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Gypsy on Parade
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Discussion Starter #1
I'm searching and studying up on cams, and it seems like gear driven is the way to go, but in the course of all of this I'm thinkin' maybe I want to upgrade to a 95" kit (2004 FXDI TC88).

Also, I am currently using the SERF fuel management and I think I would be better off moving up to a PC III.

All I really want is better throttle response/pep in the mid range RPM's. But, I also don't want to spend money now that I will regret by wishing I had done more or gone a different route later on.

Any advice on how to accomlish this in stages, where one stage builds on another so I don't have to start all over every time I want to improve performance?
 

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I'm searching and studying up on cams, and it seems like gear driven is the way to go, but in the course of all of this I'm thinkin' maybe I want to upgrade to a 95" kit (2004 FXDI TC88).

Also, I am currently using the SERF fuel management and I think I would be better off moving up to a PC III.

All I really want is better throttle response/pep in the mid range RPM's. But, I also don't want to spend money now that I will regret by wishing I had done more or gone a different route later on.

Any advice on how to accomlish this in stages, where one stage builds on another so I don't have to start all over every time I want to improve performance?
Personally I would upgrade the can support plate with the SE plate and select a chain driven can that gave performance in the range desired. At the same time I would go to adjustable pushrods.

Next stage would be a programmable fuel manager.

Last stage would be to bore the cylinders and port the heads.

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Maddog
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394 Posts
I'm searching and studying up on cams, and it seems like gear driven is the way to go, but in the course of all of this I'm thinkin' maybe I want to upgrade to a 95" kit (2004 FXDI TC88).

Also, I am currently using the SERF fuel management and I think I would be better off moving up to a PC III.

All I really want is better throttle response/pep in the mid range RPM's. But, I also don't want to spend money now that I will regret by wishing I had done more or gone a different route later on.

Any advice on how to accomlish this in stages, where one stage builds on another so I don't have to start all over every time I want to improve performance?
Gear drive really is the way to go. Especially if you want to put lots
of trouble-free miles on it. Gear drives give you more precise cam
timing and you never have to f--k with cam tensioners again.

As far as chosing a cam, there are lots of things to consider. Do you
ride two up? How much does the bike and rider(s) weigh? What type
of riding will you do most? If you're planning on doing things like 95"
top end, pipes, air cleaner and the like, I would get the cam suited
to those mods. Andrews 37(G) or 31(G) if you weigh allot.

I put a 37G in a mostly stock FX 88ci with a D&D pipe, aftermarket
ignition and a 42mm carb and had really good results. A year later,
we 95'ed it, bumped the compression and it picked it up a bunch
more. I just ported a set of heads for that bike but haven't put them
on yet...

You can call the tech department of most any cam manufacturer
and they will give you good advice. Those 2004 heads in stock form
are not very good BTW. You may want to consider mild port work
in the future to get the most from the cams.

If it were me, for starters I'd spring for some 37Gs and a good pipe
(2 into 1), then get it re-mapped on a dyno. If you're going two up
consider some 31G cams.

Then, when you get tired of that and some more $$, throw on a 95"
kit and some ported heads. you'll have a very strong bike with a ton
of midrange.
 

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Gypsy on Parade
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4,774 Posts
Discussion Starter #4
Thanks y'all. Here is what I have so far. SE heavy breather, Rush slip-ons with 1-3/4" baffles.

I do ride two up some, and occasionally have it loaded down with camping gear, but the majority of my riding is solo.

I like to go fast, and since being "inspired" last month, I would really like to race it at some of the local drag strips, but it would be a ride it there, race it, then ride it home kind of thing.
 

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Maddog
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394 Posts
Thanks y'all. Here is what I have so far. SE heavy breather, Rush slip-ons with 1-3/4" baffles.

I do ride two up some, and occasionally have it loaded down with camping gear, but the majority of my riding is solo.

I like to go fast, and since being "inspired" last month, I would really like to race it at some of the local drag strips, but it would be a ride it there, race it, then ride it home kind of thing.
With that said, you're definately going to need some better heads.
Find a set of take-offs and get them worked over with a port/valve job
that matches your requirements. There are going to be trade-offs
between towing and occasional drag strip blasts, just make sure
you make that clear to whoever does the work for you. A great
set of heads for the strip won't be ideal for two up and towing.The
inverse also holds true. So you have to decide what you're really
after before going that route.

With all that said though, those early T/C heads leave allot of room
for improvement! It's very easy to accomplish what you're wanting
to do. (You just won't be able to break strip records AND tow a 400#
trailer efficently.
 

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Gypsy on Parade
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4,774 Posts
Discussion Starter #6
I probably misled you. I don't tow a trailer. When I say loaded down for camping, I mean me, my wife, 2 sleeping bags, a tent, and everything she can stuff in the saddle bags.

