BravoZero

iTrader: (2)

You guys might want to try replicating this in Sport and Normal modes, as well as in automatic and manual shift modes. That way, we can try to pinpoint how and why it happens a little better.

richardjh

Could it be a matter of timing? Like, rolling to a stop, then a fraction of a second after stopping, flooring the accelerator pedal...?

Perhaps the SST leaves it in 2nd in a "wait and see" mode for most of the coast-down, then starts its shift action into 1st ready for the next take-off, but if you go WOT when it's half-way between the two, it gets caught out...

Do you recall if you sat there for ages, or if your "gap" came at the same time as you ceased moving from the braking-to-stop?


Now...

If I compare "v25" and "v27 Balance #17", I can't find two SST tuning tables that are even remotely close to each other. That Balance beta tune started with no assumptions, no baggage, and took its own unique development path. v25 and Balance #17 are totally different animals!

But here we have:

- a 2009 RA, in D1, on level ground, running v25
- a 2011 RA, in D1, on an incline, running v27.020 Balance #17

Years, tunes, both different... but both have reportedly done a wacky rev-to-the-moon in D1 instead of just driving off like they should.



My gut tells me we can't "fix" this with the tune.

Perhaps you guys need to take one for the team... put stockpill back, flash to stock tune, and drive around in boring-old-car mode for a fortnight. See if you can get it to happen. That would then be 3 tunes.


For a solution... SST fluid change, perhaps...?


Rich

richardjh

Low mileage, then...

Rich

mikeszutu

So far I'm pretty happy the way the SST been behaving recently. I haven't had a chance to see how the car reacts to low speed coasting.

richardjh

After mulling over this issue with razorlab, there are a couple of things to try on the TUNE side...

...but it will come at a price!

You know that lurching, clunking stuff that nobody likes? The feeling of the trans working and grabbing a bit as you coast to a stop? Well, it may be necessary to bring some of that back.

The tune is currently using STOCK level "softness" settings for coast-down and 1st-gear torque ramping. Interestingly, "GST Base Map v25" used fairly soft values for off-throttle coast-down as well (so I guess I lied when I said they were "totally" different ).

I reckon if we wind back the Quest for Smoothness in a few key cells, we stand a chance at eliminating this nasty free-rev behaviour.


There are two likely places I can see...

(1) 1st-gear LOW speed (eg. 20km/h) torque ramp rate. Currently set as soft as on any stock tune. We can nudge this up a bit.

(2) The off-throttle "requested torque" cells for lower rpm areas. Increasing these would very likely get the SST actively using its select-and-engage style of operation as you slow down to a stop... as opposed to free-wheeling it for smoothness. That means, if you go WOT, it'll hopefully be ready for it. But I reckon you'll feel it working as you decel.


That's what I've got. Thoughts welcome. After all, this has turned into a community-based beta-test extravaganza.


Rich

csmithcfg

I too, really like what I have seen with balance 17. The first high rev episode was on Balance 2 in normal manual, I believe. I've slept a few times since then. This last time was Balance 17 in normal D1. Does anyone have a way to log the SST with a Tactrix standalone? If you do, hit me with a logcfg and I'll log till my eyes bleed or the tires blow. Otherwise I'll use the laptop every time I come to job#2 to try and catch it happening. The only thing I can catch on standalone now would be high revs and no speed.

Maybe my car has ADHD?

csmithcfg

The "clunkyness" isn't that bad really. My 65 mustang automatic used to chirp the tires on every gear but high shifting up or down. I miss that car!!!

Alterna

iTrader: (1)

It only happens in normal auto mode, and it doesn't bother me. That said, I didn't mind the harsher shifts either-until I sloshed some squid in my trunk. Made for a smelly mess...

I'd flash to the newer kit, but someone broke into my car and stole my tactrix-along with a case full of electronics.

I'd get another tactrix, but a family friend rolled my Indian down the street, and I've been spending any extra money I have on replacement parts for the motorcycle.

nmilsaps

iTrader: (2)

Excuses, excuses... Let me know if you ever wanna meet up again and I'll let you borrow my cable this time.

richardjh

AFAIK, there's no way to do CAN bus requests from OP2.0 standalone logging... yet. I'd love to see it in the future.


We do need to bear in mind that one or two cars seem to have a predisposition to act like this. But that could simply be driver input mixed with the "right" (or "wrong") circumstances that occur in your regular drives.

I'll experiment on my tune...

Rich

Slee256

Not sure if this is related, but tonight I took out Balance 17 and thrashed it around a little bit to see how it felt(I was previously running Balance 15). I definitely like this basemap the best of all the ones I've tried so far(and I've tried many of them along the way as this GST basemap thread has progressed!) The only negative thing I noticed was one time I pulled out of a gas station slowly with light throttle in Auto/Sport mode and continued to accelerate slowly until the car shifted itself into D2(still in Auto/Sport), at which point I quickly went WOT and noticed that the engine started racing like crazy and the tach looked like it was going to bounce hard off the rev limiter although I wasn't moving any faster. Finally, after a couple seconds of feeling like I was flooring it in neutral, the clutches seemed to engage and off we went like a bat out of hell!!! That said, everytime I went WOT in Auto/Sport mode starting from D1 the launches were strong and perfect, so I really can't complain at all, but just wanted to report my results.

parralegend

Hey Guys i know this is off topic to the current direction of this thread but I wanted to put a turboxs stealth exhaust on the car which i believe has the front pipe and cat only, does that count as a turbo back or does the rear of the exhaust cause problems using the tbe tune?

Thankyou

richardjh

Great info, thanks!

I'll actually be happy (!) if this free-rev behaviour turns out to be something reproducible. There's nothing more frustrating than trying to address an issue that almost never happens.

Flooring it in AUTO mode isn't something I ever do. It's not part of my 300-point SST Test Drive Plan. It is therefore a perfectly logical place for something like this to lurk. Guess I need to start driving like this...


So am I correct that this free-revving downshift hasn't impacted anyone above 20mph... or thereabouts?

And only when in - or downshifting to - 1st gear?

And only in NORMAL mode?


If so, we can start with the tweak to the NORMAL mode Requested Torque Ramp Rate. For 1st gear, I lowered this down to stock 2011 USDM settings for 0-40km/h. Perhaps it's just too darn soft to keep up with sudden WOT action.

The cool thing about this edit... it will ONLY affect:

- NORMAL mode
- 1st gear
- Specific speed range, eg. 0-20km/h, or up to 40km/h.

So this edit isn't likely to introduce any side-effects/impacts elsewhere.

Watch this space!

Rich

richardjh

If you haven't already done so, I reckon you should fit a wideband. That way, you can know for certain how the tune is running... whichever one you use.

At risk of over-simplifying, it's pretty much a matter of checking your logged boost levels and AFR...

Rich

parralegend

so the catback bit doesn't hugely mater it's more along the lines of checking to see if it's running rich or lean?