Ways to Change A/F ratio

Well I admit I don't wring the bikes neck but aren't you even curious?! You won't truly appreciate the legend until you shift the first 3 gears at redline. Its jaw dropping violent, amazing the government allows this on public roads!!
I was curious but common sense prevailed and I have yet to get the revs over 9k..even at that, the thing is a missile.
 
two things.
One
If you did not check and re jet or compensate in some way for the A/F ratio with your previous slip ons you did indeed "Need to have done so"
It is just that you did not notice. Easy riding on a motorcycle will not always show the need
Two
If you are positive you will ride your bike in a consistently easy manner and not go above a particular RPM then talk to the Duno operator and explain your concerns.
There is no need to ring it out to the maximum RPM if you never do so personally. The beauty of Computor controlled A/F is it is adjustable to riding conditions
Mine will be rarely ridden over 8,000. But it is going on a adyno just so I can say (with my British accent)
It goes to 11
JP
 
Go with ECU Editor and log a run and you can see what's going on. I use it on my B King when I put Brocks alien head exhaust on a few years ago and when I put a dry nitrous kit on this year.
 
Just feel it’s hard on the bike. I know once or twice isn’t gonna hurt it, but I always ride my bikes easy and don’t want to push it to the limits unnecessarily.

Ha!
These engines were built to run high rpm's.
Running them hard is better than running them easy, especially during break-in.
Any Good dyno tuner is going to run the bike easier than most do on the street anyway.
There's nothing to worry about. :beerchug:
 
Most (all?) of the posters here are more experienced than I am, but I believe you can modify the exhaust on these bikes and still ride them WITHOUT making changes to the A/F. The bike will not be optimized, might run lean, but unless you're consistently in the high RPM range (+9,000), the risk of inflicting damage to the relevant components is minimal.

The bottom line will always be a dyno tune with some form of A/F controller, as others have said here, but changing the exhaust system doesn't mean the bike must remain off until said dyno is performed.
 
Just getting a PC5 or Bazzaz won't be enough, you need to have the proper mapping and that will require the whole setup. PC5 and Autotune + a POD-300 would be desirable. We're looking at close to $900 right there.

Get a flash from a good tuner if you're concerned about AFR.

If you tune it yourself with PC5 or Bazzaz, YES you can just do the lower throttle positions and lower rpm and that would be the only safe and legal way to self tune. You could ask a tuner to the same on the dyno but it would be paying full price for half a job IMHO.

Its always been a matter of conjecture but some feel a hard break in and regular use of the full range of engine load optimizes the power output across that range. I'd get a full tune but really----probably ONLY for a full system. I'd have to see the AFR gauge before I did that for slipons.
 
Most (all?) of the posters here are more experienced than I am, but I believe you can modify the exhaust on these bikes and still ride them WITHOUT making changes to the A/F. The bike will not be optimized, might run lean, but unless you're consistently in the high RPM range (+9,000), the risk of inflicting damage to the relevant components is minimal.

The bottom line will always be a dyno tune with some form of A/F controller, as others have said here, but changing the exhaust system doesn't mean the bike must remain off until said dyno is performed.


Anyone else for or against Haya’s comment?




I ride the bike easy but want to prevent any long term damage. I don’t mind if the bike isn’t running to full potential as long as I’m not setting myself up for failure down the road.

I think the bike is great the way it is, and try to mess with as little computer/electronics as possible. The best case scenario for me would be to run the Coffman exhaust and not do any Power Commander or tune or flash or anything. I prefer to not tinker with years or research/R&D if I can help it (at least the computer portion).

I’m leaning towards putting on the Coffman exhaust and having the A/F ratio read. If it’s at an acceptable level than I’m good. If it’s not, than I’ll have to decide if I wanna go the PC/tune route or just get a different slip-on exhaust.

I’m gonna run it with the baffles in so hopefully it provides adequate back pressure.
 
Anyone else for or against Haya’s comment?




I ride the bike easy but want to prevent any long term damage. I don’t mind if the bike isn’t running to full potential as long as I’m not setting myself up for failure down the road.

I think the bike is great the way it is, and try to mess with as little computer/electronics as possible. The best case scenario for me would be to run the Coffman exhaust and not do any Power Commander or tune or flash or anything. I prefer to not tinker with years or research/R&D if I can help it (at least the computer portion).

I’m leaning towards putting on the Coffman exhaust and having the A/F ratio read. If it’s at an acceptable level than I’m good. If it’s not, than I’ll have to decide if I wanna go the PC/tune route or just get a different slip-on exhaust.

I’m gonna run it with the baffles in so hopefully it provides adequate back pressure.

It will be fine.
The gen2 has a catalytic converter in front of the mufflers, made into the headers, so changing mufflers does very little.
You can have a bone stock bike dyno tuned and improve it, just as one would with mufflers. Small gains, because everything modern is lean from the factory for emissions anyway.
Put your tips on, enjoy the weight loss, and don't worry about it.
It's not going to harm or damage anything...other than your hearing :beerchug:
 
@Fredyp33:
I will be your crash test dummy re: A/F
Beginning sometime next week, I will be running a full exhaust with a single slip-on WITHOUT making any changes to the A/F. If the bike blows up, I'll post pics here. If it doesn't, I'll post pics here. Keep your fingers crossed, light a candle for my bike.
 
A full pipe is different than a stock header with the cat and a slip on. Stock runs lean, if your pipe is any good, you will be even leaner. Why get a full exhaust if your not going to max out what it will do?
 
A full pipe is different than a stock header with the cat and a slip on. Stock runs lean, if your pipe is any good, you will be even leaner. Why get a full exhaust if your not going to max out what it will do?
A temporary setback, I assure you. I'll probably run it like that over the summer, then get the tune and a PC5 or similar in Sept
 
Here’s another question, what causes the air/fuel ratio to change when changing exhausts? Is it the fact that full exhausts have less back pressure and allows the exiting air to flow more freely?
 
Here’s another question, what causes the air/fuel ratio to change when changing exhausts? Is it the fact that full exhausts have less back pressure and allows the exiting air to flow more freely?
Pretty much, that and larger diameters with no cats equal less back pressure which needs more fuel and air to work properly. This is why most people put free (er) flowing air filters on as well..

An engine is just a big pump, more air, more fuel, more hp and torque.
 
Dyno tuning makes a big difference with a full exhaust, it's definately an improvement.
However, it is Not a need.
If it were, there would be countless bikes out there with there engines being sold for boat anchors...which is Not the case either.
I had a full dual Akrapovic on my gen2, with no dyno tune. Even though a dyno tune would help, Akrapovic themselves advertise it as Not needing a dyno tune, yet showing average hp and torque gains regardless.
Akrapovic makes top of the line exhausts, yet they are no different in the fact that they have slightly bigger header tubes, and straight through muffler(s), like every other aftermarket exhaust.
So, do you want a dyno tune with a full exhaust? Absoloutely.
Is your engine gonna burn down, explode, or fall apart without a dyno tune? Nope.
 
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