Level of tune where TCU is required

[WeeKenny]

I've heard reports of either "increased clamping force" (unsure how as this would work as surely its a mechanical limit) or "increased torque limits" (I suppose maybe if there is some electronic fail-safe, but then how does the transmission measure the torque?)

These supposed benefits of a TCU tune seem a little fishy to me Is there a generally accepted level of tune where a TCU flash becomes necessary? I'm at a loss as to if its worthwhile, raised rev limit on the B8.5 is a bonus I guess but on the B8 I'm struggling to see the value in it.

Are there any back to back dyno runs proving DSG clutch slip and its correction after a flash? Seat of the pants feeling is too subjective.

[stereojorge]

There’s so much more about the characteristics of the DSG as a whole after a TCU tune than just some numbers on a spec sheet. Let me put it this way, and this is just my own opinion of course, but if I could take a DSG car and on Day 1 do the TCU tune, I 100% always would! It makes the experience that much better.

[WeeKenny]

But why specifically? It’s all very subjective. I’ve seen people report feeling faster or crisper shifts, they are already fractions of a second so are people feeling what they want? A $800 placebo effect??

Granted I’ve not driven a TCU flashed car but I’ve no issues with my current set up. But if at say dual pulley levels it was necessary then I’d factor it in to the cost of any future mods.

[TC_S4]

I went stage two single pulley without TCU tune, hoping to save few bucks. In my case, The driving experience was horrible, I get clutch slips during shifts, 1-2 & 2-3 were very pronounced. My 0-60 was 1 full sec slower then when the car was stock. At last, I bit the bullet, and flash tcu tune, problem solved, no clutch slips and shifts are much crisper.

[WeeKenny]

That’s odd I’m stage 2 single pulley at the moment with no issues. I wonder if this is something else that was changed in the B8.5 when they dropped the Rev limit?

[dp.s4]

I just got a TCU tune for my 2014 b8.5 and I love it. I personally drive around in comfort most of the time and the tune fixed most of my dislikes of comfort mode versus dynamic which i think holds the gears too long and i don't enjoy it for every day driving. Firstly, the kickdown switch is much more sensitive and reactive to throttle inputs. I used to switch to manual mode to downshift and make a pass on the highway, but now i just use my big toe and it drops down to the perfect gear. Just much less sluggish overall. The change in upshifts is not noticeable to me personally, but downshifts are noticeably more crisp. In terms of performance, launch control was greatly improved with the raised RPM and now it doesn't feel like its struggling right off the line. Lastly the raised rev limit is where you'll see most of the performance gain, especially if tuned.

[TC_S4]

That’s odd I’m stage 2 single pulley at the moment with no issues. I wonder if this is something else that was changed in the B8.5 when they dropped the Rev limit?

I don't know if it's related to B8.5 or the Revo tune itself. I notice Revo make more torque and less horsepower compare to others tunes. Anyway, TCU for me is to rectify a problem, the rest are just icing on the cake.

[bhvrdr]

For another experience, I have had 3 different DSG B8.5 cars and at single SC pulley / 2.85pr levels I found the stock TCU tune to do just fine at shifting. I had no slip issues at all. Even shifting at 6300rpm I believe I had no issue running 11.8 at just that level on pump gas. I think the tcu tune would have been good for another tenth or so. Not a big deal for the casual driver but certainly would be for a 1/4 mile guru.

Mike

[Nillamb]

I've heard reports of either "increased clamping force" (unsure how as this would work as surely its a mechanical limit) or "increased torque limits" (I suppose maybe if there is some electronic fail-safe, but then how does the transmission measure the torque?)

These supposed benefits of a TCU tune seem a little fishy to me Is there a generally accepted level of tune where a TCU flash becomes necessary? I'm at a loss as to if its worthwhile, raised rev limit on the B8.5 is a bonus I guess but on the B8 I'm struggling to see the value in it.

Are there any back to back dyno runs proving DSG clutch slip and its correction after a flash? Seat of the pants feeling is too subjective.

There is a reply from APR in one of my threads saying the TCU wasn't required for the ECU tune I have (Stage 2, single pulley).

I am a rarity here: given a time machine I wouldn't apply the TCU tune to my car. But I'm an old man and, I feel, not the target audience for the TCU tune.

-it doesn't address the ridiculous charge to 7th gear in D
-it made the shifts *very slightly* less smooth (I assume because of the additional clamping force)
-it "corrected" the 2nd to 1st bump by changing the shift point from 2nd to 1st from (and I'll be honest, I can't remember) about 5 - 10 mph to 1 mph. But pre-tune my car didn't bump 2nd to 1st, it was butter smooth. Now, post TCU map I am always stuck in 2nd when I pull away unless I've 100% come to a standstill which just feels slow and mechanically unsympathetic (lots of clutch slip until the road speed is high enough for 2nd)
-I don't care about the extra rev range. The only gear I ever rev to the line is 2nd by which point I'm already doing post legal speeds.

