Be careful with assumptions about air and exhaust modifications giving more power. Someone correct me if I’m wrong, but the heads on the Gen2 and Gen3 are the same. Several people worked on development of mods to the heads of Gen1 and Gen2 bikes and figured out through dyno and flow testing that the intake port limits flow. Thus, some external modifications to increase flow help up to that point of intake port limit (snorkel removal and several holes in the top of the air box), but more mods upstream or downstream have minimal influence. That is what limits external modifications to the 40 horsepower range. To get higher, you must do head flow modifications, which are not easy or straightforward. If 40 HP ain't enough for you, it will be cheaper go buy a different bike.
Modifications to the ECU tune also have limits. See this:
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Let me post here something I wrote a couple months ago in another thread about lightweight mufflers.
Since the FI KLRs are new, we haven't hashed out how FI works in this forum yet. Let me start some of that knowledge by talking about the maps in FI systems and what "open-loop" and "closed-loop" mean, and when they operate.
Closed-Loop: This is when a system is using output to moderate input and other operational parameters (i.e, feedback). In FI systems, it means that the ECU is monitoring the O2 sensor to maintain the target air to fuel ratio (AFR). The target is usually the stoichiometric ratio of 14.7:1. Depending on the sophistication of the FI system, the target ratio can be different at different operating conditions, but it's close to 14.7:1.
Open-Loop: this is when a system is not using feedback to modify the inputs. FI systems typically operate in open-loop when:
(1) The engine is cold, and the O2 sensor is not hot enough to provide correct voltages corresponding to AFR; so the ECU uses a cold operation map that sets fuel flow according to air flow and engine temperature. Once the engine temp increases and the O2 sensor gets hot, the system switches to closed-loop. And,
(2) At wide open throttle. At WOT, the ECU again goes to an open-loop map because it needs to enrich the AFR to around 12:1 to 13:1 to get best power, reduce detonation, and reduce overheating. At those ratios, the O2 sensor does not provide accurate readings either (unless you install a "wide-band" sensor and ECU that can use that sensor). The throttle body has a switch that indicates WOT to the ECU when the throttle is opened past a certain position, and that position is usually about 1/2 way open.
(3) Another condition that reverts to an open loop map occurs when the ECU detects a fault that triggers the “limp home” mode (I don’t know whether the Gen3 has this limp home mode of operation; most FI systems now do).
WIth the newest FI systems it gets more complicated, but those are the basic principles.
Thus, when doing a WOT run on a dyno, the FI system is running on its open-loop map. Since a WOT run on a dyno is open-loop, the FI system is NOT making automatic adjustments for changes in air flow. That's why physical modifications need to be remapped on a dyno--to correct the WOT static map for those changes. Whereas, the closed loop operation does not need to be remapped, because it continuously adjusts to target AFR, based on the feedback from the O2 sensor.
That said, there are advantages to remapping the closed-loop target AFRs, if the FI system uses maps for target ratios at part throttle. The main advantage one can gain is improved drivability--less tendency to surging or flat spots. Manufacturers tend to set these AFRs lean for emissions reasons and best fuel mileage, but they can cause the types of drivability problems several of you have mentioned on your 2022 bikes. Changing the target AFR from 14.7 to 14.5 or so will often improve drivability.
So, back to those advertising dyno charts: Those charts are for WOT only (if they aren't entirely invented by the marketing department), when the engine is running on an open-loop map. So, the charts can't account for increased airflow of intake or exhaust modifications, unless the testers also changed the WOT map for those mods; which they almost certainly adjusted to get the higher numbers, and which probably have a bigger effect than the physical mods in the first place! Furthermore, they don't tell you anything about power and torque at part-throttle, which is 95%+ of your operation.
Anyway, over time we will learn more about how the Gen3 FI systems works, and how simple or sophisticated it is, and thus what can be done to improve its operation. In the meantime, don't trust any dyno charts you see on sellers' websites unless they detail ALL the changes and have back-to-back runs of the engine with and without the changes. Which they almost never do. And even then, I'd say, "trust, but verify."
