Disposable Tune? Ouch!

I write again about the Stage I of the new Milwaukee-Eight 114″ engine because the case I am writing about could be used in the didactic context as an...

Timeless Sportster

Indeed very few motorcycles can boast 62 years of uninterrupted production, the Sportster (XL) is one of them. Harley-Davidson has started producing and...

Precooked? No, thanks

Today I return to Stage V, the so-called "tire shredder", installed on a 2016 Touring Police in order to try to highlight the difference between remapping and...

Twin Cam 110S: alive and vibrant!

The Harley-Davidson Twin Cam, also called "Fathead", is an air-cooled 45 ° V-twin engine, 2 overhead valves per cylinder and has two cams in the crankcase...

Stage I Stock: zero appearance, full substance

For some time I had been planning to test and compare the performance of the new Milwaukee-Eight 114" in three configurations that had as a common denominator...

More to come

With my limping English I am slowly translating the other posts on the site to share the experiences with those two or three of you who will deign to read...

Remote Tuning

Remote Tuning

For anyone who has a Power Vision or a Screamin’ Eagle Super Tuner and can’t come to the Tuning Center, we’ve developed a Remote Tuning service for Harley-Davidson engine tuning.

We do not sell maps, the result would be poor, so we developed methods to provide a service with enthusiastic results even for those who could not come to the Tuning Center.

For more information, go to the service page

Tuning, the juice is worth the squeeze

You will never had such an amazing bike before

Many are the most widespread preconceptions against the tuning of the engines of our beloved motorcycles, especially those put around by incompetent or biased people; here is a quick overview: “they break your bike”, “it invalidates your warranty”, “it’s useless”, “have you ever exceeded 120 km/h with your Harley?”, “are you going to run on the track?

Obviously, I am biased, but I will still try to give you objective advice.

Power/Torque dyno chart before and after a Tuning

It’s true that a good Tuning won’t costs two cents, just as it’s true that the performance gains are not always stunning.

What is always true is the exciting feeling you get when you ride the bike after a good engine tuning: smooth power delivery, easier to drive, exuberant torque and very quick throttle response; if you’ve ever ridden a bike with a well tuned engine not with a canned  map, but with a map accurately developed for the bike, you know what I’m talking about.

Is the juice is worth the squeeze? Yes, always.

Let’s consider prices, reliability and results.

Prices are absolutely sustainable: for our bikes we have often spent much more on accessories that have proved to be useless.

Reliability: a perfectly tuned engine is more efficient, cleaner combustion for the benefit of engine life and reliability, reduced fuel consumption, more torque and power and less overheating.

Results: increased joy of riding, smooth engine response in relaxed riding but powerful and aggressive in “critical” situations, with a motto: “you will never had such an exciting bike before”.

Tuning or not tuning depends on tuner, I speak for myself: what I wrote is true and verifiable.

What a Power/Torque Dyno chart can’t say

Figure 1 – example of a dyno chart

At the end of an engine tuning often the most desired thing by many bikers is a nice dyno chart (like the one in Figure 1) that highlights the power and torque gains.

  1. Red Lines : Standard Motorcycles.
  2. Blue Lines : Partial Stage I: Slipons and Tuning.
  3. Green Lines : Complete Stage I: Air cleaner, Slipons and Tuning.

The difference in terms of power and torque is remarkable, but dyno chart does not give a truthful idea whether the Tuning was really performed at the best.

Let us now try to give the reasons for this statement.

Figure 2 – VE Table

To obtain a dyno chart like the one in Figure 1 you keep the bike in 4th/5th gear at a regime of about 1600/1800 rpm for a few moments and then quickly accelerate to full open throttle up to the maximum engine rpm. In order to relata the dyno chart to the engine map, I have published Figure 2, which represents the table of the volumetric efficiencyIn internal combustion engine VE is defined as the ratio of the mass density of the air-fuel mixture drawn into the cylinder at atmospheric pressure of a cylinder and I have highlighted the column in which correspond to full open throttle: TP (Throttle Position) = 100%. The highlighted column is therefore the only part of the entire map table measured in a dyno run.

Read more…

Mirror, mirror of the wall, who’s the fairest AFR of them all?

Amomg a heated discussion about the one who has the best chrome accessory or the darkest bike or durnig the complain for the amount of money spent on useless accessories, often we hear about ECM and stechiometric ratios.
Stoichiometric ratio: what an evocative word, but no does not refer to strange initiatory rites of ngorongoro, although often the “technicians” first speak of it as if they were.

The Stoichiometric ratio takes its name from the Stoichiometry that is the branch of chemistry that studies the quantitative ratios of substances involved in chemical reactions. The purpose is to identify right quantities of substances so that the chamical reactions are balanced.

For our beloved bikes the Stoichiometric tells us that in gasoline engines – in normal operating conditions – the ideal air/fuel ratio for a complete combustion is 14.7:1.

So talking about “Stoichiometric ratios” is totally inappropriate, the Stoichiometric ratio for a gasoline engine is one and only one 14.7:1.

Talking about “Stoichiometric ratios” in a gasoline engine is wrong as if we assume that in order to calculate the area of a circumference A we need a π A, while for a  circumference B we need a π B.

There are no rich or lean stechiometric ratios!

Now that we have clarified what is a Stoichiometric ratios, that is: for gasoline-powered internal combustion engines the Stoichiometric ratios is one and is equal to 14.7 parts of air per 1 part of gasoline, let’s question the mirror of the wall about who is the fairest AFR and the disasters of those who venture to map based on myths and beliefs.

… continues on Jasper the “coalman”

Power Vision for Harley-Davidson 2020 models

Power Vision EPV-1
J1850 connector
Power Vision EPV-2
HD-LAN connector
2001-2010 Softail
2004-2011 Dyna
2007-2013 Sportster
2002-2013 Touring
2002-2017 V-Rod
2015-2020 Street
2014-2020 Sportster
2011-2020 Softail
2012-2017 Dyna
2014-2020 Touring

To ensure support for the entire H-D range listed, remember to update WinPV, PV Firmware, and the Tune PV Database through the Power Vision Update Client.

An Advice

Buy DynoJet Power Vision from authorized resellers in order to receive competent and certified assistance.