In contrast, of course, there will be lots of folk here that love it.

[raudiace4]

I've had a 2012 S4 that was stage 2+ FBO with TCU tune, 2016 S4 that was stage 2+ FBO without TCU tune, and currently have a regular stage 1 2013 S4 without TCU tune.
The TCU tune helps smooth out irregular shifting under normal driving, and makes shifts more crisp at WOT. But no, it's not necessary unless you're chasing every last drop of performance from the added rev range. It does help the drive-ability though. More so on the B8s, on the B8.5s I haven't encountered any issues regarding normal driving to make me spend the extra $$ on a TCU tune.

Just my .02

[WeeKenny]

Replies are much as I thought. I’m not chasing quarter mile times. I have a single pulley at the moment as I was taking the supercharger off to do the thermostat. I may in the future want to or have to change the crank pulley so I’d upgrade and don’t want to have problems.

Sounds like it’s a nice to have? But not a must have. I’ve no issue with short shifts or stopping bump to 1st, the B8 has a slightly higher limiter anyway.

Raudiace4 was your car without a dual pulley car?

[Dippy]

My tuner told me that he has seen clutch pack slip with the 2.0 engine + DSG cars but not the 3.0, but they increase the pressure on their 3.0 TCU tune anyway just in case. I did notice the shifting was a but faster after the tune but it was marginal. The main value was raising the redline, which is more beneficial on my B8.5 than it would be on a B8. IMO a TCU tune is really only of value with a stage 2 AND a driver who likes to use the full engine revs. I understand that some TCU tunes change the shift points and I can see that this might improve the characteristics when driving in auto mode.

[WeeKenny]

The standard DSG upshift is 8 milliseconds what’s a flashed DSG supposed to do it in? I’m struggling to imagine how people can feel it unless the shifts being at a less ideal point in the Rev rage you feel the shifts more so they feel quicker??

[doughboy17]

The standard DSG upshift is 8 milliseconds what’s a flashed DSG supposed to do it in? I’m struggling to imagine how people can feel it unless the shifts being at a less ideal point in the Rev rage you feel the shifts more so they feel quicker??

Did you time that yourself? Seriously though, I believe some TCU tunes provide faster shifts in certain modes (i.e. Manual) vs. using the "fart" shift, which I believe I read is a slower shift than the "WOT" shift. My understanding is that a TCU tune can shave 0.2 - 0.3 sec.s off the 1/4 mile time. I, too, conduct exhaustive research before making a purchase but believe you may be overthinking this decision.

I believe you may be correct that the benefit in quicker acceleration times may be greater in B8.5s vs. B8s due to the redline differences, but if you are unsure of the benefit of a TCU tune, why not try to negotiate with the vendor the option of purchasing the TCU tune at a later time at any "with ECU package pricing?" The worst they could do is tell you, "No." That would enable you to evaluate whether you notice any deficiencies and wish to purchase.

[WeeKenny]

Googled it 😂 one company quotes a difference in shift time of 20% so 1.6 milliseconds which no one is feeling.

The “fart” only happens in certain conditions so I can’t see it helping. I think APR offer money back if you’re not happy or a trial period on ECU flashes but not sure about the TCU.

[byront8]

I did my TCU/DSG tune alongside my Stage1 the day I bought the car.

Now running Single Pulley and getting my wallet/wife ready for the upgrade to Throttle Body, Divorced HX, and Meth.

The TCU tune has made my car way more enjoyable to drive from the get go (i owned an S4 a few years ago, which was tuned without the TCU and would never do it again).

[WeeKenny]

The TCU tune has made my car way more enjoyable to drive

In what way?

Was there any actual problems resulting from your last car not having it?

[byront8]

In what way?

Was there any actual problems resulting from your last car not having it?

Snappier shifts when I was daily driving, feel like it delivers the power to my wheels better - it’s really hard to explain. I’ve had one with and one without and I would always do a dsg tune now.


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[WeeKenny]

Snappier shifts when I was daily driving, feel like it delivers the power to my wheels better - it’s really hard to explain. I’ve had one with and one without and I would always do a dsg tune now.

Sorry but I don't see how you could feel such a minuscule difference in shift time, perhaps there is a paddle input to shift delay? Anyone know? (but this would seem a strange thing for Audi to add in).

