2017+ R6: Do gearing changes affect TC functionality?

I've seen conflicting info. Can somebody confirm if changing sprocket gearing affects the functionality of the TC system? I've seen a couple articles where Yamaha stated any changes in gearing would require updates to the ECU in order to correct TC behavior.....

I'm not talking anything drastic here. Just +2 on the rear sprocket to go from 16/45 to 16/47.

Thoughts?

 

I won't pretend to be an expert on the subject but my understanding is that most TC systems look for front vs rear wheel speed differentials, usually using the ABS tone rings so gearing shouldn't change that but changing tire sizes may assuming the circumference is different. If a predetermined amount of 'slip' is detected, TC will reduce power output. On systems that have adjustable TC, reducing intervention allows for greater slip numbers before reducing power.

 

That would have been my assumption/understanding as well. If the front/rear wheel speed sensors are the determining factors, not any engine internals, why would a gearing change make any difference at all?

As you mentioned, significant tire size changes could alter things (on my old RSV4 you could force the ECU to "re-learn" the tone rings when changing rear tire sizes), but there is no such option that I'm aware of on the R6.

 

I wouldn't think a gearing change should impact it at all. On my A bike (Daytona 765) which has TC probably akin to your R6, there isn't any way to calibrate the TC, though being wheel speed only it's not particularly sophisticated. My Tuono V4, like your RSV4, has the calibration ability. One time I had it calibrated for a larger tire and then rode it with a lower profile tire and the TC was engaging super early (and showed high slip numbers) until I re-calibrated it. That said, an OE profile tire is probably the basis for the TC on your R6 (as well as my Daytona) and going to a taller tire will likely reduce the engagement of TC however it could also impact ABS engagement (if your bike has that). This is speculation on my end but most of the manufacturers aren't particularly forthcoming on how their electronics work.

 

No. Turn off the TC, it's a 600.

 

LOL this is kinda where I'm at. I know TC is pretty pointless on a bone-stock motored R6 on a dry track. Didn't have it for the almost 2 decades I ran a 2nd-gen R6.....

 

I recall when they added TC to the R1 (2012 I think it was) it saying something about if you changed the rear tire size it would affect TC and need to be adjusted, not sure if gearing change had similar effect. But I do agree, who needs TC on a 600

I had a Bazzaz ZFI-TC on my GSXR-600 for years and even though I did have a TC map loaded into it I never bothered to turn it on either.

 

I have the R1M/GYTR CCU on my 17+ R6, so I can go back and see where TC is kicking in. I normally have TC set at 1 (least amount of TC). It does intervene sometimes, but I don't understand the logic. I have had the rear step out a few times and catch where the bike bumped me out of the seat a little, and the TC never turned on. It was turning on a lot driving onto the straight at Roebling with a worn tire, but I had no idea until I looked at the data. I can feel it cutting in and out through the first / left kink on the back straight of Pitt (t15), where I'm pretty sure wide open on a stock motor should be no problem. I'm always wondering if the TC is just slowing me down or actually saving me, but I'm too scared to turn it off to find out.

 

I have it turned on #2 on my 17 R6 at Chuckwalla. GoPro mounted to my R1 and R6 can see when the TC light turns on in some corners. Ideally I want it turned off but I am still working on setup and having some grip issues on the new Dunlop so it is staying on for now. Motor is stock for now, but with lack of grip I think its good to have as needed. Once I get setup better dialed in (seems to be mostly tire pressure related) I will drop it down to 1.

I do agree that I think the most important thing is the spin ratio between front and rear. I have changed the gearing and the new Dunlop tire is a little bigger.

 

So this is really about where the TC system gets its data from. The early R1's used a speed sensor that worked off the output transmission shaft and that was compared to the front wheel speed sensor, ie gearing changes could have implications on TC control. Later systems moved to using an actual rear wheel speed sensor and no longer would be affected by gearing changes.

 

I had a Bazzaz ZFI-TC on both of my '08 R6's for years. Unlike you, I always left mine on at either the lowest or second lowest setting.

That was until sometime in 2019 ... when a bunch of people started coming up to me after races asking if I had the TC turned all the way up and saying I need to turn the TC down or completely off because they said my bike sounded like the TC kept coming on out of T3, T6, and T12 at Loudon, NH. For whatever reason, I can't hear that sh*t while I'm racing, but I can confirm my drives out of those turns suck (I thought it was just me). So, I turned the setting to zero. They still came up to me and said the same thing. I then disabled the TC, internally, in the Bazzaz unit. Still the same issue.

I figured my Bazzaz went bad, yet again, and was going to send it back to them to fix or get a new until. If memory serves, I've had to send at least 3 units back to Bazzaz because of failures. I figured this was just another one.

Then the rona hit and things, well, frozen in time until this past year when I went to send the unit back to Bazzaz. Lo and behold, Bazzaz is no longer offering support for the Z-Fi TC. In addition, YFI racing, who I guess took over for Bazzaz, isn't offering technical support for Bazzaz products except for customers who purchased directly from YFI Racing. Wonderful.
.

 

Sheesh, what an ordeal. Bummer too, that guy Ammar was pretty cool and I did like the Bazzaz solutions better than the comparable Powercommander ones. They also provided great service/support when I reached out to them back in the back before they closed up shop.

 

Agreed, which is precisely why I stuck with them. Even though I have a YEC ECU, when I did the SS build, the tuner suggested just using the Bazzaz for fuel mapping because it was easier and more universal (I guess for others to make tweaks if need be). So all my fuel mapping is in it. I run the QS through the YEC, so even if I buy another one, just the Z-Fi fuel controller at $415 (the ZFI-TC-QS is $960), I don't know if I want to sink that much into a product I've had prior issues with and people I now don't have any connection to. I've been toying with the idea of just sticking a stock ECU back in the bike and getting it flashed by Bauce Racing of of NJ. A lot of guys I race with have had good experiences going in that direction.

 

I used to do trackdays with Anthony back in the day. Good dude, and I agree have only heard positive experiences of his work since he started Bauce.