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Discussion Starter · #1 ·
I have a 2023 GSX-R750. Shop installed a Two Brothers exhaust before I purchased (not convinced they flashed the ECU). I just purchased a Akrapovic Megaphone (slip-on) "schwing". I would also like to install a K&N air filter.

Would the bike benifit from a fuel controller with these 2 items?
 

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I guess the answer of this question depends on what you want to get from your bike? All of this changes accomplished with best tune will give you a few additional horsepower as maximum, I think. Because the gsxr is already well tuned from the factory. If you need more you can try turbo :rolleyes:
 

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Discussion Starter · #3 ·
I guess the answer of this question depends on what you want to get from your bike? All of this changes accomplished with best tune will give you a few additional horsepower as maximum, I think. Because the gsxr is already well tuned from the factory. If you need more you can try turbo :rolleyes:
Great! So for the happiness/ health of the engine, it's not needed?
 

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The exhaust will change back pressure some and the bike should benefit a bit from a tune but you probably would not notice unless you are racing and you do no harm by not doing a tune.

For what it is worth, when I got my K6 750 track bike, it had a Yoshi system on it and the dyno guy gave me the print out that showed the AFM was just fine across the band with no PC or tune.
 

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Great! So for the happiness/ health of the engine, it's not needed?
I think you don't need a PC or anything like that for this setup. And I don't recommend using K&N zero-resistance filters, which are actually a strainer and not a filter, unless you're absolutely sure what you're doing. This strainer causes rapid wear of liners and rings when using the bike in dusty conditions.
 

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Discussion Starter · #6 ·
This is exactly what I needed to hear.
The exhaust will change back pressure some and the bike should benefit a bit from a tune but you probably would not notice unless you are racing and you do no harm by not doing a tune.

For what it is worth, when I got my K6 750 track bike, it had a Yoshi system on it and the dyno guy gave me the print out that showed the AFM was just fine across the band with no PC or tune.
This is exactly what I needed to hear. Just want to ensure my bike has a long healthy life.

Much appreciated.
 

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These bikes are rather lean from the factory at lower rpms. Opening the exhaust and intake may make this worse.
I would get the ecu flashed.
I would not get a PC. This usually just serves as another point of failure and frankly is an inferior way to control fueling.
 

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Discussion Starter · #8 ·
These bikes are rather lean from the factory at lower rpms. Opening the exhaust and intake may make this worse.
I would get the ecu flashed.
I would not get a PC. This usually just serves as another point of failure and frankly is an inferior way to control fueling.
Going back to the dealer, Do you have a estimated cost for an ECU flash?
 

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A flash is about $200 from a reputable company. No, the dealer won't do it and it will likely void any warranty.

EFI sensors compensate for steady state, low throttle opening conditions. At WOT where your bike is most stressed, the bike operates in open loop conditions and runs what the ecu map tells it to run with compensations for intake air temp.
 

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Here's a link to a popular dyno tuner that shows how lean a stock bike is typically. I say typically because I've seen this with most of my bikes including my bmw k12 which was SOOO lean at the lower rev ranges at WOT it was literally scary.


This most likely has to do with emissions tuning... which reminds me... IF you get a ecu flash, it's best you run an aftermarket NONcat system as some of these tunes are rich enough that the cat overheats and fails. Good for the engine, bad for the cat.

Also, the other benefit of ecu flash is that you adjust ignition timing as well and can remove things like the exhaust valve servo error, secondary throttle plate restrictions, o2 sensor/steering damper error if desired.
 

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EFI sensors compensate for steady state, low throttle opening conditions. At WOT where your bike is most stressed, the bike operates in open loop conditions and runs what the ecu map tells it to run with compensations for intake air temp.
Exactly correct if we are talking about O2-sensor implemented models. Bike of US/Canada region code has no O2 sensor and works in open-loop mode always. It operates by IAP/MAP, TPS and current revs only and using those values for calculate ignition timing and duty cycle of injecting by flashed maps. IAT/ECT sensors along with onboard voltage value uses for temperature compensations of ignition timing, ignition coil charging time and duty cycle of injection. Changing of exhaust back pressure value is imposible to detect by the ECM and can't be compensated. Zero-resistance air strainer can be compensdated upon a values of the IAP/MAP sensor. AFAIK.
 

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Discussion Starter · #14 ·
Here's a link to a popular dyno tuner that shows how lean a stock bike is typically. I say typically because I've seen this with most of my bikes including my bmw k12 which was SOOO lean at the lower rev ranges at WOT it was literally scary.


This most likely has to do with emissions tuning... which reminds me... IF you get a ecu flash, it's best you run an aftermarket NONcat system as some of these tunes are rich enough that the cat overheats and fails. Good for the engine, bad for the cat.

Also, the other benefit of ecu flash is that you adjust ignition timing as well and can remove things like the exhaust valve servo error, secondary throttle plate restrictions, o2 sensor/steering damper error if desired.
Exactly correct if we are talking about O2-sensor implemented models. Bike of US/Canada region code has no O2 sensor and works in open-loop mode always. It operates by IAP/MAP, TPS and current revs only and using those values for calculate ignition timing and duty cycle of injecting by flashed maps. IAT/ECT sensors along with onboard voltage value uses for temperature compensations of ignition timing, ignition coil charging time and duty cycle of injection. Changing of exhaust back pressure value is imposible to detect by the ECM and can't be compensated. Zero-resistance air strainer can be compensdated upon a values of the IAP/MAP sensor. AFAIK.
I haven't had a chance to watch the video yet, but will after work! So, it sounds like I should get a tune for the health of my motor. But, after I get a full exhaust to eliminate the CAT. I planned on doing that at some point anyways. Just need to save a bit first.
 

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Open loop still modifies injection time. All we're talking about is an air filter and slip on. No sensor combination (open or closed) is going to accurately deal with changes in reversion. The slip-on won't change much at all. The filter might raise the pressure seen at the IAP. Does it get it right? No. Does it get it close enough? Yes. You only need a tune if the compensation goes beyond what the map can handle.
 

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Discussion Starter · #18 ·
Open loop still modifies injection time. All we're talking about is an air filter and slip on. No sensor combination (open or closed) is going to accurately deal with changes in reversion. The slip-on won't change much at all. The filter might raise the pressure seen at the IAP. Does it get it right? No. Does it get it close enough? Yes. You only need a tune if the compensation goes beyond what the map can handle.
I'm not opposed to only doing the slip on... if the air filter will negatively impact the engine without a tune I'd just leave it...
 
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