Have this combination. First installed the Big Sucker and Thundermax with Autotune, Big difference on power, responce, and smoothness of motor running. Installed the Fatcat Exhaust last thursday along with map# 391. Motor seems to not wind out like it did with stock exhaust. The torque seems somewhat better from say 2500 to 4000 rpm range. Is this normal in switching to the 2:1? Not terribly disapointed as Im not winding it out on a normal basis. Just an observation. Anyone elsehave this combination and if so what are your findings? Of course Im going by the old But dyno but this is what it feels like.

 

Forgot to mention I also have the quiet baffle in the Fatcat.

 

Did you load a new map for the 2-1 exhaust? That's quite a change to stick on the original map.

 

yep, map #391 is for that exact setup according to the description in the Thundermax listing of maps.

 

i have the same setup except i 've got a k&n with the same map 391. i thought that at fist, but after a few hundred miles and the front tire coming off the ground shifting into 2nd i realized it was revving quicker, i'm sure you won't have any problem bumping off the limiterfaster now as opposed to before. this was confirmed after runnig my buddies superglide who was spanking me before the mods and ain't no more, although with the stock motor we are about equal on top as his screaming setup is more than adequate for the stock motors airflow, but now i 've got way more lowned and throttle response and jump out hard on starts and rollns in any gear and stay there even with an extra 40lbs and windshield.. i think when i go with more compression, cams, and bigboreit will reap better benifits on top for the fatcat, as i think the stock motor and cam are under utilizing this exhaust imo.

 

I am not sure but is the big sucker the same size as the Zippers A/C? The zippers filter made a big difference on my bike.

 

not sure, did you have a big Sucker and change to the Zippers or go from stock to Zippers?

 

I believe the Zippers A/C is the same size filter as the BS II, 2.75" The BS I is only 2.25". As a matter of fact, I just ordered the 2.75 kit as I noticed all the tunes for my bike are 2.75 setups. Since I am changing out my head pipes to V&H dresser duals, I figured it made more sense.