Which tuner should I buy?

This is a question I often get, so I thought I would share the most recent email asking it and my response.

I would like to learn more about tuners, how they work and how to tune my HD bikes. My wife and I each have newer touring Harleys. I put V&H Dresser Duals and Monster Ovals on mine,  Dresser Duals and Monster Rounds on hers as well as a high flow AC on each.  I currently Have a Thunder Max tuner on each bike and run the auto tune a couple times a year. They both seem to run well and we ride from home at 5700’ over passes that may be 10,000’ and down to sea level. I was looking at the Harley Forums and reading posts about tuners from riders and Professional tuners trying to find out what people think of the different types of tuners, ease of operation and end results. I found it confusing, some tuner was saying Thunder Max Alpha N platform for tuning was state of the art several years ago but not now. I wish I could find straight unbiased information or material that allows me to learn the different systems and make an informed decision. I’m thinking of buying a new Rushmore FLHTK and though I’ve been happy with the Tmax would I be happier with some thing else?

I was wondering if you could recommend any literature explaining tuning and tuners.  I’m interested in learning how to read and interpret tuning tables and make an educated adjustment if possible, or to at least understand what the tuner is doing and why.

Any information you can give me is appreciated.



My reply to Bill’s email
Hey Bill,
I started writing a Harley EFI blog that I update about once a month or so. www.harleytuner.com you might find some interesting info there from time to time.
Not totally sure where to start to answer your questions and may have to elaborate on some of it in a later email.

First let’s talk about EFI.

The biggest advantage of OEM production EFI in your Harley is that it should correct for ever changing air conditions. Temperature, Pressure, Humidity. Properly set up/calibrated/tuned should never need “re-tuned” ever.

Alpha N is older technology and pretty much is only used on some race vehicles these days. FYI – Race parts are not necessarily better, especially for milder street engines.

As I’m sure you know, most modern vehicles including Harleys use Speed Density systems. Which is what I have used on race bikes I have been involved with including “The Rooster” 2003 Road King my buddy bought new and we played with. Just under 140HP and 150 ftlbs of torque. Actually very smooth and rideable.

The Thundermax is a good ECM, especially for what it was originally designed for: “aggressive Race bikes”. Big Cams, Exhausts… Race bikes that you would constantly be playing with the tuning at the track during a race.
As you know the best part about the Thundermax is its wide band auto tune add-on module.

Delpi (maker of H-D’s ECM) has been building EFI/ECMs for longer than almost any other company in the world. It is very sophisticated. Way more advanced than the Thundermax.
I have been playing this game (tuning EFI Harleys) pretty much longer than most people, which is why companies like Dynojet, Harley-Davidson Motor Co, Vance & Hines, Rinehart Racing, Speeds Performance Plus,… hire me for consulting and contract work.

I can run anything I want on my bike, and most manufacturers would give me their product to run if I asked.

For me it’s a no brainer. My daily/cross country ride runs an HD factory (delpi) ECM with a Flash Tuner.
Dynojet Power Vision, Screamin Eagle Super Tuner, TTS Master Tune…all basically do the same thing. The software interface is different, some have different features than others, some Dyno operators/tuners are only familiar with one or two, but the bottom line goal for all of them is to re-calibrate the air tables in the ECM to match your engines new airflow created by the new parts/modifications you have added/done. Pipes, Airbox, cams, heads,…

If you calibrate the ECM to the true airflow of your engine on your Harley and then set up the tune correctly (Calibrate first, Tune second), your bike will not only properly correct for ever changing air conditions caused by weather Altitude, and climate changes it will be able to correct for minor fuel blend changes (gas vs 10% or 15% ethanol) and even help protect your engine from damage that could be caused by an intake leak if you were to get one.

The best part is as long as you don’t change any parts affecting your airflow you should never have to mess with it again, just ride year after year with the ECM doing what it was designed to.

I don’t have time to hit all the details as to how and why this is right now, but the hows/whys will be trickling into this blog over time

The most efficient way to do this is on a Dyno of course. But if you want to attempt it the way you have with your Thundermax then I would recommend you buy the Dynojet Power Vision with their auto tune module. Pick a pipe with dual bungs (big and little) so you can use the wide band O2 sensors and keep the stock O2 sensors in tack.

It is near impossible to hit all the cells riding the bike around that’s why a Dyno is great for this. I can hit nearly every cell in 10 minutes.

I have been told that it doesn’t matter because you hit the cells you ride in. Fact is you hit the cells you were riding in today. When you go up or down in the mountains you will ride different cells. If you load your bike for a trip you will ride in different cells. On the Dyno you can hit all the cells needed for every riding condition very quickly.

In a follow up email Bill asked if I could recommend a dyno operator/tuner near him.
I have a list of shops I have trained on my website: http://www.danielsperformance.com/Customers.html. I plan on adding a recommended Dyno tuner list to my website in the near future.

