Victory Motorcycle Forum banner

1 - 20 of 21 Posts

·
Registered
Joined
·
2,084 Posts
Throughout the WOT power band, does the optimal AFR get progressively leaner as RPM's climb? Like 12.5:[email protected] and like 13.5:[email protected]?
Let me say at the start that I have no knowledge in this area, I can't carry on an intelligent conversation about AFRs, let alone about engines in general, and so forth.

I am responding only because last week I went to Lloydz Motorwerkz, had a PCV (and Lloydz air filter) installed, and Lloyd himself did a lengthy dyno run to map the PCV's cells. This mapping was done at assorted throttle openings and RPMs, and then repeated for the other cylinder. Attached is the dyno run when he had finished the process, which shows -- it seems to me -- a constant AFR. Lloyd says that the final numbers for my bike were "very good" (given those changes).

So, FWIW and in hopes that this sheds some light on your question, see attached (or, in larger, clearer, form, http://www.billanddot.com/Lloydz-Motorworks-Dyno-Run-2014-09-02.pdf on my web site).

Sorry that's all I can offer. Maybe someone else can discuss these results more meaningfully.
 

Attachments

·
Registered
Joined
·
290 Posts
Discussion Starter #3 (Edited)
He was tuning the whole throttle spectrum for each RPM range to maximize power and efficiency at all throttle positions and RPM's. I'm just curious about what the AFR usually looks like at WOT through the powerband.



Let me say at the start that I have no knowledge in this area, I can't carry on an intelligent conversation about AFRs, let alone about engines in general, and so forth.

I am responding only because last week I went to Lloydz Motorwerkz, had a PCV (and Lloydz air filter) installed, and Lloyd himself did a lengthy dyno run to map the PCV's cells. This mapping was done at assorted throttle openings and RPMs, and then repeated for the other cylinder. Attached is the dyno run when he had finished the process, which shows -- it seems to me -- a constant AFR. Lloyd says that the final numbers for my bike were "very good" (given those changes).

So, FWIW and in hopes that this sheds some light on your question, see attached (or, in larger, clearer, form, http://www.billanddot.com/Lloydz-Motorworks-Dyno-Run-2014-09-02.pdf on my web site).

Sorry that's all I can offer. Maybe someone else can discuss these results more meaningfully.
 

·
Premium Member
Joined
·
5,632 Posts
He was tuning the whole throttle spectrum for each RPM range to maximize power and efficiency at all throttle positions and RPM's. I'm just curious about what the AFR usually looks like at WOT through the powerband.
That graph was done at WOT. All max power graphs like that are. I think his point was that the AFR was pretty constant across the rpm range.

The way the factory sets them is to run near stoich at cruising speeds to maximize fuel efficiency and minimize emissions. From the accounts I've read, they are all mapped to run much richer during acceleration and high rpm operation. Those are not operating conditions that manufacturers need to satisfy federal requirements.
 

·
Registered
Joined
·
290 Posts
Discussion Starter #5
That graph was done at WOT. All max power graphs like that are.
A given

I think his point was that the AFR was pretty constant across the rpm range.
That's what i was wondering

The way the factory sets them is to run near stoich at cruising speeds to maximize fuel efficiency and minimize emissions. From the accounts I've read, they are all mapped to run much richer during acceleration and high rpm operation. Those are not operating conditions that manufacturers need to satisfy federal requirements.
Gotta love the EPA
 

·
Premium Member
Joined
·
5,632 Posts
Gotta love the EPA
This is an often heard line. Actually, I do like the requirements in concept, just not always in practice. As someone who enjoys a spritz of oxygen with my air, I very much appreciate them requiring vehicle manufacturers to abide by standards that help keep it that way.

For cars, trucks, and other gas powered gizmos, I think such EPA setups are great. And that's to say nothing of the gas money they save me.

Where it all falls apart for me is requiring it on bikes. Someone in the gov't needs to strap an engine between their legs before they make requirements that will increase the nut roasting heat of liter plus engined bikes. And the jerky throttle response that is manageable in a car, is much less manageable when on a bike trying to get around a corner.

So for me, the relationship is sort of a love/hate proposition.
 

·
Registered
Joined
·
290 Posts
Discussion Starter #7
Don't get me wrong. I love cars that don't stink, and i love having clean air in the city, but yea. They get out of hand, especially with bikes and diesels.

This is an often heard line. Actually, I do like the requirements in concept, just not always in practice. As someone who enjoys a spritz of oxygen with my air, I very much appreciate them requiring vehicle manufacturers to abide by standards that help keep it that way.

For cars, trucks, and other gas powered gizmos, I think such EPA setups are great. And that's to say nothing of the gas money they save me.

