how many folks understand that some mods might pick up some peek power but at the price of less power in the lower RPM rang?. like drag pipes, larger carb or race cams.
i think some just see a % increase in HP and think man am i going to feel that. not understanding that the increase might just come at the top of the power band and hurt HP in the normal riding range . most conversations just deal with how much power was picked up.
i know this is basic stuff but it does not get mentioned very much.

Who, me??????

i use my entire rpm range all the time, i feel it. i know i need more top end and can sacrifice some down low. besides after first gear, bike doesnt see 2500 rpms.

It seems to me that riders modify their bikes for many different reasons. Some are after pure horsepower numbers and dyno their bikes after every major mod. I don't read much about Sporty owners doing track days on their bikes, so this approach must not be about racing. Admittedly, some are drag racers because I do see 1/4 times quoted here occasionally, but I suspect mostly that approach is about bragging rights. Very similar to my neighbor who just bought a Saleen S281 Supercharged Mustang with 435 hp and 425 lb-ft of torque. He's never going to use that car to its potential, but he can sure talk about it.

Other riders seem to be more like me, in that they are more concerned with what the bike feels and rides like, than raw numbers. As I set about building up my '05 883 Standard, I was initially more concerned with real world issues like getting rid of the strangled feeling of the bike, the carb farts and long warmups, the stalling, etc. Stage I took care of all that and the bike ran as advertised.

My next concerns were more in terms of issues like merging safely onto interstates and keeping pace with traffic on these roads. As an 883, I wasn't comfortable with the feel or overall performance of the bike in those areas, so I did the 1200 conversion. That took care of those issues and really transformed the bike in terms of rideability and performance on the road.

I could then have gone further with cams, different heads or head work, carburetion, whatever, but I knew I would have seen gains in some areas and losses in others. Sometimes the trick is knowing when to stop.

My point is, coming at this the way I did, measuring the success of the engine mods against the feel of the bike and what I wanted to accomplish with it, rather than against raw numbers, I ended up very satisfied with the performance gains and overall very happy with my bike. I still don't know how much hp and torque it makes, and don't care. It now feels exactly right and that's what's important to me.

My point is, coming at this the way I did, measuring the success of the engine mods against the feel of the bike and what I wanted to accomplish with it, rather than against raw numbers, I ended up very satisfied with the performance gains and overall very happy with my bike. I still don't know how much hp and torque it makes, and don't care. It now feels exactly right and that's what's important to me.


im with you but i will dyno just to get a/f ratio and see where and if it needs adjusting. the numbers i will post for people here to see and make thier own decision as to weather or not the mods are worth the cost. i know the answer and so do a few riders who have been smoked on the road.

John -

I hear what you're saying, but that isn't the whole story. Why did you do your conversion? You wanted more power, right? Did you know how much more you wanted, or what it would feel like? Let's say that your 883 made 38 HP and after the conversion, your bike felt great...to you. Further, let's say that you were only making 55 HP after the conversion. You're saying that as long as it felt reasonably better, you'd be OK with that...leaving 10 or 15 HP on the table somewhere? If you don't DynoTune it, you'll never know if you only got 1/2 of you're money's worth.

That's where I'm at. I just spent $3k and should be making 90 HP...95 with a good 2-1 pipe. I'm barely making 80 and it's bugging the hell out of me. I will say it has more raw power (up from probably 68) and the front wheel comes up easily (not that I plan to ride wheelies, just stating one very obvious "Seat-of-The Pants Dyno" observation). I just don't think it's running right, no matter the numbers. However, I think when I get it right, the numbers will be there.

well, going from an 883 to a 1250 is a huge increase in power. take a step back though, my 883 was dialed in (seat of pants). i felt an increase in dispacement was the only way to go. when 1250 was done, just needed small adjustments.
adding headwork and more radical cams ide want more but the bulk of the power is made from displacement. your hitting a wall which is getting the very last drop of power, this is where its all in the tune of the bike. tuning is always the hardest part and having a carb its tough because of humidity and pressure. from day to day changes you can have a difference in 5 hp.

after my stage 1, CS slip on, ness big sucker and re jetting i am done. my bike runs so good 72 HP 74 LB TQ . i still get around 48 - 55 MPG.
so many bikes get sold from mods gone wrong. my sporty will never be a ninja eater and that is fine with me.

