{"id":4267,"date":"2019-10-03T12:14:26","date_gmt":"2019-10-03T11:14:26","guid":{"rendered":"https:\/\/american-v.cso2w.com\/?p=4267"},"modified":"2019-10-03T23:25:09","modified_gmt":"2019-10-03T22:25:09","slug":"putting-some-sport-into-the-sport-glide-part-1","status":"publish","type":"post","link":"https:\/\/american-v.cso2w.com\/hub\/putting-some-sport-into-the-sport-glide-part-1\/","title":{"rendered":"Putting some Sport into the Sport Glide: Part 1"},"content":{"rendered":"

\"\"<\/a>While the Twin Cam iterations of both the Softail\u00a0<\/strong>and Dyna were noticeable improvements over their\u00a0<\/strong>Evolution-engined predecessors, the Milwaukee-<\/strong>Eight version, in my view, is a huge leap forward.<\/strong><\/h4>\n

Words and Photography: Boz
\n<\/em>Facilities: V-Twin Custom, Rye \u2013 www.vtwinuk.com\u00a0<\/a>
\n<\/em><\/strong>Originally published in American-V magazine, Issue 95, February\/March 2019<\/span><\/em><\/p>\n

I<\/span>\u2019ve owned several Softails and Dynas, and while I got what the\u00a0Softail was about, with its rigid frame looks, the Dyna chassis\u00a0was just too much of a compromise for me. It worked in spite of\u00a0itself, rather than because of any sound engineering practices,\u00a0and was far inferior to the FXR that it ultimately replaced. But the\u00a0Dyna has gone now, even if its model designations have carried over,\u00a0and the new Softail chassis is far superior. And not just to the Dyna,\u00a0but also to it\u2019s earlier namesake.<\/p>\n

It\u2019s a brave but necessary move by Harley-Davidson, and it\u2019s\u00a0pleasing to see \u2013 and feel \u2013 that function has been less compromised by form.<\/p>\n

Having now owned a couple of Victorys I found myself to be far less forgiving of some of Harley-Davidsons previous idiosyncrasies\u00a0but even with that more critical stance, I have become a big fan of the\u00a0new Sport Glide.<\/p>\n

It\u2019s practical, it handles, has a lovely ride quality and the single front\u00a0disc actually works very well.<\/p>\n

Anyway, enough of this, and on to what this series of articles are\u00a0about: improving the performance of the M8 engine.<\/p>\n

While this new engine has been with us for a couple of years,\u00a0the aftermarket has been a little slow coming up to speed, and even\u00a0though a small number of manufacturers are putting some serious\u00a0R&D into this, many just seem to be trying to alter existing Twin Cam\u00a0products to physically fit and hope that it works.<\/p>\n

\"\"<\/a>Something that I have learnt over the years as an engine builder and\u00a0rider \u2013 and properly quantified in the years that I\u2019ve been dyno tuning\u00a0\u2013 is to assume nothing. What worked on the previous generation of\u00a0engines, doesn\u2019t necessarily work as well with the next.<\/p>\n

This is very important, and perhaps requires an explanation.<\/p>\n

Manufacturers are handcuffed to ever-tightening emission\u00a0and noise constraints, so we are looking as much at the potential\u00a0performance increases as the power output of successive generations\u00a0of engines as they leave the factory. And the only common\u00a0denominator is that they are 45-degree V-twins made by Harley-Davidson, hindered by whatever legislative constraints their\u00a0respective eras had to deal with.<\/p>\n

\"\"<\/a>When the Shovelhead was replaced by the Evolution for the\u00a01984 model year, the bore and stroke (3.498\u02ddx4.250\u02dd) remained the\u00a0same, for a nominal 80 cubic inch capacity. The Evo, however, had\u00a0a noticeably improved power potential due to better flowing heads,\u00a0better combustion, and better cooling.<\/p>\n

What worked with the Shovel didn\u2019t always carry across\u00a0to the Evo.<\/p>\n

When the Twin Cam \u2013 which had little similarity to the Evo \u2013\u00a0arrived for the 1999 model year, the bore was increased and the stroke\u00a0shortened (3.75\u02ddx4.00\u02dd) for 88 cubic inch capacity. But more than\u00a0that, the inertia mass of the flywheels was substantially altered and the\u00a0power characteristics were different.<\/p>\n

\"\"<\/a>The exhaust ports were in the same place, however, so many\u00a0existing Evo exhausts would physically fit, and many camshaft\u00a0manufacturers initially either simply transposed their Evo cam timing\u00a0figures across to the Twin Cam, or else based the design on a gut\u00a0feeling and theory.<\/p>\n

As it turned out the Twin Cam was more tolerant of higher\u00a0compression than the Evo, and of shorter cam timing if compression\u00a0wasn\u2019t increased. And when Harley improved the heads for 2006 and\u00a0increased the stroke to 4.375, the Twin Cam \u2013 depending on year and\u00a0model \u2013 became a 96, 103 or 110-inch, with the 110 having different\u00a0heads and compression.<\/p>\n