Aside from giving access to a higher rev range there is nothing about the power delivery that could be altered as its only the shift that's electronically controlled everything else is mechanical and unchanged. You say it was a day one flash so its possible that this S4 was just a better example than your last one with less play in the bushes and hence less drive train slop? I've owned cars before that are "the same" as ones I've previously had but have been very different to drive.

Actually there is a thread on here about a mod to take some play out of the paddle switches, that some people don't experience, this could have been part of the difference between the cars?

[Dippy]

The standard DSG upshift is 8 milliseconds what’s a flashed DSG supposed to do it in? I’m struggling to imagine how people can feel it unless the shifts being at a less ideal point in the Rev rage you feel the shifts more so they feel quicker??

Please let me know where you have seen 8ms specified? In SSP 990193 Audi state "The gear shifting process is completed within a few hundredths of a second."
Maybe it was my imagination but after my TCU tune I did feel the changes were marginally faster. But I'm not making a big deal about it and I did state that IMO the primary benefit of a TCU remap is moving the redline.

[ns8013]

Sorry but I don't see how you could feel such a minuscule difference in shift time, perhaps there is a paddle input to shift delay? Anyone know? (but this would seem a strange thing for Audi to add in).

Aside from giving access to a higher rev range there is nothing about the power delivery that could be altered as its only the shift that's electronically controlled everything else is mechanical and unchanged. You say it was a day one flash so its possible that this S4 was just a better example than your last one with less play in the bushes and hence less drive train slop? I've owned cars before that are "the same" as ones I've previously had but have been very different to drive.

Actually there is a thread on here about a mod to take some play out of the paddle switches, that some people don't experience, this could have been part of the difference between the cars?

I feel the S4 DSG shifts pretty slowly stock compared to the A8 in my Hellcat, especially when I put the transmission in Track mode. I'm still under warranty on the S4 so I haven't tuned it yet, but I plan to do the TCU and any improvement, no matter how slight, in shifting speed would be noticed and appreciated, I can assure you. I've seen plenty of people state that shifting seems faster after the TCU tune. Maybe it's placebo, maybe not, but for many it certainly appears to be a benefit of getting the TCU tune done.

[WeeKenny]

This page describes the transmission workings
https://www.liveabout.com/dual-clutc...mission-533860

I don’t doubt it makes changes (yes I’m dubious about how apparent some are) but what I'd like to know is, is it necessary. As I’ve no problem with how my transmission feels or functions.

[byront8]

Sorry but I don't see how you could feel such a minuscule difference in shift time, perhaps there is a paddle input to shift delay? Anyone know? (but this would seem a strange thing for Audi to add in).

Aside from giving access to a higher rev range there is nothing about the power delivery that could be altered as its only the shift that's electronically controlled everything else is mechanical and unchanged. You say it was a day one flash so its possible that this S4 was just a better example than your last one with less play in the bushes and hence less drive train slop? I've owned cars before that are "the same" as ones I've previously had but have been very different to drive.

Actually there is a thread on here about a mod to take some play out of the paddle switches, that some people don't experience, this could have been part of the difference between the cars?

As I said, hard for me to explain. Shifting from N to 1st feels smoother, and then all upshifts and especially downshifts feel better (given that the clutch pressures are adjusted to be higher), maybe could be described as more confident/consistent/concrete (tired and English is leaving my brain). Both cars had/have the same drivetrain inserts installed (034), and i tend not to use the paddles for daily driving - its either in D or S mode.

[TC_S4]

What level of tune where TCU is required? Well I guest, it depend on the tune you’re running and your personal expectation. If you’re happy with stock tcu and no clutch slipping, well, I guest you don’t need TCU tune. In my case, it’s a must and happy I did it. If you don’t have, you don’t know what you’re missing. Food of thought 💭.

[WeeKenny]

What level of tune where TCU is required? If you’re happy with stock tcu and no clutch slipping, well, I guest you don’t need TCU tune.

I'm currently APR single pulley but if (when) the crank pulley starts to fail I’ll replace it with a larger one. So I’d like to know if I’ll have to budget for a TCU tune if it’s necessary at that level.

[TC_S4]

I'm currently APR single pulley but if (when) the crank pulley starts to fail I’ll replace it with a larger one. So I’d like to know if I’ll have to budget for a TCU tune if it’s necessary at that level.

At DP level, I’m pretty sure, you’re going to get clutch slip. It won’t be a questions if the TCU going to shift faster or rev higher, it will l be a necessity to address a problem, so plan your budget in consequence.

[WeeKenny]

At DP level, I’m pretty sure, you’re going to get clutch slip. It won’t be a questions if the TCU going to shift faster or rev higher, it will l be a necessity to address a problem, so plan your budget in consequence.

Ok thanks. I’ll make sure I budget to include it.