likely to have problems introducing a chip than just adding a 4lb-6lb pulley with no chip. Not to mention to warranty issues. A chip can be a dead give away (or trying to hide the fact you had one).

-Mark