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Discussion Starter · #1 ·
Hey guys, I was wondering if there’s a hp to Cubic inch that is average? I’m not too happy with the results of my build and think my numbers should be better. Could some of you experienced builders out there tell me if I’m correct and should be better? Listed below is what I have. Thanks in advance!

03 Night Train
S&S 98”, S&S cam plate & oil pump ( w/ upgraded hydraulic tensioners )
S&S 79cc Super Stock heads ( 10.6:1 cr ) about 201 ccp
S&S 52mm throttle body, S&S fuel rail kit with 5.2 or 5.3 injectors
Fueling 574 cams
Rinehart Crossbacks exhaust
Power Vision

Dynoed at SAE 96.66 HP and 100 Tq, I thought I would have been at least 110 or close, am I wrong to expect 110? Like I said, thanks for any replies!
 

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Posting your dyno sheet would be most helpful. There are differences in the systems used by tuners, STD or SAE.
Plus, not all dyno tuners are created equal. Some suck and some are very good.
 

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Discussion Starter · #4 ·
Posting your dyno sheet would be most helpful. There are differences in the systems used by tuners, STD or SAE.
Plus, not all dyno tuners are created equal. Some suck and some are very good.
Here's the dyno sheet

https://www.v-twinforum.com/forums/attachment.php?attachmentid=241842&stc=1&d=1530833624
 

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Yah maybe a tad light on HP but like the man said are happy with how it feels. What does the butt dyno say? Things to remember... The light that burns twice as bright, burns half as long... If you got a solid dependable runner you're certainly not to shabby on the hp. If your still feeling robbed I'd say up your lift on the cam
 

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Your dyno guy may have one of the few dynos that aren't "happy". The cam is small for that build, and the T-Body is un necessary until 115-120 Hp, but it also won't help you get there if the cam is that small. Crossbacks aren't my favorite either. Big injectors won't make HP unless the engine needs them. Hydraulic tensioners don't make HP by themselves either.
Wife's 95" at 9.8 comp. 251 cam, 2 into1 V&Hs, ported stock heads with good valve job and bored (.048") stock t-body and ported manifold made 94 HP and 102 Tq. on my very stingy dyno with a Phoenix,AZ. tune (it gets really hot here, as in 117 deg today July 5 th).
Try (Borrow?) an 251 SE cam. I am not a fan of the Feulings at all, we remove more than our share of them and use either SE or Redshift cams with better results. Never had anybody want their old cam put back in the engine. The tuner could easily be up to 5-7 HP right there. Some tuners are poop, even ones with a lot of advertising! So are some dyno tuner guys, but even if he is good and the box won't let him do what needs to be done, then there's only so much you're gonna get.
As far as; "are you satisfied with it?" I believe if you were, we wouldn't be having this conversation. TIMINATOR
 

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Your results are very similar to a 95" build I did on my old Nightrain. That's a lot of HP and TQ for a Softail. Say you throw another set of cams in it and tune it again, what will you get? I'd guess about 5hp and maybe 2lb ft of TQ. I don't think I'd drop more cash to find that last bit of power. It's your money, but I'd ride it.
 

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Discussion Starter · #10 ·
Im not chasing numbers but I expected to get over 100 hp and 110 or higher for torque which is what I care about, Im not really worried about hp as I dont take my bike to 5500-6000 rarely. I think its the cams and the tuner and doesnt a good tune take about 5 hours or so from what I hear, a buddy of mine wrks at the dealer where it was tuned and from what I hear he only spent at max 2hours or so.
 

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Considering the method you chose to do the build I'd say the numbers are pretty decent.

As suggested above, you do have some parts that may not be working together as well as possible. You were warned of this a year ago when you were trying to pick a cam to work with other parts that you had. Best that I remember, you were trying to select a cam that "comes on early" to work with 10.5 to 1 compression.

Before you start piecing together a build with parts chosen out of the blue, stop. Decide what you want the end product to do and what is important to you. How are you going to ride, what RPM you want run the engine, etc. The cam is going be what determines the power band. The head ports will complement the cam and can extend the power in the upper RPM range of the power band. The proper compression will help extract the best efficiency of the combination. But I would never start with, "Hmm, I have these pistons, let's figure out what cam I can run with them." That's ass backward.

Start with a realistic goal, choose cam and head work with the goal in mind, THEN select compression. And don't forget the tune which can make or ruin the whole build.

edit: and you can enhance or compromise the build with the right or wrong exhaust
One last bit of advise since it's obvious you want a good running bike but don't have the experience to choose a combination of parts that will work together. Pick a shop with proven record of customer satisfaction and let them know what your goal is for your scoot. If the parts you have now and the other stuff you think you want (pipes, throttle body, etc.) aren't going to work well with XYZ heads, it's best to find out before you spend a lot more $$ and come back here, or the other forum wanting to how to fix it. DO IT RIGHT THE FIRST TIME. Best way to do that is with the help of a good shop that has some skin in the game because you went with their recommendations.
If 110/100 was your goal then you should have been seeking advice to reach that goal.
110 lb/ft and 100 HP is relatively easy to come by on a 98" motor with the right combination of parts and proper tuning. You could get more on a "happy" dyno or less on a stingy one but that's just number.

Bottom line is, how does it run now? You can say you're not chasing numbers but...
 

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Your dyno guy may have one of the few dynos that aren't "happy".
Well is there such a thing as a "sad" dyno?
Calibrations can go both ways ya know.