If you go Power Vision or Super Tuner I might be able to help you find a good base map to start with. I have a blog post with some insight into picking a base map http://harleytuner.com/super_tuner_map_selection/ but I might be able to get you one with closer air tables if you like.

FYI – The Rushmore TK has been my favorite bike to borrow from Harley’s Demo fleet for the past year. Great bike.

Take care,



14 thoughts on “Which tuner should I buy?

  1. Question
    Just purchased a 2010 96″street glide. Previously owned a 2000 carb road king with performance exhaust and air intake and mikuni carb. I would like to do the same here on 01 for a little better response and cooler running engine. I understand that the harley ecm adjusts for temp and altitude, which I like, especially coming from carb bike. Does harley have a flash that will work with mods and keep the ecm functioning as designed or do I need a ecm tuner and loose the auto adjustments for temp and alt? I def want to do perf mufflers and air intake at the very least, true duals if I can afford them.


  2. Thanks for quick response
    If I go with a tuner eg power vision. I decide to go with air cleaner and. Mufflers for now. I could use the map of V & h slip ons with air kit. That would work and also keep the ecm working with air temp and altitude? Then if I add true duals and get rid of cat conv, true dual map would then be loaded and ecm would still do the same?

    if so, I think that would work

    Joe danbury Ct

  3. The ECM is always trying to correct for the ever changing air conditions (Air and Altitude). No calibration from Dynojet or Screamin Eagle can disable that. However it uses the info in the calibration to use in its calculations for this which is why it is important to have a proper map.

    Keeping the the O2 sensors (closed loop) turned on is what I recommenced. Besides helping correct for small discrepancies in the map it is what gives the ECM the ability to correct for different fuel blends.
    Some of Dynojets maps turn closed loop (O2 Sensors) off. You can check for that by opening the map you are interested in with the Power Vision software. If it is turned off you can turn it on then send it to your Power Vision to load to your ECM.

    As an example Power Vision map 10T096002303 for Year: 2010 Family: TOURING SE/Air Cleaner, V&H Basic Slip-ons, Performance, 91-93 Octane on Dynojets page has closed loop turned off. If you down load it and open it with the free Power Vision Software you can check this and turn it on.
    I made a quick screen capture video PV Closed Loop Check to show you how. Below are the instructions to go with it.
    1. Open the map in Power Vision.
    2. Click the plus sign next to fuel.
    3. Click Air-Fuel Ratio which will display the air fuel table as Lambda (I will discuss Lambda in a future post) At the bottom will be a text description of the table. It states that closed loop works between Lambda Values of .98 and 1.02. Closed loop should be used in the cruise area. The cruise area is generally 70 KPA and lower and 3500RPM and lower. This map has a Lambda value of .95 in the cruise area, which means Closed Loop is turned off.
    You can turn closed loop on by changing the values to .98
    4. change cruise to Lambda of .98
    5. Save the map
    6. Send it to your Power Vision as per Dynojets instruction, then send it to your ECM

    Or if you want I can set set it up for you.

    In the very near future I will some maps and tutorials available on my website http://www.danielsperformance.com

    I hope this helps,

    This information is for discussion purposes of motorcycles being used in close course competition only. It maybe against federal and local laws to modify your motorcycle in this way for use on a public road or highway

  4. I have a Cobra 2000fi on my 2012 FLHTK. Was i wise in my selection. Bike runs fine with this plug & play.

  5. I understand that the screaming eagle street tuner has been revamped and has more adjustability would you recommend this tuner or have you had any experience with the new tuner?

  6. Mike,
    Truly appreciate the information you are disseminating. I’m about to do a stage 1 on my 2014 Fat Bob. I’ve looked at intakes and exhausts and decided on those, however I could not make an informed decision on a tuner. From reading through your articles I understand things a lot better and think it would be best for me to get the SEPST. For the most part I stick with Harley parts and I only use my local Harley dealer for work on my bike. They are a good bunch of people and I have a good relationship with them. They understand that not everyone who likes Harley is made of money. I’m sure they are trained on it so if I really screw something up they will know what to do to fix it. I want to be able to use the tuner I purchase by myself though. I’m concerned about being able to choose a canned map though as I’m not using a Harley exhaust. Can you help me understand how this works a little better before I make this purchase?

  7. I have a 2014 with thundermax 585 cams and constantly getting knocking or pinging and I’ve had it dyno before. I’m goin to put screaming eagle heads on in a few days. Debating on back to stock ecm and power vison or screaming eagle pro tuner.any advice should I keep the thundermax or go back to o2 and go to stock ecm and try power vison?

  8. Can you give any advice on TTS Mastertune 2 vs PV2? I was originally leaning TTS based on tuners advice, but more I read, looks like PV2 may do everything TTS does, but easier to use and more flexible with wideband 02 should I go that route down the road.

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