jtanda430

Hey soo I finally flashed to v30 beta boost pill 93 Oct... and I'd like to say the performance increase is great with no problems so far... however I really really really do not like the sst adjustments... I'm noticing harder downshifts at lower rpms in manual mode (normal or sport) not all the time but sometimes... and overall the shifts are not as smooth as the stock settings. Is there an easy way for me to have the exact same shift characteristics as the stock rom? I don't mind doing it myself if I can have a little guidance.

richardjh

The only difference between v30.005 and v30.005_Test_A is in the "SST Throttle Requested Torque" map, in a tiny area at low throttle.



Nothing else has changed. That means anything else that's got improved (or reduced) awesomeness is either a figment of your fevered imagination... or the usual SST randomness! The SST is "consistently inconsistent", which makes it a heap of fun to try and tune.


If this tweak fixes the judder, great. Slee256 will be flashing it on the weekend, so we'll see if the 1st/2nd gear indecisiveness gets cleared up too.

There are really only two tables that can be causing it. The above table change was the most likely suspect. We may end up massaging the other table too, depending on Slee's outcome.

Glad it's heading in the right direction, anyway.

Rich

richardjh

Give it a little time to settle down after the reflash. A number of people have commented that the SST seems to start off firmer right after a reflash, then get progressively smoother.


I'm happy to help you tweak your particular ROM if we need to. The thing is, we ended up getting best results in the community "SST beta tuning sessions" by reverting to STOCK tune values in most of the SST tables at lower throttle positions and lower loads. That's where the downshift stuff lives.

That means there isn't actually very much at all affecting it from stock downshifting! Sounds odd, but it's true.

One thing to check... are you in NORMAL mode? When I'm on 100% factory tune, I have to switch to SPORT mode to get any decent SST throttle responsiveness... but on the Base Map tune there's honestly no need to be tooling around in SPORT mode - the SST throttle responsiveness is much improved. If you've retained the habit of switching to SPORT mode as soon as you start the car, try leaving it in NORMAL mode, and see how that feels.


But yeah, give it some break-in time. I have no clue why the SST seems to get abrupt after a reflash... but I've noticed it too. Unscientific, I know, relying on anecdotal evidence and seat-of-the-pants!

Cheers,

Rich

jtanda430

Is it funny that auto normal shifts like butter? Because it makes me lol. With the base tune on I've noticed very little difference between normal and sport manual so I will give normal a chance for a few days to see if things get sorted out on their own. Ill post what I observe and we can go from there. Btw, ill be doing some evoscan logging .. would anyone benefit from me sharing logs? And what's my most affordable wideband options?

Thanks rich

jtanda430

Is it funny that auto normal shifts like butter? Because it makes me lol. With the base tune on I've noticed very little difference between normal and sport manual so I will give normal a chance for a few days to see if things get sorted out on their own. Ill post what I observe and we can go from there. Btw, ill be doing some evoscan logging .. would anyone benefit from me sharing logs? And what's my most affordable wideband options?

Thanks rich

richardjh

SPORT mode uses higher clutch pressures, and shifts faster - those behaviours are locked away in the TCU... In the SST.

For commuter street driving, I find SPORT a little harsh. NORMAL feels right. IMHO, that's the way it should be! We don't get S-SPORT like the Evo, so we need our two modes to cover more ground.

Rich

dandan2000

Hello.
When engine braking (rpm - 2000-4000, accelerator released), when SST downshifting (MANUAL mode), at this time (in moment of downshifting) slowdown of car does not occur, as if switch neutral. It somehow fix it, to slowdown did not stop? Or how to increase the speed of the downshifting at engine braking?

richardjh

That sounds like the ECU doing its random decision as to whether it's going to switch off the injectors or not.


MOST of the time, you'll go "injectors off", your wideband will show atmospheric o2 levels, and you'll slow down.

OCCASIONALLY, the wideband will stick at 13:1 or some such thing, and you won't actually decelerate.


It's annoying. People have tried to find the code that controls this, but it's a maze of crap in there!

Wish I could help, but as yet we have no "fix".

