Kawasaki KLR Forum banner
1 - 20 of 69 Posts

·
Registered
2022 KLR650
Joined
·
40 Posts
Discussion Starter · #1 ·
Did a quick search but didn't really find anything.
Question....
Modifying the airbox and/or filter allowing a higher volume of available air, along with adding a freer flowing exhaust, does the O2 sensor have enough range to compensate for those changes?
Seen some people talking about removing the snorkel then adding a UNI filter combined with a slip on open exhaust. On my carbed bikes this would require changing jets so that it doesn't lean out too much. Being such a small, lower powered motor, can the ECU adjust itself enough?
Thanks
 
  • Like
Reactions: Hvymax

·
Registered
Joined
·
393 Posts
On '22's, based on what I gather here and other forums dedicated to the '22, removing the snorkel and freeing up the intake AND fitting a freer flowing exhaust, will end up making your bike run lean. How much lean? Have no idea. You just end up with popping on deceleration, which means you're lean. No idea if this lean condition with closed throttle only exists with during closed throttle, whether it persists at part throttle and/or WOT. My guess is it will persist at WOT. Nobody in the world has released dyno charts with Air/fuel readings to go with it.

What we do know is fitting a freer flowing exhaust with no tune does indeed yield more power. We have a member here who has two bikes with the Yoshimura slip on exhaust with dyno runs that show power gains. Gains he can feel while riding. There is also additional gains to be had with an aftermarket fuel add on like the PC5. TeamGreen500 might chime in if he sees this post.

The Closed Loop FI system does compensate for a freer flowing exhaust, or an open intake. But only to a degree. It won't compensate for it at WOT since that is fixed. The ECM will always maintain as close to the 14.7:1 air/fuel ratio at part throttle. It will cut the fuel with closed throttle. And most likely, it will not allow anything lower than 13.5:1 air/fuel at WOT. Doesn't matter whether you have open intake, exhaust, or both. What this means is the power gains will be limited by the stock programming (ie. maintain as close to 14.7:1 air/fuel ratio).

We also have another member here who removed the snorkel, fitted a freer flowing slip on, and removed the Air Injection system to get rid of the closed throttle popping on deceleration.
 

·
Registered
Joined
·
58 Posts
I've got one bike with the Dyno Jet tuner: it certainly gets more fuel...virtually across the board...but, seems most noticeable at 1/4 turn on up...certainly fuels a bit more on top..."IF" that's why, as I'm assuming, it runs farther/harder on top and gets to a higher top speed...sooner. Oddly, it's a bit "poppier" when cold compared to my "stocker".

HOWEVER, my stock-ECU does just fine and doesn't seam any leaner than it did with the stock pipe.

Note: both bikes have a Yoshimura's RS-2 slip-on.
 

·
Registered
Joined
·
393 Posts
HOWEVER, my stock-ECU does just fine and doesn't seam any leaner than it did with the stock pipe.

Note: both bikes have a Yoshimura's RS-2 slip-on.
If memory serves, you still have the stock air box and air filter correct?

The bike with the tuner increases the fuel for a duration of time when you roll on the throttle. Kind of like the way a pumper carb works. It most likely also increases the fuel at WOT. That's why you're getting better acceleration, and that's the way to go. If your tuner were to be further tuned with the snorkel removed, and a freer flowing air filter (if you're willing to give up some filtration), you'll get more power. That requires more trips to the dyno unless someone sells a tuner with the tune already programmed in.

Unfortunately, a PC5 nowadays is $400. A direct ECM tune, if anyone ever makes one for our '22, would probably be $300.
 

·
Registered
2022 Pearl Lava Orange
Joined
·
1,038 Posts
I'm holding out for an ecu tune. It's always the best solution to allow the ecu to address any modifications, fueling and ignition timing etc. One stop shop control unit but finely tuned for the modifications.
On my super tenere, I got in on the ground floor with tune ecu back when you could buy a harness and use the software for free. Now you need to buy a license. It worked amazing. Installing the harness was a bit like brain surgery depinning the ecu harness. But some steady hands and fresh eyes helps.
 

·
Premium Member
KLRs: 2013, 2005, 1998; 2017 HD Electraglide Ultra
Joined
·
2,405 Posts
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:
———————

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."
 

·
Registered
2022 KLR650
Joined
·
40 Posts
Discussion Starter · #8 ·
I’m not focused on gaining power, it’s more about efficiency and making it smoother. I had my stock 1299 tuned before I did mods and it was night and day difference on how the bike acted. The dyno showed a minimal overall hp/tq increase, but how the bike put it down was much better.
Like everyone, a little better sound from the exhaust and a little smoother is what I’m after. I doubt I could feel a 20% increase in power on a KLR. It’s a 35hp/35tq bike that weighs 450lbs. But, if I can make it sound and act better without burning valves, I’ll do it.
 

·
Registered
Joined
·
393 Posts
I’m not focused on gaining power, it’s more about efficiency and making it smoother.
Opening up the intake or exhaust will add power. Tuning it after these mods will add more power. Up to the limit of what the cylinder can flow. This is no different from any other bike. If you add 5 rwhp you will feel that difference and it won't hurt anything. It's ok to want more power whether it's a KLR or a CRF300 or whatever....
 

