These are the results of my 1200R.
To date the mods are as follows: Khrome Werks slip ons, Zippers air cleaner kit, SE module, SE bolt in cams, Very mild head porting by Baisley's in Portland, rejetting with lightened slide and spring.
The blue run is not the stock bike it was everything you see in the green run minus a jetting tweak and the lightened slide and spring.
I need some input from you guys on this, it appears to be weaker in the 2500-4000 rpm range than I might have thought. We've been brainstorming whether this is strictly an issue of jetting or exhaust, possibly even carb holding it back, or whether thats just the way it is.
Unlike some, I don't know much about this kind of thing, just enough to be dangerous .
Thanks in advance for any suggestions.

Hi Joe.

So, your a Beaver too?
Cool. So who is doing the dyno runs, Paradice or Latus?
How much did the port work cost you, and you have the number?

I think your next move would be a Mikuni 42 slidebore carb.

Good to see another rider from the area. I'm not sure what happened with yur tuning but my bike with 49 State leagal slipons, 45 and 170 jets, SE air kit and N65b needle had less hp and torque but the torque line was a lot flater. My air to fuel at wot was around 13 to 1. I'm now running a Supertrapp 2 into 1 exhaust but have not had it dynoed yet with it on. Good luck in fine tuning the motor.

You might do a search on posts by awsracing. I'm sure I've seen a post by them showing the effects of exhaust reversion on the Torque curve. Nice numbers by the way.

Thanks for the replies so far.
I can't find the paperwork on the cost. I think the total package was about $1100 including the port work. Seems to me the porting itself was something like $350. I bought the cams elsewhere though, so this was primarily labor.
This work was all done at Paradise and is a combination of Harley Bob (cams, tearing down the heads and reassembly) and Jon their dyno guy.
As much negative as I hear about dealers I have to say the service guys have always treated me very well there.
I'm thinking about the 42mm, maybe that would take better advantage of the headwork. I have that carb on my FXD and am very fond of how it performs.
Mainly, in comparing my graph to others it looks like mine is a little soft below 4k. What really blew me away is how that engine could go from 67 hp to 84hp with not much more than lightening the slide and springs. Pretty dramatic.
Also, the number for Baisley Hi-Performance is 503 289-1251

The torque curve is basically a map of your cylinder fill. Your bike is filling the cylinder really well at 5200rpm but really poorly at 3200rpm. The poor fill corresponds with richness in the a/f ratio. This is a really, really, really common scenario.

Imagine the piston is sitting at top dead center during overlap. Both valves are open.

On the intake side, you've got a relatively cold charge at near atmospheric pressure.

On the exhaust side, you've got hot, high pressure gas that you just shoved there.

Now the piston starts moving down. Where is it going to pull from?

What makes it pull on the intake instead of the exhaust?

It's absolutely critical that the exhaust system comes in and generates a suction wave right then. That's the only thing that keeps it from sucking on the exhaust instead of the intake.

A good suction wave, like the one you're getting at 5200rpm, will actually get the charge in the intake tract moving before the piston even starts pulling on it. This dramatically helps cylinder fill. It's called exhaust augmented intake flow, and it's the whole reason cams have overlap.

On the other hand, if the exhaust doesn't pull right then, cylinder fill suffers.

Worse, if it comes in with a positive pressure wave, it can actually push the intake charge (that's sitting in the port & manifold) back out the carburetor, causing a fog out the mouth of the carb (aka "stand-off"). Then the piston goes down and pulls it back in. So now you've got an intake charge that's been through the carb 3 times: in, out, back in again. It picked up fuel each trip through, which makes it rich. We call this condition a "reversion".

The problem with pressure waves in the exhaust system is that they travel at pretty much a constant speed, the speed of sound, regardless of the rpm of the motor. So a suction wave that's timed to arrive during that small window of time called overlap at one rpm isn't going to be timed right when the rpm changes.

To counter this, pipe designers try to diffuse the pressure waves in the pipe, such that a negative wave gets broadened so that it arrives over a wider rpm range. This broadening of the wave also weakens the wave, but that's better than having a reversion somewhere.

The most simple diffusion device is a baffle. The problem with baffles is that they cause back pressure. Other types of diffusion devices, for example megaphones, can offer diffusion with less or no back pressure.

