I have a before and after dyno chart here so you can get an idea how some of these mods work on an 04-05 1200.

FYI: H-D states that a bone stock 04-05 1200 will dyno at approx 59 rwhp @ 5,600 / 68 ft. lb @ 3,600

The first photo is the Stage 1 dyno chart: SE Pro II slip-on muffs, SE air cleaner, an SE ignition module and some carb re-jetting. 69 rwhp @ 5,800 / 74 ft. lb @ 4,200

http://img.photobucket.com/albums/v248/Turbota/Stage1DynoChartb.jpg
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The next chart is what I would call Stage 2 mods. This added NRHS Stage 2 heads, NRHS 10.5 :1 CR forged pistons and the 04-05 specific SE cams (249/249 .551"/.551")

The carb is still the stock 40mm CV, and the displacement is still basically 1200. Actually approx 1210cc due to a .015" overbore for the new pistons. 84 rwhp @ 6,300 / 79 ft. lb @ 5,100

http://img.photobucket.com/albums/v248/Turbota/Stage2Dyno.jpg

As you can see, the fuel/air is pretty much steady at 13.8-1 all the way to where the bike makes it's max HP. I was told that the needle height is just right, but I really need to change out the 170 main jet for a 175. This will get the air/fuel ratio closer to 13.0-1 and should get a couple more HP out of the motor ... Still, the fuel/air line looks pretty good.

I was told that the motor is loosing HP after 6,300 revs because of the mufflers. With a good set of 2-1 mufflers and a tweek of the fuel/air, the bike should make right at about 90 rwhp (I think that's pretty good for a stock displacement 1200)

The dyno operator said the torque curve is real wide and not "peaky", so everything looks good with it ... 79 ft. lb is more torque than I thought it would make.

That's about all I can tell you.

Ron,

Oh ya ... Didn't get even the slightest puff of blue smoke out of the exhaust during the full dyno pull, so it looks like the new rings are sealed real good.

Nice #'s. 42% more HP over stock. But, are you satisfied(finished)?

That is one purty chart.
I am somewhat surprised that you are running a 170 main. When I rejetted for my conversion I went from a 170 to a 185 (based on input from other lists), but I haven't had it dynoed so maybe I'm running too rich.

twinsporty ... That 170 is a small jet, but the DynoJet needle is really very thin too .... My guess is that's why they can get by with a small jet ... And, while a bone stock XL may be too lean from the factory at idle and part throttle, they are really too rich at WOT.

Your just not going to really know untill you run it on the dyno and look at the air/fuel. I think anywhere between about 12.9 and 13.2 - 1 is ideal for WOT as far as making the most HP (as long as it's not detonating)

seajay ... Well, I am still going to put in a 175 jet in it if I can ever find one. The new DynoJet kits specific to the 04-05 XLs come with one now. The kit I bought almost a year ago didn't ... And the H-D dealer says H-D don't sell them. Only even sizes.

These SE mufflers are pretty good, but they are holding back my bike after the head/cam/piston changes. I may get a good 2-1 sometime and re-dyno ... I guess I could really confirm that the mufflers are holding the motor back by just pulling out the baffles on my SE muffs completely just to see where the HP peaks at on the dyno. That would at least confirm that the mufflers I have now just are too restrictive.

A couple of points Ron

A 2-1 will change the curve shape as well as give you a bit more at the top.....Typically it tends to dip around 2700 and spikes around 3500 and then steadys from there.

I'd be loathe to change much with a torque curve that flat..... if ya like the 2-2 set up a set of S&S slip ons may be worth a try...


Main jet size is dependant on a number if things, one of the main contributing factors is the needle....there is a strong relationship between the needle and the main jet (as well as the pilot)
Stock needle will rarely require a different main...........BUT change ya needle and you've opened up a whole can of worms and ya need to test to find the ideal main

stevo ...

Thanks for the input. I am very happy with the torque curve. Especially way down low. Even with that cam and the big ports, it builds torque real fast way down low.