·
Registered
Joined
·
70 Posts
Just removed the snorkel, on my new 22" added a UNI filter and put on a Delkevic 18' slip on pipe, much better sound (just a tad louder) and slightly better throttle response. For me the pipe was about weight savings, that stock pipe is heavy and my after market pipe saves over 10 lbs.. 10 pounds is 10 pounds and no matter how you slice it increases the power to weight ratio.
 

·
Premium Member
2022 KLR 650 base
Joined
·
88 Posts
I cannot stand the sound of the stock exhaust, horrible. Just ordered a Leo Vince X3 to replace it. I tried the snorkle removal and no bueno. The pops were so irritating, so I reinstalled it. I put a hole in the spark arrester, but that was not good enough. Losing the weight up top is a good thing.
I'm holding off until we have some way of adjusting fuel. Last thing I want is a toasted engine. I know it runs particularly lean even stock. But i am very anxious to get a new exhaust and intake on her...
 

·
Premium Member
KLRs: 2013, 2005, 1998; 2017 HD Electraglide Ultra
Joined
·
2,405 Posts
Opening up the intake or exhaust will add power. Tuning it after these mods will add more power. Up to the limit of what the cylinder can flow. This is no different from any other bike. If you add 5 rwhp you will feel that difference and it won't hurt anything. It's ok to want more power whether it's a KLR or a CRF300 or whatever....
The first statement is not true. It might or might not. If increasing air and exhaust flow causes a leaner mixture at WOT, the engine can produce LESS power. That is why you should do intake/exhaust mods together with adjusting the WOT map.
 

·
Registered
2022 Pearl Lava Orange
Joined
·
1,038 Posts
I'm afraid to unleash full throttle on mine. 40hp is allot! JK. It takes a bunch of throttle twist to go WFO on these new bikes with the goofy new throttle assembly. I'm patiently waiting for motion pro to produce one.
 

·
Registered
Joined
·
7 Posts
I just installed the Power Commander V and slightly adjusted their stock power tune. For example I advanced the timing 2 more degrees on top of where they had already advanced it in certain parts in the timing table. I also adjusted the fueling slightly at the 60-100% range and after that I could honestly tell a bigger difference just by doing those minor tuning adjustments, than by removing snorkel drilling three 1/2" holes in air box, adding Uni Filter and adding a Yoshimura RS-2 slip-on exhaust. But honestly I think it was a combo of all the mods I've done so far. My 2022 KLR Adventure now pulls hard and accelerates so much faster and smoother!
Next up is the Dynojet Wideband 2 with Pod-300 so I will soon be able to enable the autotune feature and it with fine tune the fuel automatically based off the wideband o2 readings. So it should smooth out across the entire fueling map table not just in certain areas.
I'll keep you all posted!
 

·
Registered
2022 Khaki no abs, Thermobob 2, tusk panniers gen2, modified crash bars gen2, Tusk D-flex, 16t front
Joined
·
428 Posts
I just installed the Power Commander V and slightly adjusted their stock power tune. For example I advanced the timing 2 more degrees on top of where they had already advanced it in certain parts in the timing table. I also adjusted the fueling slightly at the 60-100% range and after that I could honestly tell a bigger difference just by doing those minor tuning adjustments, than by removing snorkel drilling three 1/2" holes in air box, adding Uni Filter and adding a Yoshimura RS-2 slip-on exhaust. But honestly I think it was a combo of all the mods I've done so far. My 2022 KLR Adventure now pulls hard and accelerates so much faster and smoother!
Next up is the Dynojet Wideband 2 with Pod-300 so I will soon be able to enable the autotune feature and it with fine tune the fuel automatically based off the wideband o2 readings. So it should smooth out across the entire fueling map table not just in certain areas.
I'll keep you all posted!
With the airbox holes & drilling the muffler out mods mine lost some at WOT. We're all interested in hearing all about your mods and the power commander! Post up a thread or in a thread with pics BOSS!!!💪😎👍
 

·
Registered
Joined
·
7 Posts
With the airbox holes & drilling the muffler out mods mine lost some at WOT. We're all interested in hearing all about your mods and the power commander! Post up a thread or in a thread with pics BOSS!!!💪😎👍

I will for sure! I would have to say when I advanced the timing from 4 to 6 degrees advanced is when I really noticed the biggest difference. Now it was like night and day but I definitely noticed it for sure!!! Plus I have also been breaking mine in pretty hard. Right now I have just under 500 miles and I have noticed from bikes in the past the harder you break them in they are going to feel faster and just run better all around. This hole breaking in your bike really really soft i am just not a believer. This is actually my second 2022 KLR650 Adventure Model. I bought my first one back in Aug of 2021 and just last month I laid it down pretty good and it was totaled out by the insurance company. It had almost 2,400 miles on it. I Just bought my current Adventure KLR earlier this month!
 

·
Registered
Joined
·
393 Posts
I'm in CA so no Power Commander for me.

Fortunately, I'm quite happy with just No Snorkel, Yoshimura RS-1, and clutch switch disabled and zero fuel cut.

If you're advancing the timing, you're probably running 91 octane? I've been running 91 since new. I was also hard on the break in procedure. Mine runs wonderful. Not as great as your tuned version but so much better than stock. No backfiring whatsoever. 46-48 mpg average in mixed riding.
 
1 - 20 of 69 Posts
Top