Go make a bunch of post through out the forum so you can post a dyne sheet....Sure it's a fun ride.

 

You install a seat belt???

 

Over the past years I've spent a lot of money on Dyno Tuning. My results were so bad not because of the numbers but due to the drivability. I went from PA to Florida to find a person that cares about what they are doing. It's asham people have a Dynojet and don't know how to use it to the fullest. Not trying to create problems and won't through names around. I just want to say thank you Doc for your time and your ability to tune a bike correct.

 

Well done slim. Not a lot of guys out there that really do care.... All though they are out there...

 

my FXSTDSE stats are

Engine 45ş Screamin’ EagleŽ Twin Cam 95B™ (balanced)
Valves Pushrod-operated overhead valves; w/ hydraulic
self-adjusting lifters; two valves per cylinder
Bore x Stroke 3.88 x 4.0 in. (98.43 x 101.6 mm)
Displacement 95 cu. in. (1550 cc)
Compression Ratio 9.4:1
Fuel System Electronic Sequential Port Fuel Injection
(single runner, 45mm throttle bore ESPFI)
Lubrication System Dry sump, internally mounted, crank driven
gerotor pressure and dual scavenge pump
with spin on 10ľ pressurized oil filter

Engine Torque (per SAEJ607)2:
North America 91 ft. lbs. @ 3500 rpm (123.4 NM @ 3500 rpm)
Lean Angle (per SAEJ1168):
Right 37.3 degrees
Left 35.3 degrees

I have added 2 in 1 pro pipes so im probably a tad bit higher on the torque.

 

Like this?



This is for my 2014 Breakout, which has a 2014 version of the Stage 4 Race kit (before it got watered down), and a D&D Low Cat 2 into 1 exhaust.

The Breakout, particularly one with the heavy HD "Turbine wheels" like mine, dynoes low on a Dynojet, which is an inertia type dyno, because:

- The Softail engine balancer is very heavy and so has a lot of inertia
- The Turbine rear wheel is VERY heavy
- The stock Dunlop wide 240 tire is VERY heavy (about 22 lb for the bare tire)

This dyno run was made to see how much effect would be seen in the dyno cure by simply changing to a lighter weight tire. The Pirelli put on for this test weighs 16 lb versus the 22 lb for the Dunlop. This chnage all by itself raised the rwhp from 104.5 to almost 107 - about 2.5 rwhp! Just the tire!

The tuner, Mike Lozano (Yes, THAT Mike Lozano - I lived just 55 miles from his Lozano Brothers shop at the time) did a FABULOUS job of tuning the bike after my local HD dealer failed to do so. He told me that without the Softail balancer, and with a more normal wheel and tire weight, this engine would have shown "at least several more rwhp". I can only imagine how much the 250 and 260 wide tires affect dyno results.

Jim G

 

That is interesting! Never would think it would change that much. Question is was it Dyno the same day ?

 

No, it was not on the same day. But, prior results had consistently shown 104.X rwhp on both this dyno and one other one, before the tire was changed.

Lozano Brothers does a lot of engine work for big league, sophisticated auto factory race teams, as opposed to individual enthusiast hobbyists, so they need to keep their dyno honest. The other dyno used was at a shop where the historical dyno charts I was able to view showed relatively modest rwhp for even the 120 cubic inch bikes.

There are multiple factors that determine how honest and real a rwhp reading on a specific dyno actually is:

- Is the dyno tested periodically and kept properly calibrated?

- How accurately the correction formulas used on that brand of dyno really are

- How careful the dyno installer and dyno maintainers are in controlling the critical variables and inputs. For example, if the dyno temperature sensor is on a wall far from the dyno, but the air actually being inducted is right beside the hot engine, the input air temperature used in the correction formula will be wrong. If the temperature sensor is inside the dyno room, but during dyno sessions a powerful fan is used to induct outside air to cool the engine, the temperature used in the correction formula will be wrong

- How well that model of engine, and then how well that specific engine's state of tune, follow the theoretically predicted variation in power output as temperature, barometric pressure, and atmospheric humidity vary from day to day and hour to hour. Some engines simply don't - they lose power once outside a narrow tuning band, if the tune installed was carburetor based versus computer based and did not need to meet street standards. For example, a race engine needs to run well in only its used on-track powerband. Street rpm and partial throttle openings are not a concern for the tuner

- How sensitive the dyno operator or shop owner are to customer "satisfaction". If he does not like situations where a dyno customer, or a performance build customer, gets a lower than expected (or dreamed of) result, and gets angry and maybe even does not want to pay ("You told me I would get 100 rwhp and I seem to be getting only 90"), the temptation is strong to use tricks to fool the sensors and overcorrect the actual power to an inflated fiction. These tricks include things like simply putting the temperature sensor where it is hotter than ambient. Another trick that works well on non-technical people is to not correct at all if the raw number is higher than real, or to use the "STD" correction standard versus the "SAE" correction standard. The ST standard always shows a 4 or 5% higher number because it corrects to a more optimistically perfect set of ambient conditions that don't really occur very often. The more honest standard is the SAE standard.

You have to recognize that the average local dyno shop technician is NOT a scientist used to controlling important variables precisely. Most times, he is a mechanic without a college degree or any physics or chemistry education, so he does not even understood the correction formulas and what they are trying to do.

If you want dyno results that are truly honestly comparable to dyno results obtained on a different vehicle at a different shop under different ambient and control conditions, you have to pick your dyno shop very, very carefully.

If your dyno results look "too good", you have to ask yourself: How likely is it that a small local shop run by a self-trained owner and dyno operator will be able to build engines that are more powerful than HD, Ford, GM, or Porsche (without high risk of grenading)? If the OEMs are using or partnering with that shop (e.g. Roush, Lozano brothers, Shelby), then yes, they might. If the OEMs are not, it's doubtful. If they CAN do better than the OEMs, they are selling to the OEMs, not you, because they can make a lot more money there than with you.

Jim G

 

The biggest factor in the 2 runs is the near 20* difference in Temp...

 

Yes, you are right on that observation. In fact, the ambient conditions are really good examples of the potential deviations I mentioned above! The 2 runs were unavoidably some months apart. Despite the "correction formulas" being applied properly, note:

- The earlier 104.X rwhp run (blue lines) was done at much higher ambient temperature as you point out, which would depress its raw reading before correction

- On the other hand, the ambient humidity was much lower for that run, which would have increased the raw readings before correction

- The ambient barometric pressure was very close for both runs, but rather low, which produces a lower raw rwhp reading for both runs

- But the overall correction factor for the first run was 1.06. Any correction factor that calculates out to 1.05 or higher is "suspect" in terms of accuracy, and that specific 104.X rwhp run had a correction factor of 1.06, so it is "suspect"

- The later 106.X rwhp run had a correction factor of just 1.03, which means improved accuracy versus the 1.06 for the earlier run

So really, I guess we simply don't have enough control of all the variables here to know what caused the lower reading the first time and the higher reading the second time. The only physical change was the tire. There were insufficient miles between the 2 runs to have had any significant effect on the condition of the engine (i.e. insufficient miles to wear down the sparkplug electrodes, etc). A good illustration of the limitations of the current state of the art.

Jim G