The combination of parts is not very happy, simple as that.
Camshaft opening exhaust at 61° BBDC is of no help.
Just a shotgun guess the S&S 570 would be happier or one of many cams with ~40° ABDC IN closing cams with EX ~48-50 BBDC opening
You have an honest 10:1 compression ratio with a .030 HG unless the pistons are domed
 

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There are dynos that are calibrated and correct, and then there are dynos that read higher than they should, we refer to them as "happy" dynos here. In the Phx,Az. area you can see a spread of about 15+ HP on a 120 HP build. Mine and 3 of the local dealers that have "Dyno Days" HP Shootouts are within 1-2 HP at the lower level and are considered as conservative, or accurate, depending on your view point. The "Bar Braggers" use the other indys that post big numbers for their "Bragging Rights" customers, but those guys never go to the track or the Shootouts either. Around here in Phoenix, when discussing builds and HP the first question asked is "on whose dyno?" At that point you can decide whether to stop listening....
There are about a dozen common ways to trick an accurate dyno into reading high, or low, whichever you like. I'm not going to get into that because I don't want to educate the "happy dyno" owners with ideas that they didn't think of.
Bottom line. Find a reputable dyno guy, or try others just for a couple of pulls and see if the results are comparable. Asking a lot of questions of the really fast guys in your area, (you know the guys that race), will get you a start. If a fast guy giggles when you ask about a certain shop that has a dyno, you probably have a good start on an answer.
When discussing builds or dyno numbers I tell my customers " I'm not going to tell you what you want to hear, but I will tell you what you need to know." TIMINATOR
 

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There are dynos that are calibrated and correct, and then there are dynos that read higher than they should, we refer to them as "happy" dynos here. In the Phx,Az. area you can see a spread of about 15+ HP on a 120 HP build. Mine and 3 of the local dealers that have "Dyno Days" HP Shootouts are within 1-2 HP at the lower level and are considered as conservative, or accurate, depending on your view point. The "Bar Braggers" use the other indys that post big numbers for their "Bragging Rights" customers, but those guys never go to the track or the Shootouts either. Around here in Phoenix, when discussing builds and HP the first question asked is "on whose dyno?" At that point you can decide whether to stop listening....
There are about a dozen common ways to trick an accurate dyno into reading high, or low, whichever you like. I'm not going to get into that because I don't want to educate the "happy dyno" owners with ideas that they didn't think of.
Bottom line. Find a reputable dyno guy, or try others just for a couple of pulls and see if the results are comparable. Asking a lot of questions of the really fast guys in your area, (you know the guys that race), will get you a start. If a fast guy giggles when you ask about a certain shop that has a dyno, you probably have a good start on an answer.
When discussing builds or dyno numbers I tell my customers " I'm not going to tell you what you want to hear, but I will tell you what you need to know." TIMINATOR
This!! @gree: Nails it.
 

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I have read and agree also about the Dyno Jet deal. Since HP is a derived/computed number to a "standard" that was first used in the cowboy days, what does any of that matter? If the industry standard is the Dyno Jet, and all dynos relate in some way to cowboy/ "average" horse, none of how we got here matters. We are here, and use what has come before us to come up with easily comparable numbers.
If there are any (and I'm sure there are) gun guys here, the stupidest contrived "standard" is bullet energy. It factors in gravity to the energy formula! Really! If you measure the energy from 10ft. in front of the barrel how far has the bullet "dropped?" How much work has gravity done? Since on any distance shot you have to aim high to offset the bullet drop, isn't gravity working against you in the uphill part of the bullets arc? The lbs/ft bullet energy thing is entirely stupid on its first look. At the published numbers even a .357 should knock down even a reasonably sized shooter with recoil. A proper way to estimate bullet energy would be to have a suspended one pound weight from a nearly frictionless pivot, with a linear scale behind it and use a high speed camera to see how far the one pound weight moved. In a totally inelastic collision and near frictionless pivot, ft.lbs can be read off of how far the weight moved. I've tried this many times through the years and the accepted standard is waaaay off. But it is the standard and has been for many, many years, so it is what we use. Same deal. It doesn't matter how we measure, as long as we all use the same standard.
Sorry for the long winded explanation, but I hope it sheds some light on the situation at hand.
Bottom line: only Dyno Jet numbers are relevant to other Dyno Jet numbers. Super Flow numbers are different and should be only referenced to other Super Flow numbers.
Pat Hale came up with the Quarter Junior dragstrip program about 30 years ago to predict quarter mile ET and MPH from dyno numbers. It was very accurate when I had an engine and chassis dyno for cars. I can't use it any more because my copy is on a "floppy disc"!!!! I believe he had a bike version too, but have never used it. The dragstrip doesn't lie. HP can be computed from ET and MPH numbers because you have a known weight that you moved a known distance in a known time. ET can be easily changed by gearing, clutch drop RPM, and shift points, while Trap speed is more of a Horsepower indicator, assuming constant co-efficient of drag (don't sit up on one pass and crouch on the next).
Again, sorry about the length of the post. Knowledge is power. TIMINATOR
 

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What are you running for fuel? At 10.6 I suspect it has a lot of spark backed out to control detonation. And as you back the spark down the horse power follows.
With a flat top piston at 98" and 79cc head he is at an honest 10:1 and the cam has a late 46 intake closing. Proper timing settings and there would be no timing pulled.
Does put the whole tune in question however and if the timing was set wrong it would pull timing and totally blow any power and torque production
 
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