Harley\u2019s use of EFI for Big Twins, the rollout of which was\u00a0completed in all markets by 2007 \u2013 2008 for the Sportster \u2013 added far\u00a0better control over ignition and fueling, as well as helpful data logging\u00a0when tuning with the appropriate software.<\/p>\n

\"\"<\/a>And now with the Milwaukee Eight, we have four valve heads,\u00a0higher compression, twin plugs, a bigger bore \u2013 and a longer stroke\u00a0also in the case of the 114 \u2013 and a different combustion chamber and\u00a0port design.<\/p>\n

So, while potential engine power output and the way it produces\u00a0that power still remains a function of capacity, combustion\u00a0efficiency, compression ratios, port flow, valve timing and tuning,\u00a0other supporting components such as intake and exhaust systems,\u00a0camshafts, etc. may very well have a different influence on not just the\u00a0peak numbers, but the way in which the power is produced compared\u00a0to what we\u2019ve been used to.<\/p>\n

And yes, the more efficient M8 does tune differently than its\u00a0predecessor.<\/p>\n

We are dealing with a completely different animal\u00a0and the only way to learn is to get one and endeavour\u00a0to understand how it differs from what went before.<\/p>\n

And with an open mind, systematically test different\u00a0components in order to build a picture of what works\u00a0and what doesn\u2019t.<\/p>\n

This is called Research and Development, and I am\u00a0unashamedly a massive fan of it.<\/p>\n

The problem with R&D, however, is that it is very\u00a0expensive. We need a bike as a test mule, we need to\u00a0buy an assortment of various components, we need to\u00a0fit them and we need to test them.<\/p>\n

It is also very time consuming \u2013 which doesn\u2019t pay\u00a0the bills \u2013 and an appropriate test facility is required.<\/p>\n

Sorry, that infamous internet \u201cbutt dyno\u201d doesn\u2019t cut\u00a0it at this level: there is no substitute for hundreds\u00a0of hours on the dyno as a way of learning and\u00a0quantifying how the various components interact in\u00a0order to find a combination that gives the best results\u00a0relative to the way the bike will be ridden.<\/p>\n

No doubt this is why so few places\u00a0embark on proper R&D programs \u2026 and\u00a0why so many unfortunate owners can make\u00a0ill-informed and expensive decisions based solely on conjecture and\u00a0unsubstantiated sales blurb.<\/p>\n

\"\"<\/a>

1.<\/strong> V-Twin\u2019s test mule and daily driver, the excellent FLSB Sport Glide. It was essential that we started with the bike completely stock so that we could get some baseline runs first, in order to better show the potential gains from the components that we tested.<\/em><\/p><\/div>\n

So, V-Twin has purchased its own Sport Glide to use: not just as a\u00a0daily driver, but also as a development test mule.<\/p>\n

And since we have a dyno, machine shop and engine building\u00a0facility in house, we can arrive at a parts combination that can be\u00a0demonstrated to work.<\/p>\n

Every day should be a school day for those of us in the business, so\u00a0that we can then better advise our customers as to what combination\u00a0of parts, installation and tuning can best suit their riding style.<\/p>\n

So, now on to the testing method, and this initially involves testing\u00a0one component at a time.<\/p>\n

The Dyno is used not just to measure the results but to control\u00a0the engine when used in conjunction with the tuning software. This\u00a0means that the bike is tuned at each stage to ensure that fueling and\u00a0ignition timing are optimised, in order to get the best out of each\u00a0component tested. If the engine management parameters are not\u00a0optimised, we are making assumptions as to how each component\u00a0behaves, and the results are at best spurious, and at worst, totally\u00a0worthless.<\/p>\n

Yup, it is definitely time consuming \u2026<\/p>\n

This 107 Sport Glide had 2500 miles on the clock, fresh oil and the\u00a0same brand\/grade of fuel (Shell V-Power) was used throughout testing.<\/p>\n

The tuning is done with Technoresearch\u2019s Direct Link \u2013 now\u00a0distributed in the UK through Parts Europe \u2013 which I have been\u00a0working with for the last twelve years. By using the dyno to control\u00a0the engine, and measuring the results, a new \u2018map\u2019 is built on\u00a0the computer and then flashed into the bike\u2019s ECM: after tuning,\u00a0absolutely nothing is left physically connected.<\/p>\n

There is obviously a necessary learning curve here too, as not only\u00a0does the M8 have a new ECM with more sophisticated software levels\u00a0than the Twin Cam, but \u2018what the engine wants\u2019 in regard to ignition\u00a0timing and fueling, is not the same as the Twin Cam.<\/p>\n

Fortunately, I have already tuned a number of M8s, and the new\u00a0software \u2013 while more complex \u2013 retains a familiar layout.<\/p>\n

A final point to note is the relevance of what gear is used for the\u00a0testing: there are two factors at play here: the way the dyno calculates\u00a0the power, and parasitic transmission losses through the gearbox.<\/p>\n

Typically, the higher the gear, the higher the numbers due to how\u00a0the engine loads up.<\/p>\n

