Okay, I'm a tinkerer with a T-Max. That can be good or bad, depending on how you look at it. It's no secret that I'm a fan (fanboi if you must) for T-Max. Is it the best tuner out there? I don't think there IS a "best tuner" award for any system. They all have wins and warts. I think T-Max fits my needs, and being a professed tinkerer, I've learned the system enough to use it.

I've been intrigued by something you'll find in almost every ignition timing map in the T-Max. There's a "trough" in almost every map where timing dips in the mid-throttle range, and then bumps up again at WOT. It's been discussed on these forums that T-Max doesn't use the MAP sensor signal to detect load like the OEM's, Delphi system does. I believe this dip is to compensate for the lack of load-sensing with T-Max's Alpha-N control.

My thinking is, the engineers figured that if you're at WOT at 2,000 RPM, you may be in 4th, 5th, or maybe even 6th gear. That would be more load than if you were in 1st or 2nd, therefore, you'd need to pull more timing. But, as you get closer to 6,000 RPM, the chances of you being in high gear drop significantly. If I were better at math, I'd figure out how fast you'd be going at 5,500 RPM in 5th or 6th gear. WELL into the triple-digits, I'm sure.

That said, I've noticed that there are a lot of "blanket adjustments" in the canned tunes you'll receive with a downloaded map. LOTs of reasons for that, as everyone rides differently, and every bike is different, so canned tunes are conservative. This gives tuners something to improve upon, and self-professed tinkerers something to do on a sunny Saturday morning. =)
There are some really knowledgeable folks on this forum, and I can't remember who it was that mentioned the connection between timing and fuel consumption. Obviously, better efficiency warrants better fuel mileage, but too much timing can also hurt efficiency. With my recent upgrade to 96 cubes and higher compression, I've been pulling more timing than I've been adding recently. And, I think the bike likes it. I know I sure do!

I've watched a bunch of videos online, and I've done a fair amount of EFI tuning over the years. I've watched videos of folks addressing knock by jumping right onto the Ignition timing at WOT map and pulling timing there. Without getting into the weeds too deeply, it helps to know that this map illustrates the timing at WOT, but modifying this map changes the timing at ALL throttle settings at that RPM. The Timing by RPM maps allow one to adjust for various throttle settings, and in my opinion, are where adjustments should be made to reduce knock at a particular RPM and throttle setting. But I digress... So, where am I going with all this?

My theory:
I think the T-Max engineers were onto something with the timing trough, but I began to wonder if there might be some nuggets of goodness on the far-right side of the ignition timing maps at lower RPM. I have increased ignition timing at some part-throttle (tip-in) settings with great results. In fact, I think my bike runs really great, up to about 3/4 throttle. Not that it runs like crud above that, just that I've not pursued improvement much above that throttle setting. But here we are.

I'm wondering what a map might look like that was better "optimized" for my riding, with my bike's build. How pronounced would that trough be at 1500, 2000, 3500, 4500, & 5500 RPM? I know it'll change for the reasons mentioned above, but would the number of points increased on the right side of the map also change as the RPM increases? My thinking is, like the T-Max engineers, the higher the gear, the more chances of using the lower throttle settings. If that is the case, then timing at WOT could actually be increased as RPM increases, but also, could the number of points to the LEFT of WOT be increased a bit as RPM increases as well? (I hope I'm explaining this clearly and correctly.)

Think of it this way, if I'm at 5,500 RPM, I'm most likely in 1st or 2nd gear (low load). So, perhaps WOT timing could be bumped a few degrees at the trough, as well as at WOT. But also, maybe the angle to mate WOT with the mid-throttle trough might be more flattened as you near WOT? Here are two screen caps to help explain:



As always, I welcome any of the knowledgeable folks on this forum to chime in with thoughts or personal experiences. I'm just a tinkerer doing some thinking on a sunny Saturday. I wish I had a dyno, but I'll welcome any info others might have gained through their denim, butt-dyno or otherwise!

Thanks in advance!

 

I guess you could could say that it compensates for lack of ion sensing but IMO really because the volume of air/fuel mix is captured there is higher . Open the throttle fills the cylinder fully at partial throttle better than WOT. At WOT with filled earlier and air bleeds back into the intake as the intake valve is still open after BDC. Less air fuel in the intake can use more timing. As Rs increase there is less time for the some of the volume to revers and the dip goes away..

