80" Evolution Performance Upgrades


The following performance upgrades are proven, dyno tested, reliable means of increasing the output of your stock 80ci Evolution powered HD. Many hours of research and development have gone into designing these upgrades using the most reliable parts available, combined with expert workmanship. These packages work! Other options are available (e.g.: different cams, different heads, etc.) that might also work very well but the fact is, our Stage 1 and 2 packages are dyno proven, hold together like OEM and will make your bike perform better than you ever thought possible. While we strive to keep on top of the performance game, and are open to input from outside sources, please don't call and ask "what if we use this instead" or "what can we do that is less expensive". These upgrades work. Period.  Be confident in knowing that your bike will be getting top quality components in a package that makes real power (where you need it) - unlike glorified magazine claims made 2000 miles away in a different climate with different fuel compositions and riding conditions. Now on to the good stuff!



Don't be misled by the constant emphasis placed on peak hp numbers at maximum rpm. This is not where most of your typical riding is done. Be more concerned with peak torque numbers and the rpm where maximum torque is produced. We are more concerned with the "area under the graph" after a dyno run to see how a bike is performing in real world riding conditions. Torque is what makes a bike fun to ride (not revving to 6500 rpm every shift for maximum hp). Remember: horsepower is an illusionary mathematical equation - torque is real and is everything that is good in the universe!

Note: for comparison purposes most stock 80" Evos make approx 50 hp and 60 ft lbs torque at the rear wheel. Power increases are expressed as a percentage rather than actual dyno numbers due to the many variables involved with different exhaust systems/carbs/fuel injection mods etc.

STAGE 1 (approx power increase: 35%)

80ci (stock pistons), Andrews EV27 cam, Jim's updated steel breather gear, inner cam bearing, adjustable "time saver" pushrods (no top end disassembly required), James gaskets, carb re-jet or fuel injection mods (see note 1).

STAGE 2 (approx power increase: 45%)

80ci (stock or Wiseco pistons - optional see note 8), Stay Tuned Systems cylinder head rebuild/port & polish (the best!), Andrews EV27 cam, Jim's updated steel breather gear, inner cam bearing, adjustable pushrods (optional see note 8), James gaskets, carb re-jet or fuel injection mods (see note 1). Carburetor upgrade optional (S&S Super E or Mikuni HSR 42).


1. Fuel injection models for all stages require $150.00 to $300.00 dyno time to properly map fuel curves (for optimum performance) and possibly HD's Stage 2 chip and/or download (see TC88 Performance Upgrades Note 1) . All models also require a Power Commander module. HD's Stage 2 chip usually runs around $225.00 and the Power Commander is usually around $450.00. See also note 5.

2. Higher mileage engines (e.g.: 40,000 kms +) should also have the lifters replaced at the same time as the camshaft. This is very important with Evos since the rollers on the lifters often start to come apart at this mileage. New HD lifters are usually $180.00/set.

3. Power Commanders work the best on fuel injected models. Other systems (such as the Vance & Hines Fuel Pak) do work but usually only get the mapping "close enough". While such systems may be easier to tune and might be more user friendly (normally advertised as "not needing expensive dyno time") we have found that the only way to achieve maximum performance is with a properly set up Power Commander.

4. FL and FXD series bikes (Evo engines that are rubber mounted) typically produce 5% more power on the dyno (compared to solid mounted engines in Softails) due to less vibration. Vibration causes parasitic losses through the drivetrain resulting in lower rear wheel horsepower numbers.

5. Magneti-Marelli fuel injection equipped models (FL touring series 95-98) are somewhat limited to upgrades due to the inefficiency of the stock fuel injection system design and related components. Please call to discuss options.

6. We have found that the best power gains are made using a 2 into 1 type header system such as the Vance & Hines Pro-pipe. Unfortunately, many people do not like the look of such a system, so a close "second" is the stock HD header system (with cross over pipe) combined with a good set of slip on mufflers like those made by Cycle Shack or HD's old Screamin Eagle IIs (no longer available). However, most quality slip on performance mufflers will do the trick.

7. The stock CV carb works very well, and when combined with a high flow breather, can be jetted to produce almost the same power as a S&S Super E or Mikuni HSR42. However, the S&S is very easy to tune on your own (if you like to swap exhausts and play around) and the Mikuni produces great torque down low so carb upgrades do have benefits.

8. Piston replacement is optional due to the fact that when changing out the heads we are "right there" so now is a good time to save on labour if the engine is due for a freshening up. Wiseco pistons usually produce about 3hp more on the top end (vs HD pistons) due to their thinner ring design (if available). Adjustable pushrods are optional since we can easily re-use the OE pushrods while the top end is apart. Normally adjustable pushrods are used when performing a cam swap without disassembling the top end.

9. Ignition system upgrades are optional since they really don't increase power output. If you have the stock HD electronic ignition and are planning on running the bike hard (eg: up to redline) then a Screamin Eagle module is recommended (allows the bike to rev to 8000 rpm vs as low as 5200 rpm which is stock on some oem modules). The higher rev capabilities allows the engine to make maximum power without getting "shut off" early due to the rev limiter. A Crane Hi-4 single fire ignition is another alternative that allows much more tuneability (especially if you live in an area with poor quality fuel). A Screamin Eagle module usually runs around $200.00 and a Crane Hi 4 (complete kit) normally sells for $475.00. The preceding applies to carbureted bikes only - see note 5 regarding fuel injected models.


*Lest we forget*
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