Authoritative Information Wanted

"A guy told me..."

"The dealer said..."

"They say..."

Enough of this hearsay, rumor, and BS!

I want authoritative, scientific, genuine, textbook material on motorcycle engine theory and practice, carbueration, and EFI.

The shop manuals tell you 'what' to do but I want to know the science and theoy, so I can 'talk like I know what I'm talking about" and actually know what I'm talking about. I want to be able to evaluate performance options and setup with true science. Most of what I hear in the parking lots is 'old-timer gossip', and pure antecdotal crap.

Does anyone know some reference materials along these lines that is worth reading and studying. I can follow the math and science.

Yo, down the road,

Painter

info

EFI i really quite a simple concept, so is carbiration, as with most things the devil is in the details.

Here are a couple of over veiw articles. Remember HD doesn't have as many sensors as a car.

http://auto.howstuffworks.com/fuel-injection.htm

http://www.autoshop101.com/forms/h20.pdf

I just want to ride

Knowledge is Horse Sense and Horse Power

Thanks for the links. I had already been to one of them after I posted on this thread. The internet is a good place to start researhing just about anything.

I just wanna ride, too. In fact, I burned 200 miles today up to Whitewater, Wisconsin from Chicago.

I am envious of the technical jargon that some guys throw around, but I wonder if they really knew what they were talking about. One reason I am into gettting a better understanding of techno-bike stuff is because of what a real pro at the HD store told me yesterday. He runs the dyno, and is by my estimation one of the most educated people I have ever encountered in a HD store. He told me, and proved to me by his dyno graphs, that a lot of bikers add more sh*t to their bikes than necessary, apply more aggressive parts than needed, and still don't optimize power or performance. The aftermarketeers must love riders like that. I would rather 'know than not know', and be more economical and wiser in the choices I make to my bike. And ride faster, farther, and .... I think you get my drift.

yo, down the road.

Painter

Engine Education

Mr. Paint (AKA Louder & Prouder)

Commendations for your desire to understand the theory and application of engine science. As you mentioned, too much “advice" is based on what “a friend of a friend” has done, or what was done on a bike that had a completely different setup that yours and thererfore irrelevant.

I'm glad to hear that you found a dyno tech that is knowledgeable. That makes all the difference. It sounds like he can be a good source for accurate info., pick his brain and have him explain the "what if" & "what for" if he will. After you install your pipes, a/c and PCIII, I'd suggest that it would be money well spent if you dyno'd your bike and had that tech give you the details of what he's doing and why.

The dyno tech I had mentioned in a previous post was the same. He had the experience and the patience to give me solid info. He let me stand there and ask questions while he did the dyno and he explained the relation between HP&TQ. He then printed the graphs from the dyno runs and showed me the optimum RPM range for maximum torque throughout all gears. As a result, I can now better utilize my available power by getting in the optimum gear/RPM for the speed I am at.

Sidenote: IMHO, you should have a tachometer if you want to efficiently utilize your potential power. When I bought my bike, I had the speedo replaced with the speedo/tach combo gauge. This is my most used gauge in any vehicle. I don't understand why any engine is sold without having a tachometer. Understanding engine speed (RPM) is critical. Yes, you can develop a "sense" and learn to shift by the sound of the engine, but until you have a tach to show you what 4350 RPM sounds like, you are just guessing.
You won't find any performance vehicle or "motorhead" that doesn't have a tach installed. Tachometer = money well spent/optimization of power.

Keep us posted (pun intended) on your foray into the search for power.

SISK


You start with a bag full of luck and an empty bag of experience. The trick is to fill the bag of experience before you empty the bag of luck

Hey Sisk,

I'd be interested to hear what your tech's explanation of HP and Torque is. I've heard about 100 versions and what I've concluded is that we all do a lot of talking about HP but what "most" of us really want is Torque.

It's similar to asking an electrician what electricity is. Electricity and Horsepower are like these theoretical values that we employ daily in our lives in a variety of methods, but really have only a slight conceptual understanding of. Now, Torque......and electrical Power, that's something we can feel.

Of course, I'm incorrect in my assumptions. But, I survive in my ignorance by simply twisting the throttle and holding on.

Take the Torque, leave the HP

ffflhtcui,

Horsepower sells cars, but Torque wins races.

You're correct in your conclusion that "I've concluded is that we all do a lot of talking about HP but what "most" of us really want is Torque"

HP is just a calculation derived from the actual torque measurement of the engine. (HP = torque x RPM / 5252).

The measure of horsepower was first established years ago when some feller was figuring how much ore a horse could haul up a mine shaft in a given time.

One horsepower is equal to: 746 watts or one Horsepower per hour = 2545 BTU or the equilivent of 2.3 snickers bars.

All quite fascinating if you like fascinating facts, but I'd rather twist the throttle and feel my butt mash into the seat as my eyes begin to water.

The dynomometer actually measures the torque then just calculates the HP using the formula of TQ x RPM / 5252.

Another interesting factor for comparison is the "Power to Weight Ratio" (PWR). This is calculated by dividing HP by weight. For PWR, you want a larger number, ie. 0.15 is better than 0.05.

For example, my FLSTCI has a max HP of 77 and a dry weight of about 700 lbs. Therefore, my PWR is 0.11.
But in reality, after I put my butt on the bike, fill it with fuel, snacks and drinks, my actual PWR is 0.081 (77 HP / 950 lbs.)

For perspective, a Dodge Viper is rated with a pwr of 0.136, a Corvette is 0.11, a Ford Escort is 0.045.