Your comments have made me think, though about what I do the most, and what I desire performance wise.

75% of my riding is solo.

20% two up, just cruising with my wife.

The remaining 5% would be going camping, and or racing if I ever did that.

I don't want to give up any "streetability" for racing. I imagine that like your average Harley rider, my needs would be most satisfied with more torque/hp in the mid range, that continues to pull into the high end, but I don't want to give up too much low end.

As far as better heads go, I geuss the whole point of my initial question is I don't want to go with a cam now that if later I decide to have head work done, or upgrade to a 95ci that I have to do cam work all over.
 

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Maddog
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394 Posts
I probably misled you. I don't tow a trailer. When I say loaded down for camping, I mean me, my wife, 2 sleeping bags, a tent, and everything she can stuff in the saddle bags.

Your comments have made me think, though about what I do the most, and what I desire performance wise.

75% of my riding is solo.

20% two up, just cruising with my wife.

The remaining 5% would be going camping, and or racing if I ever did that.

I don't want to give up any "streetability" for racing. I imagine that like your average Harley rider, my needs would be most satisfied with more torque/hp in the mid range, that continues to pull into the high end, but I don't want to give up too much low end.

As far as better heads go, I geuss the whole point of my initial question is I don't want to go with a cam now that if later I decide to have head work done, or upgrade to a 95ci that I have to do cam work all over.
If you pick the cam properly you won't have to do it twice. The
point I was trying to make is: Get a cam suited to your riding
preferance. I didn't mean the "trailer" towing to be taken literally,
I was just trying to illustrate a point. If your ol-lady is anything like
mine, you'll think you're pulling a trailer :rollin

There are lots of good choices out there that would be perfect for
what you're wanting. I don't know how much you both weigh, but
that definately is a factor.

Call Andrews, SS or whomever and talk to their tech department!
They will give you very good advice (after all, it's in their best
interest to make you satisfied).

Since you already know you want to go to 95ci at some point, that
is also something that figures into the untimate choice.

Head work will only enhance (not hurt) the benefits of a cam swap
(provided the head porter knows what you're after and what cams
you have).

So, once you have your cams in there, doing head work is only going
to make better. MUCH better.

Hope that helps. I know picking a cam can be a daunting task, but it
dosen't have to be. Those guys in the tech departments are there to
help you get what you want the first time. And based on my
experience, you will definately want to get your heads ported b/c
stock heads flow like shit! It will only enhance your performance
and you'll be many steps ahead of your competition.

More often than not, people choose a cam based on wildass numbers
in the catalogues. DON'T go overboard! Less is more, especially if
you do head work!!! You don't need as much cam if your heads
work well.

To sum it up: 1.) Less is more 2.) better heads will give you more punch
than a big cam. 3.) Light weight girlfriends help performance
and look good too :rollin:rollin:rollin
 

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Gypsy on Parade
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4,774 Posts
Discussion Starter #8
To sum it up: 1.) Less is more 2.) better heads will give you more punch
than a big cam. 3.) Light weight girlfriends help performance
and look good too
:rollin:rollin:rollin
They do help with performance issues...until the OL finds out! :rollin

Thanks for the advice. I've been reading quite a bit the last few days and trying to absorb as much info on the subject as I can before I make a purchase.

I also am going to have to find someone to help me out as I would love to do the majority of the work myself.
 

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Maddog
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394 Posts
They do help with performance issues...until the OL finds out! :rollin

Thanks for the advice. I've been reading quite a bit the last few days and trying to absorb as much info on the subject as I can before I make a purchase.

I also am going to have to find someone to help me out as I would love to do the majority of the work myself.
My ol lady knows I take young hotties for rides (on the bike). She's
usually ok with it, but not always. What can I say? I'm a dog...

The intake closing point is one of the important factors to consider.
Again, call Andrews tech line and ask them.

If you're doing it yourself, plan on buying some special tools.
 

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Gypsy on Parade
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4,774 Posts
Discussion Starter #10
Bringing this up again

Can y'all help me understand these numbers. I understand the math, I need help understanding what the difference does for power. And some of them are so close in lift that I don't believe you could tell a difference between the two of them. Also, the difference in intake and exhaust duration is 4 to 6 degrees on most of these, but a couple are 14 and 15 degrees different.

What's bringing this up is a package deal a local indie is trying to talk me into that uses the Feuling cams.

View attachment Manufacturer.doc
 

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Can y'all help me understand these numbers. I understand the math, I need help understanding what the difference does for power. And some of them are so close in lift that I don't believe you could tell a difference between the two of them. Also, the difference in intake and exhaust duration is 4 to 6 degrees on most of these, but a couple are 14 and 15 degrees different.

What's bringing this up is a package deal a local indie is trying to talk me into that uses the Feuling cams.