Where it all falls apart for me is requiring it on bikes. Someone in the gov't needs to strap an engine between their legs before they make requirements that will increase the nut roasting heat of liter plus engined bikes. And the jerky throttle response that is manageable in a car, is much less manageable when on a bike trying to get around a corner.

So for me, the relationship is sort of a love/hate proposition.
 

·
Premium Member
Joined
·
2,436 Posts
I agree with about everything here. I can't help but think about a few things before we had EPA and pollution controls. Ever ride behind a big 8 cylinder with a screwed up carbuerator? There use to be lots of cars that would just flat gag you to ride behind. I don't miss them. That said, I'd prefer my bike without them.
 

·
Registered
Joined
·
1,858 Posts
Throughout the WOT power band, does the optimal AFR get progressively leaner as RPM's climb? Like 12.5:[email protected] and like 13.5:[email protected]?
In almost EVERY case, a tuner will target a specific AFR (like 13.7) but power will vary (very slightly) a bit above or below depending on numerous factors. I was surprised to learn that those minor AFR difference really don't make much (if ANY) difference on power (e.g. a 13.7 seting vs. a 14.1 might not make even 0.05% of a HP difference) so the bottom line is... "Don't think that AFR is the be-all, end-all for tuning" as it AIN'T thumb up

Here is a good video of a mustang on a dyno that helps better understand what part AFR plays in the HP efforts.
https://www.youtube.com/watch?v=Zzn3-ygH-v8
 

·
Super Moderator
Joined
·
5,063 Posts
In almost EVERY case, a tuner will target a specific AFR (like 13.7) but power will vary (very slightly) a bit above or below depending on numerous factors. I was surprised to learn that those minor AFR difference really don't make much (if ANY) difference on power (e.g. a 13.7 seting vs. a 14.1 might not make even 0.05% of a HP difference) so the bottom line is... "Don't think that AFR is the be-all, end-all for tuning" as it AIN'T thumb up

Here is a good video of a mustang on a dyno that helps better understand what part AFR plays in the HP efforts.
https://www.youtube.com/watch?v=Zzn3-ygH-v8
I've had a few tunes done and the difference is small as in effecting power.

Ridability on the other hand is effected a great deal.
 

·
Moderator
Joined
·
13,247 Posts
From Kevinx
Breathing equals performance............
Had a couple minutes, and a couple of cooperative customers in today. Both wanted to have their bikes spun on the dyno, and then we looked at ways to get some cheap performance in the game.
I will do this as two separate posts as to not confuse myself with the charts, bikes etc.
First bike was a BONE STOCK 13 XCT. He came in for a service, and dyno. Figured before I beat up his new oil; we would see what he has going on. Spun the bike 3 times as is. Typically the 3rd run is the highest number, and on my dyno it spun a whopping 77.94/91.67. Not real impressive, and it shows that my dyno is a bit of a pessimist.
Second run was after 15 minutes on the fan to get it back to the original runs temp. I unhooked the 02 sensors and forced it in to open loop. Not expecting to light the world on fire, but it did give me a respectable 80.34/95.04. Those numbers are more like what I expected to see, and the improvment was pretty much across the board.
Another 15 minutes on the fan, and this time we added a Lloydz performance filter. Now this woke her up. Remember BONE STOCK, and a pessimistic dyno. 83.94/99.52.
We are looking at an increase of 6HP, and 7.85FtLb with a little simple change. That is almost 10%, and it is reflected all the way across the board!!
 

·
Moderator
Joined
·
13,247 Posts
Kevinx #2
Better breathing part two.......
This bike is an 07 KP tour. It has Vic performance full pipe set, S1 filter, and Vic S1 down load. The bike runs pretty damn good as is. He originally just wanted to get a sheet to show his firend that dumped a ton in his street glide to get 76/95 out of her.
First run as is; the bike spun 82.66/103.19.....Fairly respectable for what has been invested in it. Again this was the third run on a reasonably cool bike. I asked him if he would spend $50 to get a couple HP, and Tq. Who could pass that up?!?
So i snatched off the horn, drilled a couple of 7/8 holes in the flat of the airbox, between the rails, put her back together and made another 3 pulls.......84.26/105.19. The real story here though is not in peak numbers. It is in the torque curve below 3500. there it gains 3HP, and 5FtLb. Not bad at all for a couple of holes, and a half hours work!
 

·
Registered
Joined
·
1,347 Posts
I only have 2 things to add to this thread, 1 is sarcastically.
Nobody EVER runs their Victory wide open so who cares how much power it makes at WOT?:ltr:

2) I work in a commercial heat treat, and there is a shitload of combustion going on in there as we run our our open air combustion furnaces up to 1800 F.
Our lead maintenance man has found that the O2 levels are lower in the offices and out in the shop than they are when he is inside of a furnace after it has been shut-down and purged.
Humans have no effect on the air that we breath or the atmosphere that surrounds us.
We could have more effect on MUSLIM TERRORISTS than we do on the environment in our own country.
Oops sorry, in this day and age there is no such thing as a MUSLIM TERRORIST.
They are mis-led mohammed followers.
 

