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Is it necessary to remove AI and O2 sensor for TTP map

3K views 12 replies 6 participants last post by  Hinckleyhowler 
#1 ·
I have been reading about ways of getting more power and have decided to install TTP Breathe, K&N Filter, remove snorkel, airbox baffle and the TTP 3 map
I already have dominator touring exhausts. I haven't removed AI and O2 sensors.
From my research AI removal is to prevent blue exhaust, my pipes are already blue so I am wondering if there is any need to remove this.
Similarly O2 sensors are disabled by the tune so I am wondering if there is any need to delete the sensors?

Thanks
 
#3 ·
Thanks Forchetto! I checked with Mike and he said SAI is optional but O2 sensors must be removed. The thread you shared earlier had a post mentioning that the map only disables the check engine light for O2 sensors but it does record the O2 measurements and could have an effect on the performance. I imagined the map is basically instruction to monitor the various inputs and control the air fuel mixture on that and the TTP map ignores the air input but doesn't look like that is the case.

One question on SAI, does anyone know the temperature difference in exhaust before and after SAI removal (with TTP map). Does it get really hot to warrant removal. If its just the popping then I don't mind keeping it on
 
#4 · (Edited)
SAI is only active during low rpm's...and one drawback to having it operate is snatchiness going on/off throttle...like around town, low speed corners etc. There are no enviro benefits to having once throttle gets a little above idle (is it 1500+ rpm?). Yes, bluing it also a result of the higher exhaust gas temp...you're burning fuel in the header pipes with the added air. Bluing can be a nice characteristic of our bikes, some like, some hate. On my bike, the bluing was blotchy and messy...likely b/c of sticky greasy finger prints...so I cleaned it up using BlueJob and Autosol and a strip of t-shirt cotton rag, bow-stringed around the pipe...about 40 min work pre side. Now with SAI removed, bluing has not returned in 1.5 seasons.

I believe OEM map takes into account SAI air and adjusts low rpm fueling via O2's perhaps. With TTP mapping, these presumably are not made, so could lead to more unfavourable low rpm response.
One other benefit to removing SAI...it's now dead easy to pull/replace spark plugs!

Leaving disabled O2 sensors in the pipes will change the exhaust flow somewhat, as the sensors do protrude into the air pathway. TTP developed the maps without this extra flow resistance...so you will change the effectiveness of the map by leaving them in place.
 
#5 ·
So the more I read about O2 sensors the more it sounds like the stuff VW was doing illegally. It is only active during idling and so only controls emissions during that time and after that its free to pollute. Given motorcycles in US don't have strict monitoring like cars but just enabling during idling sounds like bypassing the norms
 
#6 ·
Not quite so bad as that. O2's allow fine tuning of air/fuel mixture to a point known as "Stoichiometric"...a point which gives most complete burning of the fuel. It's not perfect b/c there will always be residual unburnt hydrocarbons due to imcomplete mixing of air/fuel, imperfect atomization of fuel from the injectors etc. (which can be more significant at low rpms). Residual hydro's get reduced even more via the catalytic converter in the exhaust headers or silencers. The cat works best when fueling is stoichiometric...but will still do its job as long as it's hot enough and has enough O2 around (one reason for SAI). I suspect at higher RPMs, there's enough flow that any tweaking by O2 sensor feedback is not going to make much difference, so it only needs to work at low RPM.
 
#7 ·
Bike manufacturers have been cheating emissions regs for years, but not quite in the same way as the VW debacle. ECU maps that fiddle with mixture and timing at the regulated testing RPMs leading to "emmissions dips" in the factory torque curves. Which is why Power Commanders are such a roaring trade in the sportbike community.

Idling emissions aren't part of the testing regime afaik, it has more to do with leaning at the mixture during idle so the catalytic converters don't self-destruct via overheating from unburnt fuel combusting there
 
#8 ·
Thanks for the info guys. Follow up questions :), do silencers such as predators, dominators etc have catalytic converter in them.
Why doesn't a stock thruxton make popping sound with SAI on. The job of the SAI is to burn residual fuel and simply changing silencer shouldn't increase unburnt fuel
 
#9 ·
I don't know of any after-market exhausts that have cats in tem.

The post-combustion of exhaust gases still takes place in standard silencers but you can't really hear them as they have all manner of chambers and compartments in them to deaden noise. After-market cans are invariably of the "straight-through" type and they become more audible.
 
#10 ·
My Thruxton most certainly did make a popping sound on the overrun when brand new last year. Disabling the SAI instantly stopped any popping, even when I fitted TORs. With the relevant TTP map, SAI and O2 sensors removed, breathe inlet, DNA filter and airbox bafflectomy there is absolutely no popping at all and it runs like a completely different bike. I don't know why one would want to retain the sensors when the map assumes they are not present.
 
#12 ·
I did all of the normal "mods" to my bike in Brazil. What a different. I just moved back to the US a few months ago. I ripped off the O2 sensors and the SAI unit. Went for a ride and the New Church was like a different bike and that is without any other mods! Of course next is a TTP tune and some cheap Emgos .. and the baffle will come out. Just so much more enjoyable to ride. I can't fathom how anyone could ride "stock"!
 
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