Ok guys. I currently have a 2008 Ultra with the Screamin Eagle Air Intake, The PC III, and the Vance and Hines Turn Down Pipes - PC III Map from Fuel Moto. It doesnt seem like it has near the power I would expect it to, Seems to run REALLY hot when its warm out (Burns Wife's Legs when she wears shorts). and seems low on torque. Now I PROMISE im not expecting this thing to be a reacehorse, but I would like some more power without spendin a lot of money. I am willing to possible change out the Air Intake and the pipes, and then have it dyno'd afterwards. What would YOU ALL put on it, or would youi leave it as is and JUST have it dyno'd? please let me know what pipes and air intake you think would be best for me. THANKS!

 

The most you can do with the basic Stage I setup at this point is dyno it. You can do what some(#'s growing daily) here have done and that would be to cam it. The SE255's or Andrews 54H cams seem to be a popular choice for the baggers. These cams put the torque between ~2200-5k RPM. There are other cams, just stating a few. Changing the existing parts as you've stated(A/C and pipes) would just be rearranging deck chairs on the Titanic.

However, at the end of the day the old saying stands, "there is no replacement for displacement".

 

A cam replacement is the next step up for you. A cam will cool the bike (stock cams are designed to be EPA compliant and NO amount of tuning can change that design).

SE 255s or Andrews 26s or 21s seem to work well on an otherwise totally stock Stage 1 bike. It will NOT make it a racehorse by any means, and actually seem disappointing at first, but THEN you will notice things like NO heat, better hill climbing, less downshifts, etc. Small but important things really. See what a set of complete pipes costs. Another AC costs. Add that up, and check out what a set of cams would cost you either you do, or installed. THEN get the dyno tune and look out! I really loved the way a set of 21s made the bike (09 SG)work out in WV riding. Would NOT go any faster. Would NOT go any quicker. But less downshifting on hills and twisties was just GREAT IMHO.

For a noticeable bump... go with what Ultrakla$$ic just did. More money, etc. but I know that HE is smiling ear to ear!

 

Ok....so maybe I should do the Adnrew's 21's. One thing I didnt mention is that my o2 sensors are diabled. Of course that was the way that PCIII said to install them since it was running off a programmed map. So I think Ill do the CAMS, And then have the bike dyno'd. Cause from what I have heard here, NO preprogrammed map will make your bike run like a map JUST for your bike. ARE there any better suggestions for pipes other than my Vace and Hines Turn Downs? im just not completely satisfied with them. Thanks for all the help.

 

I have the same set up except I use the Fuelpak and I do not have excessive heat. I have plenty of power too. I think you have a bad PC or wrong map for it.

 

255 cams are EPA compliant too aren't they?

 

You need back pressure for torque, the cams will kill the low end even more. Check out: http://www.bigcitythunder.com/pages/...rformance.html

Get a Goldwing if she wants to wear shorts! No heat, smooth with lots of low end and top end!!

 

The stock cam has NEGATIVE overlap. What that means is the valves are BOTH closed for 8 degrees of crankshaft spin. Normal cams like 255s etc HAVE overlap. Overlap means for a split second BOTH valves are slightly open.

In a 96 in bike, a 255 is NOT EPA compliant.

This aids in a cooler engine and one that runs properly. NO overlap means that the exhaust cannot help pull in an intake charge while the exhaust is leaving. overlap means a slightly dirtier exhaust because a slight amount of unburnt fuel exits the exhaust. The 'flow' of the exhaust out of the chamber aids in pulling in the intake charge for the next firing event. Bigger charge to light off when the time comes.

camshaft design and operation..... a properly chosen cam like a 255 or a 21/26 will aid the LOW end of the rpm cycle. It is NOT a race type cam, but one that aids in building compression in the engine. The KEY number for a cam in a Harley is when the intake closes.

A 21 closes at 30 degrees
a 26 closes at 35 degrees
a 255 closes at 25 degrees

stock is also 30 but with negative overlap and intake opening at a very poor point.

The 3 cams mentioned are fairly much cams from an earlier time where a dirty exhaust was NOT job #1. The 255s will make MORE corrected compression than a stocker.

ummmm.. just read the Big City Cam stuff... it says what I AM saying.

But whatever, you know.

You need to understand how cams and compression work on a Harley, and in general. The guys on the boards kind of all assume this is common knowledge.

Here's how you can think of compression. There are really TWO compression numbers that you need to be concerned with. The static compression, which is simply the squeeze the piston pushes all by itself. THAT is the one most people understand. Like your 10:1 or 9.5:1 stuff.