In any event, your pipes are pulling real good at 5200rpm but pushing back at 3200rpm.

If you're married to those pipes then I'd suggest cams with less overlap.

Here's another classic example:

http://www.nrhsperformance.com/pictures/csvsttq.GIF

Same bike, same dyno, the ONLY difference between those pulls is the pipe.

The Cycle Shack system has a big reversion from 2500 to 4500rpm. I'm not showing the a/f, but it was going rich through there. But above that range, it starts pulling hard.

The Supertrapp pulls like gangbusters through the 2500 to 4500 range, but then goes flat. Later I added some discs and got it to pull much better up high with little to no loss in the 2500 to 4500 range.

Horsepower is fundamentally torque times rpm, so to make big hp you try to move the torque peak up the rpm scale, or in other words, you try to fill the cylinder at high rpm.

Take a look at this chart:

http://www.nrhsperformance.com/images/drdannorlin82.gif

This is a race motor. We designed and built the pipe to put the torque peak way up at 6500rpm, and we totally ignore diffusion, instead doing a number of things in the pipe design to try to concentrate the wave. Ports are sized for the correct velocity at that rpm, cam timing is optimized for that rpm as well. The result is a pretty good horsepower number for 82ci. But not a wide powerband, you can see in the shape of the torque curve down low that some different kinds of waves are hitting it. This bike never falls below 6000rpm so we don't worry about it.

And finally, here's the picture perfect street exhaust:

http://www.nrhsperformance.com/images/drrichmartinez.gif

The torque curve is a nice, broad parabola, great diffusion that makes for a wide powerband. Sure, we could get him more at any given rpm with an exhaust that's focused on that rpm, but this is what we like to see in a street bike.

Always look at the torque curve to see what the pipe is doing. You'll see pipes that pull hard at one rpm but not at others, you'll see pipes with two torque peaks (most common on 2 into 1's), and you'll see parabolas. If you see a dip, it's likely pushing back right there, especially if it's accompanied with richness.

So if i understand this correctly the exhaust is the limiting factor in the low and mid rpm range.
Can you recommend a pipe that is likely to correct this?
If one changes a pipe to correct the low to mid, is it likely to cause a loss at high rpm?
Would anything be gained by going to a 42mm flat slide or the 44m CV?
Thanks very much for the input, first time I've understood much about this.

Well, the Supertrapp will likely correct it. It's kind of a quiet exhaust, that's my only gripe with it. The above ST/CS comparison was taken on a 2004.

What I found with the Supertrapp is that adding discs kept making it run better and better up top with no real effect on the bottom:

http://www.nrhsperformance.com/images/supertrappdiscs.gif

At 26 discs, it was beating the Cycle Shack 2" system on both bottom and top, giving up just a little over a narrow range at the mid-top.

For a louder alternative, the Thunderheader seems to do a reasonable job of diffusing, at least the 03 did:

http://www.nrhsperformance.com/images/drbarneyhertzog.GIF

They're available for the rubber mounts, but I haven't tested the rubber version yet.

It's possible that a pipe that redistributes the power like this will pull some away from your top end number. But if it has fewer pumping losses (back pressure), it may do just as well or better up top.

After thinking about this whole situation for some time I believe that I will eventually end up going to a different exhaust in an attempt to get the bottom end cleaned up. I decided though that I wouldn't do the exhaust unless I also did the 42mm flat slide since I've had that carb on my fxd since day one and believe it to be a great carb.
Given that, just for education I decided to do the 42mm first and just see what happened. I don't have a copy of the dyno run to post just yet (at least not that gives the direct comparison between the last run and the current one with the 42mm.) but it gained just about exactly 2hp and follows the curve of the CV carb almost exactly, just 2 hp higher. Similar gain in torque. Max hp is now 86, although the run conditions were quite different, 16 degrees colder and the humidity was quite a bit lower also, which I am told may have a significant impact.
The increased throttle response is quite significant and I'm glad I did the carb. I suspect at some point I will do the pipe when I can find one that looks right. I think the Supertrapp, as described by Aaron, would be the best way to go but I wish the dang thing didn't hang down so low on the rubber mount versions. Not like theres so much ground clearance there that you can afford to give any away.
Its for sure getting to be a fun bike to ride finally, and has certainly been an education.