·
Premium Member
Joined
·
5,632 Posts
I only have 2 things to add to this thread, 1 is sarcastically.

Humans have no effect on the air that we breath or the atmosphere that surrounds us.
I take it that that is the sarcastic part? Or maybe you should take a trip to Beijing. I hear the atmosphere is a wonderful brown this time of year.

 

·
Super Moderator
Joined
·
5,063 Posts
I have all my run files made during my dyno tunes so I can bring them up and use Winpep 7 to read what's going on with everything besides WOT. You would be surprised what your number are at 40%, 60% and 80% throttle more of what real world daily riding would be.

100% WOT is bragging rights and rightly so it is max power and shows the most the motor will do.
 

·
Registered
Joined
·
329 Posts

·
Registered
Joined
·
290 Posts
Discussion Starter #17
Now that we've discussed this a little bit, the reason i asked is because I'm buying a dobeck AFR+ wideband/autotune setup. If you're not familiar with it, you can set idle fueling, cruise fueling, and WFO fueling seperately and set the ranges at which each one engages.

At first i was worried about having a significant difference in fueling requirements between cylinders, but i talked to Lloyd, and he said it's not usually much of a difference on 07 engines. So I'd rather live with a miniscule difference between cyls and be able to command my AFR and see where it is at all times.
 

·
Registered
Joined
·
2,411 Posts
Throughout the WOT power band, does the optimal AFR get progressively leaner as RPM's climb? Like 12.5:[email protected] and like 13.5:[email protected]?
I've done HD's not vic's so keep that in mind. The theory is pretty much the same as far as I can tell.

You are talking WOT.
If you are running your cruise mixture lean for mileage, say 13.9 and up, your WOT generally must be in the 12 to 12.5 WOT because a motor running lean and advanced during cruise tends to heat the exhaust valves and possibly areas of the pistons to the point where you need a richer mixture WOT to ensure it doesn't go into detonation if the throttle is snapped open on a steep hill on a hot day.

IF you still get some pre-detonation in some cells at WOT you can run even richer in those cells effected which changes your combustion timing by interfering with the combustion process. Sort of like backing the timing off a little but without having to screw with the ignition map. But you don't want to get carried away because you can end up with excess fuel ruining cylinder lubrication and promoting wear.

Now perhaps you could if you were only building a track bike lean out the top because you weren't ever lean on the bottom but since best power is generally in the 12 - 12.5 I can't imagine why you would want to do that. You are seldom at WOT in the grand scheme of things and if your trying to get better gas mileage you are never there.
That's how I have done it. I tried a lot of different combinations and this is what worked best for me.
If you want it done right.... send it out.:D
 

·
Registered
Joined
·
1,533 Posts
"Don't think that AFR is the be-all, end-all for tuning" as it AIN'T thumb up
I whole heartedly disagree. I believe AFR is absolutely necessary for proper tuning. Excessive heat, popping, backfiring, tip in hesitation can all be controlled with AFR. Heck, our big 3 Vic guys even TARGET certain AFRs to achieve a good baseline and adjust from there. If your point is specifically in regards to power output then sure, I'll bite.
 

·
Registered
Joined
·
1,533 Posts
Now that we've discussed this a little bit, the reason i asked is because I'm buying a dobeck AFR+ wideband/autotune setup. If you're not familiar with it, you can set idle fueling, cruise fueling, and WFO fueling seperately and set the ranges at which each one engages.

At first i was worried about having a significant difference in fueling requirements between cylinders, but i talked to Lloyd, and he said it's not usually much of a difference on 07 engines. So I'd rather live with a miniscule difference between cyls and be able to command my AFR and see where it is at all times.
I have the same tuner and it works brilliantly! Regardless of what some may say, you can and will notice differences in your engine's behavior just by moving the AFR around and seeing it on the gauge will help you find the happy spot. The drawback...it's not all too consistent with cams. In the green and yellow zones with hi flow filter and ATS, my actual AFRs stayed very close to my targeted AFRs. After I installed my cams my actual numbers would move here and there depending on rpm but still stays in an acceptable range. The red zone stays dead on regardless because it's closed loop. Don't set your green zone at an idle like they recommend, this zone will mostly be used in light cruising, set it while light cruising. You'll notice it'll run richer at an idle. But if you set it at an idle you'll notice it'll run leaner at light cruise...which is why I suggest setting it while lightly cruising, say 5th gear @ 55mph and barely touching the throttle...best spot for the green. thumb up
 
1 - 20 of 21 Posts
Top