Based on my calculations I have 220 h.p. Reality sucks.

Shamdog-

I suppose if there was a dyno nearby, curiosity would get the best of me, but I live in a small farm town and the closest dyno I know of is in Los Angeles, and I'm not that curious.

As it is, I was looking for that quick acceleration from 35 to 70 to merge onto the interstate on short entrance ramps. Along with that, I wanted it to run reliably, idle smoothly, and get good mileage (I get about 50 mpg). I admit, I may not be seeing the full potential of what I've done with the bike, but I met my objectives. That said, I'm still looking for that sixth gear at 75 or so. . . .

Interesting thread.

I am one that has done my engine morphs one step at a time with an ultimate goal in mind the whole way. I have done this in this fashion simply because of finances. It has taken me several years to get to where I am and in all honesty maybe has cost me a little more because I had to do it in steps. But I am finally done and have acheived my original goal.

At each step of the way, I used a dyno AFTER I had tuned it by the seat of my pants. The dyno runs were just that....runs, not tunes. The dealer only charges me $35 to put it on the dyno and check things out. His dyno has the air fuel analyzer and feeds me with good information for a relatively cheap price. It also has the ability to hold steady speeds at various rpms and check a/f readings. The routine is to first check idle mixture, then have him make about 4 or 5 wide open throttle runs, then have him do some steady rpm holds at about 2500, 3500, and 4500 rpms. With all those a/f ratios I can verify the mixture is ideal in most conditions. If I need to make any changes, then I make those at home.

As far as peak hp vs. normal riding situation hp goes.....well you can have your cake and eat it too. Yeah the power curve changes, but you DO have some control over that. Check out the dyno graphs on the NRHS webpages and in their section on this forum. ALL of their setups outperform a stage 1 1200 at ALL rpms. So yeah, they sell and build some Sporty engines that give huge braggin rights for peak hp as well as make it an animal in the normal riding rpm range.

A dyno is a tool, just like a torque wrench. If you choose to use it, your results should be much more accurate.

Interesting thread.

I am one that has done my engine morphs one step at a time with an ultimate goal in mind the whole way. I have done this in this fashion simply because of finances. It has taken me several years to get to where I am and in all honesty maybe has cost me a little more because I had to do it in steps. But I am finally done and have acheived my original goal.

At each step of the way, I used a dyno AFTER I had tuned it by the seat of my pants. The dyno runs were just that....runs, not tunes. The dealer only charges me $35 to put it on the dyno and check things out. His dyno has the air fuel analyzer and feeds me with good information for a relatively cheap price. It also has the ability to hold steady speeds at various rpms and check a/f readings. The routine is to first check idle mixture, then have him make about 4 or 5 wide open throttle runs, then have him do some steady rpm holds at about 2500, 3500, and 4500 rpms. With all those a/f ratios I can verify the mixture is ideal in most conditions. If I need to make any changes, then I make those at home.

As far as peak hp vs. normal riding situation hp goes.....well you can have your cake and eat it too. Yeah the power curve changes, but you DO have some control over that. Check out the dyno graphs on the NRHS webpages and in their section on this forum. ALL of their setups outperform a stage 1 1200 at ALL rpms. So yeah, they sell and build some Sporty engines that give huge braggin rights for peak hp as well as make it an animal in the normal riding rpm range.

A dyno is a tool, just like a torque wrench. If you choose to use it, your results should be much more accurate.
i agree with everything you said:)

Funny...I thought that's what I said, too!