Have basically the same set up as you and had my dyno done at trask. 300 bucks and my results are 74.0 Power and 84.4 Torque

 

Same numbers that I have. Any issues with decel popping? It's not that big of a deal. i just expected it to be gone.

 

Good grief....that is just not so...it does not mean a lean condition...quite the opposite.

More than likely ... but only the guy tuning it really knows.... the dyno guy had to richen up the mixture at certain points to compensate for predetonation. If you removed the original pipes you will be more prone to afterfire since you no longer have cat sections and have reduced back pressure.Pops...often referred to as engine decel pop is where a bit of fire blows past the exhaust valve and ignites a fuel rich exhaust mixture.

An approach to minimize pop is to cut fuel from the injectors during decel from the RPM where pops start to the RPM where they stop. But you can NEVER totally eliminate it.

It's normal to get some engine afterfire on aggressive throttle and decel. Its easy to do....to say its not reveals either a very passive riding style or just lack of riding experience....or just a lack of mechanical acumen.

Late model 96b engines run very lean...with bias towards advanced timing...all intended only to meet EPA standards....they often require timing retard and enrichment particular if you pursue stage 1 nods.

You will need to see if your ECM allows for decel fuel cutoff....start with 2400 rpm to 1700 rpm cutoff ....don't overdo the dry interval so that you end up with a dry cylinder that will result in a lean hot mixture on the compression cycle....I compensate for this with a slightly longer duration upon throttle up.

This is one of the problems with dyno runs....you may achieve a tune (although not in this case) that produces bragging rights hp/tq numbers....but leaves the bike with annoying real world driveability issues...in this case pop/afterfire. Also...you turn your bike over to someone who will do who knows what to your bike and in too many cases won't sit down and explain exactly what he did or let you participate in the dyno session...a good dynoman will tell you what he did and why....or ask you to attend the session you are paying for...then ask you to ride the bike for an hour or so and report back if you have any issues....ie, pinging, dead spots or pop/afterfire then he will address these issues BEFORE you pay and ride away. If you did not get that level of service....don't go back there...but rather find someone who cares enough...or better yet....get an ECM that you can tune yourself. Learn how to do it....and take care of it yourself....its not magic....just a little reading and a little work will suffice.

If a bike is tuned on the edge...with aftermarket pipes ....I can make it pop....without really trying.

 

I can get a little popping if I'm backing off fairly hard. Not to much though.

 

Finally some good analysis... the curves look pretty good for a fairly stock Stage I setup. You could get a ThunderMax or some other tuner, and one of the settings (TMax) is the Decel Fuel Cutoff, which works great if the decel pop really bugs you that much. cpiad is right on the money...

Roger

 

+2! If you want to get rid of the decel pop, you will have to get a dyno guy that will work with you and tune the bike to your liking (fat chance!), or you will need a tuning device that you can tune yourself and on which you can get help from others on how to tweak it. I have a T-Max also and had issues with decel pop. The Decel Fuel Cutoff setting did not get rid of the pop entirely, so I got a T-Max guru to help me tune it out by adjusting the timing a little. It worked. Decel pop is no more! If you have the money to spend on dyno tunes, that money is better spent in ways that help you become self-sufficient in maintaining and tuning the bike yourself so you no longer need to depend on dyno guys and dealers to make it run the way you'd like. If you keep going to those guys (unless you have someone you really trust), you will never be satisfied and the spending will never stop.

EDIT:
Lots of tuning gurus willing to help on this forum and lots more on Harley Tech Talk forums.

 

I'll voice my 0.02 here as there is a decell enleanment feature thats built in the program. In order to get rid of it you need to have that changed. Just fatten that up a little and it will be fine. The #'s are in the ballpark for what you had done. The change in decell enleanment won't have any other effect to how the bike runs. Very simple and effective. I have a SERT and have no issues.

 

Thanks a lot guys. You guys have given me the information I needed so I am better equiped to make sure that I got a decent tune.

 

My Stage 1 A/C, Big Radius 2 into 2s and SERT tune netted me 75HP and 90TQ. Id say your numbers are where they should be.

 

I have a pretty noob question which is along the lines of this topic.. aside from being Loud and ..well.. pretty fun when some dumb broad is about to step into the street on her cell phone .. ... "Oh you want to not pay attention where you're going? RAPAPAPAPPPPAPAPPP.. yeah."... does it damage the engine in any way?