Thinking About Ditching the ThunderMax...
Thinking About Ditching the ThunderMax...
...and reinstalling the stock ECM, then getting a professional tune with the Dyno Difference guys here in Dallas.
Thoughts? Anyone else had an aftermarket tuner, then gone back to the stock ECM with a good custom tune?
Thoughts? Anyone else had an aftermarket tuner, then gone back to the stock ECM with a good custom tune?
Road Warrior
Joined: Dec 2008
Posts: 1,810
Likes: 4
From: Out and about
Why not just get a custom tune on the T-max? I understand it's an auto tuner but people dyne tune them to get optimized performance. Seems like a waste to spend all that money on the T-max then just remove it and replace it with something else. Is it not performing well for you?
Seasoned HDF Member
Joined: Jul 2008
Posts: 9,278
Likes: 1,138
From: southeast PA
Why not just get a custom tune on the T-max? I understand it's an auto tuner but people dyne tune them to get optimized performance. Seems like a waste to spend all that money on the T-max then just remove it and replace it with something else. Is it not performing well for you?
This could turn into a pretty technical discussion...
As for my experience, the bike has always run very hot with the TMax.
I was referred to this local tuner by a couple people around here...apparently he really knows his stuff. Anyway I came to him with my inquiry and he advised that ThunderMax is essentially going backwards on a stock motor...keep in mind that mine has had no internal upgrades. When you remove the Delphi ECM you lose Speed Density and Ion Sensing. They give you no utility to "free air" calibrate the AutoTune wide band sensors so when they drift, they all do, causing it to start tuning the bike incorrectly. Apparently, when AutoTuning if you don't merge the offsets with the base map then when the sensors start to drift the tune will be terrible. He said he's pulled 15 - 20 of these off over the years and gone back to the Delphi.
Interestingly, I just talked to him today but his recommendation was the same as what I suggested in my OP...reinstalling the Delphi ECM with factory O2 sensors and getting it tuned. Curious what you guys think...
As for my experience, the bike has always run very hot with the TMax.
I was referred to this local tuner by a couple people around here...apparently he really knows his stuff. Anyway I came to him with my inquiry and he advised that ThunderMax is essentially going backwards on a stock motor...keep in mind that mine has had no internal upgrades. When you remove the Delphi ECM you lose Speed Density and Ion Sensing. They give you no utility to "free air" calibrate the AutoTune wide band sensors so when they drift, they all do, causing it to start tuning the bike incorrectly. Apparently, when AutoTuning if you don't merge the offsets with the base map then when the sensors start to drift the tune will be terrible. He said he's pulled 15 - 20 of these off over the years and gone back to the Delphi.
Interestingly, I just talked to him today but his recommendation was the same as what I suggested in my OP...reinstalling the Delphi ECM with factory O2 sensors and getting it tuned. Curious what you guys think...
I'm running a Thundermax and have had no issues, runs great, and has worked through all the mods I've done. I've thought about getting it dyno tuned, mostly just to make sure I'm getting the maximum power, although I have no complaints with how it runs now.
That said, if I was going to do it again I'd probably go with a PowerVision or similar. I don't like the fact that the Tmax is a completely different ECM, and if I have an issue on a road trip and I can't find a shop that stocks a Tmax I'm screwed.
That said, if I was going to do it again I'd probably go with a PowerVision or similar. I don't like the fact that the Tmax is a completely different ECM, and if I have an issue on a road trip and I can't find a shop that stocks a Tmax I'm screwed.
I'm running a Thundermax and have had no issues, runs great, and has worked through all the mods I've done. I've thought about getting it dyno tuned, mostly just to make sure I'm getting the maximum power, although I have no complaints with how it runs now.
That said, if I was going to do it again I'd probably go with a PowerVision or similar. I don't like the fact that the Tmax is a completely different ECM, and if I have an issue on a road trip and I can't find a shop that stocks a Tmax I'm screwed.
That said, if I was going to do it again I'd probably go with a PowerVision or similar. I don't like the fact that the Tmax is a completely different ECM, and if I have an issue on a road trip and I can't find a shop that stocks a Tmax I'm screwed.
Trending Topics
Grand HDF Member
Joined: Sep 2010
Posts: 3,580
Likes: 215
From: Illinois
TMax definitely has a huge learning curve. In the beginning I was real frustrated with it not really understanding it's abilities, getting all the maps, settings, and so on.
