Cam change, do I need to remap

Discussion in 'Touring Models' started by PROWLER, May 26, 2019.


    PROWLER New Member

    So Just finished putting a new set of cams in my 2001 Road king. otherwise the drive train and fuel system is completely stock. I put a set of S&S 551 easy start cams. the bike was running pretty good, but i wanted to do a cam chain tensioner inspection and found that not only where the tensioners bad but one cam was showing sings of lobe wear. so i did a cam change, lifters, higher volume oil pump and of course tensioners. Today I took a ride just around town, no WOT yet. and its running strong and smooth. My question is should I remap it ? I know you should strongly consider it if you increase the air flow by changing air cleaners or exhaust. But cams ?
  2. dolt

    dolt Senior Member

    Assume the OP has already done the Stage I upgrade, i.e., intake and exhaust which requires a tune. The term "remap" would indicate that the OP may have had the factory Stage I ECM "flash" in lieu of a proper dyno tune so that is an unknown at this point. OP, which was it, flash or tune? A downloaded "map" is not a tune, so let's be clear on that point going forward.

    Assuming one or the other, i.e., flash/map or tune was done with the Stage I upgrade a proper dyno tune should be done with the addition of cams. The purpose of a flash or tune for Stage I is mainly to add a bit of fuel across the RPM range and generally includes increasing the rev limiter. The addition of cams should address timing since the OEM timing is pretty aggressive for aftermarket cams. The OP has added S&S 551 cams with an intake close of 18*, much earlier than the OEM cam intale close of either 34* or 38*, can't remember which for '01. The increase in compression will add a nice low end boost which will register on the butt dyno but also needs less compression to perform properly. If timing is not addressed the motor will likely run a bit hot and could ping on anything less that 91/93 octane. Of course fuel should be tweaked at partial and wide open throttle but timing is the more important issue.

    Bottom line, yeah, the OP should get a proper dyno tune. The motor will pull harder and run cooler.;)
    NCBILL likes this.