And we want to use the gear that gives a one-to-one ratio as fewer\u00a0gears are used to transmit the power, which with a stock Harley \u2018box\u00a0is sixth gear.<\/p>\n

However, with the tall overall primary gearing that Harley use\u00a0with their six-speed \u2018boxes, this equates to a road speed approaching\u00a0160mph at 6,000rpm in sixth, which is a bit unfair on an H-rated tyre.<\/p>\n

We have to be sensible with this, and while I don\u2019t mind running in sixth on an occasional basis \u2013 to get the final numbers with a good parts combination \u2013 I won\u2019t take the chance of a tyre letting go by constantly abusing it on the number of wide open throttle testing that this R&D project will entail, so most of these dyno charts are done using fifth gear, and sixth only used to illustrate the final combination as far as peak numbers are concerned.<\/p>\n

Fifth gear testing remains totally relevant for this project though, as each test is consistent and we are after comparisons rather than numbers.<\/p>\n

I hate the terms \u2018stage 1\u2019, \u2018stage 2\u2019, blah blah blah, as it tells us absolutely nothing, but since these nonsensical acronyms have become such common place in the Harley market, I will cave in and discuss what I believe a \u2018stage 1\u2019 should represent.<\/p>\n

This is the easy to get, low hanging fruit, as we don\u2019t have to go inside the engine, and it should consist of a better flowing air cleaner, an exhaust that hopefully adds power and not just noise, and an appropriate remapping of H-D\u2019s excellent fuel injection system.<\/p>\n

The first two are the laws of physics at work, and the tuning can only maximise what they give.<\/p>\n

A bad combination of parts cannot be rectified by tuning, because as clever and as educated as we might wish to become, we can\u2019t change those laws. Of course, an un-tuned or badly tuned good combination of parts cannot perform as intended either.<\/p>\n

So, to recap, this bike was tuned specifically to suit each component \u2013 or combination of components \u2013 in order to get the best from them, and make the testing valid.<\/p>\n

Something that may come as a surprise to many is that I started with air cleaners first, and not the exhaust systems.<\/p>\n

Harley\u2019s stock exhausts, while somewhat restrictive \u2013 and this varies from model to model \u2013 are not necessarily the butt plugs that they once were.<\/p>\n

Something that I found with the Twin Cams is that these engines want air more than they want more noise and we need to deal with the restrictions at both ends.<\/p>\n

Now, I am fully aware that many owners choose their exhausts mainly for the sound and the appearance but this article is not about that very subjective view, it is about finding out what works taking into account the limitations of parts availability, budget and time constraints.<\/p>\n

For the air cleaners I picked three that I had previously had good results with on Twin Cams: the S&S Stealth, K&N RK series and the Screamin\u2019 Eagle Heavy Breather from H-D.<\/p>\n

And at the time of conducting these tests, there were no slip-on mufflers available for our Sport Glide, so we picked two complete systems to try: the Bassani Road Rage 3 \u2013 which I have had good results with on Twin Cams and Sportsters \u2013 and the relatively new Two Brothers Racing system which, like the Bassani, is also a two-into-one made from stainless steel.<\/p>\n

So, finally, off we go then.<\/p>\n\n\n\n\n
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\"\"<\/a>

4:<\/strong> This overlay gives a better idea. Overall power has increased but only by around 2%, although it did feel more responsive.<\/p><\/div><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\n

DEEP BREATHING EXERCISES <\/span><\/h3>\n

Air cleaners are not just about the size and type of filter element, they are also about how they manage the air. The three that are tested here all have excellent cotton gauze filter elements, but each adopts a different approach to air management.<\/p>\n

As we shall see, the stock air cleaner is quite restrictive, and while there may be some benefit to using a better element, its air inlet is quite small and reminded me of some of the stock Evo air boxes.<\/p>\n

Another point to note is that intake noise is also a factor when H-D submit their bikes for emissions and noise testing approval.<\/p>\n

The cynical amongst us would argue that since the Heavy Breather is listed as EPA compliant, why wouldn\u2019t they use that as standard, as they did on the Dyna Low Rider S with the 110 engine?<\/p>\n

Maybe they just want us to spend more money on their accessory range?<\/p>\n

\n
\"\"<\/a>

5:<\/strong> S&S Stealth with the stock exhaust, tuned. This is relatively cheap power, around 6% through the lower and mid range, with a 10hp peak gain.<\/em><\/p><\/div>\n

<\/h4>\n

S&S Stealth and stock exhaust.<\/h4>\n

The three pictures illustrate well how S&S have approached this.<\/p>\n

The assembly is intelligently made from high strength plastic\u00a0mouldings with threaded brass inserts. The fitment is both simple\u00a0and accurate.<\/p>\n

The backplate incorporates a radiused entry into the throttle\u00a0body \u2013 air doesn\u2019t like sharp corners \u2013 and the outer cover uses a\u00a0\u2018stinger\u2019: a protruding guide to help direct the airflow.<\/p>\n

This is quite well priced, although the optional billet face plate,\u00a0which is a cosmetic addition, is bit pricey.<\/p>\n