I've probably done more than a dozen different builds on a 95/96 2002 RKC and 96/103/107 EGC. I've logged over 50000 on the RK and 117000 on the EGC with Tmax. I've used the WOT timing and Global AFR to find peak HP/TQ WOT then do the rest of the timing by riding. That works pretty well if you want the numbers but still have to take time to tune on the street. For me the hard part is getting the gas milage up on the EGC (heavier bike).

Not sure why you chose a CVO map unless you have one. They have big combustion chambers and to get those to work well, they need more compression.

 

Thanks for the reply @Max Headflow, I had a few names in mind when I posted, but didn't want to drag you, or anyone else into the conversation. That said, I appreciate your input and always learn something. Thanks for that!
About your question on the map, that's what FuelMoto sent over when I asked about the big-bore kit I used. Not sure if they adjusted it accordingly, but my butt-dyno thinks it works pretty well. Your question puts that "But wait! There's more?" thought into my head. But that'll be for another time. I'm kinda focused on this subject right now.
I just started working on it, and it'll take some time to tweak/tune to find out. There are a few places on the way to work where I can do a sufficient "field test". I REALLY wish I had a dyno. I'd never leave the house!

Yeah, I'd like to see a bump here as well. I'm clocking right around 32-34 mpg by doing the math at the gas pump. Thinking advanced timing at mid-throttle (where I do a bunch of my riding to work) is playing a part in that as well. Had some detonation as my wrist twisted, and pulled some timing. Feels good (smoother may be a good way to describe it?) and I'll be checking at the next fill up to see if there's any change. In reality, I think I'm splitting hairs, but I'm learning. I like to learn.

 

Following this thread. I am in the middle of installing a T-Max in my 2006 EG Ultra Classic. It now has a S&S T111 engine, HPI throttle body and Feuling injectors. And my S&S Power Tune Duals that I have had for a few years now. If anybody has any ideas for me fire away!

 

Hey @glasspilot
I think you'll like the T-Max. It'll definitely allow you to make adjustments to suit your bike. Key is getting the right tune to begin with and then modifying from there once the ECU has had time to adjust to your build. Use the "EFI Maps" tab at the top of the software to locate the best tune for your build. A cool shortcut is to find your engine make, size, etc., and right-click to sort out all the other options from the list. Kinda last-man-standing is your winner. LoL..

I will say this (and anyone can correct me if I'm wrong), but I suggest giving the ECU time to adjust, and doing a few "Auto Mapping" sessions before deciding to tweak the tune. There ARE benefits to be had, but let the software do its thing before you start making broad-stroke changes. It'll also give you time to find out where you'd like/need to adjust. But that's just my .02.

As mentioned, there's a lot of great info on these forums about the software and tuning, and of course, Ad-Tube as well. Take your time and learn about how the system works and you'll be happy with your purchase. IMHO.

 

Hey @Max Headflow
I got thinking about this statement, "I guess you could say that it compensates for lack of ion sensing but..."
The earlier Twin-Cams didn't have Ion sensing. I guess you could say it's accomplishing the same thing, just VERY analog at doing it? When did Ion Sensing become a thing?

 

All Delphi EFI TCs had ion sensing. 2001 softails up to M8s, 2002 touring up to M8s and something like 2004 up TC dynas . The Magneti Marelli efi touring bikes did not.

 

Wow!
I DID not know that. I learned my one thing today. I'm going to take a nap!
Thanks @Max Headflow!

 

I've recently moved to TMax from PowerVision, no real reason but just something new to play with. So far it's been a smooth transition and it runs like a beast, only complaints I have is that there's minor surging at constant RPMs and is more pronounced at low speed/throttle positions. And that the gas milage has taken a nose dive compared to the PV, getting about 36-37 MPG.

 

most people have VERY misguided idea for AFR values to run.
to get fuel mileage using a TMax,,,it really should be set up on a dyno using real world afr nubers, properly.
i have, in the past set a few hot rod builds that still net over 40mpg when ridden correctly, that is another issue as well,,,,,if you travel over 80mph you will not get mpg just due to the number of combustion events tht hapen.
i hate using the tmax because their support system goes against my grain, therefore, i do not use it or recommnd it. to each their own.
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