Therefore, my dry weight bike has the same Power to Weight Ratio as a
Corvette

IMHO Torque is the more relevant measurement, HP is just a calculation that will vary based on your RPM. For example: I can be in 4th gear at only 2500 RPM generating 73 ft lbs of torque but my HP is only 34. However, if I'm in 4th gear at 5400 RPM, I'm still generating 73 ft lbs of torque, but now my HP is 76 because of the increased RPM's.

Keep twisting and holding on


SISK


Never trade luck for skill

Is H-D I Stage #1 re-mapping enough????

Great info thanks for all the input. BUT! I just bought V-H Straight Shot HS's and a Big Sucker for my 04 softail. Don't want to go a million miles an hour just want to run and sound good. Do I have to buy a Power Commander???? Will it run to lean without??? I've heard some experts say you don't need the PC unless you want super performance. Anyone running without the PC? Like to hear from you. Thanks for the help. First H-D

Ken

ECM re-map

Those two add-ons will lean you out pretty much. Within 200 miles or so, you'll start seeing the effects of this under the heat shields. Please do yourself a favor and either pay the dealer 149 bucks to re-map, or pay 359 for the power commander, and do it yourself as often as you make changes. Just takes a few minutes, and well worth it.

Well Sisk,

Your formula (not that you really own it) explains how Kawazukis can take 45 lb ft of torque and make it into 150 hp. They just run it up to 15,000 rpm's and hope nothing slings off.

I surely do enjoy reading these comments and contributions. I thank each and every one for their input.

Knowledge is Power

Now we are getting somewhere. I found two books on the subject of the theory of engine performance (both available at Amazon.com):

"Auto Math Handbook" by John Lawlor

"Internal Combustion Engine Fundamentals" by John Heywood

I ordered the second book since it covers all the theory of the math book which is good enough for formulas only. I want to know the 'why' as well as the 'how' on crunching the numbers. This book will make some fine off-season reading. Next, of course, will be to gather the specifications from the manufacturers of performance equipment and then evaluate (knowledgeably) the choices to match the goals I have in mind.

I totally agree that TQ is the key to real performance.

Hey Painter,

That partially explains my ignorance. We don't have an off season here on the Gulf Coast to catch up on our reading. We ride year round.

Of course, that also explains why I was totally lost at how to steer my Wideglide through that snowstorm last June 7 in South Dakota. We don't have that white stuff down here either.

Oh, but you guys have those snowmobile thingys and all to make up for it.

Be careful. If you can't be careful, have fun. If you can't have fun....uh...uh...why not?

GULF COAST got my attention! I am a native of Pensacola. Been here in Chicago way too long (8 years). I am trying to move out west where it is hot all the time (Las Vegas!). In Pensacola, I rode an '80 Sportster all year long, even in the rain once in a while.

I did some modification to the Sportster, and it as a real dragster-- very fast! I punched out the pipes, and fiddled with the idle mixture until I got it right my shear guessing and tinkering (gauged the results by eyeballing the sparkplugs periodically until they were nice and gray all the time, but the pipes turned blue anyway!). The WRONG way!

Now, with a $20K '04 Heritage loaded with an EFI, I can't follow the same blindman's luck approach again like on the Sporty. I HAVE to be more scientific, and that is where things started to breakdown this week. I wanted to get rid of the wimpy stock pipes by putting on a set of Pythons. But I ended up ordering the 2:1 V&H Pro Pipe. In all of this flurry of stuff, I realized that I didn't know squat about it all, thus this thread to search out the hardcore techno nuts and bolts of it all. I am actually getting somewhere, and I should be 'in-the-know' before it snows here!

Torque is the rotational force applied to the wheel via the engines crankshaft / tranny and HP is the force generated to move 550lbs one foot in second or 1lb 550' in one second.
A high torque engine like the HD or a diesel will accelerate faster initially but a high RPM high HP motor will generally have more top end.

The way I look at is that Torque gets you off the line and HP is what gives you the top end. In other words, an engine producing torque at low RPM will get off the line faster then one with the same torque but at a higher RPM.
If you could produce an engine that had a nice big torque curve and continously built big HP up the RPM curve that would be a sweet motor!

http://www.newton.dep.anl.gov/askasci/eng99/eng99128.htm

http://www.musclecarclub.com/library/dictionary/engine-terms.shtml

Haaaa...LOL!!! You don't know what kind of disease you've infected yourself with yet. I bought an electra glide standard because I didn't need all them bells and whistles that came with the classic or ultra...Well as I figure it now I have $31,000.00 invested and still don't quite have the bike I've dreamed of in my head...but I'm getting closer. Every time I improve one thing it brings out a flaw somewhere else that needs improvement...I don't know that it ever really stops...but I do believe it slows down

Hope a little snow didn't scare you off That NE corner of Iowa has some nice scenery and roads. I've been down that way a couple times on day trips...runs about 500 miles round trip for me. All along that Mississippi river valley there are nice roads though. I have a lot of family in north central Iowa...so I won't lay into ya with the ioweagan jokes Up here in Minnesota though most of us are smart enough to stay indoors much less off two wheels during a blizzard

I got a a double whammy today: not only did my Pro Pipe and PCIII arrive, but the book "Internal Combustion Engine Fundamentals" by J. Heywood also came in.

Heywood was an M.I.T. professor, and this book is supposed to be one of ther best. Just browsing through the table of contents made my mouth water. I read a cool word in the book that I will learn more about: turbocharging! Whoa......This is going to be good. I don't think that more 'authoritative information' exists outside of a college classroom, or professional lab.

Yo, down the road,


Painter