Aaron,

Lots of us have the cycle shack slip-ons. I have the tapereds. I got a pretty nice torque curve with a big sucker and a 42 pilot, 180 main and 2 m4 shims (about 1.3mm) on the needle. I have since gone back to a 45 pilot as once the cooler, drier came down, it was carb farting more often with the stock pilot. What is your take on the baffles system used in the cycle shacks? Also, when my dyno run was done, the air/fuel probe was shoved in only to the where the baffle plate sticks up...pretty far from the ideal location I think. Anyway, how much do you think that would affect me A/F readout? I'm pretty much right on the 14 line, but the bike runs really well. I have tried a 185 main and it felt like I lost some power. Would the probe placement throw the reading off by a whole line? Can you see anything I can do to improve my curve?

heres the dyno graph: http://xlforum.net/photopost/watermark.php?file=3789&size=1

Secondly, I think you could help a lot of us with this one: sometimes as I'm slowing way down to make a turn, I'll clutch and downshift then when I apply throttle I get a loud cough through the carb.That really seems to be the only time the engine does this. Is this an ignition issue or a carb issue? 99.9% of the time the bike carburates excellent. Can this annoying trait, which seems to afflict pretty much every new sporty, be tuned out with the addition of an adjustable ignition like the Daytona Twin-tec?

Thanks in advance for your advice. FWIW, the dealers service writer told me all Harleys do this...even the injected ones, and its never fully curable.:frownthre

Supercharger, who did your dyno work? I'm looking for someone in your area who is reliable and knowledgeable.

Aaron,

Lots of us have the cycle shack slip-ons. I have the tapereds. I got a pretty nice torque curve with a big sucker and a 42 pilot, 180 main and 2 m4 shims (about 1.3mm) on the needle. I have since gone back to a 45 pilot as once the cooler, drier came down, it was carb farting more often with the stock pilot. What is your take on the baffles system used in the cycle shacks? Also, when my dyno run was done, the air/fuel probe was shoved in only to the where the baffle plate sticks up...pretty far from the ideal location I think. Anyway, how much do you think that would affect me A/F readout? I'm pretty much right on the 14 line, but the bike runs really well. I have tried a 185 main and it felt like I lost some power. Would the probe placement throw the reading off by a whole line? Can you see anything I can do to improve my curve?

heres the dyno graph: http://xlforum.net/photopost/watermark.php?file=3789&size=1

Secondly, I think you could help a lot of us with this one: sometimes as I'm slowing way down to make a turn, I'll clutch and downshift then when I apply throttle I get a loud cough through the carb.That really seems to be the only time the engine does this. Is this an ignition issue or a carb issue? 99.9% of the time the bike carburates excellent. Can this annoying trait, which seems to afflict pretty much every new sporty, be tuned out with the addition of an adjustable ignition like the Daytona Twin-tec?

Thanks in advance for your advice. FWIW, the dealers service writer told me all Harleys do this...even the injected ones, and its never fully curable.:frownthre

FIrst off, nice avatar:clap

Looking at your dyno sheet, you are lean from idle to 3500 or nearly 4000 rpms. The main jet appears to be correct (or very close). What slow jet, needle and shim were you running on the dyno run? The caugh you are asking about is typically a result of a lean off idle condition. If you were running a 42 pilot (slow) jet, then I would suggest a 45 and retuning the idle mixture. Then run it again with needle shims in hand. If the midrange needs further richening, I'd throw a shim under the needle and run it again. Continue richening to about 13.5:1.

I also wanted to point out that your torque curve has a nice shape to it with the cycle shacks. The reason yours does and the one earlier in this thread stuggled in the lower rpms is because of cams and reversion. But Aaron already explained that very well earlier.

Thanks Shu.

Neckball, sorry I didn't see your post earlier. Carolina Harley did the baseline Dyno run but I did the tuning prior to going there.

Edit: Carolina Harley is in Gastonia, about 20 minutes west of Charlotte of I-85. Good people.

I'd agree with Shu. That A/F line stays above 14:1, all the way up to 6k RPM. Bring it down, Supercharger... start with a bigger slow-jet, and work to richen it up, under 3.5k first.