Rich

dandan2000

(.
Will wait for "fix".

jtanda430

Oh I've done enough reading to know sport mode uses higher clutch pressure and shifts faster... but I SWEAR I've noticed very little difference since the retune despite what lives in the tcu. But Im assuming that's because of the "roughness" you said I might experience ... like I said ill give it a few days and go from there.

jtanda430

200 miles with the base tune and i have noticed the transmission feeling less "rough", however.. i have noticed a few things. In normal auto when speeding up after breaking the transmission takes a second to get back into gear and will jerk a little ... like its in neutral and allows me to rev up a bit before the clutch engages (not all the time but frequently especially at lowerish speeds). Also when at WOT and trying to shift at higher rpms in manual (sport or normal) there will be a slight lag and a definite feel of "slippage"... like ... 6500 rpms... hit shift up, revs a tiny bit up still.. then holds at maybe 6300ish rpms or so (slightly less than where i shifted at) then after like a second drops down the appropriate number of rpms. This happens even if im not climbing up the rpms really fast... for example... it did it doing a 5th to 6th gear shift at 115mph today. Any ideas? Is this slight slippage "good" as in something adjusted for.. or should i not experience it at all?

richardjh

Argh, such straightforward and reasonable questions... but such a complicated area to try to address in an answer.


The first thing... the little "delay" at low speed when you get on light throttle, is probably the same one that Slee256 and Silver09RA mentioned above. Those guys are testing out a small revision right now.


For the upshift feel...

SST upshift outcomes depend hugely on stuff like fluid and clutch temperature. It grips and shifts best when the fluid temp is right up at 70C-80C. In hot weather, you can get up to that in maybe 30 minutes of constant shifting in reasonably heavy traffic. But on an open road on a cool day, you can forget it - 30 minutes in winter on an empty freeway will see my SST temps still scraping the floor. *

As the fluid heats up, you'll feel it shift very differently. Harsh at first when stone-cold, then it loosens up - too much, IMO. If and when it gets toasty, it'll firm up again, and feel quite razor-sharp.

Same goes for the clutches. When not heated by recent use, the first few shifts on each clutch (odd, even) will tend to be less sharp than subsequent ones.

Well, that's my experience, anyway.

This makes the whole SST tuning thing quite challenging. Try to firm it up for the warm-fluid shifts and it'll feel totally horrible once it's really hot. Do we tune it so it's "perfect" on well heated clutches, or for when they are still cool? hehe.


As to whether a bit of slip is bad or good, well... it's a wet-clutch system, so it can certainly cope with a bit of slip. Slip creates heat, so if it slips less when it's hot, it's kind of self-correcting in a way.

The SST and ECU have lots of torque management built in, but the SST only has one headline trick for managing torque delivery... that's right... slip the clutches.

We've tuned out the worst of the "intentional" slip. It's hard to believe, but the stock SST tune has built-in "I'm gonna deliberately slip" stuff that kicks in whenever boost targets are exceeded!



I'll probably have an updated ROM fileset soon for that low speed, light throttle "indecision" issue. We may already have it sorted - hopefully it just needs testing and verification from the abovementioned owners.

Cheers,

Rich


* I have an add-on sensor and display for SST temp... but it's something that is possible to log - in several different ways. I also have an add-on cooling fan run by the temp sensor and controller, as I don't like SST temps to exceed the "ideal" levels.

Silver09RA

Hey Rich,

Looks like the judder is still there, but only when on Sport mode ... it doesn't judder on Normal mode at all. Does that make any sense to you? But the harshness of the judder on Sport mode has been reduced by 70% (which is much better than before )on the test map you gave me to try, so maybe a few more adjustments and we should be golden! Let me know if you have another test map for me to test out.

Appreciate all your work on this man.

richardjh

That is interesting - and a bit unexpected. That's par for the course with SST...

Tell me...

- Is this remaining judder there when the engine is cold, when it's warmed up, or both? You see, there are HOT and COLD interpolated maps for the area being tweaked. Currently, I'm only editing the HOT map.

- Is the judder now gone for very, very light throttle... but still there a bit if you use a little bit more throttle? As you can see from the pic above, Test_A tweaked 2.4% throttle region, but not so much 5% region. Perhaps if we push into 5%...?

Let me know. Glad it's heading in the right direction, anyway.

Rich

jtanda430

Well my concern is that I didn't notice any type of slippage before the tune. Ill take a video to show exactly what I mean and let me know about the test revision. I'm willing to test things out to give more feedback. And if it helps the day in question with the 115 shift into 6th was 90 sumthin and I definitely had things warmed up. But it did it then and also does it cold. Doesn't seem to make a difference. Just trying to sort everything out. If I can help in any way possible I am more than willing. Thanks!