Then there is the corrected compression (CCP-Cold Cranking Pressure). Remember... you have your valves opening and closing all the while the engine is running. The biggest factor to your Corrected Compression is when the intake valve closes. Think... the intake opens and lets the gas and air enter your cylinder, right? Then the piston squeezes it, and the spark plug explodes that squeezed mixture. OK? Well when the intake closes is actually AFTER the piston is heading back up to do the exploding.

When these guys talk about a cam working with varying compression ratios, what the really mean is when does the intake close.

As an example, a cam with a 40 close. So that means the crank has spun 40 degrees past bottom dead center and headed upwards 40 degrees worth before it closes.. AND there is ONLY 180 degrees total that the piston can squeeze with.You can see this would change the squeezing ability of the piston, right? The squeezing does not start until that intake closes. Other cams close at like 30 or 36 degrees AFTER the piston is heading back up.

A 21 has a close of 30. This is a very early closing cam. This allows the piston to squeeze a bunch. Makes for a higher CCP number. IF... if you mechanically change the compression, then this cam will give a higher yet number for the CCP. Ummm a 21 stock at sea level is like 180ish on the ccp. If you upgraded to 10:1 mechanical compression... then the CCP would be like 205 or better. The 255s have a 25 close, and you can see that if you already have compression, the 255s can make TOO much compression...

SMALL changes make BIG effects in a Harley.

Optimal CCP for a street engine is like 185 to 195. Anything over like 195-200, then the bike can ping (pre-detonation) and will be hard to start.

A cam that closes late, will allow your mechanical compression to bleed off before any squeezing gets done. A street bike will run poorly like this... the ccp can be down to 160s. Race cams close late. TORQUE cams close early.

I hope that you understand. This is where people says a 'cam likes' a certain compression. Big *** race cams close at 60 degrees or even more. THESE engines have a LOT of static compression like 11:1 or even 12:1, because that cam bleeds it all off. The crank moves 60+ degrees before closing and allows the compression to bleed off. This is ALSO what big city thunder says. A Harley is a 'matched' system for best results.

There is a calculator you can play with to check CCP on a Harley. Read the instructions and remember to change your head gasket size to stock diameter etc, and start with the 96 in size... see how different cam closings can effect the CCP.

Click HERE

And then... A harley is NOT an even fire engine.... There is exhaust 'revision' that allows one power stroke to try to pull the next power strokes exhaust back into the wrong cylinder!!! It is NOT the easiest thing to just throw parts on a HArley. It takes THOUGHT.

Cam selection is based upon this: how do you wish to ride your bike? FAST all the time? Go cruising and bar hopping? Riding longer distances comfortably with power to spare?

You truly can ONLY ever have two of the three. You HAVE to decide before a build or you will muck it up and hate the bike, when it's not really the bikes fault.

Most Touring Bike Riders opt for long distance power with a bit for running around town.

Once your style of riding is determined, THEN, and only then, do you even think of cams and compression. Cams and compression are totally linked and can NOT be separated.

There are 100s of folks that swear by the three cams listed as a good improvement to their bikes. Do a 'search' on cams. See what folks have to say about them. Then you decide.

Me??? I just throw this crap out there so that folks can kind of better understand what's going on, and make their OWN decision on things. My way of giving back for all the wonderful help that I have received along the way. I HAVE built a Harley engine, by myself in my own garage... I HAVE made mistakes, but have learned greatly, too. I HAVE ran 21s in my own personal bike. Like I stated, I liked the improvements. Hopefully, other will come forward and tell THEIR stories with different cams.

After you find your bike 'wanting' after all the Stage ! stuff is done, THIS is the natural progression of things. But... be advised that a cam swap can VOID your warranty, and that is something to consider, OK?

WHEW!!! HAHA!
________
John

 

Dayum John!!!

That's one helluva EXCELLENT reply!

The more I study this stuff the better I feel about my build selection.

 

LOL No Thanks. Started with A Yammie, Bought my Harley, Wont ever go back. BUT I know that before we did the MODS, Jennifer did not complain about heat. She has always worn shorts on the motorcycle, And I know that they are hot engines, but the heat is ALMOST unbarable, doesnt seem like it should be quite that bad. Anyway....Anyone keep bringin in your ideas if you got em. Thanks to EVERYONE who has posted so far, especially Wurk Truk, that was a VERY indepth message. As a matter of fact, i may print in out! LOL