Bub7 & Big Sucker - no re-map?
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Club Member
Joined: Aug 2009
Posts: 760
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From: South Carolina
Bub7 & Big Sucker - no re-map?
I ordered an Arlen Ness Big Sucker air cleaner (arrived today) and Bub 7 True Duals for my '09 Road Glide. I'd like to slap'em on ASAP - when the pipes arrive next week. If I do, will the bike run reasonably well without re-mapping? I don't see an opportunity to get the mapping done in the near future - maybe late fall or over the winter. But I'd really like to get the pipes on. Or will it run/perform like crap without re-mapping? Thoughts?
Road Master
Joined: Oct 2007
Posts: 808
Likes: 1
From: so.jersey
I ordered an Arlen Ness Big Sucker air cleaner (arrived today) and Bub 7 True Duals for my '09 Road Glide. I'd like to slap'em on ASAP - when the pipes arrive next week. If I do, will the bike run reasonably well without re-mapping? I don't see an opportunity to get the mapping done in the near future - maybe late fall or over the winter. But I'd really like to get the pipes on. Or will it run/perform like crap without re-mapping? Thoughts?
Road Warrior
Joined: Sep 2007
Posts: 1,954
Likes: 148
From: Augusta, GA
The pipes, by themselves, will not be a problem. I would not install new breather until a fuel management system is installed, or a download is done. You will be running way too lean.
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Road Warrior
Joined: Dec 2008
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From: Australia
She wont run way too lean, she has oxygen sensors. She will be a little lean at WOT when the system goes into open loop.
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The narrow band Lambarda sensor will help a little but will not be able to get you back to the already lean stock set up. The sensor also only works when in the closed loop part of the map, so on a flat throttle, low load area. The rest of the time the map is in the open loop area of the map and the Lambarda (o2) sensors do nothing.
Even when in closed loop you run AFR of 14.6 : 1 and this is plenty lean enough for an air cooled motor. I run about 14.1 : 1 closed loop to keep mpg good, and that small difference reduces my engine temp to a very comfortable level.
In short, no I wouldnt make those changes without some sort of fuel management change. Air filter alone, yes, slip ons alone yes, true duals no, pipes and filter no.
The ecu does a pretty good job at coping so IMHO you wont blow the engine, but you will find it uncomfortable, and if run like that indefinately engine life may be reduced.
KK below correct got the closed and open loop terms **** backwards, now changed in the above text.
Even when in closed loop you run AFR of 14.6 : 1 and this is plenty lean enough for an air cooled motor. I run about 14.1 : 1 closed loop to keep mpg good, and that small difference reduces my engine temp to a very comfortable level.
In short, no I wouldnt make those changes without some sort of fuel management change. Air filter alone, yes, slip ons alone yes, true duals no, pipes and filter no.
The ecu does a pretty good job at coping so IMHO you wont blow the engine, but you will find it uncomfortable, and if run like that indefinately engine life may be reduced.
KK below correct got the closed and open loop terms **** backwards, now changed in the above text.
Last edited by WildBill2566; Sep 6, 2009 at 02:10 AM.
Road Warrior
Joined: Dec 2008
Posts: 1,639
Likes: 2
From: Australia
Wild bill has it backwards. The Lambda sensor works at part throttle cruise, allowing the computer to go closed loop and tune itself. At full throttle the system goes open loop.
Dont be afraid of lean AF, my 124 runs 15-16:1 at WOT open loop in the mid range. She needs a remap, i know, but I have 4200 miles on her now and she runs just fine and never pings. I do run 98 run pump gas all the time tho. Remap is booked for next service.
I have told this story a thousand times, but when my bike was a 96 she had about 1800 miles on her and the right side muffler fell off. I ran for the next 1200 miles with no exhaust backpressure at all. I didnt notice her running any hotter, she didnt ping and she got 250+ miles from a tank. If there was a leaning problem I would have found it then.
My advice to you is to just do it. If S&S say it will be fine then I beleive them. If she is running lean she will ping like crazy and you know you need a remap.
Dont be afraid of lean AF, my 124 runs 15-16:1 at WOT open loop in the mid range. She needs a remap, i know, but I have 4200 miles on her now and she runs just fine and never pings. I do run 98 run pump gas all the time tho. Remap is booked for next service.
I have told this story a thousand times, but when my bike was a 96 she had about 1800 miles on her and the right side muffler fell off. I ran for the next 1200 miles with no exhaust backpressure at all. I didnt notice her running any hotter, she didnt ping and she got 250+ miles from a tank. If there was a leaning problem I would have found it then.
My advice to you is to just do it. If S&S say it will be fine then I beleive them. If she is running lean she will ping like crazy and you know you need a remap.