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Dirk

About changing my exhaust...

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Dirk
Hi every one!
 
I'm trying to get answers to those questions but... Let's say that, in france, they don't give a damn out it... They just throw parts and the bike and the never think about what it does to the bike!
 
I'm getting my SC Project exhaust really soon... With it I found (and bought them because at an amazing prize): SC Project AFM, DNA air filter, DNA stage 2 cover... I NOT SEING THAT I WILL INSTALL EVERYTHING ON THE BIKE! It's just that I have them, I will sell what I don't use.
 
BUT, I'm a little concerned because I don't have any EJK, PCV or other fuel controller! I bought the SC Project AFM for that matter (had a crazy deal on it, like half the prize!). It's actually a Memjet unit, made to change the air intake temperature sensor input and fool the engine thinking that it's actually colder than it is...
 
I understand that when changing the exhaust and/or the air filter, your bike tend to be to lean... And since I have no control to remap the injection, here are my questions:
 
- What are the risks when changing the exhaust (non catalytic one) without remapping the injection? Riding to lean? How bad? 
 
- What are the risks when changing the air filter (high performance one) without remapping the injection? Riding to lean? How bad?
 
- Will the Memjet/SC AFM take care correctly of the problem? I understand it's not as good as a remapping but is my bike gonna be ok?
 
- Will it be ok to add the DNA stage 2? Because since in europe we have the vacuum door on top of the air filter (not just the snorkel like you guys), it's gonna be tons more of air getting to the engine!
 
 
Please, help me to find some answers to those questions...

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topazsparrow
Any time you open up the bike's breathing it will lean it out.
 
Exhaust will lean it some, but depending on the exhaust will still be within the stock fueling range (akrapovic for instance). More backpressure means less breathing, thus a "bigger" fuel:air ratio.
 
An intake that breathes easier will also lean out your fueling.
 
The bike can compensate only so much based off of the stock O2 sensor and fuel maps. The higher you are in elevation, the more you'll be able to get away with.
 
in any case of the bike running lean, it's going to run hotter and this will likely be the biggest cause for an increase in wear. If you're exceptionally lean it could cause detonation as well - not sure if these bikes have knock sensors or not to prevent it by dialing back the ignition timing.
 
If the memjet just tricks the sensor into thinking the air is colder, it's effectively tricking the ECU to supply more fuel since it thinks it's getting denser, cold air. If you're already past the capability for the stock fuel map to supply enough fuel (free flowing exhaust + intake), there won't be any more to give. The O2 sensor will already have told the engine to max the fuel input as it's reading lean all the time (it's supposed to oscillate between rich and lean).
 
Stage 2 will almost certainly require a reflash or a fuel management system.

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Dirk
Any time you open up the bike's breathing it will lean it out. 
Exhaust will lean it some, but depending on the exhaust will still be within the stock fueling range (akrapovic for instance). More backpressure means less breathing, thus a "bigger" fuel:air ratio.
 
An intake that breathes easier will also lean out your fueling.
 
The bike can compensate only so much based off of the stock O2 sensor and fuel maps. The higher you are in elevation, the more you'll be able to get away with.
 
in any case of the bike running lean, it's going to run hotter and this will likely be the biggest cause for an increase in wear. If you're exceptionally lean it could cause detonation as well - not sure if these bikes have knock sensors or not to prevent it by dialing back the ignition timing.
 
If the memjet just tricks the sensor into thinking the air is colder, it's effectively tricking the ECU to supply more fuel since it thinks it's getting denser, cold air. If you're already past the capability for the stock fuel map to supply enough fuel (free flowing exhaust + intake), there won't be any more to give. The O2 sensor will already have told the engine to max the fuel input as it's reading lean all the time (it's supposed to oscillate between rich and lean).
 
Stage 2 will almost certainly require a reflash or a fuel management system.
Ok so if I follow you:
 
The ECU can compensate but just a bit following the O2 sensor reading... After that, it will not be able to give more fuel than the map allows it.
 
I thought that the Memjet will help to give more fuel but it probably won't because I will have maxed out what the map can do. Am I right?
 
I guess I can rule out the Stage 2 which is, like I thought, to hardcore without fuel management... (a shame since the air box is has way more restriction than what you have the US, causing some people engine to even stall!)
 
I don't think the SC Project exhaust has many back pressure: pretty short, no catalytic converter... So I think it will lean it quite much!
 
What do you advice? If I install the exhaust, should I forget about the air filter???

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gregjet
The EFI /ecu on the MT/FZ 07 has sufficient leaway to maintain the AFR even with the exhaust and filter changes. It is a long way from maxxed out. I have seen the AFR's of such mods on a stock ecu and it's all good ( stock ratio is maintained) EXCEPT that the stock AFR's are stupidly lean, except at the top reves where it is rich.
My personal path would be to reflash for a whole lot of reasons if you wish to correct the ratios

Go forth and modify my son...go forth and modify...

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sorkyah
I too would recommend the reflash
I have the dna stage 2 lid and filter as well as a yoshi exhaust w/o baffle
 
before flashing the ecu i had serious decel popping and driveability issues
Reflashing/dyno tuning your bike will certainly help your bike run to its' peak

ATGATT... ATTATT, two acronyms I live by.
 

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Dirk
Yeah, I know! I wish to do it one day... The thing is that re flashing almost dont exist in France and Dyno work is hard to access... Maybe you don't know it but you guys in the US are way more advance and aware than us when it comes to mechanics stuff and mods!!!

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gregjet
Mine was the first reflash done in Australia by a local guy and he actually sent it to Italy for the reflash ( which meant it was actually for the full/real MT/FZ07 rather than the Aussie smaller pretend one but it worked pretty close.) Not far for you.

Go forth and modify my son...go forth and modify...

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Dirk
Mine was the first reflash done in Australia by a local guy and he actually sent it to Italy for the reflash ( which meant it was actually for the full/real MT/FZ07 rather than the Aussie smaller pretend one but it worked pretty close.) Not far for you.
Yeah, I have to do some research! I'm sure they do it perfectly in Italy, there're good with bikes... And I'm only half an hour from Italy!!! 
Only problem, speaking!

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