What I don't like is how the HP drops like a rock above 6,300. I would have thought that it would stabilize maybe above around 6,500 ... But not drop down like it does. I can only think that the mufflers just don't flow that well way up high. That's what the dyno operator thought too.

I really should have just pulled the baffles out of them and made another dyno pull for for shits and giggles ... I still think they are holding this motor back at high revs.

Maybe when I started to "Modify" the baffles myself a few days ago, I kinda mucked everything up a little :) ... Should have left them alone!

I wouldn't trade that curve for a couple of hundred more rpm at the top UNLESS you are racing it and that's the difference between winning a class or loseing.

What you have is GREAT street graph.........forget the numbers and go and ride the bloody thing :D

Thanks Steve .... :)

I asked the dealer what they put in jetwise on my 1200r the other day. When i picked it up, i had the se ac and slip ons installed. THey said they put 45 slow and 185 main in all of them. No wonder i am running rich!!!!

Ron, that's a great looking sheet, nice broad powerband.

Some things I want to offer though. First is a case history:

http://www.nrhsperformance.com/pictures/barney.gif

This is a local customer with a 2001 1200. The bike has a Thunderheader and an HSR42 and a Dyna 2000 ignition.

Back in '03 he came to us. He had already installed some N4's and wasn't happy with the performance. We did a Stage 3 job to his XL1200 heads, also dual plugged them at his request, some people like that. That's the green. Not terribly different from your result.

Then he put in some SE 536's and brought it back for a tune-up. That's the red. Notice how it lost a little on the bottom and gained quite a bit on the top.

Finally in '04 he got some '04 XL1200R heads and we did Stage 3 to them. We did a 30 degree chamber and again dual-plugged them and sold him a 1250 kit. That's the blue.

We flowed your heads (as we flow ALL heads that leave the shop). They are a superb set of Stage 2's. They don't flow as well as the the set on this bike, since his are Stage 3 and have bigger valves, but your heads are more than capable of supporting more power than you're making. Other things are holding your motor back. Cams and exhaust come to mind. The E cams have lots of lift but they're pretty narrow. High lift, narrow grinds tend to make for wide powerbands. You're the poster child for a wide powerband.

Comment two: I see your posted run is pull # 3. Sounds like you did no tuning. Well, just as a point of reference, on the day we got the blue result above, I did 22 pulls tuning up his bike. The third pull was 97hp. In other words, I was a long way from getting everything out of his bike at pull number 3.

Bring me your bike, I'll get more out of that sucker!

Comment 3: did you have the SE air cleaner in place during these pulls? That thing is awful y'know. At this level, it could easily cost you 5hp or more.

But anyway, the main thing that strikes me about your sheet is how wide the powerband is. You've added a bunch of power to your bike without losing a thing down low. Nobody could blame you a bit for leaving it the way it is, because quite honestly, most of the things you could do to keep it pulling on the top end are going to take away from the bottom.

Congratulations!

BTW, I personally bored and honed those cylinders and fit your pistons, and if I remember right, I even gapped your rings and installed the pistons in the cylinders (unless I'm getting folks mixed up, which I might). They BETTER NOT have a ring seal issue!!!

Oh, and your motor is 1222.87cc.

Aaron ...

Thanks for the input here. I am very happy with the results I got from the pistons, machine work and head work that was done on my motor. The ring seal on this motor is absolutly perfect. And I was supprised how well the rings sealed the moment the motor was first run. Never a sign of smoke from the exhaust. Even day one.

Yes, that was the 3rd dyno pull. The first full was for warm up and was shut down at 5,000 revs. The 2nd ended early because the bike went past the speed limiter of the DynoJet. The speed limiter was increased and then this run was made. No tuning was done on the bike, but, I can say that the carb is slightly lean, but the line on the graph is fairly straight which is nice.

The air cleaner is an SE round unit used on the 98 FXDX and Night Train bikes. I feel it breathes better than the standard 04-05 XL Screamin' Eagle unit.

I am no expert, but I feel the pipes are keeping my engine from making more power way up high. I just wish I had removed the baffles in my SE II exhaust to verify this.