View attachment 192258
I have been trying to understand camshaft specs for a long time. There are so many variables that come into play I just can't do it. Valve opening and closing degrees have as much effect as lift and duration. Then there's overlap and lobe separation angle. Then what cams work best with which intake system & heads. Makes me want a two stroke sometimes. Ask your indie to see hard numbers on the kit he wants to use. I didn't help at all did I?? :blahblah:
 

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If you can find someone to explain
it so that a non gear head can understand it will help you tons.

Tell the shop doing the work how you ride or plan to ride. It make a big difference on cam choice and any other work your doing to the engine. Trying to do it your self might as well put your head in a vice and twist it

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Bore to 98", install a Wood 8G,(if your crank is within .003" TIR) and have your heads ported.
Rush 2/1, or a D&D pipe will finish that once you've upgraded the t/body to a 51mm HPI, or even a 55mm.
We've seen those pump-gas combo's tapping on 120 hp.
Scott
 

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Well..lets go this route..whats your budget and are you trying to retain your current exhaust system?

Also what cams are you currently looking at
 

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Gypsy on Parade
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Discussion Starter #15
Andrews 37G
S&S 510G
Screamin Eagle SE-203
Screamin Eagle SE-201
Woods TW-6
Feuling 574

The link I posted on the previous page shows the chart better, but these are the ones I'm looking at.

The Indie I've been talking to likes the Feuling .574. He quoted me $2700 to port and polish the heads, bore to 95", pistons, cams, and adjustable push rods. Add another $450 to $500 for gear drive kit, $170 parts and machining to add compression release.

Then I know I will have to use a different fuel management, because I am using the SE race fueler which is adjustable pots. I am leaning toward Cobra auto tune.

Right now, I have Rush 2" slip-ons. I would like to change to a 2 into 1.

Budget wise, the whole purpose I starteds thinking of all this was to do something about my cam chain tensioners, and I figured if I was going in there I might as well wake it up some. By the time I add everything up I'm $4K or better into it and that seems pretty steep all at once. Besides still having a $8k bike when I'm done.
 

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The fueling 574 is the better looking cam of the bunch but id stay away from cams with a big difference between inake and exhaust duration it implies intake or exhauat flows better or worse then the other....I try not to go far past 5 degrees more exhaust duration
Consider the se 251 cam maybe advance both cams 4 degrees...
Understanding cams isnt too difficult ..the more overlap the more the power band becomes a mountain rather than a hill...it peaks high but isnt really drawn out at far...overlap is related to lsa lobe separation angle the higher numerical lsa the flatter the curve is but the further it can be drawn out..
take 2 cams both with 265 duration on both intake and exhaust one cam has an lsa of say 102 the other 112 ...the 102 cam will have more peak tq but it will be weaker out of the power range the 112 cam will make good flat tq across the board but numbers will be lower..these cams are easier to ride on the street is to take the closing point of intake..say 50 degrees...minus 5 and times by 100 so 50 becomes 45..times 100 becomes 4500 this is where peak tq will want to occur however other things come into play like your intake and exhaust system along with bore and stroke ratio and so forth...the best motor builds r the ones that work best together

Another important note is the intake closing..this deturmans 2 things one is your dynamic compression which is the psi in the cylinder once the cam closes...the later is closes the more compression will be bled off for a given static compression...also it deturmans when your motor wants to make peak tq...or well when the cam wants to make peak tq..easiest way to figure that
 

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Gypsy on Parade
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Discussion Starter #17
Another important note is the intake closing..this deturmans 2 things one is your dynamic compression which is the psi in the cylinder once the cam closes...the later is closes the more compression will be bled off for a given static compression...also it deturmans when your motor wants to make peak tq...or well when the cam wants to make peak tq..easiest way to figure that
The longer the intake is open would create the overlap, right? So if the intake is open too long doesn't the air coming in get mixed with exhaust air and not burn as efficiently?

So, what is a good amount of overlap?
 

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Overlap is controlled by when the intake opens and exhaust closes...u can have 2 same intake durations but one closes say 45 and the other 60degrees..Given identical exhaust time the 45 degree intake closing will have more overlap and tighter lobe center vs the cam closing at 60 degrees...its hard for me to truely explain ad im at work using a cell phone trying to hide it from boss man..ill check back in bout 330 to further explain if need be
 

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My personal opinion on streetable motors are 245 durations on intake and exhaust plus or minus 5....overlap of 45 degrees plus or minus 5 and lobe separation of 107 plus or minus 2...lift will be based on engine size but .560 is a good all around for any normal street motor ...also keep intake and exhaust durations within 5 degrees if possible dont skew past 10
stick on the smaller side for heavy bikes

Fit these parameters and you will be happy
 

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also on cams
the earlier the exhaust opens the longer the exhaust likes to be and this typically is for better low end

I could post whole bunch of info on all this but I guess if you have any questions then don't hesitate to ask and I will answer as best as I can
 
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