Harley-Davidson XR1200 Performance upgrades

Whilst essentially a Sportster, we've decided to give the XR it's own section as we own one of these, and it is undeniably one of the best motorcycles Harley has ever built. It handles, it stops, it's quick, and it is very tuneable. It's European riding position also makes it surprisingly comfortable for long distance work.

We have now ridden over 10k miles on the XR1200 under a number of different conditions. This includes 800 miles in one day coming back from Italy, an 80 mile blast on a quiet Autobahn in Germany with the revs not dropping below 6k, and commuting through heavy London traffic. Having also dyno tuned an increasing number of customer bikes with different exhaust systems, including two Henderson cup race bikes, and our own, on going, in house R&D program, we are arguably the most experienced XR1200 specialist in the UK. As with all Harley-Davidson performance upgrades, there is a lot more involved than just selling the parts. We supply the parts, install, machine where necessary, and correctly tune. All under one roof. The buck stops here.

Dyno tuning an XR1200 at Powerglides

Our XR1200 being remapped on our Superflow dyno. The twin 22" wide screen monitors mounted in front of the bike allow us to run two software programs simultaneously and easily see what is going on during the dyno tuning process. Although complex, it is like having a 'window' to the engine and the ECM.

We run the complete Supertrapp system on ours and will be experimenting with cams, compression ratios, air cleaners, headwork, and capacity increases as the relevant parts become available. As with our other Harley tuning, we use the Direct Link Flash Tuner software and our Superflow dyno to remap the stock ECM which gives complete control over fueling and ignition requirements.

Customerís XR1200X fitted with Termignoni exhaust and dyno tuned here with Direct Link Flash Tuner

Customer's XR1200X fitted with Termignoni exhaust and dyno tuned here with Direct Link Flash Tuner.

The ports, combustion chambers, valves, guides, and springs in the XR1200 heads are the same as the 2004 up 1200 Sportster and XB12 Buell, so much of what we develop for this bike will be applicable to all the rubbermount Sportsters and also retro fit the earlier Evo XL models.

XR1200X with Termignoni exhaust system, and our own XR1200 fitted with the Supertrapp system. Both bikes have been dyno tuned with Direct Link Flash Tuner and are used as everyday transport.

XR1200X with Termignoni exhaust system, and our own XR1200 fitted with the Supertrapp system. Both bikes have been dyno tuned with Direct Link Flash Tuner and are used as everyday transport.

Dyno tuning one of the XR1200 Henderson Cup race bikes

Remapping Harley fuel injection on the dyno is the best way to get the best from the engine, Although late in the season, we had the opportunity to dyno tune one of the XR1200 Henderson Cup race bikes. The gain was an astounding 3 seconds a lap on the Brands Hatch Grand Prix circuit.

One of the XR1200 Henderson Cup race bikes

This is about as far as we can go with Harley XR1200 performance upgrades without going inside the engine.

This year's race bike (2011) is an XR1200X with the Harris race exhaust

This year's race bike (2011) is an XR1200X with the Harris race exhaust

XR1200 with the Supertrapp exhaust system, greatly benefits from dyno tuning

As with all fuel injection Harley-Davidson performance upgrades, this XR1200 with the Supertrapp exhaust system, greatly benefits from dyno tuning.

The Remus complete exhaust system for the XR1200 has a very large torque dip in the mid range.

The Remus complete exhaust system for the XR1200 has a very large torque dip in the mid range. This customer fitted a Supertrapp universal muffler to the Remus headers and, following some experimentation on our dyno, we managed to find a combination that produced a substantial torque gain from 3000 to 7000rpm, with a massive 20% improvement at 4500rpm. Accurate measurements on our Superflow dyno, and an appropriate remapping of the fuel injection system with our Direct Link Flash Tuner tuning software was essential in achieving these remarkable gains.

Ported cylinder heads for Harley-Davidson XR1200

Whilst the XR1200 performs very well with a decent exhaust system and correct dyno tune, for some of us it just isn't enough. As part of our ongoing R&D program for this excellent motorcycle, we now have Head Quarters cylinder heads. These are stock OEM castings, hand ported by the best in the business.

Head Quarters cylinder heads form the basis of our Harley-Davidson XR1200 engine performance upgrades.

Head Quarters cylinder heads form the basis of our Harley-Davidson XR1200 engine performance upgrades with no compromise of reliability.

Machining Harley-Davidson XR1200 Sportster crankcases

Machining Harley-Davidson XR1200 Sportster crankcases to accept an 88" big bore conversion. Having a dedicated machine shop, as well as the dyno, puts us at the fore front of performance upgrades for this remarkable motorcycle.

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Powerglides - In The Press