Bottom line, I am very happy that I have such a wide power band. This bike pulls very hard right from around 2,100 revs and don't slow until about 6,400. That is amazing! And I had heard that the [big ports] in my NRHS Stage 2 heads may kill torque down low due to poor velocity at low revs. Well, that certainly IS NOT the case!

As Stevo stated .... "I have a GREAT street graph"!

NRHS did a fantasic job on this work. Although the NRHS Hurricane pistons in the motor are 10.5 :1 CR, I get no detonation on premium pump gas, and again, the machine work was of very high quality :)

I still feel this 1200cc motor will make 90rwhp with a better exhaust than the SE IIs that are on it now.

Bottom line ... This combo just makes for a great street bike with excellent throttle response and great manners for everyday traffic. The motor feels like a rocket compared to when it was your garden variety Stage 1.

I'm Happy! :)

Ron Larson,

The only complaint I have is that these .551" SE cams sound like an old Singer sewing machine when idling. They were installed about a month before the NRHS heads and pistons. The cams were noisy from the moment it was first started with them in the engine. I blame it on the "fast ramps" these cams have ... But that's my uneducated guess.

Oh yes ... Aaron ... You did install the ring pack in the pistons and then install the pistons in the cylinders like you said ... Made it easy for me to just pull them out far enough from the bottom of the jugs in order to attach the wrist pins without having a ring come out of the bore ... That made the install as snap :)

Aaron Quote: "Oh, and your motor is 1222.87cc"

For some reason, I thought they had bored it .015" and not .030"

I originaly had requested a .015" overbore, but then changed my mind to a .030" overbore. For some reason, I was under the impression that it got the .015" overbore ... Now, looking again at the Invoice sheet, I see it does in fact show a 3.530" bore (.030" overbore) :)

Ron,

Well done with the response Ron.

Are you going to change the exhausts? I have read that people are not always happy with the increased noise of the freer flowing type though..

I was very happy with my engine after I fitted the Mikuni flat slide carb as it gave it a much better throttle response.

Do you think the Night-train air filter might be restricting the top end? I can't believe it must all be down to the exhausts (I'm no flippin' expert though!).

Great looking chart Ron! Thanks for sharing it with us. I just ordered a Lightning 2 into 1 and N-4 cams to go with my NHRS T-storms. Can't wait to get them installed and tuned to see where I come out.

I can't confirm how well the Night Train SE aircleaner flows on my motor, but from the looks of it, I would think it should flow good. Next time I go to the dyno, I am going to do a pull with the filter removed just to see if there is a difference.

Here is a photo of the filter element with the cover removed:

http://img.photobucket.com/albums/v248/Turbota/4EngineWithFilter.jpg

C'mon Ron

Ya gotta thro some dirt on it :D... it's tooooo pretty

Hey Bota, I noticed VERY LITTLE increase with the big twin AC off.

The factory SE sport kit was a big difference though. HP went from hmmmm, I think my stage 1 with se sporty kit was 73.5 with and without it was 78 or 79. So a 4-6 HP increase with the 04-05 SE kit.

The drop with the SE BT A/C was only 2 I think. I'll do it again later to be sure.

Here is my dyno with:
JET 1200xb heads 10-1
Andrews N3s
SE BT round AC kit
Twin Tech ignition
Cycle Shack slip ons

Not to bad I think.

Note: some of the color is off because I removed a run that had N2s and was compared to this one on the same sheet. If any one wants I can show the original with both runs.

Great read. I own a 1200 XLH and i am currently looking at cams and head work, I am getting prices from Dan at the momment for SE 497 bolt ins and stage two size valves and 40 thou shorter push rods and gaskets. Can you give me some tips and fed back about your bike when you had the N4 cams and head work and what CR were you running at that time? Did the 536 cams make a big difference with the xlh heads? Im trying to work out if I should go with the SE 497 boltins or go with the 536 cams and what size valves should I use if I go with the 536 cams? I hope this all makes sense. I would greatly appreciate your opinion. Regards David