That being said when I did my build this winter I researched the **** out of it and bugged the hell out of zippers tech to answer any questions I have had.
When used correctly there is no need to dyno it. In the TMax control center drop down after about 50 miles of riding or even 1,000 you can go in and it will tell you how much it's correcting your tune (5% range is excellent)......in there you can dump everything it learned instantly onto your tune to speed up its learning process. After few of these sessions of riding that you dump into the tuner it will make your tune perfect with barely any more changes as you ride.
If the percentages are way off in their you will know to try a new map or that something is off.
The more I have learned about this unit the better my bike runs. No other system allows you to SELF customize and tune your bike like the TMax.
If I got any other tuners I would have to get'er tuned somewhere, when I first got my pipe and breather, get a speedo healer when I regeared my bike to fix my speedo, then get a serious tune with some dyno time when I did my motor....not to mention probably have to trailer it to a shop cause I would have been able to fire it up w/o the proper map.
Really is a good system, but might be overkill IF one never plans on doing motor/trans mods.
.....also got mine used on eBay for $400 shipped!
That being said when I did my build this winter I researched the **** out of it and bugged the hell out of zippers tech to answer any questions I have had.
When used correctly there is no need to dyno it. In the TMax control center drop down after about 50 miles of riding or even 1,000 you can go in and it will tell you how much it's correcting your tune (5% range is excellent)......in there you can dump everything it learned instantly onto your tune to speed up its learning process. After few of these sessions of riding that you dump into the tuner it will make your tune perfect with barely any more changes as you ride.
If the percentages are way off in their you will know to try a new map or that something is off.
The more I have learned about this unit the better my bike runs. No other system allows you to SELF customize and tune your bike like the TMax.
If I got any other tuners I would have to get'er tuned somewhere, when I first got my pipe and breather, get a speedo healer when I regeared my bike to fix my speedo, then get a serious tune with some dyno time when I did my motor....not to mention probably have to trailer it to a shop cause I would have been able to fire it up w/o the proper map.
Really is a good system, but might be overkill IF one never plans on doing motor/trans mods.
.....also got mine used on eBay for $400 shipped!
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Southpaw Super Glide: A Left-Hand-Drive 1979 Harley FXE Built to Fit the Rider
Verdad Gallardo
The Best and Worst Harley-Davidson Moves of 2025
Verdad Gallardo
Road Master
Joined: Oct 2007
Posts: 918
Likes: 1
From: Iowa
This could turn into a pretty technical discussion...
As for my experience, the bike has always run very hot with the TMax.
I was referred to this local tuner by a couple people around here...apparently he really knows his stuff. Anyway I came to him with my inquiry and he advised that ThunderMax is essentially going backwards on a stock motor...keep in mind that mine has had no internal upgrades. When you remove the Delphi ECM you lose Speed Density and Ion Sensing. They give you no utility to "free air" calibrate the AutoTune wide band sensors so when they drift, they all do, causing it to start tuning the bike incorrectly. Apparently, when AutoTuning if you don't merge the offsets with the base map then when the sensors start to drift the tune will be terrible. He said he's pulled 15 - 20 of these off over the years and gone back to the Delphi.
Interestingly, I just talked to him today but his recommendation was the same as what I suggested in my OP...reinstalling the Delphi ECM with factory O2 sensors and getting it tuned. Curious what you guys think...
As for my experience, the bike has always run very hot with the TMax.
I was referred to this local tuner by a couple people around here...apparently he really knows his stuff. Anyway I came to him with my inquiry and he advised that ThunderMax is essentially going backwards on a stock motor...keep in mind that mine has had no internal upgrades. When you remove the Delphi ECM you lose Speed Density and Ion Sensing. They give you no utility to "free air" calibrate the AutoTune wide band sensors so when they drift, they all do, causing it to start tuning the bike incorrectly. Apparently, when AutoTuning if you don't merge the offsets with the base map then when the sensors start to drift the tune will be terrible. He said he's pulled 15 - 20 of these off over the years and gone back to the Delphi.
Interestingly, I just talked to him today but his recommendation was the same as what I suggested in my OP...reinstalling the Delphi ECM with factory O2 sensors and getting it tuned. Curious what you guys think...
I respectfully suggest you seek a second opinion before you go with his idea.