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[HD Street Performance]

http://www.cvoharley.com/smf/index.php?topic=66895.0
See post 7 & 8
This is stock cam motor, low compression.

[HILLSIDECYCLE.COM]

Need to compare apples to apples.
Get both running 205 ccp, like the 255's do, and the 555's will mark at/near the same on the strike, and take off, leaving the school bus cam in the dust, and run cooler doing so.
Scott

[ralford]

The point I was trying to make (badly, apparently!) was that if your torque output is falling faster than your HP is rising, then you are past the peak output RPM of the engine. At this point, you might as well upshift, because you are not going to be accelerating as fast once you are past that RPM point. Does this make sense?

Certainly makes more sense    However, I think it also depends on your gearing.  The optimum shift point is where the hp in the next gear matches that of the current gear. Goal is to exploit the maximum total hp (not sure why it isn't torque now that I think about it) used.

Cheers

[HD Street Performance]

Need to compare apples to apples.
Get both running 205 ccp, like the 255's do, and the 555's will mark at/near the same on the strike, and take off, leaving the school bus cam in the dust, and run cooler doing so.
Scott

So are the TW555s that much different than the TW7?

[North Georgia Hawg]

Certainly makes more sense    However, I think it also depends on your gearing.  The optimum shift point is where the hp in the next gear matches that of the current gear. Goal is to exploit the maximum total hp (not sure why it isn't torque now that I think about it) used.

Cheers

Well, I've always been of the mindset that it's torque, not HP, that produces acceleration. For the maximum acceleration rate, I try to find the point at which the torque is at its peak and the point at which the torque starts falling faster than the HP is rising, and shift to keep the engine in that RPM range. I've been taught that's the way to get down the road the quickest. The flatter the torque curve is, the wider this RPM range is. If you have a peaky torque curve, then this ideal RPM range will be narrower. It's different on every bike of course... and the Butt-O-Meter is a very good judge of this. You can feel when the power starts dropping off as the RPM rises into the stratosphere, and learn to upshift before it does. I ride it the way it FEELS the fastest. After all, that's why I bought this beast in the first place!

I haven't had the bike dynoed (yet), but the torque curve on this bike the way it's set up seems to be so flat, the engine pulls very strongly from about 2300-2400 RPM all the way to redline (and REALLY takes off at about 3000 RPM) - and seems quite happy at any RPM in that whole range! Very responsive engine that gets to 5000+ RPM very quickly... so quickly that it's a bit startling, actually. Sure a lot different than the old Evo! The duration on these 54H cams moves the torque range up some from the stock cams - but it seems to be very flat. If you don't mind turning some revs, these cams are a real kick in the pants!

[HILLSIDECYCLE.COM]

So are the TW555s that much different than the TW7?

What are you leading up to??

[HD Street Performance]

In the words of the tuner builder owner of an 07 CVO that went from the SE255 to the TW7 a very similar cam to the TW555

"Stage 2 with TW7H the bike produced 108hp and 119 ftlbs.
Stage 1 and stage 2 curves crossed at 4000rpm. What we gained above 4000, was lost below 4000 rpm
The torque curve was just moved to the right 500rpm (and therefor gained a little horsepower)."

That statement right there sums it up and answers the originals posters question

No slam on the Woods cams they work well for me with my heads but with this combination the SE255 worked a little better assuming we are trying to measure aggregate torque which is what most riders really want

After headwork that same bike made 112/124 SAE and held over 110TQ from 2100-5250rpm, that's with a CAT EU stock headpipe and Fatshot slip-ons and 9.8/1 SE255 cams

[shindo]

If you do a lot of two up riding the woods 555 would be a better fit, JMO. I like the cam it gives me a nice low end pull and even better in the higher rpm range. Of course this is coming from a x TC88 rider.

[HILLSIDECYCLE.COM]

The owner of www.grandlight.com had us upgrade his 110"er last winter.
A 555 was used with a 58mm fbw, our heads, 1.725 rockers.
He alerted us to the fact that even as "picky" as he is, it faaaar surpassed his expectations.
Scott

[cahdbiker]

SE113, I have an 09SEUC and I love the way the 255s pull. I have a Fulsac stage one kit with 1.75 baffles and HD freeflow air cleaner with K&N filter. I get good mileage even with passenger and a lot of luggage ( you know women ). Passing on a two lane road is effortless and I have learned from my 95 Heritage to leave well enough alone. Just got back from a 3500 mile trip with no issues, except for the valve train noise at certain RPMs. CAHDBIKER

[HD Street Performance]

The 255 is standard equipment, no need for an aftermarket cam, ratio rockers, and all the jazz. Saving money is good and makes real happy customers. IME the other cams that have worked similarly are the Wood TW5 and CR575 in the 110.
When somebody wants to make 120+hp we change gears and use a Wood TW400 or TW8 with a similar or better torque curve. Much more money. I do not like to dabble, either economy builds lowest cost for the most result or move on to the high hp stuff.

[hotroadking]

...............either economy builds lowest cost for the most result or move on to the high hp stuff.

Hey wait a minute there,  nobody ever told me there was an economic power build,
I always thought it was gonna cost big bucks no matter what ! LOL   

[North Star]

The 255 is standard equipment, no need for an aftermarket cam, ratio rockers, and all the jazz. Saving money is good and makes real happy customers. IME the other cams that have worked similarly are the Wood TW5 and CR575 in the 110.
When somebody wants to make 120+hp we change gears and use a Wood TW400 or TW8 with a similar or better torque curve. Much more money. I do not like to dabble, either economy builds lowest cost for the most result or move on to the high hp stuff.

I guess that's why a well reviewed local engine/tuner guy takes stock 110's, and works wonders with them without even putting in any new parts. He re-grinds the 255 cams, does head work and throttle body porting, guts the cat, and puts in different baffles- consistently gets 107+ hp and 130 torque. He says he justs opens up the breathing and flow, which realizes the stock engines true potential, which equals a cool running, rideable and reliable bike. I'm thinking about doing this over the winter- won't cost me as much since I've already got the Fullsac x pipe and Rineharts.

[HILLSIDECYCLE.COM]

Power doesn't cost a ton in some cases, and an example is this.
Client came in with his HTCC 95" Softail and a dyno chart from a dealership in Syracuse N.Y. 94/94.
We re-worked his heads, modified the pistons for better squish, installed a Thunderjet in his S&S G carb, and tuned it.
Left his S/E 257 cam alone.
Once completed, the bike ran 115 hp, and 110 ft/lbs.
He was flipped.
Only parts used were gaskets, valve seals, and a Thunderjet kit.
The rest was that was sold was knowledge.
Scott

[wfolarry]

Power doesn't cost a ton in some cases, and an example is this.
Client came in with his HTCC 95" Softail and a dyno chart from a dealership in Syracuse N.Y. 94/94.
We re-worked his heads, modified the pistons for better squish, installed a Thunderjet in his S&S G carb, and tuned it.
Left his S/E 257 cam alone.
Once completed, the bike ran 115 hp, and 110 ft/lbs.
He was flipped.
Only parts used were gaskets, valve seals, and a Thunderjet kit.
The rest was that was sold was knowledge.
Scott

A valuable commodity.